Issue 1 - June 2020
Exploring
Evolution
This book was written by grade 8 students at the American International School of Mozambique as they were spread around the globe from our shared home in southern Africa during the Covid-19 pandemic. Due to the pandemic we learned together, in our separate homes, oceans apart. It is exciting to see the ideas of a community brought back together in curiosity and wonder.
All of the topics were selected by the students. This writing was created through an outpouring of intellectual energy and ideas. It was written by an amazing group of students, from diverse backgrounds and dierent levels of understanding about evolution. It is a snapshot of young writers making sense of new ideas by reading, writing and sharing their understanding. Researched and written in 3 weeks, this book represents what can happen when students are empowered to share their voices and take ownership of their learning.
Exploring
Evolution
Life on Earth takes millions of different forms. The incredible diversity of life that lives on this planet is complex and the scientists who study it have a variety of scientific theories to explain the interaction and development of this diversity of forms. Evolution is perhaps the most supported by evidence and widely accepted scientific theory from the field of Biology. In 1859, Charles Darwin published his seminal work, On the Origin of Species. In this book Darwin explored the concept of evolution by means of natural selection. This book was based on an amalgamation of ideas and the physical evidence gathered during the circumnavigation of the globe aboard HMS Beagle. Darwin collected specimens of animals, plants, and fungus whenever and wherever the Beagle stopped. Similarities and patterns emerged between organisms collected from all over the world. Darwin sought to explain the mechanism behind the similarities and differences he observed in organisms during his voyage. Scientists use the world theory quite differently than colloquial use. Scientists produce theories to unite and explain vast amounts of observation and experimentation. Theories in science are in not gut feelings or hunches. Rather, they are explanations which are constantly being refined and honed to accurately unite all available evidence. The theory of evolution has been adapted and tweaked since the day when Darwin committed his ideas to paper. However, the revisions have made this theory more accurate and more universally accepted. Scientists pull evidence to explore evolution from multiple different fields. Of this evidence, there are four areas that scientists have traditionally explored. They are: The Fossil Record, Comparative Anatomy, Comparative Embryology, and the evidence of the process of Natural Selection itself.
Please join us in exploring the evidence of evolution from the perspective of grade 8 students.
Contents From the PAST Pages
7- 53
Explores patterns and changes to the body plans of organisms through exploration of the fossils in different time sequences present in the rock layers.
From The BODY Pages
54- 71
Explores the evidence for evolution in terms of the similarity or differences of the major body structures of living or extinct animals.
From before BIRTH Pages
72- 79
Explores the evidence for evolution in terms of the similarities or differences of body structures of embryos as they develop prior to birth.
From SURVIVAL Pages
80-158
Explores the phenomenon of selection and how certain characteristics increases an individuals chances of survival and reproduction.
Section 1
From the PAST Examining the fossil record
| Contents
Fossils
Ayman
Famous Features of Fantastic Fossils
Lucy
14
The World Before Humans Reigned
Maiya
18
Iguanodon Fossil Discovered
Malene
21
The Impact of Dinosaurs on our Planet
Juliet
24
Evidence from the Past: Fossils
Valentine
27
DNA in Fossils?
Sofia
30
Evidence of the First Life on Earth
Margo
37
The Largest T-Rex Skeleton Ever Found
Estela
40
Giant Turtle the Size of a Car
Charlotte
T History of Crocodiles
Nicolas
The Megalodon
Jordan
9
46
48 51
“Trace fossils usually show the tracks of animals that have walked on soft sediment… these types of fossils are very valuable and important because scientists can use that to discover how the animals moved.”
— Ayman
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Fossils
Fossils
By: Ayman Bahadur
Where does the word ossil come rom?
_____Ayman _____
The word ossil comes rom a Latin word ossilis which means du up.Fossils are preserved remains o ancient or anisms. Fossils are the remains o the or anism itsel .(National Geo raphic pa e #1) Fossils can be anythin to plants, to oot prints and to bones o animals and to ancient people, or example, pharos.
Types o
ossils, and how they are ormed.
Types o
ossils.
● Mold or Impression A mold or impression ossils is ormed when an animal or plant decomposes completely and leaves behind an impression, almost like a mold. ● Cast Cast ossils are the type o ossils that are most common to ind, because does types o ossils are the types o ossils people ind o dinosaurs, and are the ones you see in a museum. ● Imprint Imprint ossils are ound in silt, almost like the mold or impression ossils, but instead o leavin a 3 dimensional-print they leave behind a 2 dimensional-print.
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●
Permineneralization In permineralization, ossils every sin le part o the animal is replaced by minerals, and its leaves behind a stone copy o the animal.
●
Trace Trace ossils usually show the tracks o animals that have walked on so t sediment, the sediment hardens leavin a print o the oot print o the animal, these types o ossils are very valuable and important because scientist can use that to discover how the animal moved and that in ormation can be used to see the structure o and the li e o the type o animal.
_____Ayman _____
First Evidence o Li e. ● Hydrothermal vent Precipitates. Accordin to Wikipedia the irst known li e orms on Earth are ossilized microor anisms ound in hydrothermal vent precipitates. The recorded time o the irst evidence o li e on Earth was at least 3.77 years a o.
● Stromatolite. The oldest rocks in the world are in Australia, and the oldest ossils are 3.5 billion years old bacterial colonies known as stromatolites. A stromatolite is a structure similar to the ones made by some o today’s Australian bacteria. It looks like an unassumin lump o rock. But because the bacteria row layer by layer and the minerals as they do, stromatolites have a characteristic spiked
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_____Ayman _____
pattern. Citations: 1. https://thumbs-prod.si-cdn.com/MBJBD7_docdgs1X8ZCKQY8L0Kqs=/fit-in/1600x0/https://pu blic-media.si-cdn.com/filer/e1/d3/e1d3fee9-9aaa-4599-ba67-1c71a6d0ed03/1200px-seymour ia_fossil.jpg 2. https://www.gns.cri.nz/var/ezwebin_site/storage/images/media/images/hydrothermal-vent-dia gram/15719-1-eng-GB/hydrothermal-vent-diagram_imagelarge.jpg 3. Describe the Types of Fossils https://sciencing.com/describe-types-fossils-8147260.html 4. https://www.abc.net.au/news/image/7396740-3x25. Earliest evidence of life on Earth 'found' https://www.bbc.com/news/science-environment-39117523 6.
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“Paleontologists figure out the relationships between extinct plants and animals that once lived on Earth and their living connections/ relatives today.”
— Lucy
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Famous Features of Fantastic Fossils
_____Lucy ____ “Dinosaur Fossils .” Adventure Experience , 31 Aug. 2018, https://adexperience-uploads.s3.amazonaws.com/uploads/2018/08/shutterstock_114610390-1200x766.jpg.
Fossils have fascinated scientists for thousands of years and provide some of the earliest evidence about the existence of living organisms. They have stood the test of time because they do not disappear, leaving an imprint of their structure for modern scientists to use as they explore the evolution of our planet.
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_____Lucy ____
As stated in “ BBC Bitesize” a fossil is the remains of a dead organism that can be identified by the remnants of bones and shells. As time passes by layers of sediment accumulate on top of the organism’s structure and eventually, this hardens and becomes rocks in the shape of the original organism. Fossils are found in rocks and sometimes the remains of animals and plants can be found in amber, peat bogs, tar pits, and ice. People can also identify organisms from imprints like footprints. Preserved traces of organisms such as burrows and rootlet traces become covered with layers of sediments which in the end become rock. This is what we call a fossil. Fossils can be sources of information because us as scientists are able to tell the approximate ages of organisms through them by comparing them to others and also rocks of a similar known age. This is called relative dating. Another example of relative dating is comparing depth of discovery; the deeper in the ground the fossil is, the older it is so if there are two fossils and one is deeper than the other we will know that that fossil is older. According to “ Khan Academy ” , relative depth/dating can only be used when we know the age of one fossil because we need to use the age of that fossil to compare it with another. We can also do something called absolute dating which means finding the precise age of fossils using ways to look at the chemicals found in them. Radioactive dating is one method that scientists use to date a fossil to find the precise age. The scientists that study these fossils are called paleontologists.“Career Explore”claims that paleontologists study the fossilized remains of all kinds of organisms (plants, animals, fungi, bacteria and other single-celled living things), and are interested in knowing the history of organic life on earth. Paleontologists figure out the relationships between extinct plants and animals that once lived on earth and their living connections/relatives today. The main function that these scientists perform is the study of fossils. They use fossils to try to find out why some animals became extinct. Paleontologists may use those methods that we discussed above to figure out the ages of these fossils. There are 7 areas in which paleontologists can study and explore. These are Biostratigraphy, (“the study of vertical disturbances of fossils in rock”), Invertebrate Paleontology (“the study of animals without a backbone”), Paleobotany (“the study of plant fossils”), Micropaleontology (“the study of fossils of single-celled organisms”), Vertebrate Paleontology (“the study of fossils of animals with backbones”), Paleoecology (“the study of ancient ecosystems and how they developed”) and Taphonomy (“the study of how fossils form and are preserved.”)
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_____Lucy ____
All these areas of fossil research are important because in order to really get an understanding of fossils it is very useful to know about all kinds of fossils and the ecosystems that they may have lived in. Paleontologists usually inquire into the location of fossils, look into the layers of sediments of rock to locate the fossil. They use specific tools like drills, picks, shovels, brushes, and chisels. They may also find new discoveries by using specialized computer programs, comparing new with existing data, and can identify time periods of fossil finds. To summarize, we can see that there are a variety of ways to identify fossils and their way of living. Some of these include relative dating and radioactive dating. Paleontologists are experienced experts in this field and the information they provide us with is crucial in helping us to appreciate the past especially living organisms. All these methods of identifying fossils have made them as important as pieces of art admired by millions around the world today.
Full reference list: “Evidence of Evolution - Rock Fossils - Evolution - AQA - GCSE Biology (Single Science) Revision - AQA - BBC Bitesize.” BBC News, BBC, www.bbc.co.uk/bitesize/guides/zcqbdxs/revision/7.
Boundless. “Boundless Biology.” Lumen, courses.lumenlearning.com/boundless-biology/chapter/evidence-of-evolution/. Khan Academy, Khan Academy, www.khanacademy.org/science/in-in-class-10-biology/in-in-heredity-and-evolution/in-in-evoluti on-classification/v/fossil-dating-heredity-evolution-biology-khan-academy .
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_____Lucy ____
CareerExplorer, sokanu. “What Does a Paleontologist Do?” - CareerExplorer, CareerExplorer, 14 Nov. 2019, www.careerexplorer.com/careers/paleontologist/ .
Image Reference list: “Microscope .” Netclipart , 2019, https://pp.netclipart.com/pp/s/113-1139015_science-clipart-microscope-science-clip-art.png . Sisson, Robert. “Palaeontologist .” National Geographic , https://media.nationalgeographic.org/assets/photos/000/283/28322.jpg.
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“Fossils form when an animal dies in water, then is covered by layers of mud and sediment. Over time, more and more layers will form on top and other dead organisms will fossilize as well. The amount of layers corresponds to the age of the rock. Usually the oldest fossils are toward the bottom with the newest fossils at the top.�
— Maiya
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_____Maiya_____
The world before humans reigned. The Mesozoic Era The big bang is the idea that the universe was suddenly born. This idea contradicts with what scientists previously thought, that the earth was endless and infinite. About 4 billion years ago, in a hot dense environment, the earth was created. The first living things were microorganisms, later named prokaryotes. It was then, in the Mesozoic Era 245 and 66 million years ago, where non-bird dinosaurs lived (Kurzgesagt In a Nutshell, 2014). This era was divided into three different ones: Triassic, Jurassic and Cretaceous. At the time, all the continents were connected in a landmass called Pangea (Natural History Museum). The climate was hot and it was made mostly of deserts. Dinosaurs could live in this climate because they were reptiles who adapted to surviving in this type of weather. Their kidneys were better at storing water and their skin was less porous (Natural History Museum). This gave them the advantage of losing less water. In the Jurassic period, Pangea split, creating two different lands: Laurasia and Gondwana. Scientists learned about this because of fossil records showing the same dinosaurs in two different places on earth. Over time, the characteristics of each part of land changed causing it to be cooler in some areas, seas started to rise, rainfall, forests were growing as well as plants and vegetation. In this time, more than 43 different species have adapted to different climates and needs. In the last years of the Mesozoic Era, the cretaceous period, continents were separating and a more diverse species of dinosaurs was forming. The K-T extinction Sixty-six million years ago, the 180 million year period, reigned by dinosaurs, ended. An asteroid that ranged any size from tens to hundreds of meters in diameter crashed into the earth, killing most dinosaurs. The result of this was debris and a dust-filled sky, reducing the amount of light that plants needed to receive in order to continue growing. Herbivores that relied on plants died because they were no longer around, then carnivores had no meat to eat so they did as well. The damage that this did was not only to the dinosaurs- today, we can still see the Chicxulub crater, located in Mexico. Not all species died during this event. It is believed that dinosaurs that could fly have survived and are still around today. Scientists also believe that all crocodilians and reptiles have some relation to dinosaurs through comparative anatomy. Scientists also believe that fish survived the KT extinction and have evolved from fish.
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_____Maiya_____
KARSTEN SCHNEIDER / Getty Images In this image, you can see the meteorites coming down towards earth killing all dinosaurs.
Finding dinosaurs through fossils Fossils are made when an animal dies in water, then is covered by layers of mud and sediment. Over time, more and more layers form on top and other dead organisms will fossilize as well. The amount of layers corresponds to the age of the rock. Usually, the oldest fossils are towards the bottom and the newest at the top. In the centre of London 170 years ago, the first “complete” skeleton of a dinosaur was unearthed. In the 17th century, before geology and palaeontology existed as science, scientists did not want to believe that fossils were the remains of long-dead organisms. As BBC said towards the dinosaurs they found, “All three animals were similar to one another and different from every other animal” Fossils showed us how life was before humans reigned and the différences in life. We also learnt about extinct animals.
Citations: “How Are Fossils Formed?” The Australian Museum, australianmuseum.net.au/learn/australia-over-time/fossils/how-are-fossils-formed/. The Editors of Encyclopaedia Britannica. “K–T Extinction.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 21 May 2020, www.britannica.com/science/K-T-extinction. Barras, Colin. “Earth - Dinosaurs Were Discovered by British Scientists.” BBC, BBC, 3 June 2015, www.bbc.com/earth/story/20150603-the-land-that-gave-us-dinosaurs. “When Did Dinosaurs Live?” Natural History Museum, www.nhm.ac.uk/discover/when-did-dinosaurs-live.html.
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“Iguanadon traveled in herds because fossils were found in groups so that makes us or scientists think that they weren’t traveling alone.”
— Malene
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Iguanodon fossil discovered
_____Malene_____
Iguanodon was 9 meters (30 feet) long, stood nearly 2 meters tall at the hip, and weighed four to five tons. The animal’s fossil was found in 1822, the discovery of this fossil led us, humans, to kick-start our fascination with dinosaurs. According to Britannica, Iguanodon was named for its teeth, whose similarity to those of modern iguanas also provided the dinosaur’s discoverer, the English physician Gideon Mantell, with the first clue that dinosaurs had been reptiles. The people that did the first discoveries were “Mary Ann Mantell (1795-1869) and her husband Dr. Gideon Algernon Mantell (1790-1852), it was recorded that they had found the first evidence of Iguanodon” according to Natural History Museum. Two of the Iguanodon teeth found by Mary Ann Mantell, still embedded in rock. The discovery of this fossil led to proving that the spikes were thumbs rather than horns. But there is still speculation about what they were used for, although scientists can evaluate from fossils that the dinosaur's spikes were large, the bones are not representative of their full size in life According to the Natural History Museum. The discovery of Iguanodon teeth led to a dinosaur discovery after it was scientifically described as a dinosaur, and the first having been Megalosaurus. The pieces that were sent to Belgium and studied by Louis Dollo n the early 21st century it became understood that the remains referred to Iguanodon in England belonged to four different species so that makes that it opened up for more discovery of new dinosaurs, Iguanodon was the second type of dinosaur formally named based on fossil specimens, after Megalosaurus according to Wikipedia. Iguanodon traveled in herds because fossils were found in groups so that makes us or scientists that they weren’t traveling alone. In the 21st century, Iguanodon material is being used in the search for dinosaur biomolecules. The dinosaur fossil was named iguanodon for one reason, the reason is teeth are, as the name suggests, like those of an iguana, but larger. “Unlike hadrosaurids, which had columns of replacement teeth, Iguanodon only had one replacement tooth at a time for each position.”
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Iguanodon was part of the initial work of the dinosaur renaissance that began with the description of Deinonychus in 1969, but it was not that long that they stopped getting neglected because Iguanodon is one of the first dinosaur genera to have been named, numerous species have been assigned to it according to Wikipedia and Britannica.
_____Malene _____
Article creator: Malene Wiinblad Last edited the article: 5/27/2020
Websites: - "Iguanodon - Wikipedia." https://en.wikipedia.org/wiki/Iguanodon. Accessed 25 May. 2020. - "Iguanodon: the teeth that led to a dinosaur discovery | Natural ...." https://www.nhm.ac.uk/discover/the-discovery-of-iguanodon.html. Accessed 25 May. 2020. - "Iguanodon | dinosaur genus | Britannica." https://www.britannica.com/animal/Iguanodon. Accessed 25 May. 2020.
Picture: - "Iguanodon: the teeth that led to a dinosaur discovery | Natural ...." https://www.nhm.ac.uk/discover/the-discovery-of-iguanodon.html. Accessed 25 May. 2020. - "Iguanodon: the teeth that led to a dinosaur discovery | Natural ...." https://www.nhm.ac.uk/discover/the-discovery-of-iguanodon.html. Accessed 25 May. 2020.
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“What are the benefits of studying dinosaurs? To begin, studying dinosaurs allows humans to truly research evolution from start to finish of animals that were at the top of every land ecosystem for 160 million years, as we see mammals today.�
— Juliet
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The Impact of Dinosaurs on Our Planet By Juliet Geers
_____Juliet_____
Life on Earth was once dominated by dinosaurs, but they did far more than merely inhabit prehistoric biomes - they permanently changed the face of our planet. Today, it is commonly believed that dinosaurs were the Earth’s ancient landscapers.
Photograph by Richard Barnes for the New Yorker What are the benefits of studying dinosaurs? To begin, studying dinosaurs allows humans to truly research evolution from start to finish of animals that were at the top of every land ecosystems for 160 million years, as we see mammals today. When studying living animals, we can see only a very small snapshot of the existence of their life on Earth, but without these ancient fossils, humans wouldn’t have a deep understanding of “deep time” - clues about the diversity level of species, rates of extinction over time, and how life has succeeded multiple episodes of mass extinction. Also, Research leads to important information regarding how ecosystems function in different conditions. The study of dinosaurs has led to the discovery of fossilised remains of both dinosaurs and ancient birds and, after many years of debate, now proved that today's birds are descended from dinosaurs, which is a crucial step in our understanding of evolution. Between 135 and 130 million years ago, the Broome Sandstone of Western Australia was covered in swamps and lagoons. The sauropod dinosaurs (a distant cousin of Apatosaurus) had to take care while navigating through these murky habitats. While doing so they unknowingly changed the surrounding landscape. Also, In 2012 paleontologist Tony Thuldborn found foot-shaped potholes made by trundling dinosaurs. Many of these footprints clustered together meaning many of them followed the same route around the edges of the lagoons. Even large animals today (like elephants and giraffes) can change entire environments just by walking and eating. For example, a habitat in which many elephants live is known to look more sparse than an environment where trees are regularly being toppled down. Large animals can also trample down paths when they walk along the same root, otherwise, these paths wouldn’t otherwise exist. Although walking wasn’t the only way dinosaurs shaped the Earth The Maiasaura (aka the “good mother lizard”) deposited their eggs in vast nesting grounds. This likely turned river floodplains and other formerly flat places into very bumpy lands which were especially true when the dinosaurs would return after one season to make bowls that were used to cradle their eggs. Believe it or not, dinosaurs even had dance moves that possibly reshaped the surface of the planet! This was discovered when a group
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of paleontologists reported strange fossil scratch marks that researchers interpreted to be possible mating dances done by the Allosaurus to woo one another. Just as some birds do in the modern world!
_____Juliet____
Citations Black, Riley. “Dinosaurs Literally Reshaped The Planet.” Smithsonian.com, Smithsonian Institution, 15 July 2016, www.smithsonianmag.com/science-nature/dinosaurs-literally-reshaped-planet-180959814/ “Dinosaurs: The Benefits of Research.” The Guardian, Guardian News and Media, 7 Feb. 2009, www.theguardian.com/science/2009/feb/07/dinosaurs-research-palaeontology Jaggard, Victoria. “Why Did the Dinosaurs Go Extinct?” Dinosaur Extinction Facts and Information | National Geographic, 31 July 2019, www.nationalgeographic.com/science/prehistoric-world/dinosaur-extinction/ Image citations Barnes, Richard. “The New Yorker.” The New Yorker, www.newyorker.com/magazine/2019/04/08/the-day-the-dinosaurs-died “My Dinosaurs.” My Dinosaurs, mydinosaurs.com/blog/best-10-dinosaur-drawing-ideas
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“Preserved traces or remains of organisms are called fossils. They can help us see how an organism developed throughout time”
— Valentine
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Evidence From the Past: Fossils What are fossils
_____Valentine_____
Preserved traces or remains of organisms are called fossils. They can help us to see how an organism developed throughout time. Fossils can range in age and they can be as old as planet earth to now! They can also vary in size, from the smallest insect to the largest mammoth. Mineralized portions of the fossil, for example, bones or teeth, is usually what is found when you are looking for fossils. Skin, soft tissues, or feathers can also be traces of fossils. Footprints or feces are also left behind by the organisms and can even now still be discovered. The process of fossilization that occurs when an organism is buried, is called permineralization. (LumenLearning) The organism must be covered by sediment soon after death for permineralization to occur. Fossils provide evidence that in the past, organisms were different or similar to the ones found today. (BBC)
How they provide evidence The progression of evolution is often shown by fossils. Paleontologists can compare the anatomies of modern and extinct species and then infer the lineages of the species. The results of fossil records tell the story of the past and show how the organism has changed throughout time. Now-extinct species’ fossils can document the existence of them and compare the relationship with present day species. Fossils are often contained in rocks that build up layers called STRATA. It provides a timeline with layers near the top being newer, and layers at the bottom being older.
Fossils can also help scientists identify the evolutionary histories of present day species. The horse lineage is one of the best-studied fossils. Using the fossils, scientists have been able to create a branging “family tree� for horses and their now extinct relatives. (KhanAcademy)
Radiometric dating How do we know that the fossils found are from 3 billion years ago and not just 2 years ago? A method called radiometric dating can indicate that. In certain minerals, natural radioactive atoms
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_____Valentine _____
can be found in them. By measuring those atoms, scientists can determine the elapsed time since they were made. This method makes it possible to estimate how long when the organisms or rocks associated with them were formed. According to radiometric dating, earth was formed 4.5 billion years ago. Cyanobacteria (blue-green algae) is one of the earliest fossils to be found by radiometric dating. Ediacara fauna is known as the oldest animal fossil. About 700 million years old. The Ediacara fauna is a small wormlike creature. All of these organisms are different from the ones living now and paleontologists made a phyla to classify them. In the end, fossils record the evidence of evolution and present it in numerous ways. (Britanicca) Citations Websites:
Ayala, Francisco Jose. “The Fossil Record.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 21 May 2020, www.britannica.com/science/evolution-scientific-theory/The-fossil-record. Boundless. “Boundless Biology.” Lumen, 4 Feb. 2017, courses.lumenlearning.com/boundless-biology/chapter/evidence-of-evolution/. “Evidence for Evolution (Article).” Khan Academy, Khan Academy, 28 May 2020, www.khanacademy.org/science/biology/her/evolution-and-natural-selection/a/lines-of-evi dence-for-evolution.
“Evidence of Evolution - Rock Fossils - Evolution - AQA - GCSE Biology (Single Science) Revision - AQA - BBC Bitesize.” BBC News, BBC, www.bbc.co.uk/bitesize/guides/zcqbdxs/revision/7.
Images:
Zell, H. “Equine Evolution.” WikiMedia, 29 Sept. 2010, commons.wikimedia.org/wiki/File:Equine_evolution.jpg. Jarvis, Lisa. “Rock Layers.” WikiMedia, 8 Mar. 2008, commons.wikimedia.org/wiki/File:Rock_strata,_Belhaven_Bay_-_geograph.org.uk_-_718 142.jpg.
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“DNA in fossils have shown us what flora and fauna lived on Earth centuries ago and support evidence for evolution.”
— Sofia
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DNA in Fossils? _____Sofia _____
Fossils are important evidence for evolution because they demonstrate that life on Earth was once different from life found on earth today. The DNA in fossils have helped us discover what animals were living here before, and how they have developed/evolved to the animals they are now. (Evidence of common descent)
What are fossils? The preserved remains or traces of animals, plants, and other organisms from the past are called fossils. They can be found where sedimentary rocks, such as river valleys, cliffs and hillsides, and human-made exposures such as quarries and road cuttings. Some people wonder why some types of fossils are found in deserts, the reason is that many years ago that desert used to be an ocean with many different flora fauna we now know existed (thanks to fossils). A 40 million old whale which was not known existed in that part of the world was found in 2013 in the Southern desert in Peru. (BBC Ancient sea fossils)
(BBC Ancient sea fossils)
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After analyzing the bone structure and putting all the pieces together, scientists drew a sketch of how they thought the whale looked. (Images from BBC Ancient Sea Fossils)
_____Sofia _____
What can we find out about DNA in Fossils? The DNA in Fossils have shown us what flora and fauna lived on Earth centuries ago and support evidence for evolution. In 1993 a weevil was found in India in a forest, scientists opened the amber and tested the DNA. They found out that the weevil was more than 120 million years old. (Can we find DNA in Fossils)
Curculionidae, weevil beetle. Fossil insect in baltic amber.
Where can DNA in Fossils be found? DNA can be found in some fossils due to the ressins of tissue and bone left. According to PBS Eons, DNA can´t be found in every type of fossil and especially not from every time period.
What's the best source for preserving Fossils with DNA? The best source to keep the DNA in fossils is amber: Amber dehydrates the DNA, makes it more stable, the tree resins has antimicrobial properties which keeps the tissues from breaking down. This way fossils can be preserved longer and we can discover new ancient species that were once living on
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Earth. (BBC Ancient Sea Fossils)
_____Sofia _____
Curculionidae, weevil beetle. Fossil insect in baltic amber.
How long can DNA be testable for? Experts knew that such ancient DNA wasn't pristine and perfect because the DNA degraded. DNA degrades all the time, even in living things. The base pairs that form its code are always being changed by different processes. The most common one is depurination. Depurination is caused by water molecules in cells that attach to some base pairs, which makes them more likely to come off. Water is good for cells, but over time it causes damage, also in DNA, although this happens to everyone and is very common. (What can we find in DNA in Fossils)
Scientists wondered how long it took for DNA to degrade to the point where it was no longer readable. 100 years? 100 million years? We know that DNA has a lifetime: marks the amount of time until half the DNA in a
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sample is degraded beyond use.
_____Sofia _____
Different animals have different lifetimes. For example: a bird bones half their lifetime is 521 years.
Best environment to preserve Fossils The best environment to preserve fossils is in cold temperatures with limited fluctuations. It’s better to test the DNA from inside a bone than outside. The less interactions with nature the better the DNA is preserved. This is why testing the DNA from inside of the bone than outside is more successful. (BBC Ancient Sea Fossils)
Reading DNA To read DNA molecules you need a lot of it to make sense of what you are reading. Meaning, you need to make many copies of it, called amplification. The most efficient way to amplify DNA is called PCR, Polymerase Chain Reaction. (What can we find in DNA in Fossils) Polymerase chain reaction is a faster way to make millions of copies of a specific DNA sample, letting experts take a very small sample of DNA and amplify it to a large amount to study in detail. (Polymerase Chain Reaction, Wikipedia)
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_____Sofia _____
(The biology notes)
The DNA in fossils have helped us discover what animals were living here before, and how they have developed/evolved to the animals they are now. (Evidence of common descent)
Citations: Libretexts. “18.5A: The Fossil Record as Evidence for Evolution.� Biology
LibreTexts, Libretexts, 19 Nov. 2019, bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/Book%3A_Ge neral_Biology_(Boundless)/18%3A_Evolution_and_the_Origin_of_Species/18.5%3 A_Evidence_of_Evolution/18.5A%3A_The_Fossil_Record_as_Evidence_for_Evolu tion.
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“Ancient Sea Fossils Found in Peruvian Desert.” BBC News, BBC, 14 Sept. 2013, www.bbc.com/news/av/world-latin-america-24090109/ancient-sea-fossilsfound-in-peruvian-desert. “Can We Find DNA in Fossils?” Can We Find DNA in Fossils?, PBS Eons, 2 Oct. 2018, https://www.youtube.com/watch?v=_nJdWqtMljs .
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“Humans ask themselves a lot of questions. Like when did life start? Scientifics tried to answer that question as best they could using fossils. Even today, fossils continue to give us the pieces of the answer to this question.”
— Margo
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Evidence of the First Life on Earth
_____Margo_____
Humans ask themselves a lot of questions. Like when did life start? Scientifics tried to answer that question as best as they could using fossils. Even today, fossils continue to give us pieces of the answer to this question. What exactly are fossils? Well, when an animal, a plant, or any other living thing dies it gets buried with time under sediments like dirt. When people find the fossilized remains of animals like dinosaurs, it proves that life existed before. How do fossils help us know when life started? There are different ways to determine the age of a fossil. First of all, the deeper the fossil is, the older it is. One way to find out the approximate age of the fossil is by comparing it with other fossils who’s age is known. If you want a more precise age, you can use radiometric dating methods. In this technique, the age is still not exact but at least, it’s more precise than in the first technique. (Fossilera) How are fossils made? When organisms die, they either decay or get buried. They can get buried because of an earthquake, a volcano eruption or,most of the time, underwater. Then, sediments cover what is there until it’s completely buried. It then gets dissolved, bit by bit, and water comes in its place. The water evaporates leaving behind minerals. The cycle repeats itself until it entirely becomes a stone. If the skeleton is not buried, it decays and there is no trace of it left behind. There are other types of fossils. For example, insects and bacterias can be found trapped in resin that got hardened over time. Resin is released by trees and it’s very sticky. Resin doesn’t allow insects or bacterias to decay, so it will stay the same for many years. (Mahesh Shenoy) So to find when life began, scientists need to know how old is the oldest rock they found. For now, the oldest fossil is 3.7 million years ago, and it might go as far as 4.3 billion years ago. Fossils were found in rocks discovered in Nuvvuagittuq supracrustal belt in Quebec, Canada in the year 2004. Mathew Dodd, graduate student at the University College London, said that there are less than five other places in the world with rocks as old as these.
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But, although among the oldest fossils found in the world, the fossilized organisms they contained were surprisingly developed and complex. (Deborah Netburn)
_____Margo_____
This means that life probably started before these organisms and we might not have found the oldest fossils yet, or there are no fossils from the beginning of life. This also means that life on earth initially might have evolved faster than we thought it did. To conclude, we know approximately when life started because of fossils. Although, scientifics are still working on that answer that might never actually be answered. Citations Mahesh Shenoy. “Fossil & their formation.” Online video clip. khanacademy.org. Khan Academy, 2020. Web. May 22 2020. Fossilera. “Dating Fossils – How Are Fossils Dated?” Fossilera, Fossilera.com, 2020, www.fossilera.com/pages/dating-fossils. Netburn, Deborah. “Scientists find what could be the oldest fossils on Earth.” Newsela, newsela.com, August 03 2017, newsela.com/read/oldest-fossil-found/id/27622/. Dodd, Matthew. “This might be the oldest fossil on earth." The New York Times, Carl Zimmer, March 1 2017, static01.nyt.com/images/2017/03/01/science/07ZIMMER1/07ZIMMER1-article Large.jpg?quality=75&auto=webp&disable=upscale.
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“One of the things observed through this study was that Scotty led a considerably violent and brutal life. Scotty’s fossil showed broken ribs, an infected jaw and bite marks on its tail, which were presumed to be inflicted by a rival Tyrannosaurus rex during a fight.”
— Estela
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The Largest Largest T-Rex The T. RexSkeleton SkeletonEver EverFound Found Estela Gonzalez Pacios The largest, longest-living Tyrannosaurus Rex, discovered in 1991, revolutionised the way scientists around the world think about large, prehistoric predators.
_____Estela_____ The Scotty T. rex on display at the Royal Saskatchewan Museum. Callas. “Scotty the T Rex.” Flickr, 1900 Callas, 14 May 2016, www.flickr.com/photos/ callas1900/26985910066/in/photostream/.
In 1991, a group of palaeontologists discovered the largest Tyrannosaurus Rex skeleton in Saskatchewan, Canada. This dinosaur, nicknamed ‘Scotty’, took nearly a decade to excavate, for it was encased in compact, cement-like sandstone. Scotty, found in what is assumed to have been ‘a subtropical coastal place’ (National Geographic, 2019) nearly 68 million years ago, revolutionised the way scientists and palaeontologists thought about large, prehistoric predators. His remarkable size and weight pushes the margin of the maximum T. rex size higher than ever thought it could be. This immense Tyrannosaurus fossil is nearly 42 feet long and presumably weighed 8,870 kilograms (19,500 pounds) when it roamed prehistoric Saskatchewan (Gizmodo, 2019). 65 percent of this specimen has been recovered. This 65 percent includes his skull, hips, some of its ribs, some of its leg bones and some of its tail bones.
Scott Persons’s Study On Scotty’s Fossil Scotty’s fossil was so large and peculiar that it took nearly 30 years to excavate, prepare for analysis and analyse. All in all, these thirty years were worth the effort because scientists and palaeontologists were able to find and study each of Scotty’s remarkable traits, as well as what his lifestyle was like.
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_____Estela_____
Scotty’s study was led by Scott Persons, a famous palaeontologist, and was published in 2019. This study was an in-depth analysis of Scotty’s 66 million-year-old fossil, which revealed many aspects of the T. Rex’s life. One of the things observed through this study was that Scotty led a considerably violent and brutal life. Scotty’s fossil showed broken ribs, an infected jaw and bite marks on its tail, which were presumably inflicted by a rival Tyrannosaurus Rex during a fight. Nizar Ibrahim, a palaeontologist at the University of Detroit Mercy, who wasn't involved with the study, told National Geographic that “It was not an easy life, even for the king of predatory dinosaurs, judging by all these injuries”. Through this T. Rex’s analysis, they were also able to estimate how old Scotty was when he passed. Studying the growth patterns on the dinosaur’s bones, the palaeontologists approximated that it died in its early 30s. This was a shock to everyone, because, by Tyrannosaurus standards, this was an unusually long life. His unusually long life and remarkable size startled everyone and suggested that large predatory dinosaurs, like the T. rex, probably got older and bigger than palaeontologists assumed based on previous fossils found. The Scotty T. rex on display at the Royal Saskatchewan Museum. Ingram, Robert. “Scotty the T-Rex.” Flickr, Robert Ingram, 21 May 2018, www.flickr.com/ photos/79292369@N07/40439071460/in/photostream/.
Scotty’s notorious size has changed the way scientists and palaeontologists think about carnivorous theropods (meat-eating dinosaurs with hollow bones and three-toed limbs). Being the largest Tyrannosaurus Rex ever found, and the largest dinosaur ever found in Canada, his size might have left people with more questions than answers... To identify Scotty’s original weight (before passing), Scott Persons and his colleagues relied heavily on the size of his femur. By studying many living animals, scientists have found that the wider an animal's femur, the more weight the bone could hold up. Scotty's femur was calculated and found to be eight inches wide, which suggested that Scotty's two legs could hold up more than 8,870 kilograms (nearly 10 tons!). This means that Scotty was 8,870 kilograms in size. However, this bone-measuring method isn't fully reliable. Many animals don't relentlessly use their bones to hold up their weight. Their bones also support the forces of motion.
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_____Estela_____ The Scotty T. rex on display at the Royal Saskatchewan Museum. Ingram, Robert. “Scotty, T-Rex.” Flickr, Robert Ingram, 21 May 2018, www.flickr.com/photos/ 79292369@N07/40439067570/in/photostream/.
Amid the identified species, the T. rex is one of the best represented extinct dinosaurs, with more than 20 fossil individuals found. This is why it was convenient and helpful for Scott Persons to do up to eleven comparative analyses with Scotty’s fossil and other T. rex skeletons. In fact, Scott’s study was the first to compare the specimen to other known T. rex fossils. They compared Scotty to the famous “Sue,” who was once considered the largest T. rex fossil ever found. Sue, discovered in 1990 in South Dakota, weighed 8,460 kilograms. This means that Sue is around 5 per cent lighter than Scotty. Although the size difference between Scotty, Sue and the other T. rex fossils isn’t too broad, and the calculated size of each individual may be inaccurate, Scotty still pushes the margin of the maximum T. rex size higher than previously thought. "This is the rex of rexes," Scott Persons said in a statement. "There is considerable size variability among Tyrannosaurus. Some individuals were lankier than others and some were more robust. Scotty exemplifies the robust.”
How Fossils Such as Scotty’s Further our understanding of the History of Life and Evolution The discovery of fossils, such as Scotty’s, provide us with information that transforms the way we think about the history of life. All the fossils found around the world are part of the fossil record. The fossil record shows that prehistoric (now-extinct) organisms were very different in structure and appearance from any now. It also shows changes in organisms through time, showing their transition from one form to another. There are many methods that make it possible to estimate the time period when the rocks, and the fossils found within them, were formed. One method is radiometric dating and using it, scientists have calculated that Earth was formed about 4.5 billion years ago (Ayala). These methods along with fossils help us understand the history of life and evolution in three main ways.
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Essentially, the discovery of fossils, such as Scotty, further our understanding on the fact that the animals and plants of our planet haven’t always been the same, and that they have changed in many ways over time. This huge Tyrannosaurus has forever changed our knowledge on large, prehistoric predators and prehistoric life as a whole.
_____Estela_____ The Scotty T. rex on display at the Royal Saskatchewan Museum. Callas. “Scotty the T Rex.” Flickr, 1900 Callas, 14 May 2016, www.flickr.com/photos/ callas1900/26925283472/in/photolist-H2i7Ho-2h22kMh-2hPEyHs-HyT1Tn-aomUou-6FCxGV-2gzVGAy-26gpsTo-2gGcicrH7DQTu-24BsP51-4RHh2x-J4qyxX-bVrecQ-ap6otm-24BsMUW-iUyvnj-kcMFm-DsCY4e-2h1WU7w-6FGCEU-foim8YRHJwh9-3kq1qY-3KCPj9-w9ETy1-x6G5jP-ipFZTh-ipGJ3X-ipGK56-ipFYoU-ipFWPG-ipFwVw-ipFuih-ipFn6R-ipFGBK-ipFHzB-ipGBHTipFsHS-ipGFcg-ipGvgV-ipGs2i-ipFLSQ-ipFgP9-ipGxJF-ipFNer-ipFHMD-ipFSoE-ipEZQo-fo4aSk.
Scotty, the Peculiar and Immense Dinosaur Scotty is the largest, oldest T. Rex to have ever been unearthed. Scotty isn’t just big, he is unique for his battle scars and bone structure too. Just as Scott Persons said, “The big thing that everyone is talking about is just how large this particular individual is, but my favourite part of the specimen is actually the smaller details—the little bits of weirdness.” Nevertheless, his remarkable size and weight pushed the margin of the maximum T. rex size higher than ever thought it could be and revolutionized scientists’ and palaeontologists’ knowledge on large, prehistoric predators. At the moment, Scotty is on display at the Royal Saskatchewan Museum.
More information on this extraordinary fossil can be found at Gizmodo.com, National Geographic.org and The Anatomical Record’s online library.
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References _____Estela_____
Websites: Greshko, Michael. “World's Biggest T. Rex Discovered.” National Geographic, National Geographic, 26 Mar. 2019, www.nationalgeographic.com/science/2019/03/worlds-biggest-t-rex-found-in-canada-scotty-dinosaur/.
Pruitt, Sarah. “Canadian T. Rex Is Officially the Biggest Ever.” History.com, A&E Television Networks, 26 Mar. 2019, www.history.com/news/worlds-biggest-t-rex-canada-scotty-dinosaur.
Vega, Elijah. "Paleontologists discover world's heaviest Tyrannosaurus rex." UWIRE Text, 28 Mar. 2019, p. 1. Gale General OneFile, https://link.gale.com/apps/doc/A580558323/GPS? u=aismozam&sid=GPS&xid=ba8131fb. Accessed 24 May 2020.
"Scientists claim Canada's 'Scotty' world's largest T. rex." Xinhua News Agency, 27 Mar. 2019. Gale General OneFile, https://link.gale.com/apps/doc/A580197667/GPS?u=aismozam&sid=GPS&xid=ee09475d. Accessed 24 May 2020.
Ayala, Francisco Jose. “Evolution.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 21 May 2020, www.britannica.com/science/evolution-scientific-theory.
"Fossil record." Britannica School, Encyclopædia Britannica, 21 Jan. 2011. school.eb.co.uk/levels/advanced/ article/fossil-record/101225. Accessed 24 May. 2020.
Dvorsky, George. “Gigantic T. Rex Skeleton Found in Canada Is Officially World's Biggest.” Gizmodo, Gizmodo, 26 Mar. 2019, gizmodo.com/gigantic-t-rex-skeleton-found-in-canada-is-officially-1833547406.
Images: Callas. “Scotty the T Rex.” Flickr, 1900 Callas, 14 May 2016, www.flickr.com/photos/callas1900/26985910066/ in/photostream/.
Ingram, Robert. “Scotty the T-Rex.” Flickr, Robert Ingram, 21 May 2018, www.flickr.com/photos/ 79292369@N07/40439071460/in/photostream/.
Ingram, Robert. “Scotty, T-Rex.” Flickr, Robert Ingram, 21 May 2018, www.flickr.com/photos/ 79292369@N07/40439067570/in/photostream/.
Svec, Petr. “Scotty the T-Rex.” Flickr, Petr Svec, 14 July 2018, www.flickr.com/photos/darkwulf/48368907987/.
Callas. “Scotty the T Rex.” Flickr, 1900 Callas, 14 May 2016, www.flickr.com/photos/callas1900/26925283472/ in/photolist-H2i7Ho-2h22kMh-2hPEyHs-HyT1Tn-aomUou-6FCxGV-2gzVGAy-26gpsTo-2gGcicrH7DQTu-24BsP51-4RHh2x-J4qyxX-bVrecQ-ap6otm-24BsMUW-iUyvnj-kcMFm-DsCY4e-2h1WU7w-6FGCEUfoim8Y-RHJwh9-3kq1qY-3KCPj9-w9ETy1-x6G5jP-ipFZTh-ipGJ3X-ipGK56-ipFYoU-ipFWPG-ipFwVw-ipFuihipFn6R-ipFGBK-ipFHzB-ipGBHT-ipFsHS-ipGFcg-ipGvgV-ipGs2i-ipFLSQ-ipFgP9-ipGxJF-ipFNer-ipFHMDipFSoE-ipEZQo-fo4aSk.
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“This enormous creature lived in a lake(s), but, now it’s the Andes. ”
— Charlotte
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GIANT TURTLES THE SIZE OF A CAR DISCOVERED IN SOUTH AMERICA _____Charlotte_____
Edwen Cadena is a scientist who discovered a fossil the size of a car. This fossil is a giant turtle that goes back 5 million years ago. They found the fossil of the Stupendemys geographicus in The Andes mountain range. They discovered this extinct species in the 1970s and didn’t know much about them until now! This enormous creature apparently lived in a lake(s), but now it’s The Andes. The scientists were surprised when they found out that apparently, the male Stupendemys had horns! Meaning, they would fight. These giant turtles died around 5 million years ago. You see, the world doesn’t exactly last forever; the area turned into a mountain, which dried up all the lakes. These magnificent creatures became slowly but surely into fossils. Works Cited
“Turtles the Size of a Car Once Roamed Earth; Scientists Just Found Their Fossils.” Newsela, newsela.com/read/giant-turtle-fossils/id/2001005653/?collection_id=341&search_id=0c4d36441bf4-4ea8-b320-627a2570589e.
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“Crocodiles are viewed as the nearest living family members of the dinosaurs. They have numerous dinosaur-like highlights including fowl-like courses of action of the hip bones, and teeth that are mounted in attachments instead of being melded straightforwardly to the jawbone. ”
— Nicolas
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History of Crocodiles
_____Nicolas_____
Crocodiles are enormous semi oceanic reptiles that live all through the tropics in Africa, Asia, the Americas and Australia. Crocodylinae, the entirety of whose individuals are viewed as obvious crocodiles, is named a natural subfamily. Crocodiles have been around for 240 million years, seeming 25 million years before the primary dinosaurs and 100 million years before the principal fowls and warm blooded animals. Crocodiles that lived 230 millions years back were up to 40 feet in length. Crocodiles are viewed as the nearest living family members of dinosaurs. They have numerous dinosaur-like highlights including fowl-like courses of action of the hip bones, and teeth that are mounted in attachments instead of being melded straightforwardly to the jawbone. Ongoing ordered investigation has contemplated that dinosaurs, crocodiles and winged creatures ought to be arranged in a similar part of creatures. Toward the start of the Mesozoic Era, known as the Triassic Period, there were no crocodiles, just dinosaurs. This period started around 237 million years back and endured around 37 million years. Archosaurs, the crocodile's most established family member, were among the many plant-eating dinos that flourished during this period. Archosaurs looked particularly like crocodiles, then again, actually their noses were situated on the highest points of their heads instead of the tips of their noses. These reptiles remained alive on marine living beings in freshwater lakes and waterways around the world. Among the most important phytosaurs were Rutiodon and Mystriosuchus. The last piece of the Mesozoic Era, the Cenozoic Period, started around 145 million years back and went on until around 65 million years prior. It was during this last epic that the advanced crocodile, Crocodylidae, first showed up as a particular animal type and thrived. However, the crocodile family tree likewise forked around 100 million years prior, with the presence of the huge Sarcosuchus, which estimated around 40 feet in length from head to tail and weighed around 10 tons. There was likewise the marginally littler Deinosuchus, which was around 30 feet in length. In spite of their fearsome mass, these mammoth crocodiles presumably remained alive to a great extent on snakes and turtles.
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Reference list: ●
_____Nicolas_____
●
Hays, J., 2020. CROCODILES: THEIR HISTORY, CHARACTERISTICS AND BEHAVIOR | Facts And Details. [online] Factsanddetails.com. Available at: <http://factsanddetails.com/asian/cat68/sub434/item2435.html> [Accessed 31 May 2020]. The Conversation. 2020. Climate Change Created Today's Large Crocodiles. [online] Available at: <https://theconversation.com/climate-change-created-todays-large-crocodiles-121933> [Accessed 31 May 2020].
Picture list ●
The Conversation. 2020. Climate Change Created Today's Large Crocodiles. [online] Available at: <https://theconversation.com/climate-change-created-todays-large-crocodiles-121933> [Accessed 31 May 2020].
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“The shark became extinct around 2.6 million years ago when the whole planet started to cool down. ”
— Jordan
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The megalodon What is the megalodon?
_____Jordan_____
The megalodon is the biggest shark to ever exist. Megalodon fossils can date back to 20 million years ago. The sharks roamed the seas for 13 million years and before becoming extinct 3.6 million years ago. The megalodon is three times longer than the world record largest great white shark, it can grow from 15 to 18 meters long. They are so large that their teeth are 18 centimeters long. The meaning of megalodon is "large tooth". Large shark, large appetite. The megalodon ate a lot of things for breakfast, lunch, and dinner. It would eat around a ton of seafood a day to stay healthy. This would include things like the humpback whale to dolphins. With how large the teeth on the megalodon were, it would have to eat smaller whales or even large fish in order for the megalodon to eat something like a whale it would have to open its mouth to as large as 2.7 to 3.4 meters.
Teeth. Its jaws are lined with 276 serrated teeth allowing the shark to pretty much destroy any sea animal that gets in its way. The teeth of a megalodon can grow to sizes of 7 inches. The largest shark tooth in the world is 7.48 inches.
When did it go extinct? The shark became extinct around 2.6 million years ago when the whole planet started to cool down. This was one of the biggest weaknesses that the shark had when the planet cooled it kill many different sea creatures. Scientists say that about a third of large marine animals were killed because of the difference in temperature many come from the tropic waters where the water is warmer. This is where the megalodon hung around and ate a lot of the animals that live in those waters when they all died the shark couldn't eat as much as it needed to survive.
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Citations:
_____Jordan_____
Davis, Josh. “Megalodon: The Truth about the Largest Shark That Ever Lived.” Natural History Museum, The Trustees of The Natural History Museum, London, www.nhm.ac.uk/discover/megalodon--the-truth-about-the-largest-shark-that-ever-lived.htm l. Accessed 4 June 2020. “10 Killer Megalodon Shark Facts.” FossilEra, www.fossilera.com/pages/megalodon. Accessed 4 June 2020. W, Kate. “Ficheiro:Megalodon Teeth.Jpg.” Wikipedia, pt.m.wikipedia.org/wiki/Ficheiro:Megalodon_teeth.jpg.
27
Dec.
2008,
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Section 2
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From the BODY
| Contents
Comparative Anatomy
The History of Horseshoe Crabs
Lauren
56
61
Similarities Between Dinosaurs and Modern Day Birds
Jaan
The Evolution of Human Bone Structure
Henry
Comparative Anatomy
Misa
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64 68
“It is believed that as a whole group, horseshoe crabs have been around for more than 430 million years . Their body structure has barley changed in the last 150 million years .”
(Editors of Encyclopedia Britannica)
(Xia Xuhua 87)
— Lauren
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_____Lauren ____
1. The History of Horseshoe Crabs x
Lauren Fox
Abbey Green Have you ever heard of a horseshoe crab or Xiphosura? Whether you have or not, you’re in for a surprise… maybe. Here goes: The horseshoe crab is not actually a crab at all! Scientists have been trying to find out what they’re related to, and the quest is still underway (University of Wisconsin-Madison). If you haven’t heard of these fascinating creatures, here’s an overview. Horseshoe crabs are in the Arthropod Phylum. This means they are invertebrates and have jointed legs. (Buz Wilson) There are four species total. They live in the Indo-Pacific area and the coastlines of North America and the Gulf of Mexico. These females are one third bigger than the male. (“Horseshoe Crab | National Wildlife Federation.”) Horseshoe crabs are an example of keystone species as their eggs provide food for many birds, turtles, and fish.(“Horseshoe Crab | National Wildlife Federation.”) They eat worms, clams, and sometimes algae. The horseshoe crab has no teeth, so it crushes its food with its legs before eating. (“Horseshoe Crab | National Wildlife Federation.”)One common myth about horseshoe crabs is that their tails are dangerous. They are actually not dangerous; it is used to try to flip themselves over. (“Horseshoe Crab | National Wildlife Federation.”)
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_____Lauren ____
Horseshoe crabs are one of the oldest species on earth. One species of horseshoe crab has a similar fossil that appeared to be 450 years old. (University of Wisconsin-Madison) It is believed that as a whole group, horseshoe crabs have been around for more than 430 million years (Editors of Encyclopaedia Britannica). Their body structure has barely changed in the last 150 million years (Xia Xuhua, 87). Xai Xuhua wrote, “These species of horseshoe crabs, in spite of their wide geographic distribution, exhibit few morphological [structural] differences, and are also very similar to a fossil specimen Mesolimulus (Mesolimulus walchi).” (Xia Xuhua, 87) Horseshoe crabs are not crabs, but are related to scorpions, spiders, and trilobites. (Editors of Encyclopaedia Britannica) These exotic creatures have evolved so little that right now, there are only 4 different species: T. gigas, T. tridentatus, and C. rotundicauda are the three species of horseshoe crabs categorized together because they live in the Indo - Pacific region. L. polyphemus is the fourth one, and lives along the eastern coast of north america and the gulf of mexico (Xia Xuhua, 87). Each species obviously has differences from each other, but the whole order of Xiphosura has very unique anatomy. Their hard horseshoe-shaped exoskeleton misleads people to think that they’re more like crabs. Another one-of-kind quality of the horseshoe crabs is their book gills. These gills set them apart from any other marine animal (University of Wisconsin-Madison). The gills are very similar to book lungs that scorpions and spiders use on land. These two parts of their anatomy have relationships to two different possible ancestors. For the longest time everyone thought that horseshoe crabs were relatives of crustaceans, hence the name horseshoe c rab. In 1881 E. Ray Lankester realized that horseshoe crabs are more similar to scorpions and spiders than crabs (University of Wisconsin-Madison). After that most scientists took that point of view and thought that the horseshoe crab was a descendant of an arachnid. Throughout their quest on the
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_____Lauren ____
horseshoe crabs, there have been many methods of testing to try to discover the past of these arthropods (the phylum of invertebrates with exoskeletons and jointed legs(Buz Wilson)). Scientists have tested through genetic comparison. Unfortunately they have found that genetic studies can be misleading. Some evidence suggests possible connections where none exist or dissolve relationships that were once there. There are other flaws with some experiments. Parshant Sharma said that some “evolutionary biologists may be inclined to cherry-pick the data that seem most reliable, or to toss out data that don't seem to fit. Researchers could, for example, ‘force’ their data to place horseshoe crabs among crustaceans” (University of Wisconsin-Madison). Kamaruzzaman Yunus, Akbar John, Zaleha Kassim, and KCA Jalal did some genetic experiments on horseshoe crabs with the same question in mind: What are horseshoe crabs and what did they come from? These scientists tested their genes. More specifically the percentage of GC content in each animal. (GC content is the percentage of the nitrogen bases in RNA and DNA.) They found that beetles had more genetic similarities and common crabs had higher genetic distance to horseshoe crabs. Insects have a higher genetic similarities with horseshoe crabs indicating that they might be descended from aquatic insects. (Yunus et al. 307) An example of aquatic insects is eurypterids (extinct aquatic scorpions). Eurypterids have traditionally been considered closely related to horseshoe crabs. Some studies show that Eurypterids are related to land scorpions. (Yunus et al. 307) This connection could relate horseshoe crabs with scorpions but in genetic tests, scorpions are not similar to horseshoe crabs. This separates the three into Arachnida (spiders), Eurypterids (extinct water scorpions), and Xiphosura (horseshoe crabs). Horseshoe crabs are more genetically related to beetles than to land scorpions. (Yunus et al. 307) Xia Xuhua did another genetic experiment on all four species of horseshoe crabs to try to find relationships between each of them. L. polyphemus had the most difference between all of the horseshoe crab species as they had the highest percentage of GC content. (Kamaruzzaman Yunus, Akbar John, Zaleha Kassim, and KCA Jalal, 305) Xia found that T. gigas and T. tridentatus are similar in their structure. While C. rotundicauda and T. tridentatus are related in their amino acid sequence. The cardiac muscles are similar in the T. gigas and C. rotundicauda. While the two horseshoe crabs with the most similar skeletal muscles are T. tridentatus and T. gigas. (Xia Xuhua, 87)
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After going through genetic comparison, scientists are leaning toward the possibility of horseshoe crabs descending from beetles. Though I am not qualified, I think the horseshoe crabs are descendants of the eurypterids.
_____Lauren ____
Works Cited Editors of Encyclopaedia Britannica. “Horseshoe Crab.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 15 Oct. 2018, www.britannica.com/animal/horseshoe-crab. “Horseshoe Crab | National Wildlife Federation.” National Wildlife Federation, 2020, www.nwf.org/Educational-Resources/Wildlife-Guide/Invertebrates/Horseshoe-Crab. Accessed 28 May 2020. Trivedi, Subrata, et al. DNA Barcoding in Marine Perspectives Assessment and Conservation of Biodiversity. Springer International Publishing, 2018. University of Wisconsin-Madison “Study Confirms Horseshoe Crabs Are Really Relatives of Spiders, Scorpions.” EurekAlert!, March 8 2019, www.eurekalert.org/pub_releases/2019-03/uow-sch030819.php. Accessed 20 May 2020. Wilson, Buz, “What Are Arthropods?” The Australian Museum, 2020, australianmuseum.net.au/learn/animals/what-are-arthropods/. Accessed 25 May 2020. Xuhua Xia, Phylogenetic Relationship Among Horseshoe Crab Species: Effect of Substitution Models on Phylogenetic Analyses, Systematic Biology, Volume 49, Issue 1, 1 January 2000, Pages 87–100, https://doi.org/10.1080/10635150050207401 Yunus, Kamaruzzaman & John, Akbar & Kassim, Zaleha & Jalal, KCA. (2011). Molecular Phylogeny of Horseshoe Crab. Asian J. Biotechnol. 3. 302-309. 10.3923/ajbkr.2011.302.309.
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“Archaeopteryx and Velociraptor, despite the size of their features, both have been found to have had: wishbones, feathers, breastbones, wrists with a curved/ crescent-shaped bone and legs with 3 toes with the middle toe being the longest. So, next time you see one of the feathery animals, remember that these are the dinosaurs of the world today.”
—Jaan
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Similarities Between Dinosaurs and Modern Day Birds _____Jaan ____
By Jaan Merz
It may not look so, but birds and dinosaurs have many common features and it is thought that perhaps some surviving dinosaurs evolved into the birds of today. In fact there is evidence to support this claim, there is also evidence that dinosaurs were not all scales like you see in Steven Spielberg's Jurassic Park, but they might have had feathers just like birds. This is an illustration made by National Geographic Creative, it shows an ancestor of the Tyrannosaurus called the Guanlong which habited areas in modern day China 160 million years ago in the Oxfordian period (Late Jurassic).
This photograph, taken by Robert Clark of National Geographic Creative, shows a fossil of Epidexipteryx, this was a small dinosaur that lived in the Callovian period, Middle Jurassic(164-161 million years ago). In this fossil you can see that this small dinosaur once displayed feathers on its body.
Another example of feathered dinosaurs is a primitive bird called Archaeopteryx, which was an animal that was found to have traits of both modern day birds and theropod dinosaurs. For example, comparing the Archaeopteryx and a Velociraptor, despite the size of their features, both have been found to have had: wishbones, feathers, breastbones, wrists with a curved/crescent-shaped bone and legs with 3 toes with the middle toe being the longest. So next time you see one of the feathery animals, remember that these our the dinosaurs of our world today.
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Citations:
_____Jaan ____
● Vergano, Dan. “Birds Evolved From Dinosaurs Slowly-Then Took Off.” National Geographic, National Geographic, 25 Sept. 2014, www.nationalgeographic.com/news/2014/9/140925-bird-dinosaur-evolution-burst-scie nce/. ● “Linking Birds and Dinosaurs (Article).” Khan Academy, Khan Academy, www.khanacademy.org/partner-content/amnh/dinosaurs/what-is-a-dinosaur/a/linkin g-birds-and-dinosaurs.
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“Another factor that played a massive role in the path of human evolution is the brain size. One of modern day human’s defining features is our brain to body size ratio.”
— Henry
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The Evolution of Human Bone Structure Evolution of Human Bone Structure By Henry Smith
An representation of human evolution over time (fig 1)
_____Henry____
Evolution is a crucial piece in the puzzle of our past, it gives an explanation as to why so many creatures have similar features, like lungs, or livers. An important part of the whole idea of evolution, is the evolution of us, humans. Humans did not simply change from a prehistoric ape to a human, they evolved slowly, and over many generations, and species. This long evolutionary process results in what is here today, homo sapiens. Over the years humans have changed a lot (see fig 1) but what changed on the inside. An important characteristic of modern day humans is our ability to walk on two legs. About 10 million years ago, an ape, Rudapithecus hungaricus, developed a flexible and long lower back, which may have allowed it to walk on two legs (Barras). This ape may have been the predecessor to all bipedal apes and humans. An image of an 8-9 year old Homo erectus male (fig 2)
Humans have also evolved with the climate, and environment around us. For example, Homo erectus (see fig 2) was very tall, this was because it was easier for them to shed heat. They also had very slender bodies which also allowed them to better shed heat (Smithsonian’s National Museum of Natural History). Another example of an ancestor who adapted to its climate is Homo neanderthalensis. Homo neanderthalensis was much shorter than Homo erectus standing at only 5” 4 or 1.63 meters on average (Smithsonian’s National Museum of Natural History). This is a comparison to Homo erectus that stands on average at 6” (1.85 meters). A chart that shows the human brain size vs time (fig 3)
Another factor that played a massive role in the path of human evolution is the brain size. One of modern day humans defining features is our brain to body size ratio. How did humans acquire this unusually large brain, over years and years of evolution (see fig 3). As you can see in figure 3, the more time that passes, the bigger the brain size becomes in our ancestors. For example, Homo erectus has a brain size of 900 cc while Homo sapiens has an average size of 1400 cc (The Physical Characteristics Of Humans). The last thing that has drastically changed in humans evolution is our jaw structure and our teeth. If you look at modern day humans, they
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_____Henry____
generally have much smaller teeth and much less robust jaws (UCL). For example Neanderthals from 30,000 years ago, have much bigger incisor (the four front teeth in humans), and canines (the 2 teeth on either side of the incisors) (UCL) (Watson). Another interesting thing that we see when looking at ancient human teeth is that the wear on the teeth is much higher (UCL). Archeologist have found evidence of this in ancient human hunters and gatherers like the Inuit and Australian aborigine people (UCL). The archeologist also noted that they found evidence that many middle-aged ancient humans, had their teeth already worn down to the roots (UCL). Things like this very uncommon in modern day dentistry and goes to show how different ancient humans were to us (UCL). Overall the change in humans through the course of evolution has been drastic, humans have adapted to be taller and shorter depending on the climate. Humans have also had massive improvements in the size of our brains. Sources: Barras, Colin. “Ancient Ape Offers Clues to Evolution of Two-Legged Walking.” Nature, 6 Nov. 2019, 10.1038/d41586-019-03418-2. Accessed 11 Nov. 2019. Britannica. “Cranial Capacity of Members of the Human Lineage The Increase in Hominin Cranial Capacity over Time.,” Www.Britannica.Com, 2012, cdn.britannica.com/93/393-05012C6DE14/increase-capacity.jpg. Accessed 26 May 2020. Dresner, Marion. “Human evolution.” The Gale Encyclopedia of Science, edited by K. Lee Lerner and Brenda Wilmoth Lerner, 5th ed., Gale, 2014. Gale In Context: Science, https://link.gale.com/apps/doc/CV2644031138/SCIC?u=aismozam&sid=SCIC&xid=63ac75b6. Accessed 26 May 2020. Human Evolution Timeline. “A Image Showing the Evolution of Humans Using a Tree Chart,” Human Evolution Timeline, humanevolutionofficial.weebly.com/#PhotoSwipe1416814376779. Accessed 26 May 2020. Smithsonian Natural History Museum. “Image of Skeleton, Front View, WT 15000,” Smithsonian Natural History Museum, 19 May 2020, humanorigins.si.edu/sites/default/files/erectus_KNMERWT15000_Skeleton_front_CC_p.jpg. Accessed 26 May 2020. Smithsonian’s National Museum of Natural History. “Bodies.” The Smithsonian Institution’s Human Origins Program, Mar. 2010, humanorigins.si.edu/human-characteristics/bodies. Accessed 7 Nov. 2019. Smithsonian’s Natural History Museum. “Brains.” The Smithsonian Institution’s Human Origins Program, 22 Dec. 2009, humanorigins.si.edu/human-characteristics/brains. Accessed 26 May 2020.
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The Physical Characteristics Of Humans. “The Physical Characteristics of Humans - Brain Size.” OldWww.Wsu.Edu, old-www.wsu.edu/gened/learnmodules/top_longfor/phychar/02_brain_size.html. Accessed 26 May 2020. UCL. “Function and Form of Teeth in Human Evolution.” Institute of Archaeology, 22 Jan. 2019, www.ucl.ac.uk/archaeology/research/directory/function-and-form-teeth-human-evolution.
_____Henry____
Watson, Stephanie. “What Are the Different Types of Teeth Called?” Healthline, Healthline Media, 10 May 2018, www.healthline.com/health/teeth-names. Accessed 29 May 2020.
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“There are many forms of evidence for evolution. One of the strongest forms of evidence is comparative anatomy; comparing structural similarities of organisms to determine their evolutionary relationships.”
— Misa
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Comparative ComparativeAnatomy Anatomy By Misha Petrovic
_____Misa____
Comparative anatomy involves comparing the body structures of two species. 'Comparative' means to look at the similarities between two things, and 'anatomy' has to do with the structure of the body. Scientists can look at anatomical structures of seemingly unrelated animals to tell how related they are. There are many forms of evidence for evolution. One of the strongest forms of evidence is comparative anatomy; comparing structural similarities of organisms to determine their evolutionary relationships. Organisms with similar anatomical features are assumed to be relatively closely related evolutionarily, and they are assumed to share a common ancestor. As a result of the study of evolutionary relationships, anatomical similarities and differences are important factors in determining and establishing the classification of organisms. Some organisms have anatomical structures that are very similar in embryological development and form, but very different in function. These are called homologous structures. Since these structures are so similar, they indicate an evolutionary relationship and a common ancestor of the species that possess them. A clear example of homologous structures is the forelimb of mammals. When examined closely, the forelimbs of humans, whales, dogs, and bats all are very similar in structure. Each possesses the same number of bones, arranged in almost the same way. While they have different external features and they function in different ways, the embryological development and anatomical similarities in the form are striking. By comparing the anatomy of these organisms, scientists have determined that they share a common evolutionary ancestor and in an evolutionary sense, they are relatively closely related.
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_____Misa____ Comparative anatomy explores and establishes the correspondences between body parts of organisms from different species. It builds the concepts of the living structures and thus must not be confused with morphology (the study of the forms and their variations) nor with Evo-Devo (the study of the relations between the genetics of the development and evolution). Without comparative anatomy, naming, and understanding what can be seen in organisms would be impossible. Then, neither descriptive embryology, causal embryology, phylogeny, palaeontology nor systematics could be conducted and the understanding of both biology and evolution of species would be dead-end streets. Examining several organisms, we can establish functional correspondences (as between a wing of a fly and one of a pigeon) and correspondences of origin (as for a wing of a fly and one of a mosquito). These must not be confused, because they are different. Comparative anatomy is the study of both the functional adaptation, where the first type of correspondences plays the main role and the phylogeny, where it is assumed that the second type of correspondences is important.
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Citations:
_____Misa____
● The Editors of Encyclopaedia Britannica. “Comparative Anatomy.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 16 Jan. 2020, www.britannica.com/science/comparative-anatomy. ● STUDY.COM, study.com/academy/lesson/what-is-comparative-anatomy-definition-ex amples.html. ● “Comparative Anatomy.” Structures, Evolutionary, Organisms, and Common - JRank Articles, science.jrank.org/pages/348/Anatomy-Comparative.html. ● “The Importance of Comparative Anatomy.” AcanthoWeb, www.acanthoweb.fr/en/content/importance-comparative-anatomy. ●
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Section 3
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From before BIRTH Comparative Embryology
| Contents
Comparative Embryology and its
Evolution on Ancient Species
Johan
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74
“Fish, mammals and reptiles are all very different types of animals but they all started from the same roots and that is why some people fine comparative embryology so interesting.”
— Johan
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Comparative Embryology and Its Evolution on Ancient Species Johan
_____Johan_____
Comparative embryology is the comparison
those who give birth, originated from eggs,
of embryo development across species.
among other findings. This was also around
(education.seattlepi.com) Every organism
the time the microscope was invented and
on earth is related in some way, but
that is when comparative embryology really
evolution has allowed us to grow and
started becoming a popular subject. One of
become unique from one another. That is
the most famous scientists in this field was
why embryos start off in the same state, but
Karl Ernst von Baer, who made the four
slowly start to get unique characteristics
principles of comparative embryology (See
over time. Fish, mammals, and reptiles are
below). Anyway with some background
all very different types of animals, but they
information out of the way let's take a look
all started from the same roots and that is
at some examples of comparative
why so many people find Comparative
embryology. First of all we have the mouse,
embryology so interesting. It shows us how
which has a gestation period of around 20
all these animals were once the same but
days depending on the species (Gestation
changed over time. The first known study of
meaning reproduction). It starts off as 1 cell
comparative embryology was actually by
but quickly gets more advanced. By day 8 it
Aristotle in 400 BC back in ancient Athens.
will start developing the heart, neural, and
He would crack animal eggs and study them
limbs. And by day 9 its poster will form
closely. He actually discovered the two major cell division patterns that embryos are formed in. Aristotle was extremely erudite at a time where education was minimal. But after his death, it was not till the 1600s till scientists continued these studies. It kickstarted in 1651 when William Harvey discovered that every animal, even
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And that is why by days 7-10 the chicken
_____Johan_____
In comparison, the chicken has a gestation
will start to develop characteristics of its
period of 10 days - 14 days. And it has also
own such as a beak, new changes to its skin,
developed limbs and posters around the
growing claws and feathers, and other
same time.
features that make it unique from other species. Concurrently the rat has started getting characteristics of its own. 17 days in the rat will have grown a large tail, fingers, toes, whiskers, and other things that differentiates it to other species like the chicken.
Further Development At this time both embryos look pretty similar, right? Well, that is because, according to Karlâ&#x20AC;&#x2122;s Ernst second law, all vertebrates (A large group of animals categorized by their backbone structure) will have the same type of skin and general features. For example, even if we do not use them past birth, human embryos still have tails because we shared all those general features. And we all come from eggs, and we all start off as a 1 singular cell. But according to Karlâ&#x20AC;&#x2122;s 4th law, even if we originally share characteristics with other embryos, later we start to be diverse and therefore, nobody goes through the same stages as others.
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_____Johan_____
These two creatures started off similarly but
According to intrestingenginering.com a
as time goes they just get more distinct and
year ago a “95-million-year-old skull fossil
by the time the gestation period has ended,
points to biblical snakes with hind legs'' and
they look nothing alike.
according to the article it was discovered in Argentina. Scientists managed to piece together these fossils, and by using today's technology, they figured out that at some point it looked like this (Picture below) As you can see it is clearly bigger than your average snake and it has little hind legs that it uses to walk around. Since the fossils were mostly intact they managed to piece out that these snakes had large mouths, sharp teeth and according to the article they “fed on larger prey than previously believed and that they were very similar to our current day big-bodied, and big-headed lizards, such as the Komodo dragons.” With the use of comparative embryology, these lizards evolved from having huge heads and sharp
Evolution o Comparative Embryolo y: Now vs Then
teeth to the little snakes that are found in the wild today. But bigger is not always better and that is probably why they evolved
These two have evolved for centuries upon
to become much smaller. They might not
centuries to become what they are today,
have been as fearsome as they looked, and
but let's take a look at where they came from
therefore they started eating less food,
and how these life forms changed
getting fewer calories, and then they
throughout the history of life on Earth. This
eventually evolved to become much smaller.
part will focus on the snake and which you
And today most snakes have gotten rid of
probably already know how it looks like.
those teeth entirely.
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_____Johan_____
Works Cited Becker, Andrea. “What Is Comparative Embryology?” Education, 21 Nov. 2017, education.seattlepi.com/comparative-embryology-6455.html. Gilbert SF. Developmental Biology. 6th edition. Sunderland (MA): Sinauer Associates; 2000. Comparative Embryology. Available from: https://www.ncbi.nlm.nih.gov/books/NBK9974/ Roberts, M. B., & King, T. J. (1987). Biology: A functional approach. Students' manual. Nelson Thornes.
“Animal Development.” Embryology, embryology.med.unsw.edu.au/embryology/index.php/Animal_Development.
Lang, Fabienne. “95-Million-Year-Old Skull Fossil Points to 'Biblical Snake' with Hind Legs.” Interesting Engineering, Interesting Engineering, 22 Nov. 2019,
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interestingengineering.com/95-million-year-old-skull-fossil-points-to-biblical-snake-with-hindlegs. Pictures:
_____Johan_____
“Mouse Timeline Detailed.” Embryology, embryology.med.unsw.edu.au/embryology/index.php/Mouse_Timeline_Detailed. Chicken Embryo, www.microscopy-uk.org.uk/mag/artnov04macro/mlchicken.html. “Baby Mouse (с Изображениями): Мышонок, Милые Детеныши Животных, Домашние Крысы.” Pinterest, www.pinterest.com/pin/155726099584667238/. “A Newborn Baby Chicken Standing on the Ground.” 123RF, www.123rf.com/photo_101444443_a-newborn-baby-chicken-standing-on-the-ground.html. Cambridge University (Jan 23 2012). Mouse embryo developing over time. https://www.youtube.com/watch?v=G7H2mEQYIWc
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Section 4
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From SURVIVAL Natural Selection
| Contents
Cheetahs almost extinct again
Astrid
Does Isolation and Migration Change
Genetic Features of Elephants
Sohum
Evolution of Animal Coloration
88 92 95 99
Henry D
Evolution of Giraffes for Survival
Nisha
The Hidden Wonders of Island Evolution
Maxwell
Natural Selection
83
Eric
104
How How Have Sheep Evolved
From Ancient times Till Now?
Helen
107
The Non-Genetic Link
Leo
110
Selection for Survival
Isabelle
116
Natural Selection
Celine
119
Daanish
Why is Climate Change Effecting
the Gender of Baby Turtles
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121
From SURVIVAL | Natural Selection
The Evolution of the Peppered Moth
Maria
121
Sasha
128
Study on Wolves and the Pleistocene Epoch
Yash
132
Biological Altruism
The Silver Fox Domestication Experiment
Asyl
135
What is Natural Selection
Sydney
138
Survival of the Fittest
Tyra
141
Evolution of Humans
Jip
144
How Climate Change and
Natural Selection have made us Super-athletes
Jade
146
Tigers
Jacob
150
Octavio
The Truth About Selective Breeding
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153
“Cheetahs don’t only face problems caused by humans but caused by their own DNA. Cheetahs have a low reproductive success rate which means they are not always able to create cubs.”
— Astrid
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Astrid van Hoorn
Cheetah’s Almost extinct, Again. Again Cheetahs Almost Extinct _____Astrid_____ https://flic.kr/p/bNXprR
“Cheetahs are large cats with a small head, long legs, and a thin body. Cheetahs are the fastest land animals on the planet They can run at speeds of about 75 miles an hour! Cheetahs can also increase their speed from zero to 60 miles an hour in three seconds” (Bradford).
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Figure 1. Partners, Safari. “Cheetah.” Flickr, 22 Apr. 2010, www.flickr.com/photos/safaripartners/4839003718/. Accessed 28 May 2020.
_____Astrid_____
Cheetah’s started facing extinction a long time ago but in 2016 papers clarified that “the cheetah’s status is going to be changed from “vulnerable’’ to “endangered” cheetahs counted 1500 In southern Africa in 1975.” This number has been going down over the last few years due to human activities. “there are an estimated 7,100 cheetahs left in the wild.” (wildlifeday.org) Cheetahs don't only face problems caused by humans but also problems caused by their own DNA Cheetahs have a low rate of reproductive success which means that they are not always able to create cubs. Because they can't always reproduce cheetahs are not able to grow nor adapt to the environment.
figure 2 liegeois, emmanuel. “Cheetah.” F lickr, 7 Mar. 2015, flic.kr/p/rysKcf. Accessed 28 May 2020.
Have cheetahs faced extinction before? (body) Cheetahs genes show that cheetahs have faced extinction before “About 10,000 to 12,000 years ago, an extinction event took place. Only the African and Asian cheetah species survived this event. Cheetahs have survived at least two bottleneck events, a bottleneck event is when a number of something dramatically decreases” which in this case is the cheetahs. “ The first bottleneck event took place “ about 100,000 years ago.” It happened after cheetahs spread out across the continents. Many Coalitions of cheetahs ended up in different places far away from each other because they were all separated they were unable to exchange genes and produce cubs. Nonetheless, the cheetahs found a way to grow their population again.
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“The second bottleneck event was about 10,000 to 12,000 years ago at the end of the last ice age.” “During this second bottleneck event, a large number of mammals died all over the world.’’ “only African and the Asian cheetahs survived this second bottleneck event but their numbers decreased by a lot. Scientists estimate only about 7 African cheetahs survived during this second bottleneck event.” (Newsela )
_____Astrid_____
Reasons cheetahs face extinction today. (body) African wild life.org states that As human populations grow and expand, agriculture, roads, and settlements destroy the open grasslands that this big cat calls home this affects them because if they don’t have their habitat it will be harder for them to hunt, which in turn means that they cannot get the nutrients that they require to grow and remain healthy. National Geographic states that “Another reason the cheetahs are facing extinction is that their genes do not always allow them to reproduce” which means that they are not capable of guaranteeing a future generation. In addition to what I mentioned before these big cats are also confronted with climate change is influencing the environment they are used to and sometimes their pray is also affected by climate change which causes cheetah to not be able to feed themselves or their cubs. As a result of poaching, cheetahs have also been confronted with extinctions because humans have been using cheetah skin(Fur coats), meat.
What would happen if cheetahs become extinct? (body) Cheetahs have survived two bottleneck events in the past, however, the environment is changing so rapidly lately that it is very hard for them to adapt to their changing environment. Normally with the slow change, animal populations not individuals slowly adapt by the individuals who are best suited to being more successful and breeding more- when the changes are really rapid, there is no time for the population to adapt and they may all be eliminated and become extinct. Cheetahs are classified as carnivores “meat-eaters” which means that they feed on other animals to get their required nutrients. However, cheetah mainly eats gazelles, wildebeest calves, impalas, and smaller animals such as warthogs, birds, hares, and many more. These grasseaters eat grass as their name implies however if the cheetah population decreases the herbivore population will increase and grasslands will decrease because the herbivores will be eating too much grass Bigcatswild.com states that changes in one cause changes in all, there is always a chain reaction in a food pyramid.
What is going to happen to the cheetah population now? Cheetahs have been facing extinction for a couple of years now due to human activities however cheetahs have survived 2 bottleneck events
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_____Astrid_____
but because they have problems in their genes with reproducing they were unable to create a future generation during those times however they did manage to grow their population. As a result of climate change, it is hard for these big cats to adapt to their new environment because they might not be “fit” enough to adapt. Because the cheetah population is decreasing and the herbivore population is increasing grass and plants eaten by herbivores also decrease. Astrid van Hoorn Works Cited Bradford, Alina. “Cheetahs: The Fastest Land Animals.” L ive Science, Live Science, 23 Oct. 2018, www.livescience.com/27319-cheetahs.html. liegeois, emmanuel. “Cheetah.” F lickr, 7 Mar. 2015, flic.kr/p/rysKcf. Accessed 28 May 2020. “Cheetah | Official Website of UN World Wildlife Day.” W ww.Wildlifeday.Org, www.wildlifeday.org/content/factsheets/cheetah. “Newsela | Cheetahs: On the Brink of Extinction, Again.” N ewsela.Com, newsela.com/read/natgeo-cheetahs-extinction/id/50558?collection_id=339&search_id=75f70f0f-45f b-46fc-aee7-e9cb678c2642. Accessed 28 May 2020. National Geographic Society. “National Geographic Education.” N ationalgeographic.Org, 2019, www.nationalgeographic.org/education/. “The Fastest Land Mammal Can’t Outrun Extinction on Its Own.” A frican Wildlife Foundation, 13 Dec. 2018, w ww.awf.org/wildlife-conservation/cheetah. O&apos;connell, Daniel, et al. C heetah Extinction-Unable to Recover? And the Effects on Its Food Pyramid.
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“Six million years ago, a common ancestor of the elephant diverged into two separate species…Each type of elephant has its own various characteristics that allow them to survive and thrive in their respective environments. ”
— Sohum
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How Does Isolation and Migration Change Genetic Features of Elephants? _____Sohum_____
By Sohum Tripathi Six million years ago, a common ancestor of modern elephants diverged into two species; the African elephant and the Asian elephant. The African elephant species diverged into two subspecies; the Savanna elephant and the forest elephant. The Indian elephant diverged into two subspecies as well; Asian alpha and Asian beta. The differences between African elephants and Asian elephants are numerous. To start with, African elephants have much larger ears that look, from a perspective, as the continent of Africa. Asian elephants have much smaller and rounder ears. African elephants have rounded heads, while Asian elephants have a twin-domed head meaning that there is a divot line running down the head. (Britannica.com) Both male and female African elephants have tusks but only male Asian elephants can grow them. It is important to know, however, that not all African or Asian males necessarily develop tusks. In terms of weight, African elephants generally weigh around 8000 kg (9 tons) whereas their Asian counterparts only weigh about 5,500 kg (around 6 tons). Along with all the differences listed above, there are several minute differences such as skin texture, number of toenails and trunk characteristics between the two subspecies. The differences between African and Asian elephants can be viewed as an example as to how migration changes the genetic features of elephants. (This image shows an African Elephant and an Asian elephant side by side) “The isolated populations may develop different genetic mutations and variations in a new environment.” “After many generations, the isolated population may look completely different from the main population and may eventually become a new species, unable to breed with the original population.” (Giesen 448). In Borneo, a group of elephants became isolated from the Asian beta subspecies in Borneo. To further understand this situation we have to see where exactly Asian alpha and Asian beta species are located. According to the New York times, Asian alpha species are mainly located on the mainland and Asian beta species are mostly found on the islands of Sumatra and Borneo (The New York Times). The elephant in Borneo has
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followed its own evolutionary path and it is distinctly different from other Asian elephants due to the isolation. Borneo elephants diverged from the Beta elephants 300,000 years ago.
_____Sohum_____
Dr.Prithiviraj Fernando, the main author and a scientist at the Columbia University Center for Environmental Research and Conservation states: “The current population (estimated at 1,000 2,500) lack genetic variation, which indicates that the population arose from a small number of founders, which was never very numerous and highly inbred.” The reason as to why the isolated Borneo elephants are inbred and possibly trapped in a genetic bottleneck is because when sea levels rose, they became trapped on the island of Borneo. The Borneo elephant also possesses its own selection of unique features. According to Dr.Michael Stuewe, the Borneo elephant doesn’t attack humans when harmed or violated, unlike it’s African and Indian counterparts. The elephant is smaller than others in Asia with larger ears and straighter tusks. This can be viewed as an example of how isolation from the main species changes genetic features. (This image shows a Borneo pygmy elephant. To wrap up this information about how migration and isolation change genetic features in elephants, this quote from Quote Master about differences. “Strength lies in differences, not in similarities” -- Stephen Covey. Each Type of elephant has its own various characteristics that enable them to survive and thrive in their respective environments.
Works Cited: Derr, Mark. “Small, Isolated Elephants Follow Own Evolutionary Path.” The New York Times, The New York Times, 30 Sept. 2003, www.nytimes.com/2003/09/30/science/small-isolated-elephants-follow-own-evolutionarypath.html. Grannan, Cydney. “What's the Difference Between Asian and African Elephants?” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 2015, www.britannica.com/story/whats-the-difference-between-asian-and-african-elephants.
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Geisen, Michael. “Evolution.” Everything You Need to Ace Science in One Big Fat Notebook: the Complete Middle School Study Guide, by Michael Geisen and Chris Pearce, Workman Publishing, 2019, pp. 448–448. Images: Potter, John Micheal Evan. Side by Side photograph of African and Asian elephants. Britannica online, 2015, https://www.britannica.com/story/whats-the-difference-between-asian-and-african-elephant s. Accessed 26 May 2020. Williams, Christy. Borneo Pygmy Elephant. Worldwildlife.org, 2016, https://www.worldwildlife.org/species/borneo-pygmy-elephant. Accessed 26 May 2020
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“The coloration of some animals has evolved based on their habitat. This is an example of natural selection. The coloration, color, shape, and camouflage of animals are based on the environment they live in and this helps their chances of survival.”
— Henry
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Evolution of Animal Coloration
_____Henry_____
Edward Howard Burt states that “animal coloration, in biology, is the general appearance of an organism as determined by the quality and quantity of light that is reflected or emitted from its surfaces. He continues with, coloration depends upon several factors: the color and distribution of the organism’s biochromes (pigments), particularly the relative location of differently colored areas; the shape, posture, position, and movement of the organism; and the quality and quantity of light striking the organism. complex characteristic and must be clearly distinguished from the concept of “color,” which refers only to the spectral qualities of emitted or reflected light.” (Britannica.com) The coloration of some animals has evolved based on their habitat. This is an example of natural selection. The coloration, color, shape, and camouflage of animals are based on the environment they live in and this helps their chances of survival. A newsela article written by Wayne Iwan Lee Davies and Shaun Collin states that where animals come from determines a lot of the attributes that that animal holds. One being the color or shade of the skin and fur, coat, feathers of the animal. An example of this is the color of skin that an animal has. In colder climates of the planet the skin color of animals there normally have a lighter skin color. This is true for humans as well. The skin and ear color of humans have evolved and become lighter as they migrated out of Africa into colder areas. In hotter areas of the planet, animals tend to have darker skin pigmentation (Newsela.com). For most animals, their outer layer or their fur, feathers or other body covering has evolved into camouflage. An example of this is the arctic fox. The arctic fox has a very white coat of fur and this helps the fox hide in the snow that covers a lot of the area in the arctic. An animal's skin and ear color as well as their outer layer all help them survive in their different areas. This is an example of natural selection.
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_____Henry_____
To wrap up all of this information on animal coloration and the evolution of the outer layer and skin color of animals a quote that Charles Darwin gave, found on the Wikipedia page for animal coloration, gives a great overview of animal coloration and natural selection … “When we see leaf-eating insects green, and bark-feeders mottled-grey; the alpine ptarmigan white in winter, the red-grouse the color of heather, and the black-grouse that of peaty earth, we must believe that these tints are of service to these birds and insects in preserving them from danger. Grouse, if not destroyed at some period of their lives, would increase in countless numbers; they are known to suffer largely from birds of prey, and hawks are guided by eyesight to their prey, so much so, that on parts of the Continent persons are warned not to keep white pigeons, as being the most liable to destruction. Hence I can see no reason to doubt that natural selection might be most effective in giving the proper color to each kind of grouse, and in keeping that color, when once acquired, true and constant.” (Wikipedia.org) Over time as the population of animals changes and the “forces” of natural selection help to shave off the “imperfect of the litter” animals and their skin color and outer layer help them to survive and thrive in their environment.
Sources: “Animal Coloration.” Wikipedia, Wikimedia Foundation, 3 May 2020, en.wikipedia.org/wiki/Animal_coloration. Losey, George S., et al. “Coloration.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 7 Feb. 2019, www.britannica.com/science/coloration-biology.m Davis, Wayne Iwan Lee, and Shawn Collin. “Big Questions: Why Do Baby Animals Have Pink Ears?” Newsela, 24 Mar. 2020, newsela.com/read/elem-big-q-why-do-animals-have-pink-ears/id/40561/?collection_id=3 39&search_id=0dbfe785-a9a8-4b98-9331-9c166eef1010. Cloudsley-Thompson JL. Multiple factors in the evolution of animal coloration. Naturwissenschaften. 1999;86(3):123-132. doi:10.1007/s001140050584 Images: “Nie 1905 Darwin Charles - Charles Darwin, HD Png Download , Transparent Png Image - PNGitem.” PNGitem.com, 2020, www.pngitem.com/middle/iwwRxw_nie-1905-darwin-charles-charles-darwin-hd-png/. Library, Mountain View Public. “Animal Coloration.” Free Homework Help, 1 Jan. 1970, mvplteen.blogspot.com/2018/05/animal-coloration.html. “Arctic Fox.” Wikipedia, Wikimedia Foundation, 13 Apr. 2020, en.wikipedia.org/wiki/Arctic_fox.
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“Each species has a different colorations and the color dots represent their home territories. Their colorations help them blend into the part of Africa that they live in.”
— Nisha
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Evolution of Giraffes for Survival By: Nisha Thusay Last edited: 5/28/2020
_____Nisha_____
The Giraffe is the tallest living terrestrial animal. Males can exceed 5.5 feet, and females are around 4.5 feet. They live on a diet of Acacia trees, they are 40 feet or 3 meter long trees. It is an animal that is native the continent of Africa. Although giraffes were once spread around the world, 20 to 25 million years ago, the giraffe's ancestors also roamed around Europe and Asia. (Herbison and Frame 1) While Giraffes are only native to Africa, they have subspecies that live in different parts. Each species has different colorations and the color dots represent their home territories. Their colorations help them blend into the part of Africa that they live in. There are not many fossils of them out of Africa, but there is enough information for scientists to come up with evolution theories. (Giraffe Worlds) There are two theories, the one that the world accepts today is the Darwinian theory, the one that is not valid and not accepted anymore is the Lamarck theory. . The earliest giraffe dates back to around 25 million years ago, using fossil evidence, scientists believe that giraffes had long legs, short necks, and ossicones that pointed upward. The picture on the left is what scientists imagined giraffes ancestors looked like. The Darwinian theory is a theory created by Charles Darwin in 1859. His theory suggested that the fittest will survive. He believed that giraffes had a genetic mutation that allowed them to grow longer necks. These animals were able to eat more and so they were stronger. That meant that the stronger males would be the ones breeding more, and their genetic code would get passed down to the next generations. The animals that could not get enough to eat, were not strong enough to mate with the females, and then they would die without having offspring. (Khan Academy) There is also another theory that suggests something different. The Lamarck theory was created by Jean-Babtiste Lamarck in the early 1800’s. Food on the ground was scarce, and most of the food was on the trees. He believed that animals were constantly raising their neck to be able to reach the trees for food. He thought that overtime the size of their necks would be longer that would provide them an adaptation that allowed their survival. Although, this theory is not supported anymore, after the Darwinian theory was created, the Lamarck theory was not widely accepted anymore. Scientists suggest that the Darwinian theory makes more sense, is more valid, and that is the main theory that is accepted worldwide. (Giraffe Worlds)
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_____Nisha_____
The image on the right is fossil evidence of the evolution of giraffes. Archeologists believed that the giraffe's ancestors were the Okapia Johnstoni. They found that the Okapia had a short neck that was 1.9 feet. They believed that the Okapia Johnstoni species evolved into the Samotherium Major. The Samotherium Major had a neck that was 3.2 feet. These days giraffes have a neck that is 5.5 feet. The giraffe evolved a lot in order to become more habitable to their environment. (Geggel 2)
Citations: Websites -
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Geggel, Laura. “7-Million-Year-Old Fossils Show How the Giraffe Got Its Long Neck.” LiveScience, Purch, 25 Nov. 2015, www.livescience.com/52903-transitional-giraffe-fossils.html. Lory Herbison & George W. Frame. “Giraffe.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 12 May 2020, www.britannica.com/animal/giraffe. “Giraffe Evolution.” Giraffe Facts and Information, www.giraffeworlds.com/giraffe-evolution/. “Darwin, Evolution, & Natural Selection (Article).” Khan Academy, Khan Academy, www.khanacademy.org/science/biology/her/evolution-and-natural-selection/a/darwin-evo lution-natural-selection.
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Geggel, Laura. “7-Million-Year-Old Fossils Show How the Giraffe Got Its Long Neck.” LiveScience, Purch, 25 Nov. 2015, www.livescience.com/52903-transitional-giraffe-fossils.html.
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Briggs, Helen. “Scientists Weigh in on 'Giraffe Relative' Fossil.” BBC News, BBC, 13 Jan. 2016, www.bbc.com/news/science-environment-35292660. Gruber, Karl. “New Scientist.” New Scientist, 17 Sept. 2015, www.newscientist.com/article/2058123-giraffes-spend-their-evenings-humming-to-eachother/.
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â&#x20AC;&#x153;When animals that have traits that allow them to survive, over time those traits are amplified. This process happens far faster on islands because there are not many animals on islands initially. Natural selection is constantly happening, it is unnoticeable as it is not something that consciously happens. The phenomenon even happens to humans.â&#x20AC;?
â&#x20AC;&#x201D; Maxwell
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The Hidden Wonders of Island Evolution _____Maxwell_____
Nature doesn’t stay the same. We all know this, we know that animals change in form over millions of years as they slowly evolve. What we are going to focus on today in this article is evolution on islands, specifically, the Galápagos Islands. When evolution occurs on islands, it is known as island evolution, this will be the main topic in this article. According to the Oxford Dictionary, evolution is the process by which different kinds of living organism are believed to have developed from earlier forms during the history of the earth. Evolution can happen in 4 main ways, fossil record, comparative anatomy, comparative embryology and from natural selection. The fourth and last one is the one we are going to focus on today. The Oxford Dictionary says Natural selection is the process whereby organisms better adapted to their environment tend to survive and produce more offspring (John Simpson). The theory of its action was first fully expounded by Charles Darwin, and it is now regarded as the main process that brings about evolution. Organisms that are more adapted to their environment are more likely to survive and pass on the genes that aided their success. Over time, the characteristics that allowed the animals to survive amplified and causes animals to change due to continued breeding between animals (Osterloff).
Fig 1 - A representation of human evolution in a series of images depicting apes turning into Homo Sapiens. (Lynch, Ryan. “A Representation of Human Evolution in a Series of Images Depicting Apes
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Turning into Homo Sapiens.” Evolution or Extinction: The Path to Brand Survival Is Fraught with Peril, 26 Jan. 2016, www.campaignlive.co.uk/article/evolution-extinction-path-brand-survival-fraught-peril/1380834).
_____Maxwell_____
Now that we understand the concept of Natural selection and how it works, lets answer the big question, how and why is natural selection different on islands? Well, island species evolved faster than mainland species. The most extreme effects of isolation will be seen on the smallest, most far-flung islands (Gross). Take the Galápagos Islands, imagine several mocking birds or finches are blown off course during a storm and a handful of turtles are carried in the wrong direction because of the tide, and they end up on the island. There are only several animals of each species there. Natural selection will occur and the strongest or most well adapted will survive, considering that there were not many animals on the island in the first place, the change becomes faster (Helmuth). An example of this phenomenon on the Galápagos island are the massive turtles that dwell there, they adapted to get bigger so that they could move through the thick bushes that reside on that specific island. On a nearby neighboring island, turtles have adapted to have necks that extend far out from their shell. This is because there is a cactus that live on that island that has its edible portion high up (Helmuth).
Fig 2 - A massive Galápagos Tortoise in the grass.
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Klipp, Linda. “Giant Tortoise on Isabela Island.” Galapagos Conservancy, 2020, www.galapagos.org/conservation/our-work/tortoise-restoration/.
_____Maxwell_____
The process of natural selection occurring on islands is known as Foster's rule, or the island rule. It, is a biographical rule in evolutionary biology stating that species get larger of smaller in relation to resources available to them. Biological rule or biological law is a generalized law, principle, or rule of thumb formulated to describe patterns observed in living organisms (“Biological Rules”). What will happen is, over the course of millions of years, creatures will creatures from the mainland will turn into smaller or larger versions of themselves while on an island. (Foster’s Rule). Smaller creatures got bigger on islands when predators weren’t constantly an issue and larger creatures shrank due to their being less food on the island. Predatory pressure wasn’t as present due to the lack of animals, this caused smaller animals to grow. Larger creatures shrunk due to less land and less food. An example of a mainland animal evolving is the finch. It was discovered by Charles Darwin when he observed that the finches on the Galápagos Islands closely resembled another finch species on the mainland of South America. Darwin theorized that the finches on the island were adapted for the islands climate and conditions. As his research developed he realized that the varied beaks of each finch was a result of the different types of food available on the different islands (Learning Lumen). Natural selection is responsible for millions of different species around the world. An example of natural selection is the giraffe, giraffes with longer necks have an abundance of food whereas giraffes with shorter necks don’t have access to the bulk of food. This makes them less likely to pass on their genes as they have a higher chance of dying due to starvation. This means that longer necked giraffes have a higher survival rate and are more likely to pass on their genes. There is also randomness within evolution, therefore, the best-adapted animal will not always survive (Osterloff). In short, natural selection is one of the ways that evolution happens. When animals that have traits that allow them to survive, over time those traits are amplified. This process happens far faster on islands because there are not many animals on islands initially. Natural selection is constantly happening, it is unnoticeable as it is not something that consciously happens. The phenomenon even happens to humans.
Reference List:
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constantly happening, it is unnoticeable as it is not something that consciously happens. The phenomenon even happens to humans.
Reference List:
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1. Osterloff, Emily. “What Is Natural Selection?” Natural History Museum, www.nhm.ac.uk/discover/what-is-natural-selection.html. 2. “Foster's Rule.” Wikipedia, Wikimedia Foundation, 5 May 2020, en.wikipedia.org/wiki/Foster%27s_rule. 3. Foundation, Wikimedia. “Biological Rules.” Wikipedia, 24 May 2020. en.wikipedia.org/wiki/Biological_rules. Accessed 27 May 2020. 4. Gross, Liza. “Islands Spark Accelerated Evolution.” PLOS Biology, Public Library of Science, 12 Sept. 2006, journals.plos.org/plosbiology/article?id=10.1371%2Fjournal.pbio.0040334. 5. Helmuth, Laura. “Evolution World Tour: Galápagos Islands, Ecuador.” Smithsonian.com, Smithsonian Institution, 1 Jan. 2012, www.smithsonianmag.com/arts-culture/evolution-world-tour-galapagos-islands-ecuador5974755/. 6. Learning, Lumen. “Biology for Majors II.” Lumen, Lumen Learning, courses.lumenlearning.com/wm-biology2/chapter/natural-selection/. 7. Oxford Dictionary Oxford University Press. http://www.oed.com/viewdictionaryentry/Entry/7179;jsessionid=61494FA30F662800990 8C800D2210718 (accessed May 22, 2020). Images: 1. Klipp, Linda. “Giant Tortoise on Isabela Island.” Giant Tortoise Restoration Initiative, Galápagos Conservancy OUR EFFICIENCY, 2020, www.galapagos.org/conservation/our-work/tortoise-restoration/. 2. Lynch, Ryan. “A Representation of Human Evolution in a Series of Images Depicting Apes Turning into Homo Sapiens.” Evolution or Extinction: The Path to Brand Survival Is Fraught with Peril, 26 Jan. 2016, www.campaignlive.co.uk/article/evolution-extinction-path-brand-survival-fraught-peril/1 380834.
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“Darwin … also explained that natural selection is how animals from one common ancestor can drift so far apart over generations to best fit their environment .”
— Eric
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Natural Selection As defined by the Encyclopedia Britannica, Natural selection is a process that results in the adaptation of an organism to its environment by means of selectively reproducing changes in its genotype, or genetic constitution.
_____Eric _____
In 1835, Throughout a five year journey to the galapagos islands in the Pacific Ocean off the coast of South America to study animals, plants and fossils, english naturalist Charles Darwin developed the idea of natural selection. Which was shared more openly later on in his book, â&#x20AC;&#x153;On the Origin of Species by Means of Natural Selectionâ&#x20AC;? published in 1859. Natural selection is the process by which living organisms adapt and change to best suit the environment that is home to them. Over multiple generations, random variations that occur in the genotype of a living organism that allow it to thrive in its environment, increase its chances of survival and reproduction are preserved and passed down to future generations. Over multiple generations, these positive variations in the genotype of living organisms grow to be found more commonly throughout their populations. On the other hand, the organisms that have been born with less beneficiary variations of their genotype often die or don't last very long. Natural selection can occur in the variations of survival, fertility, development rate and other aspects of life for an organism. In undisturbed environments, the gene frequencies of living organisms tend to remain somewhat constant, since there is no reason in an environment for it's organisms to adapt. There are a couple factors that can affect the gene frequencies of living organisms such as mutation, migration, random genetic variations and natural selection. These factors all alter gene frequencies regardless of the effects, whether it is beneficial or not to the survival of that organism in its environment.
Artificial Selection Charles Dawin came up with the name natural selection as an opposite of artificial selection which is not controlled by nature and by the species itself. Darwin gave an example of a popular hobby in his time, pigeon breeding, where people choose the better looking and flying birds and breed them with each other to pass on those good genetics to future offspring. To prove his theory he argued with other scientists in his time about the process of artificial selection, trying to prove the point that there is no process like artificial selection that happens in nature, where the nicest looking and flying birds for example are the ones that reproduce more. What does happen in nature is a similar process to artificial selection only that the organisms that are breeding are the organisms with better genetics that allow them to survive in their environment instead of their visual characteristics.
In his time, Darwin was unaware of the concept of genes but he did point out that many traits from parents are passed on to their offspring. Darwin also explained that natural selection is how animals from one common ancestor can drift so far apart over
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generations to best fit their environment.
_____Eric _____
Organisms do adapt to their environment over multiple generations but when they can not adapt at the same speed at which their environment is changing, that species often goes extinct. Some of the factors that could lead to extinction of a population include an invasive species, a disease organism, a sudden environmental change, or a highly successful predator. There are a few newer cause of extinctions caused by our modern day actions such as overhunting a species and destroying their habitat for expansion of civilization
May 28,2020. Eric Drivdal
National Geographic Society. “Natural Selection.” National Geographic Society, 7 Sept. 2019, www.nationalgeographic.org/encyclopedia/natural-selection/. The Editors of Encyclopaedia Britannica. “Natural Selection.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 3 Feb. 2020, www.britannica.com/science/natural-selection. Gildenhuys, Peter. “Natural Selection.” Stanford Encyclopedia of Philosophy, Stanford University, 25 Sept. 2019, plato.stanford.edu/entries/natural-selection/.
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“All sheep now look different because of when and how they were bred, but they are all related. (History of Domestic Sheep)”
— Helen
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How Have Sheep Evolved from Ancient Times to Now? By: Helen Hirwa
_____Helen_____
The history of domestic sheep begins between 11000 and 9000 BCE. Sheep were the first animals to be domesticated by humans. There is evidence of sheep farming in Iranian statuary, where Iran’s statues are found. This animal has changed a lot overtime. Mainly because of what people did with sheep, which was to breed them for wool (History of Domestic Sheep). This goes into the idea of selective breeding. This is when two different breeds are chosen to create a different breed together. At this moment there are 2000 breeds of sheep [Ovis aries]. It is not completely clear who the wild ancestor of a sheep is. It is believed that the Mouflon [Ovis orientalis] is the wild ancestor. Since it has similar features and attitude as a domesticated sheep (History of Domestic Sheep). When ancient sheep changed into domestic sheep it was considered to be the Transition Period (History of Sheep Breeds). At that time there were several subspecies of the Mouflon that were hauled down from mountains, to be bred (Pallardy). The difference between the ancient sheep and the domesticated sheep is the techniques by which wool is collected. It was also known that the “Soay along with other Northern European breeds with short tails, naturally rooing fleece, diminutive size, and horns in both sexes, are closely related to ancient sheep.” All sheep now look different because of when and how they were bred, but they all are related (History of Domestic Sheep). Soay Breeds
In Iran “Woolly sheep began to be developed around 6000 BCE. Cultures such as the Persians relied on sheep’s wool for trading” (History of Domestic Sheep). At the time there were 59 specimens of wild Ovis that were collected by 8 localities in Iran that were possibly trying to use the specimens for breeding of sheep. Even pregnant sheep were examined for hybrid population then. Over time the number of chromosomes in some sheep have changed as well as the sizes of their hooves. The only thing that didn't change at the time was the size/type of horns. These were different in different areas of Iran (Valdez 56). Ancient sheep originally started existing in Iran. Then they started to spread from northern Turkey and Northern Iran, to Europe and Asia (History of Sheep Breeds). In the end sheep
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have evolved a lot from ancient times to now. Even though there are still some really old breeds that exist, which then leaves room for changes in sheep now to the future.
_____Helen_____
Image Citations "Mouflon - WildLife Partners, LLCWildLife 21 May. 2020.
Partners, LLC." https://wildlifepartners.com/species/mouflon/. Accessed
"Facts About Sheep | Live Science." 11 Nov. 2015, https://www.livescience.com/52755-sheep-facts.html. Accessed 21 May. 2020. "Soay sheep | The Soay sheep is a breed of domestic sheep ...." https://www.flickr.com/photos/53555654@N00/28912974918. Accessed 21 May. 2020.
Website Citations "History of the domestic sheep - Wikipedia." https://en.wikipedia.org/wiki/History_of_the_domestic_sheep. Accessed 19 May. 2020. Valdez, Raul, et al. “Evolution of Wild Sheep in Iran.” Evolution, vol. 32, no. 1, 1978, pp. 56–72. JSTOR, www.jstor.org/stable/2407410. Accessed 19 May 2020. "6 Domestic Animals and Their Wild Ancestors | Britannica." https://www.britannica.com/list/6-domestic-animals-and-their-wild-ancestors. Accessed 19 May. 2020. "History of Sheep Breeds: Part 1 of 2 - YouTube." 28 Oct. 2018, https://www.youtube.com/watch?v=f9VjRZNgioQ. Accessed 19 May. 2020.
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“ It is easier to track genetic data that has been passed down. Sexual selection is the next step from natural selection, in the same way the strongest survive in nature, only the best mates procreate in nature. As the weak are gradually eliminated by Natural Selection, the strong reproduce via sexual selection.”
—Leo
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_____Leo_____
The NonGenetic Link THE LINKS BETWEEN HUMANS AND OTHER PRIMATES THAT AREN'T PASSED GENETICALLY
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_____Leo_____
"It's classic in primates that when there is a new innovation, particularly in terms of tool use, the younger generations pick it up very quickly. The last ones to pick up are adults, mainly the males" -Jill Pruetz, Anthropologist at Fongoli Savanna Chimpanzee Project
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_____Leo_____
"The sexual struggle is of two kinds; in the one it is between individuals of the same sex, generally the males, in order to drive away or kill their rivals, the females remaining passive; whilst in the other, the struggle is likewise between the individuals of the same sex, in order to excite or charm those of the opposite sex, generally the females, which no longer remain passive, but select the more agreeable partners." - Charles Darwin
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Bibliography:
_____Leo_____
Barras, C. (2015, August 18). Earth Chimpanzees and monkeys have entered the Stone Age. Retrieved May 25, 2020, from http://www.bbc.com/earth/story/20150818chimps-living-in-the-stone-age Walker, M. (2014, December 21). Earth - Wild gorilla creates a food tool in 'eureka' moment. Retrieved May 26, 2020, from http://www.bbc.com/earth/story/20141218-wildgorilla-has-eureka-moment Taylor, K., & Welker, B. (2017, June 13). 4. Primate Social Organization. Retrieved May 25, 2020, from https://milnepublishing.geneseo.edu/thehistory-of-our-tribe-hominini/chapter/primatesocial-organization/
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“ Darwin’s grand idea of evolution by natural selection is relatively simple but often misunderstood. Since the environment can’t support unlimited population growth, not all individuals get to reproduce to their full potential.”
—Isabelle
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Selection For Survival By: Isabelle Torres Santos
_____Isabelle_____
Natural selection is one of the basic mechanisms of evolution, along with mutation, migration, and genetic drift. Darwin's grand idea of evolution by natural selection is relatively simple but often misunderstood. Since the environment can't support unlimited population growth, not all individuals get to reproduce to their full potential. In this example, green beetles tend to get eaten by birds and survive to reproduce less often than brown beetles do. End result: The more advantageous trait, brown coloration, which allows the beetle to have more offspring, becomes more common in the population. Charles Darwin and Alfred Wallace are the two co-discoverers of natural selection (Darwin & Wallace 1858), though, between the two, Darwin is the principal theorist of the notion whose most famous work on the topic is On the Origin of Species (Darwin 1859). Much like breeders choose which of their animals will reproduce and thereby create the various breeds of domesticated dogs, pigeons, and cattle, nature effectively “selects” which animals will breed and creates evolutionary change just as breeders do. To use one of Darwin’s own examples, wolves with especially long legs that allow them to run more quickly will be more likely to catch prey and thereby avoid starvation and so produce offspring that have especially long legs that allow them, in turn, to breed and produce still more long-legged descendants, and so on. Multiple bouts of Darwin’s process involving different traits, acting sequentially or in concert, may then explain both how speciation and the evolution of complex adaptations occur through the gradual evolution (change over time) of natural populations. Darwin aimed to convince his audience that even such structures as the vertebrate eye, which at first seem explicable only as the product of design, could instead be explained by incremental, directional evolution, a complex but still naturalistic process (Darwin 1859: ch.
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_____Isabelle_____
One usage, the “focused” one, aims to capture only a single element of one iteration of Darwin’s process under the rubric “natural selection”, while the other, the “capacious” usage, aims to capture a full cycle under the same rubric. Okasha interprets the covariance of offspring number and offspring phenotype as quantifying the causal influence of selection (Okasha 2006: 28) Clearly, these uses of “natural selection” are meant to capture only an element of Darwin’s process; As discussed further below, controversies over the focused notion of selection have to do with whether the focused notion of selection can be distinguished from that of drift (section 3), and whether selection, in the focused sense, should be counted as a cause (section 5). Because Darwin’s process is cyclical, specifying what is sufficient for a single cycle of it, a single instance of, say, replication of genes for long legs caused by long-legged wolves making narrow captures, is sufficient to specify a process that may explain adaptation and speciation. The capacious notion, capturing a cycle of Darwin’s process, is used by Lewontin and later authors working in the same vein, who put forward conditions for evolution by natural selection: these include variation, inheritance, and reproduction. While falling within the scope of “natural selection” in the capacious sense used by Lewontin, these elements of Darwin’s process are treated as distinct from natural selection when that notion is used in its focused sense. Sources: "Mechanisms: Natural selection - Understanding Evolution." https://evolution.berkeley.edu/evolibrary/article/evo_25. Accessed 25 May. 2020. "Natural Selection (Stanford Encyclopedia of Philosophy)." 25 Sep. 2019, https://plato.stanford.edu/entries/natural-selection/. Accessed 25 May. 2020. "Darwin, evolution, & natural selection (article) | Khan Academy." https://www.khanacademy.org/science/biology/her/evolution-and-natural-selection/a/darwin-evolution-nat ural-selection. Accessed 25 May. 2020. "10.36 Natural Selection and Populations Advanced - cK-12." 11 Dec. 2015, https://www.ck12.org/book/ck-12-biology-advanced-concepts/section/10.36/. Accessed 25 May. 2020.
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“This is a perfect example of natural selection at work, with only those able to adapt to living too adulthood and passing their traits to their children.”
—Celine
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Natural selection is the force driving evolution, with “hazards” or selective pressures being the factors around us forcing us to adapt in the first place.
_____Celine_____
This is the “survival of the fittest” mentality, meaning only the strongest survive, but the question is if we’re still being affected by it today. In short, we aim to answer if humans are still evolving, and what are some examples of said evolution. According to genetic studies, humans are still evolving as natural selection is in play. One such example of this is the lactase gene. In most parts of the world, adults are unable to digest lactose. The reason is that their bodies switch off the lactase gene, the enzyme that digests the sugar in milk, after they’ve outgrown breastmilk. In Europe, however, 70% of adults are able to digest lactose without any problems. They have different DNA that leaves the lactase gene on throughout their lives, even after outgrowing breastmilk. This seems to have happened between 5,000 and 10,000 years ago, which was around the time cows were domesticated in Europe. Some explanations for this are linked to how important cow’s milk was. Sun exposure was low, so people needed Vitamin D they’d receive from milk. Milk was safer than drinking potentially diseased water, and prevented death from starvation when food was scarce. As a result, those who couldn’t tolerate cow’s milk died from starvation, and those who could tolerate it would live to adulthood. Being able to digest lactose is so common now that being lactose intolerant is seen as unusual in Europe. This is a perfect example of natural selection at work, with only those able to adapt living to adulthood and passing their traits to their children. In this case, said trait is the lactase gene being active throughout the length of their lives. Work Cited “Are Humans Still Evolving?” Stories, The Public Engagement Team at the Wellcome Genome Campus, 13 June 2016, www.yourgenome.org/stories/are-humans-still-evolving.
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“Sea turtle genders are not effected like humans are, human genders are affected by the amount of chromosomes we have, and turtles and other reptiles such as crocodiles and alligators are affected by the temperature of when the eggs were developing.”
—Daanish
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Why is climate change affecting the gender of Baby Sea Turtles?
_____Daanish_____
We live in a day and age where the world has been polluted and destroyed and climate change is a major problem for us. However, it’s not just affecting us humans. Sea turtles are very important to the world's oceans, keeping the seagrass beds and coral reefs healthy, but they are being affected massively even before they are born. Sea turtles are reptiles, which means they lay eggs and Sea Turtles lay their eggs in the sand, normally on a beach. (Deleniv "Why climate change is creating more female sea turtles and crocodiles" 2020). Sea turtle genders are not affected like humans are, humans genders are affected by the amount of chromosomes we have, and turtles and other reptiles such as crocodiles and alligators are affected by the temperature of when the eggs were developing. Research from the National Oceanic and Atmospheric Administration (US Department of Commerce & National Oceanic and Atmospheric Administration 2017) shows that if turtles eggs incubate below 81.86 fahrenheit or 27.7 celsius, the turtle will be a male and if turtle eggs incubate over a temperature of 87.8 fahrenheit or 31 degrees the turtle will be female and anywhere between the two will be a mix of the two. Climate Change has recently caused the temperatures of sand to sky rocket causing predominantly female eggs to hatch. As an example of this, in 2018 on an island east of Australia called Raine Island, there was a massive influx of turtle eggs on the beach. There were 18,000 turtles all across the island and for the last 20 years it has been producing almost exclusively female eggs. A team of scientist’s on Raine Island reported that female turtles outnumbered males 116 to 1. (Newbert "99% of These Sea Turtles Are Turning Female-Here's Why" 2018). If this pattern continues to exist and female eggs are being produced this highly, it is very likely that males sea turtles could go extinct which will end up affecting the species altogether. Citations: Balaraman, Kavya. “Is Climate Change Producing Too Many Female Sea Turtles?” Scientific American, Scientific American, 3 Apr. 2017,
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_____Daanish_____
www.scientificamerican.com/article/is-climate-change-producing-too-many-female-sea-turtl es/. Deleniv. “Why Climate Change Is Creating More Female Sea Turtles and Crocodiles.” New Scientist, 19 Feb. 2020, www.newscientist.com/article/mg24532700-800-why-climate-change-is-creating-more-femal e-sea-turtles-and-crocodiles/. Newbert, Chris. “99% Of These Sea Turtles Are Turning Female-Here's Why.” 99% Of Australian Green Sea Turtles Studied Turning Female From Climate Change, 8 Jan. 2018, www.nationalgeographic.com/news/2018/01/australia-green-sea-turtles-turning-female-clim ate-change-raine-island-sex-temperature/. Skerry, Brian. “Sea Turtles Are Being Born Mostly Female Due to Warming-Will They Survive?” National Geographic, 4 Apr. 2019, www.nationalgeographic.com/environment/2019/04/sea-turtle-sex-ratio-crisis-from-climate -change-has-hope/. “ABQtodo.” ABQtodo, 23 May 2019, https://www.abqtodo.com/wp-content/uploads/2019/11/seaturtle.jpg.
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“However, due to massive increase in air pollution caused by the industrial revolution, the lichens slowly died out and the trees darkened by the soot in the atmosphere. This occurred for may decades and over time the light-colored moths, or typica, dried off due to predators such as birds and bats spotting them on the trees, and … the dark colored moths, or carbonaria, flourished.”
—Maria
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Evolution of the Peppered Moth The Evolution of the Peppered Moth
By Maria Olivenca By Maria Last edited: 27/05/2020
_____Maria_____
The Peppered Moth is considered a temperate Moth species and is mostly nocturnal. It is a species of European Moth that has black and white speckled wings. (The Editors of Encyclopedia Britannica) The wingspan of the Peppered Moth ranges from 45mm to 62mm. It is small-bodied, with long forewings. (Wikipedia Contributors, “Peppered Moth”) The wings are white with small black spots. This species exemplifies natural selection and population genetic change. (Wikipedia Contributors, “Peppered Moth”) The Peppered Moth population consists of two types of moth. The original Moth which had a white body and small black spots morphed into a Moth that’s body was fully dark with large blotting of black spots. This species changed genetically to survive throughout the course of the industrial revolution.
Figure #1: Original Peppered Moth with Wings spread out.
Natural selection has been described by Hank Green from Crash Course as “ The process by which certain inherited traits make it easier for some individuals to thrive and multiply, changing the genetic makeup of the population over time." (Green) This was first discovered by none other than Charles Darwin in 1859. Charles Darwin, a famous naturalist, demonstrated his theory of evolution with natural selection as an explanation of adaptation and specification. Charles Darwin explained the process of natural selection as “the principle by which each slight variation of a trait, if useful, is preserved". (CK-12 Foundation) The concept was plain and simple but powerful. Individuals, such as the peppered moth, that adapted to their environments are more likely to survive and reproduce. For instance, the Peppered Moth best adapted to its environment, by changing color to match the trees it laid on so that the population of Peppered moths was more likely to survive and reproduce. And over the years that's what happened… During the Industrial revolution Peppered Moths were thought to be Native to England, specifically London as certain trees made Peppered Moths practically
1
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unseeable for predators like bats, and birds. Peppered Moths have been studied for over 200 years and all of the peppered moths experimented with had been collected in traps at night and many of those were eaten from tree trunks as they were glued to the trees where they were found by opportunistic birds.
_____Maria_____
The evolution of the peppered moth has been looked over by many scientists over the past two hundred years and ever since the industrial revolution began. At the start of the era, the majority of Peppered moths were light coloured with small, dark spotted wings. Their wings helped them blend in and camouflage with their surroundings. However, due to massive increase in air pollution caused by the industrial revolution, the lichens slowly died out and the trees darkened by the soot in Figure #2: Four Morphed Peppered Moths Camouflaging into dark tree bark
the atmosphere. This occured for many decades and over time the light-colored moths, or typica, died off due to predators such as birds and bats spotting them on the trees, and the rise of the dark-colored, moths, or carbonaria, flourished. (Wikipedia Contributors, â&#x20AC;&#x153;Peppered Mothâ&#x20AC;?)
2
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Reference List:
_____Maria_____
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“Peppered Moth.” Wikipedia, Wikimedia Foundation, 22 Mar. 2019, en.wikipedia.org/wiki/Peppered_moth. Accessed 27 May 2020.
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Wikipedia Contributors. “Natural Selection.” Wikipedia, Wikimedia Foundation, 17 Mar. 2019, en.wikipedia.org/wiki/Natural_selection. Accessed 27 May 2020.
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“Peppered Moth.” Wikipedia, Wikimedia Foundation, 22 Mar. 2019, en.wikipedia.org/wiki/Peppered_moth. Accessed 27 May 2020.
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Green, Hank. “Nerdfighteria Wiki - Natural Selection - Crash Course Biology #14.” Nerdfighteria.Info, Crash Course, 1 May 2012, nerdfighteria.info/v/aTftyFboC_M. Accessed 27 May 2020.
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CK-12 Foundation. “Theory of Evolution by Natural Selection.” CK-12 Foundation, CK-12 Foundation, 17 June 2017, www.ck12.org/earth-science/theory-of-evolution-by-natural-selection/lesson/The-Theoryof-Evolution-Advanced-BIO-ADV/. Accessed 27 May 2020.
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Images:
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"Peppered Moth Biston Betularia Camouflaged On Stock Photo ...." https://www.shutterstock.com/image-photo/peppered-moth-biston-betularia-camouflaged -on-62065939. Accessed 26 May. 2020.
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"Peppered Moth. Biston betularia | Cradley, Malvern, Worcs. S ...." https://www.flickr.com/photos/gails_pictures/24540903214. Accessed 26 May. 2020.
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"Peppered Moth Biston Betularia Melanic Light Stock Photo ...." https://www.shutterstock.com/image-photo/peppered-moth-biston-betularia-melanic-light -681825820. Accessed 26 May. 2020. 3
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“Baelaev’s team tested hundreds of foxes and selected the top 10% tamest individuals for breeding…researchers found that after only about six generations, many of the focus would like the scientists hands, allow themselves to be picked up and petted… Some of them also showed traits from the domestication syndrome and started to look different from their wild relatives… they had less stress hormones and had increased serotonin (which makes you happy).”
—Sasha
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The Silver Fox Domestication Experiment
_____Sasha_____
The silver fox domestication experiment started in 1959 with the goal of recreating the domestication process, but using foxes. Dmitri Belyaev, the leader of the experiment, wanted to find out if domestication was linked to an animal’s genetic makeup. The experiment consisted of breeding the tamest individuals in each generation of foxes, to hopefully create a fully domesticated fox after many generations. Belyaev also hypothesized that many of the traits that domesticated animals share, such as floppy ears, curly tails, or rounder bodies, are genetically linked to the traits that cause tameness. After only six generations, the experimenters found that not only were the majority of foxes domesticated and drawn to humans, but many also featured the traits previously mentioned. This showed that Belyaev’s hypothesis was indeed correct, and that domestication is a genetic process associated with a multitude of traits. (Dugatkin) The silver fox domestication experiment started in 1959 at the Institute of Cytology and Genetics in Novosibirsk, Siberia. The team of researchers working on the experiment were led by Dmitri Belyaev, a Russian geneticist who became the director of the Institute after his predecessor was fired due to Lysenkoism. Lysenkoism was a movement against genetic research that occured in the Soviet Union during the mid-1900s, where hundreds of scientists were imprisoned or executed. Luckily for Belyaev, he and his experiment were spared from this fate, and the experiment is still happening today. (Dugatkin) Belyaev’s goal was to recreate the domestication process, specifically the evolution from wolf to dog. (Dugatkin) He chose to use foxes because they were a close relative of the dog, and he had also worked with them during his work as a fur breeder. (PBS NewsHour) Belyaev knew that domesticated animals often share a group of traits called the “Domestication Syndrome”, which include floppy ears, mottled fur, short and curly tails, rounder features, reduced stress hormone levels, and relatively long reproductive seasons. He hypothesized that “tameness”, which humans looked for when selecting the animals to domesticate, was actually a genetic trait, and that it was genetically linked to the other traits in the domestication syndrome. (Dugatkin) Belyaev’s team tested hundreds of foxes and selected the top 10% tamest individuals for breeding. They also selected a group of aggressive, defensive foxes to breed, to prove that tameness was inherited genetically. Belyaev wanted to see if the tame foxes would get tamer and tamer over generations, and if the traits in the domestication syndrome would start showing up more and more. He would continue to breed the tamest foxes from each generation so that their gene(s) would become more and more common. (Dugatkin) The researchers found that after only about six generations, many of the foxes would lick the scientists hands, allow themselves to be picked up and petted, whine when the humans left, and wag their tails when they returned. Some of them also showed traits from the domestication syndrome and started to look different from their wild relatives. Over each generation, more and more of the foxes became tame. They developed less stress hormones and had increased serotonin (which makes you happy.) (Dugatkin) The most tame foxes were known as “elite”. Lyudmila Trut, one of the researchers for the experiment
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who continues to work on it to this day, explained: “By the tenth generation, 18 percent of fox pups were elite; by the 20th, the figure had reached 35 percent… Today elite foxes make up 70 to 80 percent of our experimentally selected population.” (PBS NewsHour)
_____Sasha_____
These results show that Belyaev’s hypothesis was correct, even though he didn’t live to see the results. Thanks to this experiment, we now know that domestication is a genetic process, and it causes a multitude of other traits to appear along with tameness. (Dugatkin) This knowledge will help scientists to better understand the domestication process, and in the future, it might even be possible to rearrange the DNA of an animal to domesticate it in a lab. (Verge Science) For now, scientists continue to study the foxes from Belyaev’s experiment, and they have already started to decode the fox genome to develop an even further understanding of the genes that cause domestication. (PBS NewsHour)
Mechta, the first domesticated fox to have floppy ears, 1969.
Works Cited:
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Works Cited
1. Dugatkin, Lee Alan. “The Silver Fox Domestication Experiment.” Evolution: Education and Outreach, vol. 11, no. 1, Dec. 2018, evolution-outreach.biomedcentral.com/articles/10.1186/s12052-018-0090-x, 10.1186/s12052-018-0090-x. Accessed May 2020.
_____Sasha_____
2. PBS NewsHour. “Why Domesticated Foxes Are Genetically Fascinating (and Terrible Pets).” PBS NewsHour, 31 Mar. 2017, www.pbs.org/newshour/science/domesticated-foxes-genetically-fascinating-terrible-p ets. Accessed May 2020. 3. Verge Science. “We Met the World’s First Domesticated Foxes.” YouTube, 11 Sept. 2018, www.youtube.com/watch?v=4dwjS_eI-lQ. Accessed May 2020. Image: “Mechta (Dream), the first of the domesticated foxes to have floppy ears, 1969” Biomed Central, 1969, evolution-outreach.biomedcentral.com/articles/10.1186/s12052-018-0090-x/figures/2.
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“People are often interested in knowing which is smarter, a wolf or a domestic dog.”
—Yash
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Study On Wolves And The Pleistocene Epoch By Yash Lyall _____Yash_____
What is a Wolf?
A wolf (Canis Lupus) also known as “gray wolf” is a large canine, and is native to Eurasia and North America. (Wikipedia). It is the largest member of “Canidae”. Canidae is a biological family of dog-like carnivorans; a member of this family is called a “Canid”. There have been many discussions about the differences between the domestic dog, and a wild wolf. People are often interested in knowing about which is smarter; a wild wolf, or a domestic dog. Mostly, it depends on the situation or consideration. If people consider that an animal has to stay in the wilderness to survive, then a wild wolf is smarter, but if people believe that animals need human interaction to live, then a domestic dog is smarter.(livescience). A wolf is an animal that resists on socializing with humans as they consider humans as predators. Therefore, wild wolves can be very dangerous.
The Beginning The first wolves lived in the time of the “Pleistocene Epoch”. The Pleistocene Epoch was a time period which lasted for a very long time starting from around 2,580,000 years ago, and ending around 11,700 years ago, making it the world’s most recent period of repeated glaciations. It was known to have been the time period when a big part of earth was covered in glaciers.(livescience). The first wolf, “Canis Lupus”, has been assumed to have lived in Eurasia during the Pleistocene Epoch. The Canis Lupus 38 sub species, including the domestic dog; scientifically known as “Canis Lupus Familiaris”. The C. L. Familiaris is known to be the closest to Canis Lupus despite its major differences in behavior as wolves are carnivorans who hunt in the wilderness, and the familiaris is a domestic dog.(Wikipedia). Although they have differences, they share 98% of their DNA making them able to interbreed. A dog the size of a wolf has the same average life expectancy which is 12 - 14 years in captivity. Along with that, they share similar body language at times, and both work well in packs.(SchertzAnimalHospital) Domestic dogs interact well with humans, and wolves interact well with their pack, and they share the same sort of protective instinct.
Adaptivity Wolves have almost no body-heat loss when they are in the snow as they have adapted to living in the cold during the Pleistocene Epoch. Along with that, their thick coat of fur protects them
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from the cold. They also live and hunt in packs as they work together to take down their prey, but they hunt and kill only to eat and survive. They are known to walk large distances, such as 12 miles in a single day.(NationalGeographic).
_____Yash_____
Wolves are very dangerous carnivorans because they live in packs and they are very smart when they hunt. Although all animals have ways to train, a wolf has been known to be the largest member of the Canidae family, being a canine.
Citations: ● "Pleistocene Epoch: Facts About the Last Ice Age | Live Science." 29 Aug. 2017, https://www.livescience.com/40311-pleistocene-epoch.html. Accessed 30 May. 2020. ● "Evolution of the wolf - Wikipedia." https://en.wikipedia.org/wiki/Evolution_of_the_wolf. Accessed 30 May. 2020. ● "Dogs and Wolves: More Different Than They are Alike?." https://schertzanimalhospital.com/blog/dogs-and-wolves/. Accessed 30 May. 2020. ● "Wolves Beat Dogs on Logic Test | Live Science." 3 Sep. 2009, https://www.livescience.com/5672-wolves-beat-dogs-logic-test.html. Accessed 30 May. 2020. ● "Wolf - Wikipedia." https://en.wikipedia.org/wiki/Wolf. Accessed 30 May. 2020. ● "animals/mammals/g/gray-wolf - National Geographic." 8 Sep. 2006, https://www.nationalgeographic.com/animals/mammals/g/gray-wolf/. Accessed 30 May. 2020.
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“These altruistic behaviors have challenged evolutionary theories, especially Charles Darwin’s survival of the fittest theory. This theory states that the strongest, smartest, and fittest individuals in a species are often the ones that survive and reproduce. Natural selections leads us to expect animals to behave in ways that increases of survival, not those of others. ”
—Asyl
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Biological Altruism _____Asyl_____
In evolutionary biology, altruism is when an organism’s behavior would benefit other organisms, at a cost to itself. This means that behaving altruistically would decrease the organism’s chance of having offspring itself, but increases another. Although humans are used to taking care of each other and doing selfless tasks, most animals are in direct competition with each other. Altruistic behavior is common within the animal kingdom, particularly ones with complex social structures. For example, in numerous bird species, a breeding pair receives help in raising its offspring by “helper” birds who protect the nest for predators and help feed the fledglings. Vervet monkeys give an alarm signal to fellow monkeys of nearby predators, even though by doing so, they attract more attention to themself. In social insect colonies, sterile workers devote their whole life to caring for the queen. They do not leave any offspring of their own but their actions greatly assist the reproductive efforts of the queen (Okasha B iological Altruism). hese altruistic behaviors have challenged evolutionary theories, especially Charles Darwin’s T survival of the fittest theory. This theory states that the strongest, smartest, and fittest individuals in a species are the ones that survive and reproduce. Natural selection leads us to expect animals to behave in ways that increase their own chance of survival, not those of others. By behaving altruistically, animals reduce their own fitness. If an altruistic organism is sacrificing itself for the group, how will its genes be passed on so that there are more altruistic individuals in the future? And how can the existence of altruism be reconciled with Darwin’s principals? (STUDY.COM) Well, one proposed explanation to this question is kin selection, which says that altruism persists because by helping a relative reproduce, an individual still passes their own gene to the next generation. (Howgego N o more goody two shoes: Why true altruism can't exist). So from the point
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_____Asyl_____
of view of the gene, altruistic behavior can be selfish. This theory of “inclusive fitness” is what most evolutionary biologists have predicted since the 1960s. British evolutionary biologist, W.D Hamilton first founded the theory in 1963 and noted that it plays a role in the evolution of altruism, cooperation, and sociality (The Editors of Encyclopaedia Britannica K in selection). Jerram Brown pointed out that the inclusive fitness of an individual is divided into two components “direct fitness” and “indirect fitness”. Direct fitness is gained through the production of offspring, and indirect fitness is gained through a ny impact that an individual has on the survival and reproduction of relatives. Biologists know kin selection is accurate because s election normally favors a gene if it increases reproduction because the offspring share copies of that gene, but a gene can also be favored if it aids other relatives, who also share copies. ( c ell.com).
Citations Okasha, Samir. “Biological Altruism.” S tanford Encyclopedia of Philosophy, Stanford University, 21 July 2013, plato.stanford.edu/entries/altruism-biological/. Howgego, Joshua. “No More Goody Two Shoes: Why True Altruism Can't Exist.” N ew Scientist, 11 Dec. 2019, www.newscientist.com/article/mg24432601-600-no-more-goody-two-shoes-why-true-altruismcant-exist/. Gilbert, Natasha. “Altruism Can Be Explained by Natural Selection.” Nature News, Nature Publishing Group, 25 Aug. 2010, www.nature.com/articles/news.2010.427. The Editors of Encyclopaedia Britannica. “Kin Selection.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 14 Apr. 2018, www.britannica.com/topic/kin-selection. STUDY.COM, study.com/academy/lesson/altruism-in-biology.html.
Image Citations “Kin Selection.” Wikipedia, Wikimedia Foundation, 14 Apr. 2020, en.wikipedia.org/wiki/Kin_selection. WildSolutions.nl. “Vervet Monkey Chlorocebus Pygerithrus, West of Busia, Uganda.” Wildsolutions, www.wildsolutions.nl/portfolio/western-uganda-october-2019/vervet-monkey-chlorocebus-pyger ithrus-west-of-busia-uganda/.
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“Natural selection is when living things have traits better suited to the environment than others, and they reproduce and that gene line is passed on and passed on, eventually creating an animal that is more efficient in that specific environment. ”
—Sydney
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What is natural selection?
_____Sydney_____
Natural selection is when living things have traits better suited to the environment than others, and they reproduce and that gene line is passed on and passed on, eventually creating an animal that is more efficient in that specific environment. In shorter words, it is when living organisms adapt and change based on their environment.
Human induced evolution Humans have influenced the change in living over time, like in corn. Farmers used to pick and replant the biggest corn crops, causing that gene to be passed down through each and every plant, until they got to what we have today.
Examples of natural selection A fictional example of natural selection is, there are red, and green bugs in a habitat, and the birds that live in the same habitat like the taste of the red bugs better. Since the red bugs are eaten more than the green bugs, they eventually go extinct, leaving only green bugs
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C, Rachna, et al. “Difference Between Natural and Artificial Selection (with Comparison Chart).” Bio Differences, 3 June 2019, biodifferences.com/difference-between-natural-selectionand-artificial-selection.html.
_____Sydney_____
“Evolution: Natural Selection and Human Selection Article (Article).” Khan Academy, Khan Academy, www.khanacademy.org/science/ap-biology/natural-selection/artificial-selection/a/ evolution-natural-selection-and-human-selection. Examples of Natural Selection, examples.yourdictionary.com/examples-of-naturalselection.html.
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“Better adapted organisms in their environment tend to survive and reproduce. ”
—Tyra
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Survival of the Fittest _____Tyra_____
The phrase, “Survival of the fittest” comes from Darwinian evolutionary theory, it is used to describe the result of natural selection. Natural selection is the process that stands by better-adapted organisms in their environment tend to survive and reproduce. The theory was expounded by Charles Darwin, and it is now said to be the main process of evolution.
Fig 1: Representation of Natural selection (Pinterest- “Darwin and Lamarck PowerPoint” https://www.pinterest.co.uk/pin/99782947968511064/ This diagram is a good example of natural selection, it shows that animals that are better adapted to their environment are more likely to survive. It is ideal for animals that are better adapted to their environment to survive rather than the animals that lack these adaptions. I say this because when the better-adapted animals have offspring they can pass down there traits to them. This allows their offspring to have a better chance of survival which in turn saves their species. Natural selection may be harsh but it is needed as it causes populations to become adapted/well-suited to their environments over time. This applies to both humans and animals.
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_____Tyra_____
"Darwin, evolution, & natural selection (article) | Khan Academy." https://www.khanacademy.org/science/biology/her/evolution-and-natural-selectio n/a/darwin-evolution-natural-selection Dictionary-Natural Selection https://www.google.com/search?safe=strict&rlz=1C1EJFC_enMZ861MZ862&ei=CszUXunUCYX8gKm4raQCQ&q=natural+selction+meaning&oq=natural+selction+meaning&gs_lcp=CgZwc3k tYWIQAzIECAAQRzIECAAQRzIECAAQRzIECAAQRzIECAAQRzIECAAQRzIECAAQRzIECAA QR1AAWABgzaECaABwAXgAgAEAiAEAkgEAmAEAqgEHZ3dzLXdpeg&sclient=psy-ab&ved=0 ahUKEwjpgZizqODpAhWPi1wKHSaxDZIQ4dUDCAw&uact=5
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“When they split from other primates they experienced some major changes such as losing body hair and developing sweat glands. The evolution of primates to humans took a very long time.”
—Jip
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The evolution of humans _____Jip_____
Fossils show that humans originated in Africa. Human skeletons and the skeletons of other primates are very similar. Human move around with straight legs while most primates move with bent legs Over time, humans developed a much bigger brain than their gorilla and orangutan ancestors. Humans started to genetically part ways from other primates around 8 million years ago. When they split from the other primates they experienced some major changes such as losing a lot of body hair and developing sweat glands. The evolution from primates to humans took a very long time. Scientists recognize around 20 different species of early humans. Early humans migrated out of Africa around 2 million years ago.
Sources -https://www.smithsonianmag.com/science-nature/the-top-tend aily-consequences-of-having-evolved-72743121/ -https://www.britannica.com/science/human-evolution -https://en.wikipedia.org/wiki/Human_evolution -https://humanorigins.si.edu/education/introduction-human-ev o lution
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“Bipedalism lets us not to spend to much energy to move. A human use 1/4 the amount of a chimpanzee.”
—Jade
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How Climate Change and Natural Selection has made us Super Athletes
_____Jade_____ “Fast Woman Runner.” Edition.cnn.com, Edition.cnn.com, 11 2011, https://edition.cnn.com/2012/04/11/sport/olympics-2012-campbell-brown/index.html.
5.5 million years ago, with the progressive closing of the Panama isthmus, generated the first cooling of the earth: it led to an aridification of eastern and western Africa. In the light of this climate change, scientists have sketched the evolution of our ancestors. In the savannas, in the east and south of Africa, our ancestors progressively exacerbate the bipedalism, colonising savanas while maintaining their characteristics, allowing them to get shelter in the trees. Their legs are shorter, their arms were more developed, and their feet kept their grip capacities. Those primates are regrouped into the genus of australopithecus. We all know the most famous representent, Lucy, a young woman who lived 3.3 million years ago. Evolution has shaped us to run. How Body changes have made us marathon runners? Savana development has probably enabled an environmental pressure favoring more and more bipedalism. Bipedalism leads to a series of adaptations in our body: Foramen magnum located in the extension of the spin, migrates towards the center of the skull in order to better stabilize the head. The spine becomes sinuous and acts as a shock absorber. Pelvis shortens and enlarges, to guarantee balance (moving forward on two legs is not as stable as 4 legs) and at the same time it accompanies the growth of the head (the opening of the female pelvis conditions the maximal size of a newborn baby that will have to go thought). The knee centers and thickens, loses flexibility although it guarantees better balance. Gluteus maximus, the largest muscle
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in the human body develops in order to assure power and endurance when running.
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The foot flattens while the foot planter stifen, it loses its grip capacities but can now when flattened on the ground furnish more energy for propels. Finally the over development of the tendon boosts our capacity of running. This ligament acts as a spring by accumulating ⅓ of the energy released by the running at each stride to restore for the next stride. The achilles tendon measures 10 cm, 10 times more than a chimpanzee. Our cousin the Chimpanzee has been optimized to alternate from trees to ground. In fact, it is the climate that has made us athletes programmed for endurance running.. The foot grip becomes useless as the trees dwindle. On the other hand the standing position coupled with the trichromatic and tridimensional vision allows us to see further away for predators or food. The standing position also autorises better regulation of the body temperature. Standing in a vertical position our body is less exposed to the sun and it's probable that the loss of hair coincides at that time to allow a better function of the corporal cooling. The veins network that flows under our skin and removes the surpler of heat. In fact the hair never really disappears (there is as much hair in humans and in chimpanzees!), but it lightens and becomes thinner to the extent of becoming almost invisible. In addition to the armpits and the sexual organ region, only the head has retained the fur as a natural protection against the sun. Our african ancestors had of course a darker skin and frizzy hair to maintain freshness. Sweat glance multiplies to allow the regulation of the temperature by releasing sweat. The face flattens because the skull straightens. The ear anatomy expands because the inner ear, related to the balance, is more solicited. The size of the olfactory system reduces in size and therefore in performance because the face has flattened. As buccal cavity develops, our ancestors' vocalises more sound range which will allow them to develop language. And a better audition allows them to hear this wide range of sounds. Adapting to our new environment Finally the brain is going to grow in size during the next upcoming 2-3 million year, develop new areas, and lead to the progressive amergins of cognition as shown by the element of our forehead. The increase of intelligence and the capacity of communication go together with the better adaptability of all biotops. Canine shrink. Probable sign of the modification of our diets, as our ancestors became omnivorous which is a major advantage to adapt to different environments. Bipedalism allows us to spend much energy to move. A human uses ¼ energy less than a chimpanzee. Being omnivorous allows us to spend less energy in digestion, run faster because our digestive organs are smaller. Our entire body structure is made for the race. Our body structure is one of a racer. It protects our organs when we run. In addition, our noses allow us to breathe more air than chimpanzees, and our larynx going down to the throat eases the influx of oxygen in our lungs so that we are capable of controlling our breath with muscles. Comparing us now and back then we have seen these many changes in our body and our body can go from a tree creature to an athlete runner so that we could adapt to our environment. The most important changes we have seen are: the extended standing position, stiff foot, lengthened bones of the limbs, flexible spine, reduced dentition, a complete omnivorous diet, smaller bowel, reduced hairiness, and an abundance of sweat glands made so that the Homo (Sapiens, Herectus, Habilis…) is the only mammal table to run a marathon under the midday sun.
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“Fast Woman Runner.” Edition.cnn.com, Edition.cnn.com, 11 2011, https://edition.cnn.com/2012/04/11/sport/olympics-2012-campbell-brown/index.html.
Testot, Laurent. Cataclysmes: Une Histoire Environnementale De lhumanité: Document. Voir De près, 2018.
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â&#x20AC;&#x153;All species organisms arise and develop through the natural selection of small inherited variations that increase the individuals ability to compete, survive and reproduce.â&#x20AC;?
â&#x20AC;&#x201D;Jacob
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Tigers How did Tigers develop their stripes? Well, this is something called natural selection which comes from Darwinism.
_____Jacob_____ Darwinism is a theory of biological evolution developed by a man named Charles Darwin from 1809–1882. stating that all species of organisms arise and develop through the natural selection of small, inherited variations that increase the individual's ability to compete, survive, and reproduce. So what does this have to do with tigers? Tigers come from many different biomes; rain forests, grasslands, and savannas. Even though these are all completely different types of biomes, tigers still find a way to blend in with them. Tigers are a hunter species that rely on their fur as camouflage while spying on their prey before making a move. Tigers and many other species have gotten their looks depending on what biomes they’re from. As shown in the picture, the tiger really blends in with the surroundings which fool their prey into thinking they’re safe right before the tiger strikes.
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Image link: https://www.pinterest.es/pin/330733166378005915/ “Why do TIGERS have stripes?” Youtube, uploaded by Kiddopedia, Feb 2, 2019, https://www.youtube.com/watch?v=S3F3FpePGFg
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“From the Neapolitan Mastiff to the Chihuahua, selective breeding is responsible for all the different types of dog breeds, but there is a trade-off for having pure beed dogs, and the trade-off for having pure breed dogs, and the trade-off is most of the time the dogs health.”
—Octavio
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The Truth About Selective Breeding and how its harming Dogs
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From the Neapolitan Mastiff to the Chihuahua, selective breeding is responsible for all the different types of dog breeds, but there is a trade-off for having pure breed dogs, and the trade-off is most of the time the dog’s health. Artificial selection (or selective breeding) is the process of breeding plants or animals to obtain qualities that the breeder wishes to have. Selective breeding works when a parent has offspring and if an offspring has a trait that the breeder likes, then the breeder will breed more of that trait. (The Editors of Encyclopaedia Britannica Domestication) This process is how all dog breeds were made but as we breed more unique dogs, the dogs themselves are not benefiting from this sometimes this process is harming the dog. (The Editors of Encyclopaedia Britannica Selection) Issues that can arise from selective breeding are skin problems. According to PBS as many as 15 per cent of all dogs have skin allergies, atopic dermatitis (very itchy skin), and inflamed skin but certain breeds have it worse than others Dalmatians, Vizslas, and several terriers, such as the Boston Terrier, Bull Terrier, and the West Highland White Terrier are all prone to atopic dermatitis, And the numerous skin folds of a Chinese Shar-Pei, so valued by some breeders, can become breeding grounds for staphylococcus and other bacteria, which cause frequent skin infections. Also, excess wrinkles of skin on the face can rub on the eye, causing lesions and, potentially, blindness. (PBS Dogs That Changed The World) & ( Jezierski Evolution: Library: Evolution of the Dog) Some more issues that can arise from selective breeding are blood disorders and neurological, behavioural and sensory difficulties Bassett Hounds are prone to an inherited abnormality the effects the ability of the platelets in the blood to clump together after an injury. The blood doesn’t clot properly, leading to haemorrhage and bruising. Clotting problems also plague dogs with von Willebrand’s disease, a genetic condition frequent in Doberman Pinschers. Neurological and behavioural problems afflict many pure breeds. Bull Terriers, for example, often compulsively chase their tails. Pugs are be predisposed to Pug Dog encephalitis, a fatal brain disease. Scottish Terriers are affected by Scottie Cramp, a disorder that causes the dogs to lose muscle control when they get excited. German Shepherds may inherit degenerative myelopathy, a crippling spinal cord disease that causes weakness and eventually paralysis. (PBS Dogs That Changed The World) One of the biggest issues that plague all purebred dogs is cancer, Cancers are strongly influenced by genetics, and so it is not surprising to find various types of cancer among different dog breeds. For example, bone cancer, or osteosarcoma, is considerably more frequent among large and giant breeds of dogs, such as the Irish Wolfhound, Great Dane, Rottweiler, Labrador and Golden Retriever, Greyhound, and Saint Bernard, because their bones are stressed by carrying so much weight. High rates of malignant blood vessel tumours are seen among Golden Retrievers, which
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are also prone to leukaemia and brain tumours. German Shepherd Dogs and Chow Chows are predisposed to gastric cancer, while Scottish Terriers are 18 times more likely to develop bladder cancer than are other breeds. (Curley Purebred Dogs Offer Insight in Cancer Research) & (PBS Dogs That Changed The World) Selective breeding works on the basis of natural selection but instead of nature choosing the traits that get to be passed on, the breeder is the one who can choose which trait he would like. Natural selection can be seen everywhere, an example of where we can see this is in the bacteria that infect us. When we get infection we usually use antibiotics to cure but sometimes when a bacteria mutates is may develop a trait that can make it more resistant to that antibiotic that you are taking, This is also known as antibiotic resistance. It is speculated that the detective breeding of dogs started over 14000 years ago before we started to practice agriculture. The “original” dog that we started to breed was a wolf but the species of wolf that dogs come from went extinct, some scientist speculate that the “original” dog came from a variation of the grey wolf that is no longer around. And ever since then we have created over 300 different dog breeds! Making dogs the most diverse man-made animal.
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Work Cited
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Curley, Kendall. “Purebred Dogs Offer Insight in Cancer Research.” PetMD, 15 May 2018, www.petmd.com/news/health-science/purebred-dogs-offer-insight-cancer-research-37084. The Editors of Encyclopaedia Britannica. “Selection.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 2 Dec. 2015, www.britannica.com/science/selection. The Editors of Encyclopaedia Britannica. “Domestication.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 6 Dec. 2018, www.britannica.com/science/domestication. Anonymous. “Dog Breeding.” Wikipedia, Wikimedia Foundation, 29 May 2020, en.wikipedia.org/wiki/Dog_breeding. “The Selective Breeding of Dogs.” OpenLearn, The Open University, 1 Mar. 2019, www.open.edu/openlearn/science-maths-technology/science/biology/the-selective-breedin g-dogs. “Dogs That Changed The World.” PBS, Public Broadcasting Service, 21 Oct. 2014, www.pbs.org/wnet/nature/dogs-that-changed-the-world-selective-breeding-problems/1281/ . Anonymous. “Origin of the Domestic Dog.” Wikipedia, Wikimedia Foundation, 29 May 2020, en.wikipedia.org/wiki/Origin_of_the_domestic_dog. Jezierski, Chet. “Evolution: Library: Evolution of the Dog.” PBS, Public Broadcasting Service, 2001, www.pbs.org/wgbh/evolution/library/01/5/l_015_02.html. Hadden, Joey. “Fascinating Photos Show How Drastically Some Popular Dog Breeds Have Changed over the Past 100 Years.” Business Insider, Business Insider, 16 July 2019, www.businessinsider.com/how-dog-breeds-looked-100-years-ago-2016-2. RuralNews, Redação. “Seleção De Bovinos - Melhoria Do Rebanho.” StackPath, 29 Apr. 2016, ruralnews.com.br/visualiza.php?id=326. Anonymous. “Seleção Artificial.” Wikipedia, Wikimedia Foundation, 16 Apr. 2020, pt.wikipedia.org/wiki/Sele%C3%A7%C3%A3o_artificial. “What Is Selective Breeding?” Facts, The Public Engagement Team at the Wellcome Genome Campus, 30 July 2019, www.yourgenome.org/facts/what-is-selective-breeding.
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“Evolution: Natural Selection and Human Selection Article (Article).” Khan Academy, Khan Academy, www.khanacademy.org/science/ap-biology/natural-selection/artificial-selection/a/evolutionnatural-selection-and-human-selection.
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BioLogos. “Artificial Selection and the Origins of the Domestic Dog - Articles.” BioLogos, BioLogos, 4 Apr. 2013, biologos.org/articles/series/evolution-basics/artificial-selection-and-the-origins-of-the-dome stic-dog. Akey, Joshua M., et al. “Tracking Footprints of Artificial Selection in the Dog Genome.” PNAS, National Academy of Sciences, 19 Jan. 2010, www.pnas.org/content/107/3/1160.
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“It seems to me that the natural world is the greatest source of excitement; the greatest source of visual beauty, the greatest source of intellectual interest. It is the greatest source of so much in life that makes life worth living.” —Sir David Attenborough
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Exploring
Evolution AISM Science Magazine | 160
