Quest 8(2) by Academy of Science of South Africa

Science Science for for South South Africa Africa

ISSN 1729-830X ISSN 1729-830X

The DNA Project: solving crime

Volume 8 • Number 2 • 2012 Volume 3 • Number 2 • 2007 R29.95 R20

Forensic science: what is it? Reading the bones: age and sex from skeletons Laid to rest: the missing identified Barberton: where continents collided On the move: species respond to climate change Africa reaches for the stars: the SKA Sc A c Aacdaedmeym yo fo fS c i ei ennccee ooff SS o u u tt hh AAffrri c i ca a

c i d e M c i s n e r

who are you?

o F s t i W t a y g o l o h t a P & e n i c i d e Fo r e n s i c M The Division of Forensic Medicine and Pathology forms part of the School of Pathology in the Faculty of Health Sciences, University of the Witwatersrand. Forensic pathologists, forensic scientists and lab technologists make up the staff working in the Division of Forensic Medicine. The Division has responsibilities to perform autopsies as well as train medical students, paramedics and the police to name a few. Forensic Pathologist vs Forensic Scientist – what’s the difference? A “natural” death is defined as a death that results from natural disease processes and does not include trauma related deaths or deaths that have resulted from a hospital procedure. Forensic pathologists carry out autopsies on these cases of unnatural deaths. Forensic scientists perform a supportive role in the death investigation process. How do I become a forensic pathologist or a forensic scientist? To become a Forensic Pathologist, you must study medicine first. This 6 year long degree is followed by two years internship and then one years’ community service. You will then “specialise” in forensic medicine and pathology for a further five years and then become a “Specialist Forensic Pathologist”. A Forensic Scientist studies a Bachelor of Science OR Bachelor of Health Science degree at the undergraduate level. This is then followed by an Honours degree (one year), then a Masters (MSc) degree (two years) and then Doctoral (Ph.D) degree (3 years). Forensic Science Studies at Wits Forensic Science studies have not been possible in the past and the University of the Witwatersrand is the first University to introduce “forensic science” studies. The Division of Forensic Medicine and Pathology now offers a new one-year postgraduate Honours degree titled “Forensic Science”.

Upon successful completion of this Honours course, a “Bachelor of Health Sciences Honours (Forensic Science)” degree will be awarded. Students will then have the option to continue with further postgraduate studies in the Division of Forensic Medicine and Pathology, with Masters and PhD studies. The Honours course in “Forensic Science” aims to be a broadly based forensic sciences degree, where students will be exposed to different fields of forensic science and learn how they operate. Topics to be covered in the degree include: • Forensic Anthropology • Forensic Entomology • Investigative Psychology and Analysis • DNA and Molecular Techniques • Forensic Pathology (Brief overview) In addition to the above topics, a research methodology course will also be offered, so as to support students in their research-related activities. The Division is aspiring to stimulate and encourage research in the rapidly advancing fields of the forensic sciences and in doing so, is striving to become a research-active entity within the Faculty of Health Sciences. For more information contact the Student Enrolment Centre (SEnC) on (011) 717 1030 or admission.senc@wits.ac.za

www.wits.ac.za

Cover stories

Solving crime with DNA Vanessa Lynch and Carolyne Hancock explain about the DNA Project 10

What is forensic science? Alan Morris separates reality from perception

What the bones can tell us Jacqui Friedling shows how to use bones to identify age and sex

Contents Volume 8 • Number 2 • 2012

How to we monitor air quality in South Africa? Gregor Feig explains

A day in the life of the Missing Persons Task Team Kavita Lakha explains how the missing are finally laid to rest 35

Air quality: its impact on climate change Tirusha Tambrian looks at the challenges ahead

Barberton metamorphosis Kathryn Cutts explains how geologists know when mountains grew and continents collided 38

Air pollution: what is its effect on health? Riëta Oosthuizen looks at potential harms

Environmental change: its effect on species distribution Mike Lucas shows what happens to the ranges of plants and animals as the climate changes

It is probably probable ... Steve Sherman explains what is possible

Africa celebrates SKA bid outcome Justin Jonas answers all your questions about the SKA 44

Science for development: a regional centre for climate change research Jonathan Diederiks explains about SASSCAL

Features 12

What is forensic anthropology? Alan Morris explains what old bones can reveal

Regulars 32 18

Estimating age from the hand and wrist: what these bones tell us Belinda Speed and Kundisai Dembetembe at the cutting edge of forensic science

Becoming a forensic pathologist Linda Liebenberg explains how she stops dinner party conversations

Air pollution – one of mankind’s major impacts on the environment Rebecca Garland explains what air pollution is

Fact file Acid rain – p. 32

Science news Pulling the plug on shipwreck pillaging – p. 51 • SAYAS general assembly – p. 55

Careers How to become a forensic pathologist

Books

Diary of events

Obituary – Professor Philip Tobias

Subscription form

Back page science • Mathematics puzzle

Quest 8(2) 2012 1

Science Science for for South South AfricA AfricA

ISSN 1729-830X ISSN 1729-830X

Volume 8 • Number 2 • 2012 Volume 3 • Number 2 • 2007 r29.95 r20

The DNA Project: solving crime

Forensic science: what is it? Reading the bones: age and sex from skeletons Laid to rest: the missing identified Barberton: where continents collided On the move: species respond to climate change Africa reaches for the stars: the SKA Sc A c AAcdAedmeym yo fo fS c I eI eNNccee ooff SS o u u tt hh AAffrrI c I cA A

Images: University of Cape Town, Wikimedia Commons and NASA

SCIENCE FOR SOUTH AFRICA

ISSN 1729-830X

Editor Dr Bridget Farham Editorial Board Roseanne Diab (University of KwaZulu-Natal) (Chair) Michael Cherry (South African Journal of Science) Anusuya Chinsamy-Turan (University of Cape Town) George Ellis (University of Cape Town) Kevin Govender (IAU OAD) Penny Vinjevold (Western Cape Education Department) Neil Eddy (Wynberg Boys High School) Correspondence and The Editor enquiries PO Box 663, Noordhoek 7979 Tel.: (021) 789 2331 Fax: (021) 789 2233 e-mail: ugqirha@iafrica.com (For more information visit www.questinteractive.co.za) Advertising enquiries Barbara Spence Avenue Advertising PO Box 71308 Bryanston 2021 Tel.: (011) 463 7940 Fax: (011) 463 7939 Cell: 082 881 3454 e-mail: barbara@avenue.co.za Subscription enquiries Patrick Nemushungwa and back issues Tel.: (012) 349 6624 e-mail: Patrick@assaf.org.za Copyright © 2012 Academy of Science of South Africa

The CSI effect

couple of years ago there was a murder in our quiet street in Noordhoek, Cape Town. A young woman who was employed as a cleaner was restrained so forcably by three men who were intent on theft that she suffocated to death. The whole street was alerted by our neighbourhood watch and I contacted a friend in a different part of the area to warn her that these men were around. She gasped when she heard about it – the men had been begging at her house earlier in the day. Fortunately she, very uncharacteristically, locked them out while she went upstairs to find them some food – and also gave them an old silver knife to eat with. When she came to our street to talk to the police she was invited into the crime scene – in fact just about everyone in the street was being invited into the crime scene. There were people everywhere – I could not tell who were police and who were onlookers. At the time I thought that the police’s behaviour was strange. Like many people, I am an avid fan of television series such as Silent Witness and I read crime fiction regularly – and of course I had some undergraduate forensic medicine training as part of my medical degree. So I expected the scene to be ‘secured’ so that evidence could be collected. As it was, there must have been traces of half of Noordhoek in that house by the time the poor woman’s body had been collected and the police had gone. The three men were caught and brought to trial some months later. It turned out that the entire trial hung on my friend’s identification of the men who had come to her house and on their possession of the old silver knife. Two were convicted of manslaughter and one was acquitted. The whole process was traumatic in the extreme, with my friend forced to confront the men in court – understandably feeling a bit unsure of her identification so many months previously and the circumstantial nature of all the evidence. This issue of Quest has the theme of forensic science – note that last word – science. The science of forensics is about the careful collection of evidence, something that takes time, teams of people and a lot of hard work. This has little to do with how forensics is portrayed in CSI for example – where everything is wrapped up in a matter of days by a few people. The CSI effect has been officially described as any of several ways in which the exaggerated portrayal of forensic science on crime television shows such as CSI influences public perception. The term is most often used in the USA where jurors have started to demand more forensic evidence in criminal trials, thereby raising the effective standard of proof for prosecutors. The Fish Hoek police had obviously not heard of this! The topic is one that catches the imagination, but also one that provides a look at science in action. Hopefully by the time you finish reading this issue of Quest, you will understand just how important evidence is and how it should be collected.

Published by the Academy of Science of South Africa (ASSAf) PO Box 72135, Lynnwood Ridge 0040, South Africa Permissions Fax: (021) 789 2233 e-mail: ugqirha@iafrica.com Subscription rates (4 issues and postage)

Bridget Farham Editor – QUEST: Science for South Africa

(For subscription form, other countries, see p. 56.)

South Africa

Erratum

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Unfortunately, in Quest 8(1) Dr Manfred Scriba's surname was incorrectly spelt on page 40. The editor apologises for this oversight.

Design and layout Creating Ripples Graphic Design Illustrations James Whitelaw Printing Paradigm

2 Quest 8(2) 2012

All material is strictly copyright and all rights are reserved. Reproduction without permission is forbidden. Every care is taken in compiling the contents of this publication, but we assume no responsibility for effects arising therefrom. The views expressed in this magazine are not necessarily those of the publisher.

Q The DNA Project

Solving crime with DNA What is the real story around DNA and crime scenes? Vanessa Lynch and Carolyn Hancock look at the facts.

SI has undoubtedly become one of television’s most popular series. But, while many of the scenarios and characters depicted in CSI are far from believable, continuous references to the cutting-edge DNA technology used by the CSI crime labs in solving their cases are not too far from the truth. Moreover, the use of DNA profiling for criminal intelligence in this popular TV series has increased public awareness to the point where people cannot conceive of a case being investigated without DNA – regardless of whether the case calls for it or not! But how much of these TV programmes is actually fact and how much is fiction? Let’s look at the facts and establish to what extent forensic DNA technology is used in South Africa and to what effect ...

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DNA in real life A young girl is brutally attacked and viciously raped in the small town of Louisvale in the Northern Cape. Her injuries are so substantial that gang rape is assumed. This horrifying attack provokes outrage in the local community and six men are swiftly arrested and subsequently spend the next three months in jail – for their own safety, as the community have

threatened them with their lives for committing this monstrous attack. All six men lose their jobs. On examining the case the public prosecutor calls for DNA analysis to be used to assist in the investigation. First, samples are taken from the crime scene, which in this instance is the young girl herself. A doctor collects DNA samples from her clothing and body, which are sent to the forensic science laboratory’s DNA unit for analysis. In the meantime, DNA reference samples are also taken from the six suspects and sent to the same laboratory for analysis to determine whether the DNA profiles of these six men match those analysed from the samples taken from the victim. The DNA results reveal an unexpected turn in the investigation as they show that only one rapist is responsible for this terrible attack and that none of the six accused men have a DNA profile that matches that of the real assailant. Based on these results, the six falsely accused men are immediately released and cleared of the crime. Another suspect, a former boyfriend of the young girl’s mother, is subsequently arrested and a DNA reference sample is taken from him and sent to the DNA laboratory for analysis. The DNA results show an exact DNA match with the rapist. He

Sexual assault evidence kits awaiting analysis.

The Forensic Science DNA laboratory.

Image: DNA Project

Table 1: Where to look for DNA Evidence

Possible location of DNA evidence

Source of DNA

Knobkerrie, cricket bat or similar large blunt weapon

Handle end

Sweat, skin, blood tissue, hair

Hat, bandana or balaclava/mask

Inside item

Sweat, hair, dandruff

Sunglasses or reading glasses

Nose or ear pieces, lenses

Sweat, skin

Facial tissue, cotton wool swab, ear bud, wash cloth

Surface area

Mucus, blood, sweat, semen, ear wax

Clothing, including underwear worn during AND after attack

Surface area

Blood, sweat, semen

Toothpick or dental floss

Tips

Saliva, semen, skin cells

Used cigarette

Cigarette butt

Saliva

Stamp or envelope

Licked area

Saliva

Tape, cable tie or ligature

Inside/outside surface

Skin, sweat, saliva, hair

Bottle, can or glass

Sides, mouthpiece

Saliva, sweat

Used condom

Inside/outside surface

Blood, semen, vaginal or rectal cells

Blanket, pillow, sheet

Surface area

Blood, sweat, hair, semen, urine, saliva

Bullet

Outside surface

Blood, tissue

Bite mark, area licked

Person’s skin or clothing

Blood, saliva

Fingernail, partial fingernail

Scrapings

Blood, sweat, tissue

Quest 8(2) 2012 3

Scrapings from under fingernails can provide DNA samples. Image: DNA Project

A hijacking crime scene showing how the crime scene investigator dresses to prevent contamination (staged). Image: DNA Project

A forensic science laboratory in action. Image: DNA Project

4 Quest 8(2) 2012

The chain of evidence The chain of events leading up to the conviction of the perpetrator by means of the revolutionary technology known as ‘DNA profiling’ begins at the crime scene itself. A crime scene is usually the physical area or location where a crime has been committed, which contains clues, or records, of what happened at the scene. It can also include the body of a victim, as in the case of sexual assault. Clues that perpetrators leave behind at a crime scene are what can be used to link them to that crime. These clues are called evidence. While evidence can include testimony from eye-witness reports, digital footage or a fingerprint, it can also be found in biological material, which contains DNA. Forensic crime scene investigators (CSI personnel) are specially trained to look for biological samples which may contain DNA at the crime scene so that they can be used as evidence to link the person who committed the crime to the crime scene. As Edmond Locard, the father of forensic science, clearly stated more than 100 years ago, ‘Wherever he steps, whatever he touches, whatever he leaves, even unconsciously, will serve as a silent witness against him. Not only his fingerprints or footprints, but his hair, the fibers from his clothes, the glass he breaks, the tool mark he leaves, the paint he scratches, the blood or semen he deposits or collects. All of these and more bear mute witness against him. This is evidence that does not forget.’ This quote is often summarised in the famous phrase ‘every contact leaves a trace’ – the CSI’s simply need to find the evidence and send any biological samples to the DNA forensic laboratory for further analysis.

Why is DNA evidence considered to be so valuable in investigations? DNA is found in every cell (except red blood cells) in our bodies – it can therefore be found in biological samples left at a crime scene or on a victim’s body, e.g. blood, semen, skin cells, tissue, organs, muscle, brain cells, bone, teeth, hair, saliva, mucus, perspiration and even fingernails. While blood, saliva and semen are the main sources of DNA for forensic testing, trace amounts of DNA, for example from epithelial cells, are now able to be acquired from touched objects, such as the handle of a weapon, the steering wheel of a stolen car or the inside of a glove. This is one of the reasons that DNA is such a useful form of evidence – it is almost impossible for criminals NOT to leave some of their cells behind at a crime scene! In addition, it remains unchanged throughout a person’s life, and because every person has a unique DNA profile (except an identical twin), it does not matter whether a person is arrested years after they have committed the crime: if their DNA profile matches the DNA profile found on a crime scene years before their arrest, it indicates that they were present at the crime scene at the time the crime was committed. What happens when the biological sample arrives at the forensic science laboratory? Once the biological samples have been received at the forensic science laboratory, the genetic material, or DNA, is isolated from the sample and quantified. This is then referred to as the DNA sample. Selected fragments containing the forensic DNA regions under analysis, called short tandem repeats (STRs) are then replicated, using a process called PCR (polymerase chain reaction), which can be described as a form of molecular photocopying. After being placed in a special gel, the fragments are separated according to their length, using an electric current, a process called electrophoresis. A laser then lights up fluorescent tags on the fragments, so that the fragment length of each STR marker can be measured. The fragment length is determined by the number of repeats of a given sequence at every chromosomal ▲ ▲

DNA analysis relies on careful and accurate laboratory technique. Image: DNA Project

is sentenced to life imprisonment. This is not a scene from CSI, but an account of an true case, which occurred in South Africa. What is particularly significant in this case is that DNA not only proved the innocence of six people but also led to the conviction of the man who was the rapist. DNA can therefore be used not only to link suspects to a crime but to exclude innocent people from an investigation. Let us look closely at the steps taken by the police, the forensic analysts and the criminal justice system, which led to the exoneration of the six innocent men and successful prosecution of the real perpetrator.

What is DNA? DNA, or deoxyribonucleic acid, is a chemical found in almost all of the 60 trillion cells that make up our bodies. DNA is the ‘instruction manual’ that tells each of our cells how, where and when to function. For example, some cells will produce enzymes to digest food while others will determine what you look like – your height, skin, hair and eye colour. DNA consists of two long chains of subunits, twisted around each other to form a double helix. All DNA is made up of four components, called nucleotides. The nucleotides, or bases, are guanine (G), adenine (A), thymine (T) and cytosine (C). In a similar fashion to the way in which the 26 letters of the alphabet can be ordered to create a message, the instruction that the sequence of nucleotide bases in DNA delivers depends

on their order. For example, ‘mlaina’ means nothing whereas ‘animal’ tells us we are considering a biological creature. Similarly a DNA sequence of C-T-T-G-A-T may be meaningless whereas C-G-T-C-T-A may be an instruction to manufacture a certain protein in your white blood cells. The instructions encoded in any specific combination of DNA bases (e.g. GATCCAT) directs all our biochemical processes by instructing the cell which amino acids to put together to form proteins. As our bodies are made up of and regulated by different proteins, our DNA determines all our characteristics and makes each of us unique. DNA is contained within chromosomes, which are located in the nucleus of our cells. All people have 46 chromosomes arranged in pairs – one of each chromosomal pair coming from each of our parents. We have 22 pairs of chromosomes (called autosomal chromosomes) as well as two sex chromosomes. Males have one X chromosome, and a Y chromosome (46, XY), while females have two X chromosomes (46, XX). More than 8 trillion possible combinations arise from any two parents which is why none of us (except identical twins) are alike. Just by observing people’s appearance you will notice that none of us look the same (except identical twins) and that is because our DNA is different. What differs between people is the sequence of the four nucleotides on the DNA molecule. Interestingly, only 5% of our DNA is made up of areas called genes, which code for all the proteins that our bodies need for growth and to function. Very little variation between people exists in these genes or coding regions. However, some regions in

The structure of the DNA double helix. The atoms in the structure are colour coded by element and the detailed structure of two base pairs is shown in the bottom right. Image: Wikimedia Commons

A set of normal human chromosomes.

The chemical structure of DNA. Hydrogen bonds are shown as dotted lines. Image: Wikimedia Commons

Image: US National Library of Medicine

The way in which STRs are used in forensic DNA analysis.

Image: The DNA Project

Quest 8(2) 2012 5

How DNA is used for a person’s DNA profile.

Image: The DNA project

the other 95% of the DNA, that do not code for any proteins, are highly variable and may be used to tell the difference between people. As the

location under analysis. The resulting patterns are photographed and examined and converted into a digital profile. The fragment length of each STR marker is recorded as a series of numbers. This sequence of numbers is called the ‘DNA profile’. The resultant DNA profile is a series of letters and numbers that are representative of the physical DNA sample. How can we use DNA to link a suspect to a crime scene? Once DNA profiles have been obtained from the evidential samples collected at

purpose of many of these ‘non-coding’ chromosomal regions is unknown they are loosely referred to as ‘junk DNA’. The stretches of our DNA that are used for forensic purposes are found in a number of different places (loci) within the non-coding regions of the DNA molecule. The chromosomal locations chosen for forensic DNA analysis are called short tandem repeats (STRs) because, at each locus, a pattern of two or more nucleotides is repeated in what has been termed a ‘genetic stutter’. An example would be the two nucleotides, A and C, repeated a number of times: e.g. ACACACACACAC which would be abbreviated to (AC)6 as the sequence is repeated six times. In any person there will be two forms (alleles) of the repeated sequence at every location under analysis; one is maternally inherited, one paternally. This means that you may inherit five repeats of the sequence from your father and ten from your mother. We would then say your genetic make-up at the place in your DNA where the AC sequence is repeated is 5,10. The number of repeats of these DNA sequences varies considerably among individuals and allows scientists to differentiate between people. A person’s DNA profile is simply a list of the number of repeats of a given sequence at every chromosomal location (locus) under analysis. Forensic scientists analyse a number of loci simultaneously to make sure that no two people will have the same DNA profile. Currently in South Africa, ten loci are analysed to provide a forensic DNA profile. The greater the number of STR regions that are tested simultaneously, the lower the chance (probability) of any two individuals sharing a profile. By analysing ten loci there is less than one in a billion chance that two people will share a DNA profile. This is a very accurate science! It is very important to remember that because forensic scientists analyse non-coded regions of our DNA, or ‘junk DNA’, a DNA profile does not provide any information regarding people’s physical characteristics, apart from gender, and is used as a unique identifier only. Therefore the information gained from a DNA profile reveals no more about a person’s private information than a conventional forensic fingerprint.

the crime scene they will be compared to the DNA profiles obtained from known suspects as well as DNA profiles obtained from other crime scene evidence. Profiles that are obtained from known people are called ‘reference profiles’ and they are usually obtained from suspects, victims or other people that may have been at the scene such as crime scene investigators. A typical DNA case would involve comparing the DNA profiles obtained from two types of samples: the unknown, or crime scene sample, such as semen from a rape, and a known or

reference sample, such as a buccal or cheek swab from the suspect. If the resultant crime scene profile and the reference profile from the suspect are identical then this is called a ‘match’ or ‘inclusion’. A pair of profiles is reported to ‘match’ only if every allele at every locus that occurs in one profile occurs in the other. A ‘match’ would then indicate that the suspect had been at the crime scene – in other words that the two samples have a common source, namely, the suspect. It does not always mean that the person actually committed the crime; it just indicates

Steps in DNA Analysis

COLLECTION

1 ng 0.3 ng No DNA 0.5 ng 0.5 ng 0.7 ng 1 ng 1 ng

SPECIMEN STORAGE EXTRACTION QUANTITATION

Blood stain

Buccal swab

Sample collection & storage

Slot blot

DNA extraction

DNA quantitation

GENOTYPING INTERPRETATION OF RESULTS DATABASE STORAGE & SEARCHING

6 Quest 8(2) 2012

DNA amplification STR Typing Male: 13, 14-15, 16-12, 13-10, 13-15, 16

Interpretation of results

DNA database

DNA Laws and the status of DNA legislation South Africa National DNA databases have been established in countries all over the world, as their enormous value to law enforcement is being recognised. In May 2012, Brazil became the 56th country in the world to pass DNA laws to regulate its DNA database. In South Africa, we are still in the process of elevating the status of our National DNA Database (NDD) to an international level of acceptance. This will, if achieved, ensure that DNA evidence plays a key role in crime detection and prevention in a country which has one of the highest crime rates yet lowest rates of conviction in the world. The existing DNA database in South Africa contains approximately 130 000 DNA profiles, the majority of which are crime scene (unknown) profiles. Compare this to the NDDs held by the USA (>10 000 000 million profiles) and the UK (>5 500 000 profiles) both of which contain a higher number of known or reference profiles than crime scene profiles, thereby allowing for a greater chance of a match or ‘hit’ when crime scene profiles are entered onto their NDDs. Furthermore, our DNA database has, through default, evolved under the governance of the Criminal Procedure

Act of 1977, which was promulgated long before the advent of DNA profiling was used for crime resolution. It is however regarded as the legislative source for the current gathering of DNA evidence. Legislating policies and procedures to regulate a national DNA database for criminal intelligence purposes has become a matter of some urgency, not only because of the potential value of DNA as a law enforcement tool but also because of the civil liberties issues that these practices raise. The expansion of the DNA database in South Africa is however only possible with the implementation of new DNA legislation, which will allow for the inclusion of all types of profiles on the NDD, as well as for comparative searches between crime scene and reference profiles. To this end, The Criminal Law (Forensic Procedures) Amendment Bill B2-2009 was drafted and adopted by Cabinet in December 2008. The DNA Bill, currently still under review by Parliament, seeks to address gaps in our current legislation dealing with the collection, storage and use of DNA evidence and to provide for the expansion and administration of a national DNA database, which will be called the National DNA Database of South Africa (NDDSA). Promulgation of this DNA

Table 2: Legislation – International DNA databases Country (year established)

Approximate number of profiles Removal criteria on DNA database

UK (1995)

> 5 500 000

Never removed – under review

USA (1998)

> 10 000 000

Depends on State law

Germany (1998)

> 750 000

After acquittal or 5-10 years after conviction

China (2003)

> 5 500 000

No data

Canada (1998)

> 150 000

Convicted offenders never removed for primary offences

Netherlands (1994)

> 142 000

Convicted offender removed after 20-30 years

New Zealand (1995)

>100 000

Convicted offenders 10 years after release

South Africa (1998)

> 130 000

Inadequate legislation

DNA profile. In such cases the court will not regard the DNA results from those samples as providing a large enough contribution towards the determination of whether the suspect was in fact at the crime scene and will look for other forms of evidence to prove the guilt or innocence of the suspect. A partial match may however help to exclude a suspect where none of the alleles at any one locus match. Probabilities Once a match has been identified between a crime scene profile and a suspect this information can be used as evidence to support the case presented by the prosecution in court. DNA evidence is always presented to a court of law in terms of a random match probability – this value will provide an indication to the court on how much ‘weight’ should be attached to an evidential item. For example, the report from the laboratory might describe an exact match between a semen sample found in the body of a rape victim and a blood sample taken from the suspected rapist. If the probability of another person (other than the suspect) in the South African population having the same profile is in the region of one

in a billion, the court will consider this to be very valuable evidence, indicating that the suspect was in fact the source of the DNA found in the victim’s body. On the other hand, if a probability of one in a thousand were reported then the court would not consider that item of evidence as compelling in terms of absolutely clearly linking the suspect to the alleged crime. Due to the fact that forensic scientists analyse at least nine

▲ ▲

that they were present at the crime scene and they would now be required to explain their presence at the crime scene. It is important to remember that DNA evidence is not the only form of evidence in a case and that other supporting evidence will still be needed by a court of law to convict a person of a crime. However, DNA is a very strong form of physical evidence and the technology used is exceptionally accurate and objective – DNA evidence doesn’t lie! If there is no match between the crime scene profile and the reference profile, then the samples may be considered to have originated from different sources. The term used to indicate that there is no match between two DNA profiles is an ‘exclusion.’ In some cases, forensic analysts may report that a match has been ‘inconclusive’ or that it is a ‘partial match’. A pair of profiles are said to be a ‘partial match’ if there are allelic matches at some of the loci. There may be several reasons for this type of inconclusive result or partial match. For example, contaminated samples often yield inconclusive results. So do very small or degraded samples, which may not have enough DNA to generate a full

Case report: the South African DNA database leads to the successful conviction of a serial rapist On 6 June 2011 Shavani Phophi, known as the Muldersdrift rapist, was found guilty of six rapes, three robberies with aggravating circumstance, and two cases of theft. Five of the rape victims were adult women to whom Phophi offered work and then lured to Nooitgedacht to rape them in the veld. The Investigative Psychology Unit of the SAPS used a number of strategies, including DNA, to successfully link all the adult rape cases and to locate the suspect in his shack in KyaSands. After arrest the suspect was then also linked through the DNA database to the rape of a 10-year-old girl in 2005. Without the database, the case of the little girl would not otherwise have come to the attention of the police, because the other victims were adult females raped between June 2009 and May 2010. Phophi subsequently stood trial for all of these cases of sexual assault and received a combined sentence of two life sentences and a further 95 years behind bars.

Quest 8(2) 2012 7

Comparing the crime scene DNA to the reference DNA.

STR loci simultaneously, the chances of anyone other than the suspect having a matching profile are exceptionally small, making DNA a very strong form of evidence in criminal cases. DNA databases: the key to criminal intelligence A national DNA database (NDD) can be described as a repository of DNA profiles held by the government to identify suspects of crimes. The purpose of establishing and thereafter expanding a NDD is to provide the police with more useful criminal intelligence by linking DNA evidence found at crime scenes to unknown offenders, in much the same way as a fingerprint database works. This supports crime investigation and also reduction (where persons are convicted and prevented from committing further crime). If however, you exclude a DNA Database from the criminal justice system and only use DNA profiling on a case-by-case basis or as a prosecutorial tool, then DNA profiling falls short of being used to its full potential as a criminal intelligence tool. It is for this reason that countries throughout the world are embarking on extensive DNA database expansion programmes, as they realise the benefits of a NDD for crime resolution, detection and deterrence. How does it work? DNA profiles obtained from both crime scenes and suspects are entered into the NDD for comparative searching between the reference or convicted offender index (which contains profiles of known people) and crime scene profiles (unknown persons). In this way, a NDD provides valuable criminal intelligence to the police, because it can: n identify the real perpetrator of the crime by comparing different crime

8 Quest 8(2) 2012

scene profiles on the database to determine if there is a match n link crimes where there are no suspects n eliminate suspects where there is no match between the suspect and the crime scene profile n determine whether there is a serial offender involved n link a suspect, victim and crime scene/s. For example, in cases where there is no known suspect in a case, the police will compare the crime scene profiles on a NDD with all the reference profiles stored on the NDD. If the perpetrator has been previously arrested or convicted of an offence then their profile may already be on the NDD, in which case a match would occur. In South Africa, where many criminals re-offend, this is extremely helpful in providing a ‘lead’ in a case. By helping to identify or rule out a suspect at an early stage in an investigation, a NDD also saves investigating officers valuable time which they can use to solve and prevent further crimes being committed. Unfortunately, the South African DNA database is currently very limited in size and so is not used to its full potential. This is because our legislation does not allow for more DNA profiles to be loaded onto the NDD nor for the efficient management and regulation of the information uploaded onto the database. The database in its current form does not provide vital criminal intelligence that can be used to solve and prevent many of the heinous crimes committed daily in South Africa. The notorious criminal, Moses Sithole, is a case in point. He began raping women in his twenties, claiming three victims before one testified. He was sent to prison for six years. Shortly after his release in 1993 he embarked on a murder spree: in total he is known to have raped 40 women, 38 of whom were strangled with their own underwear. On 5 December 1997, he was sent to prison for 2 410 years with eligibility for parole in 930 years. If South Africa had kept his profile on a DNA database after his first release from prison in 1993, he could have been identified and apprehended after his first victim was raped and killed – 37 women’s lives could have been spared! The DNA Project By now you will have understood that DNA profiling used in conjunction with

a national DNA database is a reality that has fast become one the most powerful criminal justice tools used in the world today and is increasingly vital to ensuring accuracy and fairness in the criminal justice system. In South Africa, DNA evidence has been shown to have helped, and when used to its full potential, will continue to help solve and prevent some of the most serious violent crimes taking place here today. Before this can happen, current systems need to be reviewed, and some of them replaced, to ensure that we are fully able to utilise the benefits of DNA profiling as a crime-fighting tool. The DNA Project, a non profit organisation was established in 2005 in response to this need in South Africa. It identified that the impact of DNA profiling in this country was limited due to a combination of factors such as inadequate legislation, insufficient laboratory capacity to meet the demands of an expanded DNA expansion programme, lack of awareness at the crime scene to preserve critical DNA evidence, outdated DNA databasing systems and a lack of specialised forensic DNA analyst skills. As a result of the lagging awareness by the government of the value and importance of an expanded DNA database the DNA Project’s interventions include: 1. Creating greater awareness at the scene of the crime by educating people on the value of DNA and other forensic evidence as an evidential tool and the need to protect and preserve a crime scene to allow for the proper collection of all types of forensic evidence by qualified crime scene investigators. This is being done through a national crime scene awareness campaign which provides free DNA awareness workshops to first responding, non forensic crime scene personnel as well as the general public, paramedics and as members of the criminal justice system. 2. Developing a specialised forensic analyst honours degree which may be offered at all tertiary institutions throughout South Africa. 3. Lobbying support for urgent changes in current legislation, which are needed to regulate the area of the law that relates to the use of DNA for the investigation, prosecution and resolution of crime.

Definitions

Conclusion The advent of DNA profiling and its use for identifying perpetrators of crime has transformed law enforcement investigations throughout the world, by allowing forensic laboratories to match suspects with minuscule amounts of biological evidence collected from crime scenes. The past two decades have seen extraordinary advances in DNA testing procedures, allowing investigators to test evidence collected from over 40 years ago with accuracy. The time needed to determine a sample’s DNA profile has dropped from eight weeks to only a day or two – very soon the time needed to process samples may decrease to as little as a few hours. While the glossy laboratory environment, expensive cars and beautiful people capable of exacting a confession out of every suspect without the need for a court of law, which appear in CSI, are a far cry from reality, the possibility of collecting tiny amounts of biological evidence to link perpetrators to a crime scene is very real and is happening in the world – and South Africa – today. ❑ Vanessa Lynch, a commercial attorney, left her job in 2005, in order to run the DNA Project full time. Vanessa decided to stand up and be counted after her father was murdered during a robbery in 2004. Realising the vital role that DNA evidence could play in investigating crime, she gave up her career as an attorney and began lobbying to expand the existing DNA database in South Africa. Vanessa’s legal background and her acquired skills in drafting and research, together with an innate determination and ability to ‘think on her feet’, are the ingredients required to fulfill the objectives of the DNA Project. Carolyn Hancock has a PhD in genetics and was a genetics lecturer at the University of KwaZulu-Natal for 15 years. After watching an episode of Carte Blanche in 2007 in which Vanessa spoke about the important work being undertaken by the DNA Project, Carolyn felt she could help in developing a postgraduate qualification in Forensic Biology. She contacted Vanessa immediately and subsequently became part of the DNA Project team. Her scientific knowledge, passion for teaching and desire to help make South Africa a safer place to live, have assisted the DNA Project in achieving its objectives in terms of developing skilled analysts for work at the forensic laboratory as well as educating people on the benefits of DNA evidence in crime detection and prevention.

Allele – A different form of a gene at a particular locus. The characteristics of a single copy of a specific gene, or of a single copy of a specific location on a chromosome. For example, one copy of a specific short tandem repeat (STR) region might have 10 repeats, while the other copy might have 11 repeats. These would represent two alleles of that STR region. Cell – The smallest component of life capable of independent reproduction and from which DNA is isolated for forensic analysis. Chain of custody – A record of individuals who have had physical possession of the evidence and the process used to maintain and document the chronological history of the evidence. (Documents can include, but are not limited to, name or initials of the individual collecting the evidence; each person or entity subsequently having physical possession of it; dates the items were collected or transferred; from where the item(s) were collected; agency and case number; victim’s or suspect’s name (if known); and a brief description of the item.) Chromosome – The biological structure by which hereditary information is physically transmitted from one generation to the next. Located in the cell nucleus, each chromosome consists of a tightly coiled thread of DNA with associated proteins and RNA. The genes are arranged in linear order along the DNA molecule. DNA (deoxyribonucleic acid) – Often referred to as the ‘blueprint of life’, DNA is the genetic material present in the nucleus of cells, half of which is inherited from each biological parent. DNA is a chemical substance contained in cells which determines each person’s individual characteristics. An individual’s DNA is unique except in cases of identical twins. DNA analysis – The process of testing used to identify DNA patterns or types. In the forensic setting, this testing is used to exclude or include individuals as possible sources of body fluid stains (blood, saliva, semen) and other biological evidence (bones, teeth, hair). This testing can also be used to indicate parentage. DNA profile (sometimes referred to as a DNA fingerprint) – The result of determining the relative sizes of repeated DNA sequences at several locations on an individual’s chromosomes. Each person (except identical twins) has a unique DNA profile and DNA profiling can thus be used to discriminate between unrelated individuals, such as in the context of the National DNA Database. Electrophoresis – A method of separating large molecules (such as DNA fragments) from a mixture of similar molecules. An electric current is passed through a medium and molecules separate according to their electrical charge and size. Separation of DNA markers or fragments is based on these differences. Elimination/reference samples – A term used to describe a sample of known source taken for comparison purposes. An elimination sample is one of known source taken from a person who had lawful access to the crime scene (e.g. blood or cheek (buccal) swabs for DNA analysis, fingerprints from occupants, tire tread impressions from police vehicles, footwear impressions from

emergency medical personnel) to be used for comparison with evidence of the same type. Evidence – Something that can help to identify the persons responsible for a crime, items used to establish an element of crime or to reconstruct crime events or link crimes. Evidentiary samples – A generic term used to describe physical material/evidence discovered at crime scenes that may be compared with samples from persons, tools, and physical locations. Exclusion – A DNA test result indicating that an individual is excluded as the source of the DNA evidence. In a criminal case, ‘exclusion’ does not necessarily equate to ‘innocence’. This occurs when one or more types from a specific location in the DNA of a known individual are not present in the type(s) for that specific location in the DNA obtained from an evidence sample. Gene – The basic unit of heredity – a functional sequence of DNA in a chromosome. Genetic loci – Specific locations in the genetic material of an organism where certain DNA sequences can be found. Genotype – The genetic constitution of an organism, as distinguished from its physical appearance (its phenotype). The designation of the two alleles at a particular locus in one individual is referred to as their genotype. Polymerase chain reaction (PCR) – A process used in DNA identification testing in which one or more specific small regions of the DNA are copied using a DNA polymerase enzyme so that a sufficient amount of DNA is generated for analysis. Polymorphism – Variations in DNA sequences in a population that are detected in human DNA identification testing. Random match probability – The probability that the DNA in a random sample from the population has the same profile as the DNA in the evidence sample. Recidivism – A tendency to relapse into a previous condition or criminal behaviour. Reference samples – A standard/reference sample is material of a verifiable/documented source which, when compared with evidence of an unknown source, shows an association or linkage between an offender, crime scene, and/or victim (e.g. a carpet cutting taken from a location suspected as the point of transfer for comparison with the fibres recovered from the suspect’s shoes, a sample of paint removed from a suspect vehicle to be compared with paint found on a victim’s vehicle following an accident, or a sample of the suspect’s and/or victim’s blood submitted for comparison with a bloodstained shirt recovered as evidence). Short tandem repeat (STR) typing – DNA analysis method which targets regions on the chromosome which contain multiple copies of an identical DNA sequence in succession. Short tandem repeats (STR) – Multiple copies of a short identical DNA sequence arranged in direct succession in particular regions of chromosomes.

Quest 8(2) 2012 9

Above: Dr Jacqui Friedling (a forensic anthropologist) and Dr Itumeleng Molefe (a forensic pathologist) laying out a forensic bone case for examination. Image: Alan Morris Right: Students in the MSc Forensic Biomedical Science course doing a practice excavation of a human burial (with some hidden surprises for their benefit, such as the dog skeleton in the foreground). Image: Alan Morris

Alan Morris tells Quest about the exciting science of forensics

What is forensic science?

orensics is an exciting word. It conjures up police investigations, dead bodies and bullets under microscopes, but it actually isn’t terribly well understood by most people. ‘Forensic’ simply means ‘pertaining to the law’ and comes from the Latin name ‘forum’, which was the place in ancient Rome where court cases were heard. Technically, anyone in the legal system, from judges to court orderlies are part of the system, but the reason we associate the word forensics with dead bodies and bullets is because today the term is most often used to describe ‘forensic science’. Sometimes we use the general term ‘forensic scientist’ to represent all expert scientific witnesses, but this is not technically correct. In my opinion, there is no such thing as a forensic scientist, only a scientist with knowledge of a specific field who gives his or her opinion about that subject in court. There are many

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scientific specialties that can contribute to the legal debate – psychologists who talk about a criminal’s state of mind, geneticists who can show who was the real father of a baby, entomologists who can tell you about how insects give clues to the time since death, engineers who can tell us why metals break or bridges collapse, chemists who talk about drug purity, toxicologists who tell us about poisons, pathologists who know about causes of death and even zoologists and botanists who talk about poaching plants and animals. There are even a few experts out there who have knowledge in several of these fields and come very close to being undifferentiated forensic scientists. Each of these authorities has a different expertise, but what they share is an approach to the presentation of their information to the courts. Each authority needs to be able to explain technical issues to non-specialists and also needs to

understand legal procedures. In theory these people are neutral, presenting the scientific facts so that the court can make an informed decision, but our legal system, unlike that of the traditional courts, is adversarial and the expert witness may be called by either the prosecution or the defence. An adversarial legal system is one in which the defence and the prosecution confront each other and use evidence to do so.

This does present potential conflicts. Although the facts are always the facts, a scientific witness called by the defence may concentrate on the unreliability of the date being used in evidence to sow doubt. The same witness, if called by the prosecution, would emphasise his skill of observation in order to boost the reliability of the data. This becomes critical when the case is being built on circumstantial evidence. In fact our

CSI or real life? Introducing the CSI effect! expert is a specialist whose primary job is explaining his or her field of knowledge to the court. Circumstantial evidence is indirect evidence, for example someone says that the accused was seen near the scene of the crime. This is not as solid as, for example, physical evidence that the accused was actually present at the scene of the crime, such as body fluids or fibres from clothing.

Changing evidence So what do forensic scientists talk about in the witness stand? It is science, of course! What the court wishes to hear is the scientist’s opinion about scientific evidence. Judges and magistrates are not trained to understand scientific data and they need someone who can clearly tell them the meaning of the evidence and how it should influence their decision about the case. If there is more than one scientific expert giving evidence in a trial, which one should the judge believe? It used to be enough for the expert to recount all of his or her skills to impress the court. How many scientific papers have you published? How many higher university degrees have you obtained? In how many court cases have you previously given evidence? But times have been changing and this is no longer always the measure that the judge uses to be convinced that one scientist is better informed than another. The big change in how scientific evidence is presented in court began in the United States about 20 years ago. A judge was asked to decide whether or not a chemical company was guilty of poisoning the water in such a way that a baby born in the area had birth defects. He listened to expert witnesses for both the family and the chemical company but he was very frustrated because it all seemed to be one opinion after another without real evidence being presented. In the end, the judge issued a guideline for future cases which are now known as the ‘Daubert Standards’, named after the case that triggered them. The Daubert Standards ask five questions: 1. Has the technique been tested under field conditions (rather than just in a laboratory)? 2. Has the technique been subject to peer review and publication?

Police secure a crime scene in Britain using a tent.

Image: Wikimedia commons

Forensic anthropology is a relatively new field, only recognised for the last 30 years or so, but it has become incredibly well known to the public over the last few years because of the popularity of television programmes such as Crime Scene Investigation, Silent Witness, Da Vinci’s Inquest, Cold Squad, Waking the Dead and Bones. I must admit that I enjoy watching television shows that have anthropological or forensic themes. I know that it is only make-believe, but sometimes these characters do the most amazingly unscientific things. I watched in disbelief a couple of years ago when the ‘professor’ in the English TV series Primeval reached down and counted the ribs in order to identify the sex of a skeletonised body that had been dispatched by a prehistoric creature. Come on, the guy is supposed to be a palaeontologist! Counting ribs doesn’t identify sex. What mis-informed writer got that into the screenplay without the knowledge of the science advisor? It would be laughable if it was only about television, but you would be surprised to discover exactly how much forensic and anthropological science knowledge is being passed down to the lay public by such sources. American forensic specialists are starting to call it the ‘CSI effect’ after the forensic science drama CSI: Crime Scene Investigation. Now anyone who has a television set, goes to the movies or reads a good detective novel thinks he knows more about forensic science in general and forensic anthropology in particular than many of the practitioners in the field. It is actually a dangerous phenomenon because few of these media-educated popular investigators know much about solving crimes and even less about the science that forms the backbone of investigative techniques. The CSI effect creates problems by creating a misconception that forensic science can solve crime as quickly and definitively as it is done on television crime shows. Not only that, but it creates the impression that scientific data are absolutely infallible. The public is developing unrealistic expectations that forensic science can solve all questions and it gives no idea of the real costs of tests and time involved. The writers of these television shows often show the investigation, laboratory work and police interrogation as all happening at the same time and done by the same individuals. The CSI investigator finds the evidence, analyses the data and interviews the suspects all in a day or two. This makes the stories dramatic and entertaining, but not very much like real life. The reality involves different teams of people and potentially long periods of investigation before a suspect is even identified. Certainly in South Africa a forensic pathologist will be brought out to a crime scene, but it is rare for a forensic anthropologist to be called out to a crime.

3. What is the known or potential rate of error? 4. Do standards exist for application of the technique? 5. Has the technique been generally accepted within the relevant scientific community? What these questions have in common is that the court is asked to consider the validity of the evidence along with the qualifications of the scientists. Although South African courts are not compelled to use these

Daubert guidelines, most forensic scientists are very aware of them. ❑ Alan Morris is a professor in the Department of Human Biology at the University of Cape Town. He has published extensively on the origin of anatomically modern humans and the Later Stone Age, Iron Age and Historic populations of Malawi, Namibia and South Africa. He has a particular interest in forensic science and recently published Missing and Murdered: A personal adventure in forensic anthropology.

Quest 8(2) 2012 11

What is forensic anthropology? Alan Morris tells Quest about the specialised field of forensic anthropology.

orensic anthropology is a specialist field that deals with the evidence that can be collected from human remains – both hard tissue in the form of dry bones and soft tissue in the form of dried flesh from dried up or mummified bodies. A forensic anthropologist needs a detailed knowledge of anatomy, particularly the anatomy of the human skeleton, since

A skull from a forensic case showing chop marks from a panga on the back of the head. Image: Alan Morris

A forensic anthropologist and a forensic pathologist on site of the discovery of human remains. Image: Alan Morris

A forensic case laid out in the lab waiting for analysis. Image: Alan Morris

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the bones are usually all that remains when a forensic anthropologist is called in to identify a body. Anthropology is the broad study of people from all periods of time and in all areas of the world. Anthropology focuses on both biological and cultural characteristics and variation, as well as biological and cultural evolution. Applied anthropology is a branch of anthropology that is devoted to applying anthropological theory to practical problems. Forensic anthropology is an example of this – a forensic anthropologist is someone who has specialised knowledge about the human skeleton.

The anthropologist who has specialised in the biology of the human skeleton understands a great deal about the growth, ageing, structure, function and variation of bone. It is the variation in bone that makes anthropological understanding of anatomy different from the understanding that a medically trained, clinical pathologist would have. Variation, in this case, is not just the differences between individuals, but also the differences between populations and between species. A medically qualified pathologist focuses on the study of disease and the causes of death, but is out of his or her depth once the body is so decomposed that the organs cannot be recognised. Once the body is down to bones, it is the anthropologist who is better qualified to deal with the evidence than the medically trained pathologist. Forensic anthropology versus anthropology When an anthropologist studies the human skeleton, he or she is looking at the skeletons of different populations of people to find out how they lived and died, and the skeletons are usually from an ancient archaeological site. In this case the anthropologist will be interested in all sorts of questions about the ancient population including historical demography, health issues, and patterns of human behaviour. Forensic anthropology has grown from this approach and the application of this knowledge has become highly specific. The forensic anthropologist is interested in only two key issues: the identification of the individual, and the evidence that relates to the events at death. The forensic focus also requires a different analytical approach. The anthropological approach examines as many individuals as possible in order

to quantify the range of variation within the group and uses statistics to look at this variation and determine trends. The forensic approach, on the other hand, works with single individuals and uses statistics much less frequently. Not only is the anatomy of the bone important in forensic anthropology, but also the events that have lead to the preservation of that bone. Archaeologists and palaeontologists call this the study of ‘taphonomy’, which includes the evidence of death, and the accumulation and preservation of bones over time. Forensic anthropology has borrowed this knowledge and applied it directly to forensic questions. Forensic anthropologists speak of four taphonomic periods in relation to a dead individual: n the ante-mortem period, which covers the whole of the time before the death of the person n the peri-mortem period, which is around the time of death n the post-mortem period which includes the time between death and discovery n the post-recovery period which includes the process of recovery, analysis and storage of the bony evidence. Each period provides different contexts for enquiry. During the antemortem period (before death), the skeleton is living and records its own details of growth and development. These can be used to develop a biological profile of the individual and help in securing identification. The perimortem period is obviously important because it includes the events around the death and the cause of death. However, the post-mortem period is important as well because it gives the time context of the crime by revealing information about the post-mortem interval (PMI). Each and every event after the discovery needs to be recorded as part of the ‘chain of custody’ so that there are no questions about the data when the case is discussed in court. ❑ Alan Morris is a professor in the Department of Human Biology at the University of Cape Town. He has published extensively on the origin of anatomically modern humans and the Later Stone Age, Iron Age and historic populations of Malawi, Namibia and South Africa. He has a particular interest in forensic science and recently published Missing and Murdered: A personal adventure in forensic anthropology.

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Telephone: 086 069 3888 Email: callcentre@idc.co.za To apply for funding online visit www.idc.co.za

What we offer you The IDC assists start-up and existing businesses with a minimum funding requirement of R1 million and a maximum of R1 billion. Funding is offered across its mandated sectors under the following Strategic Business Units: • Agro-Industries • Chemicals and Allied Industries • Forestry and Wood Products • Green Industries • Healthcare • Information and Communication Technology • Media and Motion Pictures • Metal, Transport and Machinery Products • Mining and Minerals Beneficiation • Strategic High Impact Projects and Logistics • Textiles and Clothing • Tourism • Venture Capital Special funding schemes are available that address transformation and entrepreneurial development (TES); topping up equity contributions from entrepreneurs (TES & RCF); and sector-specific schemes (horticulture, forestry, clothing and textiles, hospitals). The IDC Gro-e-Scheme provides funding for projects from R1 million to R1 billion at prime less 3% for up to five years. The IDC’s business support programme addresses non-financial support to entrepreneurs. Assistance is provided with capacity building to improve project viability. If you have a project that can contribute to building South Africa’s industrial capacity and creating jobs, visit www.idc.co.za to find out how the IDC can help build your opportunity.

What the bones can tell us How do we identify age and sex from skeletal material? By Jacqui Friedling.

Figure 1 B

Figure 1 A A – male pelvis; B – female pelvis

Figure 2 A

Figure 2 B

A – male skull; B – female skull

ne of the first questions that is asked of the forensic anthropologist when confronted with human skeletal remains concerns the sex and age of the individual. We estimate age and sex because you can never be 100% sure whether an individual is male or female or the exact age at death. There is considerable variability between men and women and between individuals of the same sex and age, as well as between individuals exposed to different environments and diets. Although estimates of sex and age can never be exact, errors can be minimised by careful interpretation of the data. Why the word sex and not gender? You are either born a man or a woman. This is genetically determined by your X and Y chromosomes. Thus only two sexes can be estimated from skeletal material. Gender is a social construct. In other words, someone can be born genetically or physically

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male but may decide to portray themselves as a woman socially. The converse is also true. The estimation of sex Sexual differences begin to develop in the skeleton before birth. Sexual dimorphism becomes more marked through infancy, childhood and into adolescence, and thus determining the sex of skeletal remains becomes more accurate. It is also easier to estimate sex in adults than in younger (juveniles and children) individuals. The two most dimorphic regions in the body are the pelvis and the skull. Sexual dimorphism is the term used for anatomical differences between males and females in a species over and above the differences in sexual organs.

There is a functional difference between the male and female pelvis. The female pelvis is designed for

childbirth while the male pelvis is not. The female pelvis is wider in its superior (top) and anterior (front) views and shallower than a male pelvis. Features on the posterior and anterior pelvis are assessed for male or female characteristics. The female pelvis has a wider greater sciatic notch, obtuse sub-pubic angle and triangular shaped obturator foramen. Thus the pelvis is the most sexually dimorphic bone and the most accurate for estimating sex in skeletal material. The skull is the next most useful bone for estimating sex on the skeleton. Men tend to have a more ‘square-shaped’ chin, and smaller and square eye sockets with rounded edges. They have a better developed brow ridge (supraorbital ridge above the eyes). On the back of the head, men have a larger mastoid process and the occipital area is also more pronounced. When the pelvis and/or the skull are not available for sexing and ageing, you

The order in which the epiphyses close as we get older

Polymerase chain reaction

The sequence in which teeth appear

can also look at the long bones such as the arm (humerus, radius and ulna) or leg (femur, tibia and fibula). Most men have larger and heavier muscles than women – another example of sexual dimorphism. The muscle markings on the bones of males are also more prominent. The long bones of men are generally more robust than those of women. Females grow faster and mature earlier than males, so age is important when you are estimating sex in children. n Children – compare the stage of calcification of the teeth and the stage of maturation of the postcranial skeleton n Adults – look at the landmarks on the pelvis, skull and long bones. Sex estimation using skeletal material can also be done by means of DNA. This is done by using the amelogenin gene, found on the X and Y chromosomes, using the polymerase chain reaction (PCR) and a non-radioactive dot blot procedure. This method is especially useful when examining juvenile or fragmentary remains. However, the bones and teeth (and thus the DNA) have to be well preserved. The method is destructive and more expensive because part of the skeletal material is destroyed. The estimation of age at death Determining how old a person was when they died is much more difficult than estimating their sex. The estimation of age at death involves observing morphological changes (changes in structure) in the skeletal remains. We use what is known about chronological changes (changes that happen as we get older) in the skeleton. These changes do not occur at the same rates in the different bones and structures. During infancy most of the changes involve the appearance and growth of bones and teeth. During childhood and through adolescence,

bone growth, dental eruption and calcification of the teeth continue. In addition, the epiphyses (ends of the long bones) on the post-cranial skeleton (from the neck downwards) develop and unite. Between 18 and 20 years of age, most growth is complete, all the teeth have erupted and are fully calcified and most of the epiphyses are united. After 20 years of age, landmarks are provided by the progressive union of the cranial sutures, changes in the symphyseal face of the pubis and changes in the macroscopic structure of bones and teeth. Besides age, activity patterns, nutrition and health also affect the pattern of change in the skeleton. Good nutrition and healthy activity patterns give good, strong and healthy bones. The opposite is also true. There are various criteria for ageing a skeleton: n Infants and children – look at dental development, length of long bones and the union of epiphyses. n Adults – look at landmarks on the pubic symphysis, cranial suture closure, degenerative changes, resorption of cancellous bone and dental changes. Teeth are harder than any other element in the body and often the only part that survives because they can withstand the decay process and general wear and tear. Because of this, teeth can also be used to estimate the age of an individual. This is particularly useful in ageing children because their teeth erupt in a specific sequence. After all the permanent teeth have erupted, the indicators of age on teeth are wear and tear as well as changes in the gum line and the surrounding alveolar bone (bone in which the teeth are anchored). Microscopic changes to the bone can also be used as a way of estimating the age of an individual. The process is destructive because it requires very thin slices of bone. The method involves

The polymerase chain reaction is a technique used in molecular biology to amplify a single copy or a few copies of a piece of DNA across several orders of magnitude, so generating thousands to millions of copies of a particular DNA sequence. This means that a very small amount of DNA can be useful. A strip of eight PCR tubes, each containing 100 µl of reaction mixture. Image: Wikimedia commons

Non-radioactive dot blot procedure A dot blot is a technique used in molecular biology to detect biomolecules and for detecting, analysing and identifying proteins. In a dot blot the biomolecules that the scientist is looking for are not first separated by chromatography, but a mixture containing the molecule to be detected is applied directly onto a membrane as a dot. This is then spotted through circular templates directly onto the membrane or paper.

Dot-blot filters.

Image: Wikimedia commons

Suggested reading Burns, KR. Forensic anthropology training manual. 1999. Prentice Hall, New Jersey. Kerley, ER. The microscopic determination of age in human bone. American Journal of Physical Anthropology. 1965; 23:149–164. Schwartz, JH. Skeletal keys: An introduction to human skeletal morphology, development and analysis. 1995. Oxford University Press, New York and Oxford. Stone, AC., Milner, GR., Pääbo, S. and Stoneking, M. Sex determination of ancient human skeletons using DNA. American Journal of Physical Anthropology. 1996; 99:231– 38. Ubelaker, DH. Human skeletal remains: Excavation, analysis and interpretation. 1978. Aldine Publishing Company, Chicago.

cutting the bone and looking at the internal structure of the bone and the changes that occur during life. ❑ Dr Jacqui Friedling is a lecturer in Anatomy, Forensic and Biological Anthropology at the Medical School, UCT. She has a special interest in health, disease and activity patterns in historical populations.

Quest 8(2) 2012 15

Above: The grave of Patrick Mahlangu being exhumed by former Umkhonto we Sizwe members â&#x20AC;&#x201C; grave number 52, Shoshanguve Cemetery. Image: Missing Persons Task Team

Left: Kavita Lakha examining and photographing the very fragmented remains of Patrick Mahlangu recovered from the grave. Image: Missing Persons Task Team

A day in the life of the Missing Persons Task Team What is it like to search for missing persons? Kavita Lakha outlines a day in her life.

y name is Kavita Lakha and I work in the Missing Persons Task Team in the National Prosecuting Authority. Our division was formed as the result of a mandate within the Truth and Reconciliation Commission (TRC) that recommended that a task team be formed to deal with the question of the people who went missing during the apartheid era in South Africa â&#x20AC;&#x201C; from 1960 to 1994 and the release of Nelson Mandela and the start of democracy.

16 Quest 8(2) 2012

During apartheid many young South African men joined the armed wing of the ANC, Umkhonto we Sizwe (MK), and were trained locally or abroad. Many members of MK, as well as civilians who did not form part of any formal armed group, died fighting for the freedom we enjoy today. It is part of my responsibility as a special investigator and forensic anthropologist to: n search for the remains of the missing individual

n to exhume them once found and n complete a skeletal analysis of the remains once brought to the lab. This is not CSI! The search for and identification of missing persons involves routine administrative work, detailed investigation, and time consuming document analysis, all of which is underpinned by scientific and anatomical knowledge. Our cases often donâ&#x20AC;&#x2122;t start with a clue but rather with interactions with the families who are searching for their loved

The contents of bag 1 include a fragment of the left humerus and clavicle as well as smaller fragments of skeletal elements. Image: Missing Persons Task Team

The contents of bag 2 show the skeletal elememts of the vertebral column as well as some ribs. Image: Missing Persons Task Team

ones. This adds an element of humility to the task. The process We begin our investigations by visiting the families to confirm that the person is still missing. We usually begin our search for the remains at the mortuary nearest to where the death took place, depending on the source of the information. Mortuary information is often vague, e.g. ‘unknown black male’. These cases form the bulk of our investigations. We look up the details of where the person was buried and what the cause of death was. We then conduct an exploratory dig to confirm whether these are the remains stated by the mortuary. In many cases these people are buried in the paupers’ section of the cemetery, which means that they were unidentified individuals buried by the state and not by their families. The exploratory dig is needed because the paupers’ section is frequently not organised and there are no tombstones to mark graves. Once we confirm that the remains are consistent with the cause of death recorded in the mortuary book we can perform a public exhumation to which family members, political parties and the media are invited. Once we have completed the exhumation the remains are taken to our lab where they are analysed. We determine the sex, age, stature and manner of death using these remains. For finality a sample of the bone is also sent to a DNA lab together with a DNA reference sample from a family member. Once the remains are confirmed as being those

of the missing individual a public ceremony is held to hand over the remains to the families and to honour those who died. Patrick Mahlangu A good example is the case of Patrick Mahlangu, who was killed by the security police in March 1986. He was an active MK member and was also involved with civic organisations and youth structures in the Mamelodi area near Pretoria. The TRC testimony stated that Mahlangu was taken from his home in Mamelodi, questioned and killed. His body was blown up next to the railway line to give the impression he had accidentally blown himself up while trying to plant explosives. His highly fragmented remains were subsequently found and reported to the local police by members of the public, but with no way to identify the body, his remains were buried in a pauper’s grave at Soshanguve Cemetery two months later. In 2011 the Missing Persons Task Team undertook the exhumation. After three attempts the correct grave was found. We presumed that since the body had been blown up, the remains would not be found articulated in anatomical position – that the head would not necessarily be associated with the vertebrae and the ribs, and the arms would not be associated with the thorax, the hips with the femur, and the femur with the tibia. Instead we thought that we would find a body in pieces. On the day of the exhumation we found approximately ten bags with human remains. The findings of the medico-legal report were consistent with what was

The contents of bag 9 include an articulated femoral head and pelvis and fragments of the left femur. Image: Missing Persons Task Team

found in the forensic anthropology investigation and we were certain that we had discovered the remains of the young man in question. In November 2011 the remains of Patrick Mahlangu were handed to his family in a public event to pay tribute to a freedom fighter and allow the family to perform their cultural final rights. ❑ Kavita Lakha has a BSc from Wits and completed an honors in Anatomy at the Wits Medical School. She was given a Nelson Mandela Scholarship in 2006 that allowed her to study at the University of Central Lancashire in Preston, UK. where she graduated with a Masters in Forensic Anthropology and Crime Scene Investigation. She began working for the National Prosecuting Authority in 2008 and is in the Process of completing a PhD at UCT.

Quest 8(2) 2012 17

Estimating age from the hand and wrist: Belinda Speed and Kundisai Dembetembe tell Quest how important the hand is in forensic investigations. What do your bones say about you? Do you ever wonder what your skeleton could say about you 100 years from now? That is the job of the forensic anthropologist. Through careful observation and measurement it is possible to reconstruct your life story, whether it is from a whole skeleton or from a simple X-ray. From bones, we can tell sex, age, healed and recent fractures and sometimes also areas of infection on the bone. Even habits such as smoking or activities like weight-lifting leave evidence on the skeleton. Despite all these fascinating research areas, our specific research focus has been on using the skeleton for age estimation of South Africans. Why do we need to know the age of an individual? It is easy to tell someone’s age when you have their birth certificate or identity document available. But what happens when there is no documentation? One option would be to measure the person’s weight and height and match the results to a growth chart. The growth chart plots your weight and height against a known standard and these measurements correspond to your age. Unfortunately, this is more useful in infants and young children, and is difficult to apply to teenagers and young adults because weight tends to fluctuate. For teenagers and young adults, the question is not whether they are growing more but whether they are developing ‘normally’. To do this we use standards relating to the development of the skeleton and we use what we know about bone development to estimate age more carefully. Why is this important? Estimating age helps to narrow down the search categories of missing persons and even confirm identity of missing persons. It is also used if the unknown person has committed a crime and the judge must decide whether to prosecute them as an adult or a juvenile. Such cases sometimes involve the trials of child soldiers. A recent application of this type of age estimation is to catch ‘agecheats’. These are sportsmen/women who pretend to be younger than they are in order to compete in regional, national or even international events. In many cases it is in the athlete’s best interest to claim to be younger than they really are as that means that they can compete for longer. In other words, they are employed for a longer period before they have to retire. How do we estimate age? The easiest method involves taking an X-ray image of the hand and wrist. This X-ray image or radiograph shows the degree of development of the bones in the wrist, palm and fingers. There are 30 different areas in the hand and wrist that can be used by the anthropologist to estimate age (as shown in the picture). Each of them develops at a different time and age, from the time you are born, until about 18

18 Quest 8(2) 2012

The 30 regions in the hand and wrist which are used for age estimation. These are numbered in order of their time of appearance. Image: Greulich and Pyle, 1959.

years of age. We compare this radiograph to standard radiographs from children of known ages. We look at the standard which is the closest match in terms of bone size and the level of fusion between the ends of certain bones and their respective shafts. One such set of standard radiographs used for estimating age is the Greulich and Pyle ‘Radiographic Atlas of Skeletal Development of the Hand and Wrist’. The standard provides an estimate of age, based on the development of certain bones, for cases where the age of an individual is unknown. What does the research say about skeletal maturation in South Africans? Recently it has been found that, during their growing years, South Africans develop at a different rate to other populations. More specifically, we differ from North Americans – the sample group on which the Greulich and Pyle standards are based. Children under the age of 14 years have such varied development (some develop much faster or slower than others), that the Greulich and Pyle standard does not estimate age correctly. The Greulich and Pyle standard tends to underestimate age for older South Africans (over the age of 14 years), meaning that the standard will show age to be 14 years when the individual is actually 16 years old chronologically. Because of this discrepancy it is essential for us to create new standards that are more applicable to the South African population so that age estimates are accurate. The hand and

what these bones tell us

wrist region is still useful to estimate age, but the method which is currently being used is not. â?&#x2018; Belinda Speed has honours in Biological Anthropology from UCT and an MSc in Applied Anatomy. Her masters research showed that the age estimation method used since the 1950s is not applicable to South African children. Kundisai Dembetembe has an MSc in Anatomy from UCT. Her research focused on testing appliations of the Greulich and Pyle Atlas methods for estimating skeletal age in a population of

Above left: A child having an X-ray taken of her hand.

Image: www.childaddenbrookes.org.uk

Above: Radiograph (b) shows boy X, who suffered a broken finger. We estimated his age by comparing his radiograph (b) to two radiographs from the Greulich and Pyle age estimation standards shown in (a) and (c). From that we concluded that he must be 19 years old as shown in (c). His chronological age was actually 16 years and 4 months, in which case we would expect his hand to look more like 13 years old in radiograph (a). Boy Xâ&#x20AC;&#x2122;s bones look older than his birth certificate says he is. Image: Belinda Speed and Kundisai Dembetembe

African ancestry. She currently works as a forensic anthropologist, specialising in human rights cases.

Quest 8(2) 2012 19

Becoming a forensic pathologist Linda Liebenberg tells Quest what it takes to become a forensic pathologist in South Africa.

Figure 1: Poor man: stabbed, shot, axed, poisoned. Some examples of unnatural death.

am a forensic pathologist. For a living, I examine dead people and come to conclusions as to the way they died. I assist the police and the courts in establishing whether somebody or something should be held accountable for the death of these persons. Polite dinner conversation, for me, hiccups when a fellow diner puts forth the dreaded question: ‘And what do you do?’ I venture, in a cowardly way: ‘I am in the medical profession’, hoping that it will stall the inevitable. It rarely does. ‘Oh, so where do you practice?’ – I can feel the ‘I-need-to-ask-you-a-quick-questionabout-my-medical-problem’ coming up. Swallow and sigh. ‘I am a forensic pathologist and I work at a mortuary.’ Count one, two, three ... and the reaction is there. Half my dinner companions are gagging on the meat they were so enjoying, the other half put down their cutlery in fascination, loaded with questions, ‘so you cut up dead people for a living?’ Considering that death is the ultimate disease, it is understandable that medical doctors will go beyond treatment of living patients and fight the ultimate disease by examining deceased patients. Death is not a nice topic at a social event, so I do try and avoid the job-specific question at dinner tables. And no, I am not a vegetarian.

Forensic pathology in South Africa The Inquest Act of South Africa, Act 58 of 1959 is the major legislation instructing the performance of forensic post-mortem examinations. Forensic post mortem examination defined Figure 2: A body with a an identification tag attached to the toe. Image: Linda Liebenberg

The Locard principle The scene of a crime, the perpetrator of the crime and the victim of the crime all leave traces of themselves on each other. In Figure 3, it is clear that a motor vehicle’s tyre hit and imprinted a mirror image of its markings during a collision.

Forensic: for the purpose of presenting evidence to a court of law Post: after Mortem: death Examination: a process of answering questions by means of looking at, studying, and describing what was found. In a nutshell: answering legal questions by examining a dead individual.

The Forensic Pathology Service falls under the Department of Health and deals with all cases of unnatural and unexplained deaths. Many of the unexplained death cases turn out to be due to natural causes, such as undiagnosed heart disease or an infection. South Africa is burdened with a huge load of outright unnatural deaths due, for example, to road traffic accidents and homicides, to mention but two of the main culprits.

Figure 3: A tyre imprint on the trouser leg of the victim of a road traffic accident. Image: Linda Liebenberg

20 Quest 8(2) 2012

The number of unnatural deaths in South Africa in 2008: the National Injury Mortality Surveillance System (NIMSS) recorded the total as 36 795.

What does a forensic pathologist do? Post-mortem examinations

Assisted by a Forensic Pathology Officer, the pathologist examines dead individuals to accurately establish their identity, the day of death and the cause of death. We consider the body of the deceased to be a crime scene that we, as medical detectives, process in order to find and preserve evidence to present in future court evidence. External examination This reveals tell-tale signs on clothing, such as blood spatter or gunshot soot. The deceased’s body may exhibit signs of a medical condition such as emaciation, indicating a severe disease like cancer or AIDS. The body is examined from top to toe and special test samples can be taken to assist in a variety of ways: toxicological analysis, microbiology to identify infections, chemical analysis, anthropology, odontology – the list of possibilities is very long. Anthropology: this is the scientific study of people from all periods of time and in all areas of the world. Odontology: this is forensic dentistry, which is the examination and evaluation of dental evidence, which is then presented in court.

In the Western Cape two of the big mortuaries have Lodox X-ray

Q Careers Who helps the forensic pathologist at the mortuary? machines, which we use to do a full body X-ray. Other mortuaries have access to X-ray facilities at government hospitals. This assists hugely in many cases, as you can see in the X-ray in Figure 4. Now the pathologist has an idea of where to look for the bullets! These bullets will be retrieved and examined by ballistic experts to match them to the murder weapon. Internal examination After the external examination, the internal examination is done by removing the chest and abdominal organs and the brain. Each organ is examined individually and weighed. Samples for microscopic and toxicological examination can be taken. DNA samples may assist in identifying the deceased and/or the murderer. In some instances, a natural disease process is discovered, which means further criminal investigation is not necessary. The finding may be very important for the relatives of the deceased, to come to understand the death and maybe even have themselves tested for risk factors. Apart from doing autopsies, forensic pathologists are kept busy in many ways: n Going to scenes of death when requested by police investigators. n Compilation of autopsy reports. n Special investigations, for example microscopic examination of organ sections. n Drafting medical opinions on cause of death for the court. n Giving testimony in court. n Advising relatives of the deceased of possible familial disease so that they can go for a check-up and preventive treatment. n Teaching undergraduate and postgraduate medical students, lawyers and forensic pathology officers. n Research. How do you become a forensic pathologist in South Africa? This is a summary of qualifications and time required to become a forensic pathologist: n matric/Grade 12/Umalusi with recommended subjects such as Life Science, Physical Science, Mathematics and English n six years of medical school n one year of internship under supervision

The forensic pathology officer, who is trained on the job. These officers are not medically qualified, but are taught how to assist. They need a Grade 10, a valid driverâ&#x20AC;&#x2122;s licence and the ability to work respectfully with living and dead people.

A laboratory assistant in protective gear while he works with formalin-fixed human tissue. Dangers of fume inhalation, eye splashes and skin contact must be kept in mind at all times. Personal protective gear is mandatory in our work. Image: University of Cape Town

Figure 4: A full-body Lodox X-ray image in the case of multiple gunshots. Many of the white spots are bullets but some are metal press studs of the jeans the deceased is wearing. Red arrows indicate the bullets. The yellow rectangle encircles the press studs.

n two years of COSMOS (community service medical officer service) n four years of registrar training at a medical school. â?&#x2018;

Figure 5: Heart attack, also called a myocardial infarction. The tan to yellow areas of the heart muscle aredead tissue, usually caused by blockage of the heart arteries. High blood cholesterol is a risk factor for myocardial infarction and the family of this person need to be tested and treated. Image: Linda Liebenberg.

Linda Liebenberg is a medical doctor who specialised in Forensic Pathology. She is a Senior Forensic Pathologist for the Forensic Pathology Service, Department of Health and she does postmortems at the Salt River Forensic Pathology Laboratory (the medicolegal mortuary) in Cape Town. She is also a senior lecturer, Division of Forensic Medicine and Toxicology, Health Sciences Faculty of the University of Cape Town. Her research interests are fire-arm deaths and the legal outcomes of subsequent court procedures and the use of X-rays in forensic pathology. Some helpful web sites: http://www.justice.gov.za/legislation/acts/1959-58.pdf http://www.sahealthinfo.org http://www.mrc.ac.za/ http://www.unisa.ac.za/dept/ishs/index.html

Figure 6: Creepy little helpers, maggots. These maggots found in a decomposed body can assist in establishing the date of death. Forensic entomology is another helpful discipline when it comes to forensic autopsies. The pathologist might not like the wriggly worms, but they have a role to play. Image: Wikimedia Commons.

Quest 8(2) 2012 21

The Cape Peninsula University of Technology with Table Mountain in the background.

How to become a forensic scientist By Marise Heyns and Alan Morris

n recent years there has been a tremendous increase in the interest in forensics, partly due to the popularity of television programmes such as Crime Scene Investigation, Silent Witness, NCIS, Cold Squad, Waking the Dead and Bones. We are frequently contacted by students wanting to know more about where one can study forensic science and how to become a forensic scientist. Can you think of a country more suitable for a career in forensics? With our crime statistics we need high-calibre scientists, with advanced training, laboratory and legal expertise, who can manage and operate laboratories, but who can also conduct exemplary research. So, how do I become a forensic scientist? The usual pathway would be to obtain a bachelor’s degree, preferably in science or medical science. Some forensic sciences require advanced degrees – take chemistry, biology and maths. You will need good speaking skills, so join the drama club or the debate team. You also need the ability to write an understandable scientific report. Of course, intellectual curiosity and personal integrity are paramount. As is the case with most BSc degrees, the degree does not qualify you directly for a professional career. Although some job opportunities exist with the BSc degree only, students are advised to continue their studies to qualify themselves for a particular career.

How much money will I make? Income in the forensic sciences varies greatly depending upon your degree, your actual job, where you work, and how many hours you work. You may never ‘get rich’ but you will have a good income. You will be satisfied with your job, knowing you are contributing to justice — keeping the good guys on the street and helping put the bad guys in jail. Where will I work? Forensic scientists work in laboratories, at crime scenes, in offices and in mortuaries. They may work for the state (South African Police Service, Department of Health) or forensic laboratories, hospitals, universities, toxicology laboratories or as independent forensic science consultants. The Forensic Science Laboratory (FSL) accepts BSc students. They train candidates internally, especially in advanced laboratory techniques (e.g. DNA extraction and interpretation, PCR techniques). This career involves mostly laboratory work which, for example, includes DNA matching of suspects, semen analysis and queries regarding paternity. Some universities accept candidates with only a BSc degree as a junior lecturer. You would need a master’s or higher degree to ensure a future career as an academic, which can be acquired in any of the specialities.

List of institutions Traditional Universities

Comprehensive universities

Universities of technology

North-West University

University of Johannesburg

Cape Peninsula University of Technology

Rhodes University

Nelson Mandela Metropolitan University

Central University of Technology

University of Cape Town

University of South Africa

Durban University of Technology

University of Fort Hare

University of Venda

Mangosuthu University of Technology

University of KwaZulu-Natal

Walter Sisulu University

Tshwane University of Technology

University of Limpopo

University of Zululand

Vaal University of Technology

University of Pretoria University of Stellenbosch University of the Free State University of the Western Cape University of the Witwatersrand

22 Quest 8(2) 2012

Q Careers

The South African Police Service

Forensic Anthropology Research Centre

Another career path can be to join the South African Police Service in thebiological units, chemical units, ballistic unit and scientific units. You can also be employed in the Forensic Science Laboratories of the South African Police Service. For some of the career opportunities in SAPS you may need a BSc degree / national diploma. For others you can enter with a matric, but will undergo basic training and additional in-house training. Almost all will undergo further training including specialized training in the relevant field of forensic science.

The Forensic Anthropology Research Centre (FARC) is an entity at the University of Pretoria that is involved in research, including contract research, that is either wholly defined academically or in consultation with a commissioning client. The FARC aims to establish a centralised resource base with a single, welldefined identity, for all aspects regarding human remains, whether it be forensic, heritage related or humanitarian in nature or origin (and as is often the case, overlapping these distinctions) in South Africa foremost, but also for the region, continent and globally. The main thrust of the Centre will, however, be forensic and pertaining to matters of violent crime and missing persons. The Forensic Anthropology Research Centre recognises the sanctity of human remains and acknowledges the religious and cultural rights of descendants of all and any human remains it deals with. It supports the principles of restitution and repatriation and will fulfil the role of custodian on behalf of the national community for the remains it holds. The Forensic Anthropology Research Centre undertakes to treat all human remains with dignity and respect and to uphold and pursue the ethical and morally correct course of action in all cases.

Cape Town Forensics Laboratory – Plattekloof This custom-built forensic facility for the SA Police Service compares favourably with international operations, and will support criminal investigation. Situated in Plattekloof, Cape Town, the 17 000 m2 facility incorporates high-tech features and a sophisticated security system. This development consists of five separate arms accommodating the various specialised investigation units. These radiate from a central hub in a semi-circular ‘star’ pattern. The design was integrated with the sloping site, with views looking out towards Table Mountain. The buildings vary between two and three storeys in height. It is hoped that this unique project will become a flagship for the Department of Public Works and the SA Police Service. The image being created is one of scientific and technical sophistication, and excellence equal to some of the best crime fighting institutions in the world.

Research posts are currently scarce, but organisations such as the Medical Research Council (MRC) or museums may have posts for research assistants. A postgraduate qualification enhances your chances of getting a job and as the field of forensics widens, more universities will support and promote research in forensics. Forensic scientists work different hours, depending upon what they do. Some work in forensic laboratories and work 40 hours a week, Monday through Friday. Others work out in the field on digs and may work different hours. Still others are ‘on call’ and work after their regular shift and may receive overtime payment. Essentially every branch of forensic science offers opportunity for personal growth, career advancement, and increasing financial compensation.

NEW MASTER’S DEGREE IN BIOMEDICAL FORENSIC SCIENCE, A FIRST IN SOUTH AFRICA! Are you a scientist, legal expert or clinician, or currently performing forensic work? You could gain a Master’s in Biomedical Forensic Science and be part of a selected group of scientists with advanced training as well as laboratory and legal expertise, who can manage and develop forensic laboratories as well as conduct research.

www.ayandambanga.co.za

Where can I train? In South Africa training in forensic science is still in its growth phase. All of the universities offer basic science degrees which would allow you to proceed to a postgraduate qualification. Apart from the Bachelor’s degrees in basic sciences at most of the universities listed in the box on page 22, Cape Peninsula University of Technology also offers a four-year Bachelor degree: Health Sciences in Medical Laboratory Science, which would qualify you as a medical laboratory scientist. This is the only undergraduate programme on offer where you can elect to do forensics. UNISA is the only institute that offers Bachelor degrees in the format of distance education. Very few institutions offer postgraduate programmes, and current programmes are at the University of Cape Town (BSc (Med) Hons in Forensic Genetics, MSc in Biomedical Forensic Sciences), University of Free State (BSc Hons in Forensic Genetics), and University of Pretoria (BSc Hons and MSc in Medical Criminalistics). ❑

University of Cape Town

Job Opportunities • National and International Opportunities • State or Private Sector • Possible employers include CSIR, the National Prosecuting Authority, SA Police Forensics, universities, overseas forensic laboratories and forensic pathology services. Contact: Dr Marise Heyns at the Division of Forensic Medicine, Faculty of Health Sciences, University of Cape Town on 021 406 6604 or via e-mail marise.heyns@uct.ac.za Visit http://www.forensicmedicine.uct.ac.za/ www.uct.ac.za

University ofQuest Cape Town 8(2) 2012

Limestone.

Marble, formed from limestone.

Image: Wikimedia Commons

Kyanite crystals – kyanite is an index mineral which is formed at high pressures. Image: Wikimedia Commons Andalusite, which forms only at low temperature and pressure.

How do geologists know when mountains grew and continents collided? Why are such events important for unravelling what happened during Earth’s early history? How are some rocks from South Africa providing clues on crust formation on early Earth? Some geologists from Stellenbosch University are investigating. By Kathryn Cutts. Metamorphism Rocks are metamorphosed when they are subjected to intense heat and pressure within the Earth’s crust. This can happen when mountains form, when one tectonic plate subducts under another (subduction zones), when a large magmatic body is emplaced (increase in temperature causes metamorphism in the surrounding rocks) or even by the impact of a meteor.

Image: Wikimedia Commons

A magmatic body is a clump of hot molten rock, usually formed in the Earth’s upper mantle, some of which finds its way into the crust and the Earth’s surface.

A common metamorphic rock is marble – this forms from the heating and burial of limestone. Metamorphism is an important process within the rock cycle because particular tectonic settings

24 Quest 8(2) 2012

Image: Wikimedia Commons

are more likely to form certain metamorphic rocks. For example blue schists and eclogites occur in subduction zones (see The Barberton granites, Quest 8(1)). In addition, when some rocks are metamorphosed they grow minerals that can be used to indicate the minimum pressure and temperature that the rock reached. These are called index minerals. Some important index minerals are chlorite, biotite, garnet, kyanite and sillimanite. Kyanite, sillimanite and another mineral called andalusite are polymorphs. This means they all have the same chemical formula (Al2SiO5) but adopt different crystal structures at different temperatures and pressures. Importantly, andalusite only forms at low temperature and pressure, kyanite forms at high pressure and sillimanite forms at high temperature, so the presence of any of these minerals gives you an indication what sort of pressures and temperatures the rock reached. Often the minerals in metamorphic rocks contain a record of the order they

Q Earth Science

Metamorphic facies All metamorphic rocks are split into different groups called facies, depending on the pressure and temperature that they experienced. Blue schist and eclogite are both metamorphic facies that occur in a subduction zone setting. Japan is presently situated on top of a subduction zone, where the pacific plate is being recycled into the Earth’s mantle.

A garnet-bearing rock.

Image: Wikimedia Commons

A diagram showing the pressures and temperatures that produce the different metamorphic facies. Image: Adapted from Spear 1993

This thin section of metamorphic rock contains garnet (pale brown), biotite (dark brown), staurolite (yellow). Image: Kathryn Cutts

is wrapped by it, then it grew early in the metamorphic cycle. Understanding this order of mineral growth defines the P-T path of the rock – the pressure and temperature path. The P-T path of a sample reflects what sort of metamorphism it has undergone. Radioactive isotopes and geochronology Geochronology is the dating of formation or metamorphism of rocks. Ages are obtained by looking at the amount of radioactive isotopes present within a mineral. Isotopes of an element have the same number of protons but a different number of neutrons in their atoms. For example, carbon has 6 protons but can have 6, 7 or 8 neutrons

▲ ▲

grew in. This is seen where one mineral is included in another (as a small grain – this mineral must have been in the rock before the other one grew). Another helpful indicator of growth order is what is called the foliation of the sample. The foliation of a rock is the preferred orientation of needle-shaped or flat minerals and is a result of the deformation that the rock undergoes as it is moved through the Earth. This deformation is closely related to the metamorphism in a way that means that minerals that follow the foliation of the rock are thought to have grown during metamorphism. If a mineral cross-cuts the foliation, it grew late in the metamorphic cycle or if a mineral contains no evidence of foliation but

Other facies such as amphibolite (see The Barberton granites, Quest 8(1)) and granulite are more likely to occur in a collisional setting where two tectonic plates are colliding. This is happening today with the collision of India into the Eurasian plate to produce the Himalayas. Such collisions build up mountains which cause high pressures for the underlying rocks and the crust gradually heats up as it is buried so that the underlying rocks melt. Metamorphic rocks that have been in mountain building events (orogenies) have very characteristic pressure-temperature paths – they form a clock-wise loop in pressure-temperature space. This is because the rock is cold when it is buried to its maximum pressure and burial can happen faster than the rock can heat up. Following burial the rock heats up slowly, surrounded by other hot rocks. However, by this time the mountains have started to erode and the rock is on its way back to the surface. Sometimes the minerals in a rock will show us the path based on the order that they grew in. Some minerals are particularly useful because they grow with a different composition at different pressures and temperatures, which effectively records the pressures and temperatures that the mineral grows through. One such mineral is garnet, which has variable iron, magnesium, calcium and manganese contents depending on the P-T path of its growth. This is especially useful because garnet occurs in most of the metamorphic facies. Another important aspect in looking at the evolution of metamorphic rocks is figuring out how old they are. If we have a rock that has a mountain building P-T path it is important to know when the mountains formed. This information can be used to reconstruct supercontinents by connecting bits of crust that had collisions at the same time. When looking at very old rocks, the timing and P-T path can show us whether plates were colliding with each other like they do today or if something different was happening.

Quest 8(2) 2012 25

Diagram illustrating the order of mineral growth within a rock.

Pressure-temperature path of a rock during contact metamorphism.

Pressure-temperature path of a rock during collisional metamorphism.

rate of decay, determine its age. Since garnet is a metamorphic mineral, this age would reflect the timing of the metamorphic event which caused the garnet to grow.

Thin section of a metamorphic rock shows garnet (pale brown) containing staurolite (yellow) and chloritoid (blue) wrapped by a foliated matrix containing chlorite (green), muscovite + quartz (white) and chloritoid (blue). Staurolite also occurs in the matrix and is also wrapped by the matrix foliation. Inclusions in garnet appear to be foliated but those in staurolite are not, so staurolite and chloritoid are early, followed by garnet and the foliated minerals. There is also late chlorite surrounding garnet and staurolite.

giving it the isotopes 12C, 13C and 14C. Two of these isotopes are stable (12C and 13C) while 14C is radioactive. When an element is radioactive it means that the forces holding the nucleus together are not strong enough and decay occurs. In the case of 14C, radioactive decay involves a neutron becoming a proton and the emission of an electron producing nitrogen 14 (7 protons and 7 neutrons).This is referred to as beta decay. Another common type of radioactive decay is alpha decay. This involves the emission of 2 neutrons and 2 protons (a helium nucleus). When looking at radioactive isotopes, the radioactive isotope that is decaying is the parent isotope (i.e. 14C) while the isotope that is produced is referred to as the daughter isotope (i.e. 14N). The rate at which a radioactive isotope decays is referred to as its half-life. This is the amount of time taken for the abundance of the radioactive isotope to halve. The half-life of 14C is 5 730 years so if we started off with 160 atoms of 14C, 5 730 years later we would only have 80 and with another 5 730 years we would be down to 40 atoms. It is this attribute of radioactive isotopes that makes them so useful for geochronology. However, since the Earth is 4.54 billion years old, we need radioactive isotopes with longer half-lives to look at geological processes. Fortunately two isotopic systems can be used to date garnet â&#x20AC;&#x201C; these are Lu-Hf and Sm-Nd. The Lu-Hf system has a half-life of 37.8 billion years and decays by beta decay, while Sm-Nd has a half-life of 106 billion years and decays by alpha decay. Both of these systems work in garnet because as the garnet grows it takes up the parent isotope (176Lu and 147Sm) but not the daughter (176Hf and 143Nd). As time goes by, the parent isotopes break down to the daughter isotopes at a certain rate and since the only daughter isotope in the garnet is from radioactive decay we can measure the parent and daughter isotope amounts in the garnet and using the

This diagram shows collisional pressure-temperature (P-T) paths with the ages are which these occured (By = billions of years ago). Image: Adapted from Spear 1993

26 Quest 8(2) 2012

What can garnet tell us about some of South Africaâ&#x20AC;&#x2122;s oldest rocks? Presently, geologists from Stellenbosch University are using garnet dating and P-T path studies to investigate the metamorphic evolution of the Barberton granite greenstone belt. The Barberton Granite Greenstone belt (BGGB) contains the oldest preserved rocks in Africa and some of the oldest rocks in the world. These rocks are very important scientifically because while plate tectonics is accepted as the geological process that is shaping Earth today, it is unknown whether plate tectonics was operational during the Archaean era (4.0 - 2.5 billion years ago). The metamorphic rocks from the southern region of the BGGB were metamorphosed at amphibolite facies conditions and contain garnet, staurolite, kyanite and sillimanite. Garnet dating by Lu-Hf has revealed that metamorphism occurred 3.23 billion years ago. Looking at the garnet compositions, it is apparent that the metamorphism involved a clockwise P-T path with burial followed by heating and exhumation. This style of P-T path is similar to those found in rocks involved in continental collision. Rocks from a different location in the southern BGGB were found to contain andalusite and kyanite or garnet and chlorite. The garnet from these samples looked different to those in the first samples. It contained two distinct compositional domains, potentially indicating that it records two separate metamorphic events. While garnet from this sample has not yet been dated, the associated andalusite-bearing sample was found to have a datable mineral called monazite. Monazite is dated using the U-Pb

This image clearly shows the distinct compositional domains of the garnet as it was formed â&#x20AC;&#x201C; magnesium (Mg) and iron (Fe) and manganese (Mn) and calcium (Ca). Image: Kathryn Cutts

Andalusite-bearing rock from Barberton.

Image: Kathryn Cutts

(uranium-lead) dating system and generally gives ages associated with metamorphism. The monazite from this sample gave an age of 3.45 billion years, indicating that this sample experienced a metamorphic event before the 3.23 billion year metamorphism found in the other sample. When the garnet compositions are used to determine P-T conditions, the garnet core occurs within the andalusite stability field while the rim occurs within the kyanite stability zone. This suggests that the cores are 3.45 billion years old and record high T, low P metamorphism while the rims are 3.23 billion years old and record burial metamorphism similar to the other sample. The early low P, high

T metamorphism could be contact metamorphism. Contact metamorphism occurs when hot molten rock from the lower crust moves to the upper crust and heats up the surrounding rocks. This is a plausible scenario because there are plutonic rocks (formerly lower crustal melts) close to where this sample comes from that are the right age (also 3.45 billion years old). Importantly, this sample indicates that the BGGB has experienced at least two metamorphic events, one 3.45 billion years ago perhaps related to pluton intrusion and one 3.23 billion years ago as a result of collision. The P-T path for the 3.23 billion year old metamorphic event suggests that mountains were being created in the

These images show how garnet is made up of different elements calcium (Ca), irons (Fe) and magnesium (Mg)) as it is formed. The way in which these elements were laid down shows us the P-T path involved. Image: Kathryn Cutts

Archean, potentially as a result of plate tectonic processes. These results are important because debate is ongoing as to whether plate tectonics was operating during the Archean or if crust was being created/recycled by some other mechanism. The results here, which suggest a collisional tectonic setting for the 3.23 billion year metamorphic event, are consistent with previous work by researchers from Stellenbosch. â?&#x2018; Kathryn Cutts completed her PhD on the metamorphic evolution of rocks from Scotland and Australia at the University of Adelaide, Australia. She is presently conducting research on Barberton as a SARChi Postdoctoral Researcher at the Centre for Crustal Petrology at Stellenbosch University.

Quest 8(2) 2012 27

Advertorial Q

Research is all about investigating M iniscule traces of pollen, each with their own characteristic patterns, recently helped to place a double murderer at the scene of his crime and to ensure a successful court conviction. ‘A wise policeman realised that the flowering patch of forest where one of the bodies was found could hold some clues,’ remembers pollen and fynbos fundi Prof Leanne Dreyer of the Department of Botany and Zoology at Stellenbosch University, whose expert knowledge of plants was called on to help with the investigation. ‘Pollen is like the unique fingerprints of a flower,’ she explains. ‘You can use it not only to match the type of flower involved, but also the region in which it is found.’ Prof Dreyer’s first task was to identify pollen samples collected from the crime scene. Then she used a light microscope to patiently pick traces of pollen off the suspect’s clothing. The breakthrough came when, thanks to the close-up eye of an electron microscope, she could match samples from the site with that of the grains collected from the clothing. A colleague of Prof Dreyer in the SU Department of Botany and Zoology, marine biologist Dr Sophie von der Heyden, recently helped the investigative television programme Carte Blanche to expose cases of ‘fish fraud’. She painstakingly analysed and compared the DNA samples of various edible fish species.

28 Quest 8(2) 2012

‘Many restaurateurs fool their patrons by preparing one type of fish but then serving it up under the pretences of being the pricier one that customers had ordered from the menu,’ she explains the findings of her genetic tests, which was also published in a scientific journal. Prof Dreyer and Dr von der Heyden, who both teach courses in the BSc in Biodiversity and Ecology programme, are among the many scientists at Stellenbosch University and other South African institutions whose expertise aid forensic investigations. Some physics professors help to work out the speed at which car crashes happen, while entomologists make specific deductions based on the insects that are found around a buried corpse. Computer scientists use their skills to investigate cyberfraud, while applied mathematicians write software programmes to make fingerprint analyses and facial recognition easier. ‘I will never be a full-time forensic scientist, because I like basic biology and research far too much,’ Prof Dreyer says. ‘However, I believe it’s my call of duty to help the police in cases where they need an expert opinion on a specific matter.’ Typically, if students want to study at Stellenbosch University and further a career in the forensic sciences, they either follow a BSc in Molecular Biology and Biotechnology, a BSc in Chemistry, a BSc in Physics or a BSc in Mathematical Sciences with a focus on

applied mathematics or computer science. ‘Many scientists and researchers, although not in the fulltime employment of South Africa’s judicial service, actually wear a forensic hat in their everyday line of work,’ adds Prof Ingrid Rewitzky, vice dean: teaching of the Faculty of Science at Stellenbosch University. ‘Ultimately science, research and innovation are all about problem solving and using the clues and techniques at your disposal to do so.’ ‘With a science degree in the biological, mathematical or physical sciences, you can do investigative work in most industries, and these do not have to be crime-related per se,’ she explains. ‘We teach our students the tools and analytical methods that they will need to solve the industry specific problems they will encounter during the course of their careers.’ ‘Wine analysts trying to work out how to stop wine from becoming hazy, or water specialists developing new ways to clean bacteria from water are all trying to solve some kind of real-life puzzle with the clues and tools at their disposal,’ adds Prof Rewitzky. ‘Polymer scientists trying to develop a waterresistant paper, or botanists doing field work to find the insect responsible for pollinating a specific plant, are all on the trail of a mystery of some kind.’ For more information about the study programmes of Stellenbosch University, visit www.maties.com or phone (021) 808 9111.

Quest 8(2) 2012 29

Environmental Science Q

Air pollution has many sources, both natural and man-made, and can have large impacts on people’s health, the environment and climate change. But what is air pollution? By Rebecca Garland

Air pollution – one of humankind’s major impacts on the environment T Above: This spectacular image of sunset on the Indian Ocean was taken by astronauts aboard the International Space Station (ISS). The image presents an edge-on, or limb view, of the Earth’s atmosphere as seen from orbit. The Earth’s curvature is visible along the horizon line, or limb, that extends across the image from centre left to lower right. Above the darkened surface of the Earth, a brilliant sequence of colours roughly denotes several layers of the atmosphere. Deep oranges and yellows appear in the troposphere, which extends from the Earth’s surface to 6 – 20 km high. This layer contains over 80% of the mass of the atmosphere and almost all of the water vapour, clouds, and precipitation. Several dark cloud layers are visible within this layer. Variations in the colours are due mainly to varying concentrations of either clouds or aerosols (airborne particles or droplets). The pink to white region above the clouds appears to be the stratosphere; this atmospheric layer generally has little or no clouds and extends up to approximately 50 km above the Earth’s surface. Above the stratosphere, blue layers mark the upper atmosphere (including the mesosphere, thermosphere, ionosphere, and exosphere) as it gradually fades into the blackness of outer space. Image: NASA

30 Quest 8(2) 2012

he lowest layer of the atmosphere is the troposphere, which extends from the ground up to the stratosphere. Gases, liquids and particles are injected into the troposphere through many processes. Because we live in the troposphere and breathe the air in the troposphere, we can be exposed to these gases, liquids and particles, as can the rest of our environment. When these constituents cause harm to humans or the environment, they are called air pollutants. Increased levels of air pollutants will lead to a decrease in the air quality. Air quality is a concern both in ambient (outdoor) air and indoor air. Poor air quality can negatively affect people’s health (as described elsewhere in this issue). In addition, air pollutants can have an impact on the environment, for example through acid rain. And some air pollutants also

can potentially lead to climate change because they can also absorb radiation and lead to changes in the Earth’s surface temperature (see ‘Air quality: its impact on climate change’, in this issue of Quest). Internationally, air pollution is regulated by governments in order to mitigate these negative impacts. What is happening in South Africa is described in ‘How do we monitor air quality in South Africa?’ in this issue of Quest. What are main constituents of air pollution? There are many possible air pollutants. Which pollutants are in your air depends strongly on what is emitted into the atmosphere from local sources, or what is transported in from further afield. For example, in agricultural areas pesticides can become air-borne when sprayed and can contribute to air pollution. In a

Above: Industries can be large emitters of air pollution. Left: Layers of the atmosphere (not to scale).

home that uses biomass, wood or coal for cooking, heating or lighting, carbon monoxide (CO) may be a large contributor to indoor air pollution from the incomplete combustion of the fuel. Also, in areas with dirt roads or in mining areas, windblown dust may be a large part of air pollution. However, there are a handful of pollutants that are found in most areas and these are generally the pollutants that governments regulate in order to decrease air pollution. These pollutants are highlighted in Table 1.

Image: Kelvin Case, with permission from US Government and Wikimedia Commons

(VOCs). NOx is a term used to refer collectively to nitrogen dioxide (NO2) and nitrogen oxide (NO). VOCs are organic compounds that have a high vapour pressure at ambient conditions. Particulate matter (PM), also called aerosol particles, can be liquid or solid particles. The aerosol particles that are regularly measured for air quality are those with diameters ≤10 µm (called PM10) and those with diameters ≤2.5 µm (called PM2.5). For comparison, raindrops generally have a diameter of ~1 000 µm or larger. Aerosol particles can sometimes be primary pollutants, such as sea salt, dust and those from combustion. Secondary pollutants are not emitted directly into the atmosphere, but rather are created when primary pollutants or other atmospheric constituents interact. Surface ozone (O3) is an example of a secondary pollutant. O3 is not directly emitted into the atmosphere, but forms in the atmosphere. In addition, some aerosol

▲ ▲

Primary and secondary air pollutants Air pollutants can be thought of as either primary or secondary pollutants. Generally, primary pollutants enter the atmosphere directly from a source. An example of a primary pollutant is CO released from a car. Other common primary pollutants include sulphur dioxide (SO2), nitrogen oxides (NOx) and volatile organic compounds

Image: Caradee Wright

Table 1: Main constituents of air pollution and examples of their major sources Pollutant

Major sources

Sulphur dioxide (SO2)

Volcanoes, industrial process, combustion of sulphur-containing fossil fuels (e.g. coal, diesel)

Nitrogen oxides (NOx)

Lightning, soils, fossil fuel and biomass burning

Tropospheric ozone (O3)

Secondary pollutant produced from reactions in the atmosphere (e.g. reactions involving NOx and VOCs)

Volatile organic compounds (VOCs)

Plants, fossil fuel burning, industrial processes

Particulate matter (PM)

Sea salt, dust, fossil fuel burning, biomass burning

Carbon monoxide (CO)

Combustion

Quest 8(2) 2012 31

FactFile Q

Acid rain Rainwater is naturally acidic. This is because CO2 can react with water to produce a weak acid. The natural pH of rainwater is around 5.6. However, many areas experience rainwater with lower pH values as a result of anthropogenic emissions and this rainwater is called ‘acid rain’. These lower pH values are due to the air pollutants NOx and SO2. Both of these can react with water and produce nitric acid and sulphuric acid, respectively. These acids will then decrease the pH of the rainwater.

Statues made of marble, limestone and sandstone can be damaged by acid rain. Image: Wikimedia Commons

Processes involved in acid deposition (note that only SO2 and NOx play a significant role in acid rain). Image: Wikimedia Commons

Acid rain is detrimental to ecosystems, such as freshwater lakes and streams, where the aquatic life can be negatively affected by changes in pH. In addition, acid rain can be detrimental to the built environment. For example, statues that are made from limestone, sandstone and marble are degraded by acid rain. These pollutants are therefore regulated in many areas, not just to improve air quality, but also to prevent acid rain.

particles are also secondary pollutants. This is the case when, for example, SO2 gas is oxidised to sulphuric acid, which can create liquid particles.

Garbage burning, releasing pollutants into the air. Image: Caradee Wright

32 Quest 8(2) 2012

Where does it come from? Air pollutants can come from both biogenic (natural) and anthropogenic (manmade) sources. For example, when a volcano erupts it releases large quantities of SO2. Industrial processes also produce SO2. Lightning can produce NOx and it can also be released through soils as part of the nitrogen cycle. Large anthropogenic sources of NOx are cars and industry. In fact, many satellites see a ‘hotspot’ of NOx over South Africa, and this hotspot is the largest NOx signal in the southern hemisphere! Plants and biomass can release VOCs, as can industry. And plants can also release pollen. The main anthropogenic sources of air pollution in general are from combustion of fossil fuels and from industrial processes. In South Africa, the main anthropogenic sources of air pollution are from transport, industry and burning fuels such as wood, coal and biomass indoors for heating, cooking and/or electricity. At certain times of the year, biomass burning (such as veld fires) can also contribute

largely to ambient air pollution. Also, air pollution can be transported into an area from the surrounding areas. This air pollution can travel very long distances. For example, at times the southern United States has been affected by dust from the Sahara. Here in South Africa, there have been times when pollution from biomass burning in South America has been detected. What can you do? There are many ways that individual people affect air quality, and there are many ways that individual people can improve air quality. Large emissions that individuals have control over are from cars, personal electricity use and burning wood, coal or biomass. Also, even smaller emissions in your house, such as VOCs from paint, pollutants from smoking, might not have large impacts on ambient air quality, but can still affect your health. Think about your own emissions and how you could decrease them. ❑ Rebecca Garland is a Senior Researcher at the CSIR in Pretoria. Her interests include environmental health research, which focuses on how human health is affected by environmental factors (such as AMD, air quality and climate change).

Q Environmental Science

How do we monitor air quality in South Africa? Gregor Feig tells Quest about air quality management in South Africa.

Ambient air quality standards The quality of the air that citizens are exposed to is set by national requirements for air quality. These are called the national ambient air quality standards. These standards are set for criteria pollutants. Criteria pollutants are those air pollutants that are the most common air pollutants. The criteria air pollutants in South Africa are: n Particulate matter with diameters ≤10 µm (PM10) n Sulphur dioxide (SO2) n Nitrogen dioxide (NO2) n Carbon monoxide (CO) n Ozone (O3) n Lead (Pb) n Benzene n Particulate matters with diameters ≤2.5 µm (PM2.5). In order to know the level of these pollutants in the ambient air they are measured continuously in monitoring stations across the country. Figure 1 shows an ambient air quality monitoring station in Sharpeville, which is in the Vaal Triangle area. This station continually measures the concentration of the criteria pollutants and the weather conditions. These measured values must meet the ambient standards. The ambient standards are set at differing time scales, including 10-minute averages, hourly average concentrations, 24-hour average concentrations and annual concentrations, to assess short-term and long-term concentration of pollutants and impacts. For many of these averaging periods a certain number of

Figure 1: An ambient air quality monitoring station at Sharpeville. Image: Njabulo Masuku

exceedances are allowed to account for natural emissions of the pollutants. These are indicated in the table below . Air Quality Officers at the municipalities and the Department of Environmental Affairs use the information on the concentration of these pollutants and the number of exceedances to develop Air Quality ▲ ▲

he quality of the air that people are exposed to while going about their daily activities can have an important impact on their health and physical welfare (see Air pollution – wjat is its effect on our health?, in this issue of Quest). The South African Constitution gives everybody the right to an environment that is not harmful to their health and wellbeing. This constitutional right drives air quality management in South Africa. The person ultimately responsible for ensuring that the air quality in South Africa meets the constitutional requirements is the Minister of Environmental Affairs. However, the local municipalities have Air Quality Officers who are responsible for the day-to-day management of air quality. The National Environmental Management: Air Quality Act (NEMAQA) is the main law that controls air quality. Controls for air quality are done at two levels. First at the ambient level – this is the concentration of pollutants in the air that the general population is exposed to. The ambient concentration is measured at a number of air quality monitoring stations throughout the country. The second level is concerned with control of the amount of pollution that is released into the atmosphere (or emitted) from some important industrial activities that are called listed activities. Activities can be listed because they are either very large in size or in the amount of pollution they emit, or because they emit particularly harmful pollutants (e.g. lead).

Table: South African ambient air quality standards Pollutant

10 minute average

1 hour average

24 hour average

8 hour running average

Annual average

Number of exceedances 526 88 4 11 allowed annually

PM10 NA NA 120 µg/m3

50 µg/m3

40 µg/m3

µg/m3

350

µg/m3

125 NA

µg/m3

SO2

500

NO2

200 µg/m3

30 mg/m3 NA

10mg/m3 NA

O3 NA NA NA 120 µg/m3 NA Lead NA NA NA NA

0.5 µg/m3

Benzene NA NA NA NA

10 µg/m3

PM2.5 (proposed)

65 µg/m3

25 µg/m3

Quest 8(2) 2012 33

Figure 2: Daily average PM10 concentration for the Highveld monitoring stations.

Management Plans for their area. The goal is for the air quality across the country to always be within these limits. Listed activities In many areas industry is a large emitter of air pollution. One way to ensure that the ambient air quality stays within the limits set by the national air quality standards is to control the amount of pollutants released by the major industrial polluters. These limits on the emissions are set by the National Emission Limits for a list of activities. Again, only those industrial activities that are either large emitters or emit

particularly hazardous pollutants are controlled in this way. An example of such an emitter would be one of the large coal-fired power stations that supply most of the electricity in South Africa. For such a power station the emissions of particulate matter, SO2 and NO2 is regulated. These emission limits for the listed activities capture most of the major industrial activities but do not capture all the industrial pollution sources, because these other operations are too small to require the licensing. In addition, other sources of pollution, such as those from transportation and domestic fuel burning, are not covered in the NEMAQA. Local municipalities can develop local by-laws to address these sources of pollution. What’s the air quality in my area? Information on air quality legislation and measurements is available to the public on the South African Air Quality Information System website (www.saaqis.org.za). On this website you can create graphs

of the concentrations of the criteria pollutants for some of the monitoring networks in South Africa to see what the air quality is like in those areas. Figure 2 is an example from the Highveld area for the 24-hour average values of PM10 for five monitoring stations in December 2011. The red line is the national 24-hour average ambient standard for PM10. All the values are below this line, so for this month the stations were in compliance with the standards. ❑ Dr Gregor Feig is the Unit Manager of the Air Quality Information Unit at the South African Weather Service. His responsibilities include the operation of the Ambient Air Quality Monitoring Network in the Vaal Triangle Airshed Priority Area, the operation of the South African Air Quality Information System (SAAQIS) and he is involved in the development of the National Emissions Inventory. He obtained his PhD from the Johannes Gutenberg University in Mainz (Germany) while based at the Max Planck Institute for Chemistry. Before that he obtained his MSc from the University of the Witwatersrand.

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Figure 2: Using alternative forms of energy such as wind-generated power has benefits for air quality and climate change. Image: Wikimedia Commons

Air quality: its impact on climate change Air quality and climate change are among the most challenging environmental problems facing mankind. By Tirusha Tambrian.

these pollutants in the atmosphere differ greatly. For example, SO2 can remain in the atmosphere for a few days whereas CO2 can remain in the atmosphere for a hundred years. Secondly, air pollutants have more immediate and local impacts on human health and ecosystems, whereas the effects of the greenhouse gases are more long-term, as they are able to absorb sunlight and thus contribute toward long-term changes in surface temperatures and have impacts on the global climate. As a result of these differences, the policies to deal with air quality

and climate change issues have also been developed at different scales. Policy to deal with air pollution is generally developed at a national level, with opportunities for regional and local policies, where the ultimate goal is the protection of human health and ecosystems through air quality management. Climate change policy has, however, developed at an international level, where the main aims are to mitigate or slow down climate change through a reduction of greenhouse gas emissions, and to adapt to the consequent damage that could occur as a result of climatic changes. â&#x2013;˛ â&#x2013;˛

he combustion or burning of fossil fuels such as petroleum and coal emits pollutants such as sulphur dioxide (SO2), carbon monoxide (CO), particulate matter (PM) and carbon dioxide (CO2). Even though these emissions can originate from the same sources we find that SO2, CO, PM are traditionally classified as air pollutants, whereas CO2 is classified as a greenhouse gas. Air pollutants and greenhouse gas emissions are often studied, monitored and managed separately. There are various reasons for this. The first is that the lifetimes of

Quest 8(2) 2012 35

Figure 1: Summary of the key linkages and interactions between climate change and air quality.

Air quality and climate change have complex linkages and interactions In the last decade significant progress has been made towards improving our scientific understanding of how the issues of climate change and air quality are related, revealing that the linkages between these issues extend beyond a commonality of sources of emissions. Specifically, air pollutants have the ability to absorb or reflect solar radiation, and thus can have warming or cooling effects on the climate. Sulphate particles, for example, can contribute to cooling the Earth by reflecting sunlight back into space and preventing it from reaching the Earth’s surface, whereas other particles such as those of black carbon are able to absorb sunlight and contribute to climate warming. Thus, air pollutants can sometimes be referred to as ‘shortlived’ greenhouse gases – because of their atmospheric lifetimes they only have an impact on surface temperatures and the climate in the short term. Climate change is also likely to have impacts on air quality. Poor air quality generally results from a combination of air pollution and weather conditions that are unfavourable for the removal of these pollutants from the atmosphere. Climate change is expected to result in progressive changes to weather patterns. These include changes

36 Quest 8(2) 2012

to the distribution and amount of precipitation, change to temperature, changes to wind speed, wind direction and to large-scale weatherproducing systems. These are key factors responsible for the dispersion of pollutants. Furthermore, climate change could lead to changes in fossil fuel consumption patterns as well as changes to natural sources of emissions. Thus, climate change is expected to impact on air pollution and ambient air quality by affecting the sources of emissions of air pollutants, as well as the ability of pollutants to be dispersed in the atmosphere. These changes are likely to have an impact on the number, duration and intensity of air pollution events. Linking air quality and climate change interventions Because air quality and climate change have many complex linkages and interactions as shown in Figure 1, there is growing recognition of the need to tackle both these issues together. One opportunity to do this is by implementing interventions within the key polluting sectors that will simultaneously reduce or avoid the release of both air pollutants and greenhouse gases. As fossil fuel combustion is a major source of emissions, one option is to move towards greater use of renewable sources of energy, such as wind generated power (see Figure 2),

that do not emit air pollutants or greenhouse gases and thus avoid the release of further emissions. However, if we continue to use fossil fuel-derived energy we must ensure that we use it more efficiently. Furthermore, by taking a more holistic approach to how we manage atmospheric emissions, there are opportunities for countries to be more cost-effective in the ways in which they reduce air pollution and greenhouse gas emissions. The concept of dealing with air quality and climate change issues together may be of particular relevance to developing countries that are still grappling with air quality issues and do not prioritise climate change mitigation. Using a holistic approach to air quality management, where climate change linkages and interactions are considered, may allow these countries to more effectively meet their existing goals for air quality improvements and also make contributions toward climate change mitigation. Behavioural changes in society are likely to be key factors in determining how successful nations are in simultaneously tackling air quality and climate change challenges. We all have a role to play, and every person needs to be made aware of how their actions and decisions contribute toward air pollution and greenhouse gas emissions. Taking the appropriate actions now to reduce atmospheric emissions will allow current generations to experience air quality improvements, whilst also creating the prospect of long-term climate and air quality benefits for future generations. ❑ Dr Tirusha Thambiran is a researcher at the CSIR. Her main research interests are in the areas of climate change mitigation and air quality management in cities, which is also the focus of her current research activites.

Natural environment

Industry

Built environment

Defence and security

Energy

Health

This year the CSIR conference, comprising several targeted symposia, also features our stakeholders - organisations that help us to achieve our mandate. The conference also has a public engagement component that aims to introduce the CSIRâ&#x20AC;&#x2122;s work to youth groups and members of the public. This event is an opportunity for key players in government and business, as well as the academic and research community, to find out about cutting-edge, world-class CSIR research, its contribution to national priorities for the benefit of all South Africans and its contribution to the global knowledge pool. Please visit www.csir.co.za for updates and registration dates.

Industrial pollution is one source of harmful air pollution.

Image: Wikimedia Commons

Air pollution: what is its effect on health? Riëtha Oosthuizen explains how air pollution affects our health.

he average person breathes about 16 m3 air every day. You will know from the other articles in this issue that the air that we breathe may be polluted and also what the sources of the pollution may be. We are also not exposed to one pollutant at a time and the air that we breathe consists of a mixture of different pollutants that may have an adverse effect on our health. The most common pollutants in this mixture are gases such as sulphur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO) and ozone (O3) as well as particulate matter (PM) of different sizes. PM may also consist of different elements

38 Quest 8(2) 2012

and compounds. In addition, gases, including volatile organic compounds (VOCs) such as benzene, may adsorb to particles, which then act as a vehicle transporting these volatiles as far as the gas exchange region of the lung. In this article we will discuss the possible health effects from exposure to these pollutants. The body’s mechanisms to protect against air pollution The body has several mechanisms in place to protect us against PM. For example, the hair in our nostrils filters out the larger (>10 µm in diameter) particles. The smaller particles (≤10 µm in diameter) penetrate deeper into

the respiratory system. The smaller the particle, the deeper it may enter into the respiratory system, until it is able to reach the gas exchange region of the lung. In the trachea we get ciliated cells, containing very small hair-like structures, which beat in synchrony to ‘sweep’ particles up to the throat, from where they may be coughed out or swallowed and excreted. Cells in the lungs, called macrophages, will phagocytose (engulf and digest) particles using their pseudopodia. When particles stay in the lung, they may lead to cell injury resulting in the formation of fibrous connective tissue. Our eyes, nose and throat may

Q Environmental Science

Particular matter is often responsible for the wonderful sunsets seen in polluted cities. Image: Wikimedia Commons

act as warning mechanisms against certain gases, such as SO2, by reacting with a burning sensation, even at low concentrations. Other gases may trigger our olfactory sense, for example the rotten egg smell from hydrogen sulphide (H2S) at levels well below the detection limit of sophisticated instrumentation. We could, however, also be overcome by some gases such as CO without any warning, as they are colourless and odourless. Health effects of air pollution The health effects of air pollution may vary from a reversible effect such as irritation of the eyes, to irreversible and debilitating effects, such as central nervous system effects that may resemble Parkinson’s disease, for example following exposure to elevated levels of manganese. The World Health Organization (WHO) has stated that ‘...no threshold for particulate matter has been identified below which no damage to health is observed’. The health effects of particulate matter depend not only on the size of the particles, but also on the chemical composition. Particles that stay in the lung may lead to the formation of an excess of fibrous connective tissue (fibrosis) referred to as ‘scarring’ of the lung. For example, when a person is exposed for a long time to relatively high concentrations of silica, they may develop lung fibrosis. SO2 dissolves easily in water to form sulphuric acid (H2SO4) and will therefore dissolve in the moisture of the mucous membranes of the eyes, nose and throat, causing upper respiratory irritation. SO2 also causes

constriction of the bronchi, which will have a negative effect on people with asthma, whose bronchi are already inflamed and therefore swollen. NO2 does not dissolve as easily in water as SO2 and will therefore enter deeper into the respiratory system following inhalation. Both SO2 and NO2 damage ciliated cells and impair the phagocytotic function of the macrophages. Moreover, both these gases oxidise proteins and unsaturated lipids in cell walls, thereby increasing their permeability, which may lead to inflammation of the tissue. CO causes an oxygen (O2) deficiency in cells. Haemoglobin, the O2-carrying substance in red blood cells, has a much higher affinity for CO than for O2 and will therefore rather bind to CO than to O2. The carboxyhaemoglobin that is formed as a result of this reaction does not carry O2, thereby causing an O2-deficiency in the tissue of organs such as the brain. What can you do to reduce air pollution and its associated health effects? n Save electricity. If we do not use electricity wisely, we are contributing to the need for more coal burning at coal-fired power stations. n Use motor vehicles only when absolutely necessary. Rather make use of public transport. n Do not smoke, especially not indoors. n Do not start a veld fire (sometimes started by people throwing away burning cigarette butts). n Do not burn refuse – rather start recycling and composting.

Scanning electron micrograph of lung trachea epithelium, showing the cilia that protect our airways against pollutants. Image: Wikimedia Commons

Steps of a macrophage ingesting a pathogen: a. Ingestion through phagocytosis, a phagosome is formed b. The fusion of lysosomes with the phagosome creates a phagolysosome; the pathogen is broken down by enzymes c. Waste material is expelled or assimilated (the latter not pictured) Parts: 1 = pathogens; 2 = phagosome; 3 = lysosomes; 4= waste material; 5 = cytoplasm; 6 = cell membrane. Image: Wikimedia Commons

n Do not use pesticides – rather investigate the use of natural pesticides and repellents that do not pollute the air. ❑ Riëtha Oosthuizen is a senior scientist with more than 20 years’ experience in the field of air pollution and human health and registered with the Health Professions Council of South Africa as a medical scientist. She is focussing on the impact of chemicals and particulates in air on human health, as well as on factors that make communities more vulnerable to these impacts.

Quest 8(2) 2012 39

Environmental change: In response to environmental change, some of South Africa’s marine plants and animals are on the move. By Mike Lucas and Charles Griffiths

S A composite satellite image of sea surface temperature (°C) showing the cold Benguela Current on the west coast and the warm southward flowing Agulhas Current on the east coast. The Agulhas Bank region just to the east of the Cape Peninsula and False Bay shows mixing of both warm and cold currents. Image: Christo Whittle, UCT Oceanography Department.

A schematic illustration of the major currents and oceanographic features of the south and west coasts of South Africa. Image: Field and Shillington (2010)

outh Africa’s marine environment is unique globally, being surrounded by three major oceans – the cool South Atlantic Ocean to the west, the very cold Southern Ocean to the south and the warm Indian Ocean to the east. South Africa’s west coast is bounded by the cold (~10°C) but nutrient-rich Benguela upwelling system, one of six major west coast upwelling systems world-wide. Benguela upwelling here is driven by south-easterly along-shore winds blowing towards the equator. Because of Earth’s rotational forcing, surface water is blown offshore and is replaced by deep, cold, nutrientrich water that ‘upwells’ to the surface at rates of 50 – 200 cm per day depending on the wind speed. South Africa’s east coast is dominated by the warm (23 – 26°C) south westerly flowing Agulhas Current, which hugs the east coast and flows southwards at speeds of up to 5 knots in a band 100 m across and 3 000 m deep, delivering about 65 million m3 of water per second towards Cape Agulhas. Once past the Agulhas Bank and released from the frictional drag of shallow water, the current turns southwards, then eastwards back towards the south-west Indian Ocean as the Agulhas Return Current. Environmental variability and climate change are, however, altering these and other oceans around the globe. As climate change cools the west coast’s southern Benguela upwelling system and the near-shore south coast marine environment, but warms the Agulhas Current along the east coast, many of South Africa’s marine organisms are now moving in response. Migrating species The obvious migrants include kelps, mussels, barnacles, crabs, rock lobsters, anchovy, sardine and sub-tropical fishes, as well as seabirds and seals. Less obvious migrants will certainly include certain planktonic organisms such as

zooplankton species that can only tolerate a specific temperature range. Changes in water temperature will also affect phytoplankton community structure due to changes in nutrient supply, since cooler waters have usually originated from deep nutrient-rich sources. All of these changes will alter the structure of ecosystems and the way they function. Altered currents and changing water temperatures restrict some organisms, but provide opportunities for others, with some species becoming ‘winners’ and others ‘losers’, just as it has been for millennia. The biogeographic distribution of invertebrate marine animals and algae is primarily influenced by their tolerance to species-specific temperature ranges, as well as by currents that allow them or their offspring to re-colonise existing or new areas. For mobile organisms such as fish, this may simply involve migration by the adults into new territories. But for sessile organisms fixed permanently to rocks, such as kelps, barnacles and mussels, changing location can only be achieved by dispersal of their spores (kelps) or their planktonic larval stages. Many slow-moving organisms such as marine snails, crabs and rock lobsters also make use of planktonic larval stages to achieve population dispersal. Organisms at the edge of their temperature range are the ones most likely to move, either by retreating from adverse temperatures, or by expanding into new areas as changing temperatures allow them to. However, not all movements are driven directly by climate change. Warm-blooded seabirds and seals, for example, can control their body temperature, so it is not changing temperatures that force them to move, but the re-distribution of their food. Predatory fish must also follow their prey, or switch diets if they can. Who is moving and where? So which organisms are moving? False Bay in the Western Cape provides good

Left: Trends in sea surface temperature (°C) per decade from 1982 to 2005, adapted from Rouault et al. (2009, 2010). Oranges and reds represent warming, while blues represent cooling. Note warming of the Northern Benguela upwelling system on the west coast, but cooling of the Southern Benguela on the south-west and south coasts. Where the Agulhas Current flows southward then eastwards along latitude 40°S, there is considerable warming.

40 Quest 8(2) 2012

Q Biogeography

its effect on species distribution

A relict population of the warm-water-loving brown mussel Perna perna at Bailey’s Cottage, False Bay. These mussels are migrating eastwards to escape the intrusion of cooler water. Image: Prof. Charles Griffiths, Zoology Department, UCT

These two photographs show how cold-water loving brown kelps have invaded the Oatland’s Point area of False Bay since 1986 as False Bay has cooled. Image: Prof. Charles Griffiths, Zoology Department, UCT.

These diagrams illustrate the eastward shift in the distribution of anchovy spawner biomass onto the south coast as a result of a changing environment. Image: Data and diagrams from Carl van der Lingen et al. (2011)

area just east of Cape Hangklip, while west coast populations have substantially declined due to over-fishing. Consequences – the west coast Secondary ecosystem consequences have been dramatic. For example, the numbers of breeding pairs of the west coast Bank cormorant (Phalacrocorax neglectus – what a wonderful name!) have declined significantly, since scarce juvenile rock lobsters are a mainstay of their diet. Rock lobsters themselves are also major predators of bottom-living organisms, and where they have colonised the area east of Cape Hangklip, spiny sea urchins and marine winkles (Turbo cidaris) have virtually disappeared. Both of these are herbivores like the abalone, Haliotis midae, which was once abundant prior to rampant illegal poaching. Their removal has allowed algae to flourish, transforming the ecosystem structure. Movements of west coast marine biota are not restricted to algae and ▲ ▲

examples to start with, because records of the distribution of rocky shore biota from 1986 can be compared with similar surveys completed in 2007. Over this period, the large coldwater brown kelps (Ecklonia maxima and Laminaria pallida) that typically characterise the near-shore kelp-beds of the west coast have extended their range into False Bay as this body of water has cooled. At the same time, the native warm water brown mussel, Perna perna, has retreated eastwards out of False Bay, except for a tiny relict population that hangs on at Bailey’s Cottage, the warmest remaining location in False Bay. The commercially exploited and sought after west coast rock lobster, Jasus lalandii, typically inhabits cold water loving kelp-beds in less than 30 m water depth from just north of Walvis Bay (Namibia) to Cape Point. However, since the early 1990s, rock lobsters have extended their range eastwards into a now cooler and previously unoccupied

The west-coast rock lobster, Jasus lalandii, which has extended its range along the south coast. Image: Prof. Charles Griffiths, Zoology Department, UCT.

The African penguin.

Image: Wikimedia Commons

Quest 8(2) 2012 41

The tropical east African ghost crab, Ocypode ryderi, has extended its range southwards as far as Port Elizabeth. Image: Prof. Charles Griffiths, Zoology Department, UCT

The large rosy pink coloured sub-tropical intertidal ‘volcano’ barnacle, Tetraclita rufotincta, has migrated southwards from its former southernmost range of St Lucia to about 100 kms south of Durban. Image: Prof. Charles Griffiths, Zoology Department, UCT

invertebrates only. From the early 1980s to 1995, about 60 – 70% of all anchovy biomass was distributed along the west coast nearly as far as Cape Agulhas. However, coincident with a fall in sea surface temperatures east of Cape Agulhas from 1996 to 2008 due to winddriven coastal upwelling new to the area, the bulk or ‘centre of gravity’ (70 – 80%) of the anchovy population abruptly moved eastwards to the eastern Agulhas Bank region, taking advantage of improved feeding conditions associated with greater phytoplankton production. Sardine also moved eastwards at the same time, but more slowly, occupying the eastern Agulhas Bank only after 1999/2000. Whether the re-distribution of anchovy and sardine will be permanent or transient is still uncertain. Surveys of fish abundance from 2008 to the present are still being analysed, but early indications suggest that fish populations may be returning to their more favoured west coast environment, presumably once again in response to better food availability. About 400 000 tonnes of sardine and anchovy are caught annually by the purse seine fishery. Anchovy and sardine form a major part of the diet of seabirds such as Cape gannets, African penguins and Cape cormorants, as well as for fish such as snoek and Cape fur seals. When the anchovy and sardine moved eastwards,

42 Quest 8(2) 2012

this created a severe geographical mismatch between seabird and seal breeding colonies on west coast islands and their now distant prey. Following eastwards was limited by a lack of suitable island habitats for nesting or pupping, so foraging distances increased substantially, particularly for penguins with a limited foraging range. This also forced seabirds to forage for lowquality trawler discards, mostly hake, rather than feeding on high-quality (oily) anchovy and sardine. For both reasons, sea bird breeding success fell dramatically, with populations of African penguins nesting on west coast islands declining by 70% between 2004 and 2009. As Namibian anchovy and pilchard stocks disappeared through overfishing, the numbers of Cape gannets, African penguins and Cape cormorants breeding there declined by 95%, 90% and 62% respectively. Seal populations are, however, less sensitive to the loss of anchovy and pilchard because they can turn to deeper-living fish such as hake that are not accessible to plunging or diving birds, so their populations have in fact grown. Consequences – the east coast Turning now to the east coast, examples of marine organisms on the move are found here too. The diminutive ghost crab, Ocypode ryderi, that can be seen scuttling around on tropical east African sandy beaches, has extended its range southwards as far as Port Elizabeth, not because of a warming ocean, but because of a warming upper shore due to rising air temperatures. Ghost crabs spend almost their entire lives out of water, living in burrows up to 1 m deep, so are more sensitive to changing air rather than water temperatures. The large rosy pink coloured subtropical intertidal ‘volcano’ barnacle, Tetraclita rufotincta, has also migrated southwards from its formal southernmost range of St Lucia to about 100 km south of Durban, in this case due to warming of near-shore waters as well as warmer air temperatures. KwaZulu-Natal’s small isolated patches of reef-building corals were until recently at the southernmost extension of their range, but as the Agulhas Current has warmed, their range is also slowly expanding southwards. Tropical and sub-tropical fishes are also following these migration trends, as well as leap-frogging southwards from estuary to estuary as they too progressively warm. The subtropical cat-

faced rock-cod (Epinephalus andersoni) was previously confined to the southeast African coast, where it is endemic. Today it is common between Durban and Richards Bay, although occasional specimens had been found as far west as Knysna Lagoon prior to 2008. Since then it has pushed 200 km further west into the De Hoop Marine Reserve, where six fish have been recorded for the first time during a 28-year long fishmonitoring project there. This confirms an ongoing westward shift in rock cod distribution. In another example, an estuarine fish species abundant throughout the western Indo-Pacific is the river bream, Acanthopagrus berda. Today it is commonly appearing in eastern Cape estuaries as far south as the Kei River, where once it was absent. Barracuda, an Indian Ocean predator, have recently been recorded as far south as Struisbaai on the South Coast, near Cape Agulhas. Lessons learnt So what lessons can we learn from these changes? Firstly, some animals and plants can be a useful barometer of climate change, as long as changing population structures and biogeographical shifts can be disentangled from other human influences, such as commercial exploitation. Secondly, a general overall effect of migrating organisms is that they substantially alter the ecosystem structure of newly occupied areas. Meanwhile, the biogeographic range of typical south coast communities is being compressed into a smaller geographic area which, for intertidal organisms, will be compounded by rising sea level that will slowly force them up the shore. From a human perspective, movements of exploitable resources incur socio-economic costs that demand adaptive strategies and flexibility that are difficult to implement. Finally, Marine Protected Areas (MPAs) may need to be increased in number, enlarged or even moved to accommodate climate-driven migration of South Africa’s marine heritage. ❑ Associate Professor Mike Lucas and Prof. Charles Griffiths are both members of the Marine Research Institute (Ma-Re) of the University of Cape Town and both teach within UCT’s Zoology Department. Mike Lucas is also an Honorary Research Associate at the National Oceanography Centre (NOC) in Southampton, UK.

Q Mathematics

Above: Four coloured dice showing all six possible sides (on a right-handed, 6-sided die with pips). Image: Wikimedia Commons

Right: A spinning roulette wheel – it’s all about chance! Image: Wikimedia Commons

It is probably probable… Quest’s resident mathematician, Steve Sherman, has a look at the reality of probability.

robability involves the idea that some things might or might not happen. You can measure the possibility of the event taking place and this allows people to make decisions based on these outcomes. By way of example, there is a chance that it will rain tomorrow. According to the satellite images, the chance is pretty good. Using various tools and equations, the weather reporter can declare that there is a 75% chance of rain. Effectively it means that you should seriously consider taking an umbrella with you! With probability all around us we should be making more use of it! We know that you have a one in six chance of throwing a six on a die and you have a one in almost fourteen million chance of winning the lotto! These are just examples that stick out. The reality is that probability governs our lives. According to statistics, 57% of marriages in South Africa end in divorce. This fact alone should influence the process you follow when selecting a future partner in an attempt to beat the odds. Approximately 10.5% of our population has HIV – this means that when you are dating someone, there is a one in 10 chance that they have HIV. One in six married people in the USA actually met online. This indicates that with the growth of the Internet and social networking, you are quite likely to meet your future life partner though the Internet! People often say that you are one in a million, but if that was the case in China, there would be 1 300 people just like you. The top 10 jobs in 2010 did not even exist in 2004. There is a strong probability that some of the subjects that you are studying at school will not prepare you for your future career. We are also preparing learners for jobs which involve technology that has not been invented yet. It is however a strong probability that studying maths and science will give you a competitive edge, as they teach you to reason, solve

problems, adapt and think! Probability is a very interesting field of mathematics. It helps people make important decisions every day. If your city gathered crime statistics and mapped it out over Google Earth, you could see a visual representation of the crime in your area. You could also assess the chance of being a victim of crime, based on the time of day, your current location and the day of the week. This is essentially a means of improving your chance of avoiding a crime. High numbers of crimes in a particular area also affect property prices and should discourage you from buying property in that area.

A pack of playing cards.

Image: Wikimedia Commons

When it comes to solving crimes, forensics and putting criminals behind bars, a sound understanding of probability comes in handy. One has to determine the probability that someone is a potential suspect, the probability that a case has been proven beyond reasonable doubt and the probability that DNA matches with a potential suspect and the crime scene. When evidence is examined, the probability that person X strangled person Y needs to be supported. In other words, if clothing fibres from person X are found on person Y, this is strengthening

the hypothesis that person X strangled person Y. Of course the probability decreases if they live in the same house, since it is reasonable that clothing fibres could have found their way to person Y. Probability is not always clear and simple to understand. Take the following brainteaser for example. A dealer and a player are facing each other at a table. The dealer takes four playing cards out of a deck. Two of them are red and the other two are black. He shuffles them and places them face down on the table. The player selects any two at random and these two cards are turned face up. If they are both the same colour (i.e. both red or both black) then the player wins. Otherwise, the dealer wins. Is this a fair contest ? If you think that the contest is fair then it would imply that the dealer and the player have a one in two chance of winning, or 50% probability. You might feel that perhaps either the dealer or the player have a distinct advantage over their opponent. I am not going to divulge the solution. Instead, I am going to challenge you to discuss this with your friends and teachers. When you feel you have the solution, please email me on livmath@iafrica.com and include your contact details. I will place all the correct entries into a hat and draw one lucky name. They will receive a super cool scientific calculator. Given your maths knowledge, how smart your friends are, which teachers you have consulted, how long you have spent trying to solve this teaser, what is the probability that you will win? You will need to enter to find out! ❑ Steve Sherman is a multi-award purchasing educator and was voted fifth best-looking mathematician in the world by his mother. His mother contested this and now he is ranked sixth! He knows karate, Ju-jitsu and three other

Quest 8(2) 2012 43

Sand dunes in the Namib desert, Namibia. Without adaptation and mitigation measures, this type of landscape will become all too familiar across southern Africa. Image: Wikimedia Commons

SASSCAL (Southern African Science Service Centre for Climate Change and Adaptive Land Use) has the task of conducting climate change research that will guide appropriate development and increase relevant capacity and services in southern Africa. Jonathan Diederiks explains.

Science for development: a regional centre for climate change research The bigger picture In the context of climate change it is beyond debate that the impacts will be greatest in Africa, more specifically sub-Saharan African. These impacts will have major implications on the productivity potential of the land, which affects general food security in the region, as well as water availability and quality and ecosystem services. Because a large majority of the population are dependent to some degree on the natural resource base as part of their livelihoods, these last two are critical. SASSCAL aims to go beyond merely doing research but rather will prioritise the whole ‘value chain’ where capacity development and services and products needs will delineate the research undertaken. ‘Science for development’ is the programme’s mantra. The German government, through the Federal Ministry of Education and Research (BMBF) in 2009 initiated discussions with five southern African countries (South Africa, Namibia,

44 Quest 8(2) 2012

Angola, Zambia and Botswana) on a joint initiative that would lead to the establishment of a Regional Science Service Centre for Climate Change and Adaptive Land Use in Southern Africa. The SASSCAL initiative focuses on three thematic areas – climate change, water and land management and has three thrusts: research, capacity development and regional advisory and information outputs (products and services). This programme will be run over four years and has an initial funding commitment from BMBF of about €50 million. The partner countries have also pledged co-funding towards the programme over the four years (initial phase). The goal is that SASSCAL will be financially self-sufficient (to a degree) by the end of the four years. The six partner countries will probably continue contributing towards the operation of SASSCAL after the initial four years, but this will be dependent to a large degree on the success of the initiative during the initial phase.

SASSCAL and South Africa In South Africa, SASSCAL will be implemented under the auspices of the Department of Science and Technology (DST), through the National Research Foundation (NRF) and the Applied Centre for Climate and Earth Systems Studies (ACCESS), with close linkages to other relevant role players nationally and regionally. The grounding of SASSCAL in the institutional matrix as described above also ensures that it is sufficiently aligned with the country’s national climate change priorities as set out in the 2nd National Communication to the United National Framework Convention on Climate Change (UNFCCC). SASSCAL is closely linked and aligned with elements of the DST’s Ten-year Innovation Plan for South Africa – Innovation Towards a Knowledge-based Economy 20082018 – which identifies five key Grand Challenges for the National System of Innovation over the next decade. One of these Grand Challenges is

Above: The Southern Ocean is an enormously important factor in the climates of four continents – South America, Antarctica, Africa and Australia. Image: Wikimedia Commons Right: The stormy seas of the Southern Ocean.

Understanding a changing planet

contemporary debate and discussion. With the above as an overall context alignment we can now look at SASSCAL in more detail. The SASSCAL team (coordinators from each of the six countries involved) has chosen the following statement as reflective of its vision: SASSCAL is a REGIONAL driver for innovation and knowledge exchange to enhance adaptive land use and sustainable economic development in Southern Africa within the context of global change. The SASSCAL Mission: n To establish a network of science service centres in the southern African region, thereby strengthening the regional scientific capacity and existing initiatives, n to support adaptation by the participating countries to cope with climate change and land use change and the resulting impact on ecosystem functions and services, and n to generate and provide scientifically sound, relevant and timely information for policy and development planning processes that will promote the improved livelihoods of the broader society. More specifically, emphasis will be placed upon: n supporting capacity development, both in terms of human resources and infrastructure, and thereby improve the ability of the region to effectively manage natural resources at national and regional scales n providing an innovative services platform that will raise awareness and provide sound scientific support to a broad range of stakeholders to ensure participation and ownership of interventions and implementation

Reducing the human footprint

n providing a regional platform for knowledge sharing, and thereby integrate and co-ordinate regional initiatives in the SASSCAL thematic areas. SASSCAL in detail Let’s look a bit more closely at what SASSCAL aims to do and how. One of the programme’s priorities is to enhance the science capacity and the application potential of science within the region. This means that there will be systematic integration of appropriate training opportunities, along with setting appropriate scientific standards in relation to data and information integrity and research methods. This will be implemented through core capacity development elements including research strengthening, graduate programmes development; non-academic training, and scholarships system. The integration of the full value chain of science and technology development from the acquisition, assimilation, dissemination of information and knowledge to practical assistance related to its implementation and/or use is an essential part of SASSCAL’s objectives. This takes the form of specific activities around a product portfolio which is both relevant to a specific context and based on the most advanced science available. The team of international and local professionals, scientists and experts will ensure that these products will

Adapting the way we live

▲ ▲

science and technology in response to global change. This Grand Challenge has two main aspects: enhancing scientific understanding of global change, and developing innovations and technologies to respond to global change. An inclusive process involving a wide cross-section of the science and policy communities in South Africa was followed to develop a detailed implementation plan for the first of these, i.e. enhancing scientific understanding. This process has culminated in the development of this 10-year national research plan for the Global Change Grand Challenge (the Global Change Research Plan). The Global Change Research Plan identifies four major cross-cutting knowledge challenges and 15 key research themes, summarised in the table below. For South Africa specifically, but also with relevance to the region the Global Change Research Plan is notable for the following reasons: n It adopts an Earth system approach. n It is strongly interdisciplinary. n It is based on the unique geographic location and developmental challenges of South Africa. n It is grounded in a social-ecological paradigm. n It supports making a contribution to the international knowledge base as well as locally relevant and required research. n It aims to advance a better understanding of the functioning of the Earth system and to support efforts to respond effectively to changes. n It is intended to be policy-relevant. n It has a strong focus on climate change, and takes into consideration

Image: Wikimedia Commons

Innovation for sustainablity

Observation, monitoring and Waste minimisation methods and Preparing for rapid change and adaptive management technologies extreme events

Dynamics of transition at different scales – mechanisms of innovation and learning

Dynamics of the oceans around southern Africa

Conserving biodiversity and ecosystem services, e.g. clean drinking water

Resilience and capability

Dynamics of the complex internal Earth systems

Institutional integration to manage Water security for South Africa ecosystems and ecosystem services

Linking the land, air and sea

Planning for sustainable urban development in a South African context

Options for greening the developmental state

Food and fibre security for South Africa

Improving model predictions at different scales

Quest 8(2) 2012 45

Climate change Q

The interaction of SASSCAL’s objectives.

Understanding the waste hierarchy is key to planning waste minimisation. Image: Wikimedia Commons

Wetlands provide a number of ecosystem services. Image: Wikimedia Commons

46 Quest 8(2) 2012

be the most appropriate, user defined and practical available. The research is focused on identifying appropriate interventions, opportunities for integration and collaboration within the following themes including their overall strategies: n Climate (to understand and project climate well enough to promote sustainable and adaptive management of water, forestry, agriculture and biodiversity in the region) n Water (to develop a common water resources information base and analytical methods to further strengthen capacity to implement integrated water resources management strategies for improved trans-boundary river management and resource use) n Forestry (to conserve enough forest in southern Africa to ensure continued delivery of vital ecosystem services to the region) n Agriculture (to understand resources, drivers and changes of land use well enough to promote sustainable food production and food security in the region) n Biodiversity (to understand patterns, processes and driving forces of biodiversity well enough to ensure delivery of vital ecosystem services to sustain agriculture, forestry and ecotourism in the region). South Africa’s projects as part of SASSCAL Water: (water project is broken into four work package components) n Hydrological and hydro-geological baseline data and modelling n Management strategies (IWRM) n Risk assessment and early warning systems n Recycling, sanitation, wastewater treatment, water use efficiency, urban planning Forestry: n Adaptation strategies for the South African, Namibian and Zambian dryland forests (natural and plantation) to climate change Climate change: n Climate modelling for the improvement of seasonal forecasts and its applications for southern Africa n Climate change, impacts and adaptation Biodiversity: n Land cover change and adaptation to climate change impacts in mixed

crop-livestock production systems in southern Africa Agriculture: n Adaptation to climate change impacts in mixed crop-livestock production systems in southern Africa. As a legal entity, it is proposed that SASSCAL take the legal form of a Section 21 company (a not for profit entity) eventually evolving into an international organisation (according to UN regulations). The head office, based in Windhoek, Namibia, will be made up of the core units: Science and Technology, Services and Products, Capacity Development, and Marketing supported by Finance and Administration. Each of the participating countries will have a national node (country office). The broad functions of the head office include coordination and administration of the portfolio of work packages, liaison and service delivery, funding distribution and planning and monitoring and evaluation (M&E). The national nodes will consolidate the implementation of projects and the commensurate flow and management of data and broader integration and collaboration at a national, regional and international level. The Governing Body of SASSCAL will be a board, which will be directly responsible for all high-level decision-making and guidance and direction, based on a national steering committee’s input and regional needs, trends and priorities, while a steering committee will be responsible for all technical guidance received from national steering committees. A major focus point in the programme is the importance of getting the research (data) to the appropriate role players, stakeholders and service providers in a way that it can be used to improve livelihood opportunities within society. The SASSCAL planning (development) phase, which started in 2010, is coming to a close, with implementation starting in mid-2012. ❑ Jonathan Diederiks is the National Coordinator: Southern African Science Service Centre for Climate Change and Adaptive Land Use (SASSCAL). Email: jonathan.diederiks@nrf.ac.za Mobile: +27 (0) 72 1908 702 Office: +27 (0) 12 481 4104 SASSCAL website: http://www.sasscal.org

Conservation through Science and Research

www.nzg.ac.za The National Zoological Gardens of South Africa, Pretoria, is a place of learning and a source of inspiration to action for science and biodiversity. Our research areas cover Veterinary Parasitology, Wildlife Medicine, Wildlife Molecular Genetics, Zoo Animal Nutrition, Public Interface Research, Biomaterial Resource Banking, Behavioural Ecology and Wildlife Epidemiology.

National Zoological Gardens of South Africa 232 Boom Street, Pretoria, GAUTENG Telephone +27 12 328 3265 Fax + 27 12 323 4540 E-mail info@nzg.ac.za

Africa celebrates SKA bid outcome ‘W

The majority share of the iconic telescope is coming to the African continent. By Justin Jonas

e have always said that we are ready to host the SKA, and the world has listened to us,’ Ms Naledi Pandor, South Africa’s Minister of Science and Technology said at a crowded media briefing on 25 May 2012 in Pretoria, South Africa. Earlier that day, the SKA Organisation announced that a majority share of the iconic SKA telescope would be built in South Africa, with the lion’s share of the dishes and dense aperture array destined for the Northern Cape Province. Some dishes and the low-frequency array will be built in Western Australia. ‘I am ecstatic! I’m happy for our scientists, I’m happy for our country, I’m happy for Africa!’ Minister Pandor added. ‘We’ve done it! Who would have thought?’ Everything you wanted to know about the SKA …

1 What is the SKA?

The Square Kilometre Array Radio Telescope (or SKA) will be the world’s biggest telescope – and one of the biggest scientific projects – ever! 2 Why is it called the ‘Square Kilometre Array’?

It is called an array because it will be made up of many large antennas (and other types of radio wave receivers) that will be linked together via optic fibre cables. The total surface area of all the antennas together will add up to approximately one square kilometre. 3 What makes the SKA so special?

Its sheer size and power! Thousands of antennas – spread over 3 000 km – will work together as one gigantic, virtual instrument – creating a radio telescope at least 50 times more powerful, and 10 000 times faster than any other radio telescope currently in existence. 4 What will the SKA cost to build?

About R20 billion. 5 Who is building the SKA? An artist’s impression of the MeerKAT dishes that will be an integral part of of SKA Phase 1 . Image: SKA South Africa

48 Quest 8(2) 2012

Many different countries are working together to build – and pay for – the SKA. At least

A panoramic view of KAT-7.

13 countries and close to 100 organisations are already involved, and more are joining the project. 6 Who is working on the SKA project in South Africa?

Dr Bernie Fanaroff is the Project Director of the South African SKA Project. Dr Fanaroff has a PhD in radio astronomy from Cambridge University. In addition to the scientists and engineers working on South Africa’s bid for the SKA, there are also about 100 engineers and radio astronomers designing and building South Africa’s 64-dish radio telescope – MeerKAT. The South African SKA Project is funded by the Department of Science and Technology via the National Research Foundation. Mrs Naledi Pandor has been a champion for South Africa’s bid to host the SKA, and continues to support this project as one of the flagship projects in her department. 7 What will the SKA look like?

8 How will the SKA work?

Radio telescopes work in much the same way as your radio. As you tune your radio to different frequencies, the receiver in your radio picks up different music stations. Radio telescopes do pretty much the same thing. However, they collect radio waves from objects millions or billions of light years away from Earth. If you heard what was being received, however, it would sound like static hiss. These radio signals are then processed by computers that can interpret the

9 What will the SKA be used for?

Radio astronomers will use the SKA to understand how stars and galaxies formed, and how they evolved over time, what the so-called ‘dark-matter’ is that occupies 95% of the Universe, how magnetic fields formed and evolved in the Universe and how they influence astrophysical processes, to investigate the validity of Einstein’s theory of relativity, and perhaps detect life elsewhere in the Universe. The SKA will also discover new aspects of the Universe that we had not predicted, and will generate more questions that need to be answered. 10 Where will the SKA be built?

The majority of the SKA – the full dish array and the dense aperture array – will be built in Africa. The core, i.e. the region with the highest concentration of receivers, will be constructed in the Northern Cape Province, about 80 km from the town of Carnarvon (the same site as where the MeerKAT is being constructed). The sparse aperture array (low frequency array) will be built in Western Australia. 11 Why build the SKA in Africa and Australia?

On 25 May 2012 the SKA Organisation announced that the SKA would be shared between both countries, but with a majority share coming to South Africa. Following a competitive bidding process, South Africa and Australia were both shortlisted in 2006 as potential sites for building the SKA. Both countries have invested a huge amount in this project – including building pathfinder radio telescopes with associated physical infrastructure, and developing capacity with the skills and expertise to build and use the SKA. Phase 1 of the SKA (about 10% or the full Phase 2 implementation) will make optimal use of the existing infrastructure and telescopes already built by the two countries. 12 Why is the SKA built in such remote locations?

Radio telescopes must be located as far away as possible from manmade electronics or machines that

emit radio waves that will interfere with the faint radio signals coming from the distant Universe. The site should also be as high and dry as possible, because some radio waves are absorbed by the moisture in our atmosphere. 13 When will the SKA be built?

n SKA Phase 1 construction is scheduled to begin in 2016. n SKA Phase 2 should be built from 2019 to 2024. 14 How does the MeerKAT telescope fit into all of this?

South Africa’s MeerKAT telescope is an SKA precursor or ‘pathfinder’ telescope. It will consist of 64 dishshaped antennas and will be the most powerful radio telescope in the southern hemisphere. MeerKAT (and the Australian SKA Pathfinder, called ASKAP) will become part of SKA Phase 1. MeerKAT will form 25% of the Phase 1 dish array in South Africa. 15 What is KAT-7?

South Africa has already built seven dishes (KAT-7), as an engineering prototype for the MeerKAT. It is the world’s first radio telescope with dishes made of composite materials (fibre glass). KAT-7 has already produced its first scientific images,

▲ ▲

The SKA will be made up of three different kinds of receiving technologies: n The mid-frequency dish array – which look like DSTV dishes, but much bigger – will be about 15 m in diameter. The dish array of the SKA is the most well known of the three receiver types, and make up the majority of the SKA. n Large, flat disk-shaped receivers – each about 60 m wide (known as the dense aperture array), which will operate at mid frequencies. n Small upright radio receivers – about 1.5 m high (known as the sparse aperture array), which will operate at low frequencies.

signals, to form images that give us snapshots of the Universe.

Image: Ian Heywood

Cool SKA facts and figures (Source: www.skatelescope.org) n The data collected by the SKA in a 24-hour period would take nearly two million years to play back on an iPod. n The SKA will generate enough raw data every day to fill 15 million 64 GB iPods. n The SKA central computer will have the processing power of about 100 million PCs. n The SKA will use enough optical fibre to wrap twice around the Earth. n The dishes of the SKA will produce 10 times the current global Internet traffic. n The aperture arrays will produce more than 100 times the current global Internet traffic. n The SKA super-computer will perform 1018 operations per second – equivalent to the number of stars in three million Milky Way-size galaxies. This is needed to process all the data that the SKA will produce. n The SKA will be so sensitive that it will be able to detect an airport radar on a planet 50 light years away. n The SKA will contain thousands of antennas with a combined collecting area of about one square kilometre (that’s one million square metres).

Quest 8(2) 2012 49

An artist’s impression of the SKA sparse aperture array.

Image: SKA

An artist’s impression of the SKA dense aperture array.

Image: SKA

and radio astronomers are using the data from KAT-7 as part of their research work. 16 What spin-offs can be expected from the SKA?

The split of SKA components across Africa and Australia – as announced by the SKA Organisation on 25 May 2012 SKA Phase 1 (2016 – 2020; about 10% of the total SKA) South Africa

Australia

South Africas precursor array – the 64-dish MeerKAT telescope – will be integrated into Phase 1. An additional 190 mid-frequency dish-shaped antennas, each about 15 m high will be built

Australia’s 36-dish SKA Pathfinder (ASKAP) will be integrated into Phase 1. An additional 60 midfrequency dish-shaped antennas, each about 15 m high, will be built, as well as a large number of small, low-frequency antennas – each about 1.5 m high

SKA Phase 2 (2018 – 2024; about 90% of the SKA) South Africa & African partners

Australia

Telescope will extend to long baselines of 3 000 km or more A total of about three thousand mid-frequency dishes, with the highest concentration in the Northern Cape, South Africa, but some dishes in Namibia, Botswana, Zambia, Mozambique, Kenya, Ghana, Madagascar and Mauritius. In addition, a large number of flat mid-frequency antennas, each about 60 m in diameter (number to be determined)

Telescope extends over a baseline of possibly more than 200 km Up to 10 times more of the small, low-frequency antennas – each about 1.5 m high

50 Quest 8(2) 2012

The technologies and systems required for the SKA will require engineers to work at the cuttingedge of design and innovation. There will certainly be technology spin-offs for more generic and commercial applications. For example, the SKA will collect and process significant amounts of data, which will require advances in high-performance computing; while producing thousands of antennas within short time scales will lead to new manufacturing and construction techniques. The most important spinoff, however, will be the generation of new knowledge and knowledge workers – young scientists and engineers with pioneering and expertise in a wide range of scarce and innovative fields. 17 How can young scientists and engineers get involved?

The SKA has an active bursary and capacity development programme ranging from artisan and in-service training programmes to advanced studies at postgraduate level. About 400 students have received SKA bursaries since 2005. Find out more at www.ska.ac.za/students ❑ Professor Justin Jonas is the Associate Director: Science and Engineering at SKA South Africa. Find out more about South Africa’s SKA project at www.ska.ac.za

Q News

Pulling the plug on shipwreck pillaging By Nicky Willemse

unken ships have long captured the imagination of treasure hunters – and today is no different. Divers who dive around the many shipwrecks off Nelson Mandela Bay frequently take souvenirs from these historical relics or even blast away pieces of copper, brass and lead to cash in at local scrap metal dealers – even though many of these ships are protected under the National Heritage Resources Act. While the authorities are aware of the problem, it has been difficult to police – and the pillagers, some of whom have forged permits, have until now been able to get away with their illegal haul. In a bid to protect these sunken ships, Nelson Mandela Metropolitan University’s Research Diving Unit spearheaded a unique ‘think tank’ for key law enforcement officers, with the aim of developing a plan across all agencies to effectively enforce the conservation of the Bay’s underwater cultural heritage. The workshop on Thursday, 22 March, was attended by the South African Heritage Resources Agency (Sahra), the South African Police Services (including police divers, explosives experts, border policing officers and the non-ferrous metal task team), the municipality’s Coastal and Environmental Services, Nelson Mandela Metropolitan University's (NMMU’s) public law department and members of local recreational diving organisations. Research Diving Unit head Anton Cloete said: ‘We are now in the process of finalising a comprehensive plan that will address this plundering, from the first report of a transgression by the public through to prosecution in court’. One of the unit’s first tasks is to set up a local group of recreational divers to document these wrecks through video footage, thereby creating a baseline of evidence, which will enable them to monitor the plundering and provide evidence in court. Another is to set up a panel of experts, including Sahra and legal experts, who will be available throughout the investigation and prosecution process. For a diver to remove anything from a shipwreck more than 60 years old, of which there are about 105 known wrecks in South African waters, a permit from Sahra is required. However, Jonathan Sharfman, marine archaeologist and manager of Sahra’s Underwater Cultural Heritage Unit, said no Sahra permits had been issued for Port Elizabeth’s wrecks. Along with the Sahra permit, a diver would need a salvaging licence from customs and permission from the

Underwater theft: The illegal pillaging of protected shipwrecks in South African waters is destroying the country’s underwater cultural heritage. Image: Supplied by the South African Heritage Resources Agency (Sahra)

authorities managing the area, e.g. National Ports Authority or South African National Parks. Sharfman said plans were on the cards to allow for the removal of items for archaeological or scientific purposes only, rather than commercial purposes, to safeguard vulnerable artefacts. There is no Sahra legislation pertaining to the removal of items from wrecks younger than 60 years old – and one of the problems for law enforcement officers has been pinning down the wrecks from which goods had been removed. In Nelson Mandela Bay, there are only three wrecks younger than 60 years. While they do not require Sahra permits, salvagers must still obtain a number of other permits for these wrecks. Sharfman said South Africa’s wrecks were of national and international importance. ‘South Africa was the pivot of trade between the East and the West, resulting in a whole range of ships passing our coastline, and contributing to the 38 nationalities represented in this country. The ships passing back and forth contributed to how South Africa developed socially and politically – hence their being declared cultural heritage items.’ He said items had been pillaged from shipwrecks from as early as 1720 – but the advent of scuba diving after the Second World War had made it much more prolific. Pillaging was at its highest between the 1960s and 1980s when there were few

Solution seekers: Attending a Nelson Mandela Metropolitan University workshop geared towards protecting Nelson Mandela Bay’s sunken ships are (from left) Jonathan Sharfman, marine archaeologist and manager of the South African Heritage Resources Agency’s (Sahra’s) Underwater Cultural Heritage Unit, historical shipwreck expert and author Malcolm Turner, NMMU Research Diving Unit head Anton Cloete and Mike’s Dive Shop owner Mike Klee. Image: Nicky Willemse

egulations, and a number of pristine dive sites were destroyed. The current legislation makes it more difficult for divers to remove items from wrecks illegally and sell them to scrap metal dealers. NMMU maritime law expert, Prof. Patrick Vrancken, said wrecks within 24 nautical miles of South Africa’s coastline were subject to South African regulations – and the country was bound to take action to protect these items of cultural heritage. Beyond 24 miles, they fall under international legislation.

Quest 8(2) 2012 51

Books Q Sea mammals Watching Whales and Dolphins in Southern Africa. By Noel and Belinda Ashton. (Cape Town. Struik Nature. 2012.) I am lucky enough to live in the South Peninsula region of Cape Town, surrounded by the sea. One of the joys of running and cycling in this area are the opportunities that constantly arise for watching whales and dolphins – an excellent excuse to stop and catch my breath! There are large notice boards between Fish Hoek and Simon’s Town with photographs, line drawings and explanations of some of the species that can be seen from that point, but this little book is small enough to keep in the glove compartment of your car, or even in the pocket of your cycling jersey, if you would like something that will help you to identify all the possible species to be found. Noel Ashton studied environmental and geographical science, but for over 20 years he has specialised as a whale and dolphin scientific illustrator. And he is not simply an artist, faithfully recording what he sees. He has developed a complex process of morphological mapping, making his illustrations particularly accurate. His wife, Belinda, is an environmental journalist. Together, they have worked towards whale and dolphin conservation through their Oceans of Africa programme. We are fortunate that South Africa offers some of the best land-based whale watching in the world. We also have over half the world’s species either resident here, returning to our waters each year to mate or calve, or following migration routes along our coastlines. The southern right whale is probably the best known of the cetaceans because it comes back to our shallow inshore waters every year in the winter and spends a lot of time at the surface. The book starts with the classification of whales and dolphins – of which there are 84 species around the world. They are divided into two distinct groups – the odontocetes and the mysticetes. This division is on the basis of anatomical characteristics that reflect their different lifestyles. The odontocetes are the toothed whales and are active hunters. The mysticetes are baleen whales, which feed passively through long, fibrous baleen plates. Each group is divided into families. The section on evolution explains that the original ancestors of whales were land animals, with an ancient transitionary whale, Archeocetes, that filled the gap between primite terrestrial mammals and today’s whales and dolphins. The next section explains the adaptations that were necessary to mammals with an entirely aquatic existance – and the adaptations to living in cold water and differential pressures. Senses are particularly interesting in this group and there are simple explanations of how the cetaceans navigate

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by sound and the importance of sight and touch. Before we get to identification there are excellent sections on how to find the species, what kind of equipment you need for optimal watching and the distribution of the different species. The identification sections are concise and easy to use, with photographs and illustrations of the main features of each species. There is also an important section on the legislation governing whale watching in our waters. Stargazing Guide to the Night Skies of Southern Africa. By Peter Mack. (Cape Town. Struik Nature. 2012.) Astronomy is the oldest of all the sciences. Societies have always studied the stars and the constellations and the movements of the planets have been the basis of much myth and legend. Modern astronomy is built on thousands of years of knowledge, but obviously the biggest advances have been made since the invention of the telescope in the first part of the seventeenth century. However, the most important advances have arisen in the last 60 years – since the use of computers and space exploration. Only a few years ago we had sparse knowledge of the outer planets. We are living in one of the most exciting times in the science of astronomy, as our technology advances to levels that allow us to see back into time. This book is essentially a concise introduction to astronomy and the casual reader does not need any previous knowledge of the subject. But, as the author points out, anyone will benefit from studying the book in some detail before starting to look at the sky. The book starts with basic astronomy – the constellations, the celestial sphere, astronomical distances, how astronomers measure distance and brightness. The electromagnetic spectrum is covered and the astronomer’s tool kit. With reference to the latter, because the book is designed for a newcomer to astronomy, most of the objects discussed can be seen with the naked eye or a pair of binoculars. But for those who become hooked, there is a good section on what to look for when buying a telescope. Astronomy is covered from the outside in – starting with the solar system: the Sun, the planets, dwarf planets, ceres and the asteroid belt, comets, meteors and other solar system phenomena. Then we meet the galaxy – stars, stellar evolution, intersteller medium and star clusters. Extragalactic astronomy introduces the classification of galaxies and the expanding universe.

Q Books The star charts are comprehensive and provide what you need for stargazing throughout the year from different angles. There is also a section on interesting objects such as the Andromeda galaxy and the different constellations. For the technically minded there are appendices of mathematical expression, constants and the Greek alphabet and planetary data. If you were not intested in astronomy when you first picked up this book, you will be by the time you finish reading it. Africa in perspective The Story of Life and the Environment – an African perspective. By Jo van As, Johann du Preeze, Leslie Brown and Nico Smit. (Cape Town. Struik Nature. 2012.)

illustrated with drawings and photographs. There is even a snakes and ladders game in the desert section. You can learn to identify animal tracks, who eats who and what, and how to collect water in the desert. There are numerous ‘Test your skills’ questions throughout the book, with answers at the end. You will learn how to survive in the desert, how not to drown in the river and how not get eaten in the bushveldt. Above all, you will learn what a wonderful land you live in and become passionate about conserving it. Enjoy! The Cape Floral Kingdom

I can’t wait for this book to be published – I have access to a sneak preview and I would strongly recommend that you place an order at your local bookshop now, for its publication in July this year. This book looks at life from an African perspective – using our wonderful continent to showcase diversity – in all its aspects – species, populations, communities and ecosystems – all richly represented in Africa. It concentrates on the three major ecosystems: fresh water, the ocean and the land. No book on Africa would be complete without a discussion of evolution – with our rich fossil record and our place as the origin of humankind. But the rise of humans has not all been good for the continent or the planet and human impacts on the environment are covered, as well as how we can lessen these and care for the planet. This is the story of life and the environment in Africa – order it now! Bushwise On Safari: desert, river, bushveldt – a young explorer’s guide. By Nadine Clarke. (Cape Town. Struik Nature. 2012.) Did you know that the black-tailed tree rat makes its nest in the camel thorn tree? Or that a gymnogene uses its double jointed legs to reach into nests to grasp young birds, which it eats? Or that all South African toads lay their eggs in strings in the water? No – well then you need this book. If you want to really enjoy the environment around you – wherever you are in the country – then this is the book for you. The book is split into sections on three major ecosystems – desert, river and bushveldt. Each section is full of useful information, lavishly

Exploring Fynbos: plants, animals, interactions. By Margo Branch. (Cape Town. Struik Nature. 2012.) I have a bias towards the Cape Floral Kingdom because I live among it – I run in the Cape mountains and look out across them from my home every day. So I was delighted to see a book devoted to introducing the fynbos and how to explore it. The Cape Floral Kingdom is a ‘living treasure’, occupying a narrow strip of land along the southwestern coast of Africa. There is no-where else in the world where there are so many different species of plants in such a small area. Not only is the whole area made doubly spectacular by the mix of mountains and beaches, but the fynbos is at least as spectacular in close up. Fynbos plants are colourful, with unusual flowers that attract many birds, insects and other small creatures. The Cape Floral Kingdom stretches from Nieuwoudtville in the west to Port Elizabeth in the east and is a biodiversity hotspot. The fynbos biome also contains patches of wetland, thicket forest and succulent karoo vegetation – all of which are introduced. The concept of an ecosystem is introduced and used to place the major communities of plants and animals that occupy the fynbos. The climate is influenced by two oceans, several mountain ranges and by a winter-rainfall climate (under threat from climate change). The geology of the area is particularly interesting as well – contributing to the evolution of the nitrate-poor soils that fynbos thrives on. Fynbos plant groups are covered with easy to read descriptions, illustrated with drawings and photographs, ‘did you know?’ boxes and ‘things to do’. There is also an excellent explanation of how plants photosynthesise and the importance of the process. Food chains are covered in the context of the fynbos , as is pollination. No modern nature book is complete without discussion of threats to the environment and Exploring Fynbos finishes with a section on alien vegetation and conservation.

Quest 8(2) 2012 53

Diary of events Q Shows and exhibitions Iziko Museum, Cape Town The World’s Oldest Chemistry Set? New Discoveries from Blombos Cave Location: South African Museum From: October 13, 2011 at 12:00am To: October 13, 2014 at 12:00pm ‘What makes us human?’ This topical question receives some answers in the form of two unique 100 000-year-old ochre preparing kits from Blombos Cave, South Africa. This remarkable archaeological discovery is the oldest known evidence of the human use of containers, and also the oldest known evidence of people practising chemistry. Enquiries:  Sven Ouzman Tel. 021 481 3883  email souzman@iziko.org.za Workshop for the June/July school holidays! Make your own Star Wheel and learn how to use it – to identify stars and constellations Dates: 27 June, 4 July, 11 July  • Time: 09:00 – 10:30 •  Age: 8 – 12 years  • Cost: R20,00 per workshop * Please bring your own torch Tickets available at the Iziko S A Museum’s Main Entrance from 1 June (open daily 10:00-17:00). Davy and the Dinosaur Davy Dragon finds a newly hatched creature that he thinks is a baby ostrich. But is it? Davy and his grandfather magically take the creature back to its mother. Join us and discover what kind of creature Davy found and what it has to do with the Milky Way! 23 June – 15 July  • Monday to Friday: 11:00, 12:00 and 15:00 Saturday – 12:00 and 15:30 Sunday – 12:00 and 15:30 For children aged 5-12

2012: the end or the beginning? The famous Mayan Long Count would seem to indicate that, after three failed worlds, we are living in the fourth – and that will come to an end (perhaps) on 22 December 2012. Whether the Long Count defines the end of the world or not, the astronomical calculations that led to it are fascinating and indicate an astounding and accurate observation of those heavenly bodies that form part of the universe around us. 23 June – 20 July  • Monday to Friday – 14:00  Tuesday evening – 20:00 (and sky talk)  Saturday – 14:30 Sunday – 14:30 Living Inside the Cosmic Egg On a clear night you cannot see forever, even with the most powerful telescope imaginable. The observable universe ends abruptly at an opaque wall, created by the conditions that followed the big bang beginning. 25 June – 13 July Monday to Friday – 13:00   Oceans in Space The search for life in the universe begins deep in Earth’s oceans – and extends out to the stars! Inspired in part by the goals of NASA's Origins Program. 21 July – 28 September • Monday to Friday – 14:00 (excluding 6 and 9 Aug, 3 and 24 Sep)  • Tuesday evening – 20:00 (and sky talk) • Saturday – 14:30 • Sunday – 14:30 • 9 August – 14:30 • 24 September – 14:30

Talks, outings and events The Cape Bird Club Outings and talks Evening meetings are on the 2nd Thursday of every month at 20h00, we meet at The Nassau Centre, Groote Schuur High School, Palmyra Road, Newlands. Visitors and non-members, are very

welcome, tea and biscuits are served afterwards. Thursday 12 July In search of the elusive African Pitta – Otto Schmidt • Thursday 2 August The art of bird photography – Peter Steyn • Saturday 7 July Rondevlei  Leader Merle Chalton on 021 686 8951 • Tuesday 10 July Wildevloevlei, kommetjie Leader Eric Barnes 021 782 5429 • Sunday 15 July Foxenberg Nature Reserve, Wellington. Leader Mike Saunders 021 783 5230 or 082 882 8688 • Saturday 4 August Rondevlei  Leader Merle Chalton on 021 686 8951 • Tuesday 7 August Newlands • Sunday 19 August Blaauberg Conservation Area Leader Elzette Klue, Senior Conservation Officer Co-ordinator Anne Gray 021 713 1231 or 083 311 1140

Diarise World Population Day 11 July 2012 – 7 billion and counting For more than 20 years, 11 July has been an occasion to mark the significance of population trends and related issues. In 2011, as the world population is expected to surpass 7 billion, UNFPA and partners launched a campaign called 7 Billion Actions. It aims to engage people, spur commitment and spark actions related to the opportunities and challenges presented by a world of 7 billion people. In many ways a world of 7 billion is an achievement: Globally, people are living longer and healthier lives, and couples are choosing to have fewer children. However, because so many couples are in, or will soon be entering, their reproductive years, the world population is projected to increase for decades to come. Meeting the needs of current and future generations presents daunting challenges.

Obituary Q

Philip Tobias (14 October 1925 – 7 June 2012) Professor Philip Tobias, one of South Africa’s greatest scientists, died on 7 June 2012. Tobias had a long and illustrious career of over 50 years at the University of Witwatersrand (Wits) and inspired generations of medical and science students. He was internationally renowned for his scholarship and dedication to a better understanding of the origin, behaviour and survival of humanity; for his many major scholarly contributions to palaeoanthropology, anatomy, human biology, cultural anthropology, the evolution of the brain, cytogenetics and the history and philosophy of science. He was nominated for a Nobel Prize three times. Tobias was also renowned for his sustained campaign against racism and for upholding and fighting for human rights and freedoms. In recent years he publicly

54 Quest 8(2) 2012

protested against xenophobia, government’s initial HIV/AIDS policies and government’s delay in granting the Dalai Lama a visa to enter South Africa. Earlier, Tobias was one of the scientists who, in 1953,exposed the 1912 Piltdown Man as a hoax, explaining that an orangutan’s lower jaw bone had been buried in the English site, with a human skull and passed off as a specimen of ancient man. His name is synonymous with the initiation of the research and excavation of the Sterkfontein caves where over a third of all known early hominid fossils has been found. The site is now a World Heritage Site. He is associated at various levels with ‘Mrs Ples’ (Australopithecus africanus), ‘Little Foot’ (the most complete Australopithecus specimen ever found), the ‘Taung child’ (Australopithecus africanus)

Philip Tobias holding the skull of the Taung child. Image: University of Witwatersrand

and ‘Dear Boy’ (Australopithicus boisei) – some of the most famous hominin fossils in the world. He was arguably one of the greatest scientists that South Africa has ever produced and certainly one of the greatest in the world. His contribution to the field of palaeoanthropology was enormous, not least in the number of students, undergraduate and postgraduate, he has trained. He was a true scholar, excptionally well read in a wide variety of fields, not just in science, and held five degrees in the fields of medicine, genetics and palaeoanthropology.

Q SAYAS News The new council of the Global Young Academy. Image: SAYAS/GYA

Global Young Academy wraps up very successful general assembly meeting in Johannesburg, South Africa With a programme headlined by the South African Minister for Science and Technology, the Editor-in-Chief of Science magazine and other luminaries, the Global Young Academy (GYA) recently completed a very successful general assembly meeting. The meeting, held in Johannesburg, South Africa, included 80 young scientists from 40 countries, distinguished senior scientists, and science administrators from around the world. With a theme of ‘Sustainability: Lessons on the road between Rio and Rio+20’, the conference focused on concrete actions young scientists can take to advance a sustainable future. Additionally, the meeting included the founders and founding members of the South African Young Academy of Science (SAYAS), who convened an inaugural meeting to participate in the GYA assembly. Minister Pandor reminded delegates that, ‘Rio+20 is an historic opportunity to define pathways to a sustainable future – a future with more jobs, more clean energy, greater security and a decent standard of living for all’. Young scientists have a particular responsibility towards this, and much of this lies in the arena of engaging with the wider society and policy makers to promote an understanding of what is needed to achieve the goals of sustainability. Other speakers provided examples of how this goal can be accomplished.

Prof Bruce Alberts (Editor-in-Chief of Science magazine and GYA Board Member) made a strong call to scientists to get more actively involved and to care deeply about science education. ‘The future of the world depends on it,’ he said. Current approaches that are focused on simply transmitting lists of facts, can bore children, and does not promote an understanding of how science works and what its value to society is. This needs to change urgently and scientists have a responsibility to get involved in changing educational approaches and perceptions. This is exactly the aim of GYA. In addition to stimulating discussion and action in developing more effective strategies for young scientists to contribute to challenges in sustainability, the General Assembly meeting defined the GYA’s new projects for the upcoming year. In brief, the following examples illustrate a few of the projects developed at the General Assembly meeting. 1 An inquiry-based science game for high school students was first translated into English before a world-wide rollout in other languages. The game was played and tested the day after the meeting with learners in a South African school with disadvantaged children. 2 Several conferences aimed at identifying best practices and creative approaches to science education and outreach along with frontiers in science were planned. 3 By coordinating regional meetings

and other forums of exchange of experience GYA will continue to promote the establishment, development and cooperation of National Young Academies around the world. 4 A project aimed at defining how to measure academic creativity and scientific output was launched. 5 Statements drafted included both the importance of scientific outreach and education in achieving sustainability, and the crucial need for gender equality in scientific research. This includes an urgent call to re-evaluate the systems that promote or suppress these goals within the scientific community. 6 Expansion plans for the GYA’s Young Scientists Ambassador program, which stimulates non-traditional scientific exchange and science-society engagement, were developed. 7 The GYA’s statement on grant writing mechanisms was evaluated, and strategies for improving its impact were developed. GYA members also exchanged their latest scientific results, including new discoveries and insights in quantum materials, open source information, green materials, and genetic analysis. Such science sessions drove the formation of new, interdisciplinary collaborations. Learn more about the GYA at: http://www.globalyoungacademy.net/

Quest 6(3) 2010 55

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56 Quest 8(2) 2012

Q Back page science Robotic arm for the paralysed reported to reach new level of sophistication A new study reports that two paralysed people were able to control a robotic arm through brain signals picked up by a computer system, and use it to make point-to-point reaches and grasps. One patient was able to use the device, which reads electrical nerve signals in the brain through a tiny implant, to pick up a bottle fitted with a straw and drink from it. The devices work by translating brain activity directly into control signals for assistive devices. Previous studies had shown that paralysed people could use such technology to control computer cursors. Monkeys were also found to be able to control a robotic arm using the devices. One of the patients, a 58-year-old woman, used the system to reach and grasp a bottle of coffee, drink from it through a straw, and put it back on the table in four out of six attempts. It was the first time in 14 years that the patient was able to bring any drinking vessel to her mouth and drink from it solely from her own will. Source: World Science, http://www.world-science.net

The researchers had previously found vinclozolin exposure could affect subsequent generations by affecting how genes are turned on and off, a process called epigenetics. In that case, the epigenetic inheritance altered how rats choose mates. Source: World Science, http://www.world-science.net

Light from ‘super-Earth’ reported seen for first time NASA’s Spitzer Space Telescope has detected light from a ‘super-Earth’ planet beyond our solar system for the first time, astronomers report. While that hefty world is not thought to be habitable, scientists call the achievement a historic step toward the search for signs of life on other planets. The planet, called 55 Cancri e, falls into a class of planets called super-Earths, which are heavier than our home world but lighter than giant planets like Neptune. It is about twice as big and eight times as massive as Earth, and hugs its home star – 55 Cancri – in such a tight orbit that its year lasts 18 hours – not even one of our Earth days. Infrared is a type of low-energy light that we feel as heat but cannot see with our eyes. A planet is hard to see in the glare of its parent star when viewed in visible light. However, viewed with cameras that record infrared light, it stands out better. Source: World Science, http://www.world-science.net

UCLA life scientists view biodiversity through a whole new dimension How can blue whales, the largest animals on the planet, survive by feeding on krill, shrimp-like creatures that are the size of a penny? According to UCLA life scientists, it is all a matter of dimensions. In findings published on 30 May in the journal Nature, the researchers demonstrate for the first time that the relationship between animals' body size and their feeding rate – the overall amount of food they consume per unit of time – is largely determined by the properties of the space in which they search for their food. An animal searching for food in a threedimensional space, like the ocean or sky, is likely to consume much more than a similarly sized animal searching in a flat, two-dimensional space, like a savannah or a seabed, they found. The UCLA researchers developed a new mathematical model that predicted that feeding rates increase more quickly with body size in three dimensions than in two. The model helps explain why huge whales can subsist on tiny krill in three dimensions – but probably could not in two dimensions, if they had evolved to live on land. The scientists are currently looking at the effects of temperature – another major driver of feeding rates – and studying how to combine that with the results of the current study on feeding rates and dimensionality. Source: UCLA

The patient can control this prosthetic arm through brain signals. Image: World-science

Your environmental exposures might haunt your great-grandchildren Scientists have found increased stress sensitivity and differences in weight gain in rats whose ancestors were exposed to a hormone-disrupting chemical three generations earlier. The researchers exposed pregnant rats to vinclozolin, a popular fruit and vegetable fungicide known to disrupt hormones. They then put the rodents’ great-grandpups through various tests and found them more anxious, stress-sensitive and prone to greater activity in stress-related brain areas than unexposed rats’ descendants.

As this artist's concept shows, a planet is hard to see in the glare of its parent star – when viewed in visible light. However, viewed in infrared light, the planet stands out better. This is largely because the planet's scorching heat blazes with infrared light. Even our own bodies emanate more infrared light than visible due to our heat. An adult blue whale.

Image: NASA/JPL-Caltech

Image: Wikimedia Commons

MIND-BOGGLING MATHS PUZZLE FOR Q uest READERS Q uest Maths Puzzle no. 21

Win a prize!

In a game of chess, how many different choices do you have for your first move?

Send us your answer (fax, e-mail or snail-mail) together with your name and contact details by 15:00 on Friday, 31 August 2012. The first correct entry that we open will be the lucky winner. We’ll send you a cool Truly Scientific calculator! Mark your answer ‘Quest Maths Puzzle no. 21’ and send it to: Quest Maths Puzzle, Living Maths, P.O. Box 195, Bergvliet, 7864, Cape Town, South Africa. Fax: 0866 710 953. E-mail: livmath@iafrica.com. For more on Living Maths, phone (083) 308 3883 and visit www.livingmaths.com.

Answer to Maths Puzzle no. 20: 1, 2 and 3 1x2x3=6 1+2+3=6 The winner of Maths Puzzle no. 20 was Alta van der Linde, Carnarvon.

Quest 8(2) 2012 57

kids love chemistry Getting the next generations excited about chemistry is important for humankind’s future. That’s why we’ve created “Kids’ Lab” in 15 countries, where the young ones can learn about chemistry and science in a fun, hands-on way. Little students and test tubes finally getting along? At BASF, we create chemistry. www.basf.com/chemistry www.basf.co.za Tel: +27 11 203 2400

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