Evolve Magazine by Anne Bradt

November 2012

The science of who we are

CLEVER WAYS FEMALE ANIMALS CONTROL REPRODUCTION The ladies of the animal kindgom have wiles all their own Pg.5

INTERVIEW WITH TULLIS ONSTOTT He found microbes that live on radiation Pg. 10

DRUG DETECTIVES

FEATURES:

Scientists try to find a way to curb the growing number of lethal overdoses Pg. 19

Book Scientist Unusual Organism Advances in Biology For Your Information

THE LANGUAGE OF THE

BRAIN Pg.13

OCTOBER 2012 $4.99

Contents -

ARTICLES 5

8 Clever Ways Female Animals Control Reproduction A look into the amazing ways the ladies of the animal kingdom take control.

Interview with Tullis Onstott He went two miles down and found microbes that live on radiation.

The Language of the Brain How the worldâ&#x20AC;&#x2122;s most complicated machine processes and communicates information

Drug Detectives Physicians struggle to curb the growing number of overdoses

Advances: Advances: Best of the Blogs Underground Network

Unusual Organism Bouncer Bees

Amazing Scientist Shawn Douglas

For Your Information Prehistoric Birds

Must Read The Brain that Changes Itself

Advances in Biology Male Contraceptives

Evolve Magazine, November 2012

COLUMNS

Editor’s Note

ow many scientists are in your govern-‐ ment?” People asked me all sorts of things when I visited Moscow last year, but that simple question, and its expectation that naturally there should be many, many made me pause. I knew Russia’s multimillion-‐dollar “megagrant” investments to encourage expatriate research-‐ ers to work in the country and the around $11 billion set aside to gin up nanotechnology businesses. Visiting Doha, Qatar; I learned about that country’s pursuit of a “knowledge-‐based economy” and its aims to foster solar energy for desalination as well as telemedicine. At the annual Lindau Nobel Laureate Meeting in Germany, I saw nearly Ǧ ǯ ϐ ǡ -‐ ty-‐style. Clearly, many nations see science as their ticket to a better future. ϐ ǯ science. Technology innovation is responsible for half the U.S.’s economic growth since World War II. It has been the engine of our modern prosperity. Yet today we are faltering in critical areas of science, technology, engineering and mathematics (STEM) education and in maintaining ϐ Ǥ ǡ ǡ that the U.S. started focusing on what matters. With that ambitious goal, we began work on this issue’s special report, “State of the World’s Science.” Executive editor Fred Guterl has organized and array of stories on the critical themes in global science today, from the rise of China to the manufac-‐ turing power of Germany to the best ways to encourage ϐ Ǥ highlight such features as research spending and the number of papers published in select journals. Turn to page 36 for the start of the section. As I hope you will agree, the result is Ǧ Ȅ Ǥ ϐ country’s uneven relationship with science. Technology innovation is responsible for half the U.S.’s economic growth since World War II. It has been the engine of our modern prosperity. Yet today we are faltering in critical areas of science, technology, engineering and mathematics (STEM) ϐ Ǥ It was high time, I decided, that the U.S. started focusing on what matters. With that ambitious goal, we began work on this issue’s special report, “State of the World’s Science.” Executive editor Fred Guterl has organized and array of stories on the critical themes in global science today, from the rise of China to the manufacturing power of Germany to the best ways to ϐ Ǥ graphics highlight such features as research spending and the number of papers published in select journals. Turn to page 36 for the start of the section. As I hope you will agree, the result is though-‐provoking—and inspiring.

Evolve Magazine, November 2012

Features

Best of the Blogs:

Underground Network

Unusual Organism:

Bouncer Bees

he stingless jataí bee lives in a viciousworld where marauding robber bees steal its food and plunder its hive. For protection, Jataí worker bees have evolved a specialized variant: the bouncer bee, a burly guardian with massive legs and a surprisingly small head. ǡ ϐ Ǥ The queen lays eggs; male drones mate with the queen; and female workers guard the nest, collect food, and construct honeycomb. Scientists rarely observed physical differences among workers and widely assumed their size was uniform. But while studying Jataí in São Paulo, entomologist Cristiano Menezes noticed that the females at the hive entrance looked larger than other workers. Measure-‐ ͳʹ ϐ Ǥ Àǡ specialized for guard duty [$], are 30 percent heavier, with legs about 40 percent larger than those of foragers. Their heads are oddly disproportionate, only 25 percent larger than foragers’ noggins. Guarding is a grisly job made necessary by food raids from Lestrimelitta limao, a strong-‐jawed robber bee. Bouncers chomp down hard on the base of the enemy’s wing. But intruders can twist around and decapitate a guard with a powerful bite. “You’ll often see a robber bee walking, and on each wing is a separate Jataí mandible,” says entomologist Christoph Grueter, who published the work with Menezes. Even when killed, the bouncers prevail: Robbers with Jataí heads on their wings can no ϐ Ǥ By Josie Garthwaite

Evolve Magazine, November 2012

Must Read:

The Brain that Changes Itself

hat is neuroplasticity? Is it possible to change your brain? Norman Doidge's inspiring guide to the new brain science explains all of this and more An astonishing new science called neuroplasticity is overthrowing the centuries-‐old notion that the human brain is immutable, and proving that it is, in fact, possible to change your brain. Psychoanalyst, Norman Doidge, M.D., traveled the country to meet both the brilliant scientists championing neuroplasticity, its healing powers, and the people whose lives they've transformed-‐-‐people whose mental limitations, brain damage or brain trauma were seen as unalterable. We see a woman born with half a brain that rewired itself to work as a whole, blind people who learn to see, learning disorders cured, IQs raised, aging brains rejuvenated, stroke patients learning to speak, children with cerebral palsy learning to move with more grace, depression and anxiety disorders successfully treated, and lifelong character traits changed. Using these marvelous stories to probe mysteries of the body, emotion, love, sex, culture, and education, Dr. Doidge has written an immensely moving, inspiring book that will permanently alter the way we look at our brains, human nature, and human potential.

o human eyes, the soil may look like a ϐ rocks, but it is actually a highly complex living environment. Not only must the bacteria that live within it share their space with small animals, protozoa and fungi, but they also must work around giant complexes of tree roots. These roots are not just static objects but take an active part in shaping the microbial communities around them. As an ex-‐biochemist, I am used to the idea of studying plant-‐microbe interactions by exploring only one plant and one microbe, so I was fascinated by recent research at the University of North Carolina at Chapel Hill and other institutions that looks at entire microbial ecosystems. Researchers collected two types of soil from different locations and grew samples of the plant Arabidopsis thaliana in each one. They then collected soil that had grown around the roots and looked at the bacterial species within that soil, as well as the bacterial species growing within the roots themselves. Collabora-‐ tion with a next-‐generation sequencing team allowed them to identify the various bacterial species present. They found that a subset of all the bacteria in each soil was found clustered around the roots, and an even smaller subset was allowed inside. Examining the bacteria inside each plant revealed a core microbiome common to all the plants as well as a separate set of bacteria that plants recruited depending on soilBecause bacteria help to provide nourishment for plants, such ϐ plant-‐bacteria interactions in ways that enable vegetation to grow and possibly even thrive in nutrient-‐poor soils. -‐S.E. Gould

Advances in Biology:

Gel Birth Control for Men

hen it comes to taking charge of one’s reproductive fate, women have had reliable birth control methods for decades now. For men the story is completely different. Though not for lack of trying, the medical establishment has failed to produce a consistent-‐ ly reliable method of contraception that is both non-‐per-‐ manent and healthy for men to take. But research coming out of Los Angeles Biomedical Research Institute at Harbor-‐UCLA Medical Center could change that via a simple gel applied directly to the skin. The key ingredients here are well-‐known-‐-‐they’ve been combined in hopes of creating a male contraceptive before. The male hormone testosterone, which naturally possesses some contraceptive effectiveness, and progestin, which boosts the effectiveness of the testoster-‐ one, have been tried in tandem before. Previously these methods involved injections of progestin, or pills or even implants that administer it. And they’ve been largely ineffective. The breakthrough here is the introduction of a new synthetic progestin called Nestorone, which along with testosterone leads to dramatic reductions in sperm production that make pregnancy a far outside chance. Applied to the skin together through transdermal gels, ϐ reduced sperm counts in roughly 89 percent of men. Moreover, the gels can be easily applied by men at home; no need to swing by the clinic at regular intervals for a booster shot of progestin. Nestorone also cuts down on some of the side effects-‐-‐acne, changes in cholesterol levels, etc.-‐-‐associated with some other progestins. Of course, reduced sperm count in 89 percent of men isn’t exactly perfect (women using approved birth control experience pregnancy at a rate of just three-‐tenths of a percent per year, by comparison). Figuring out that last ten percent or so will no doubt be the hardest part of this research, so don’t look for these lotions on store shelves anytime in the near future. By Clay Dillow

For Your Information:

Amazing Scientist:

Did Birds Evolve Flight Shawn Douglas By Falling Out of Trees? hawn Douglas grew up building R/C cars and

Possibly. The trees-‐down (or “arboreal”) hypothesis has been around for many years, says evolutionary biologist Richard O. Prum of Yale University. Researchers guessed that the scales of tree-‐dwelling Triassic reptiles elongated into feathers, which helped them leap away from predators. Once the proto-‐birds could glide, they were en ϐ Ǥ ǲ ǡ ideas all stuck together,” Prum says. What’s wrong with the story? Scientists have largely worked out the origin of birds and feathers, two thirds of what Prum calls the “holy trinity” of evolutionary ornithology. In the 1970s, Yale professor John Ostrom developed anatomical evidence strongly suggesting that birds evolved from theropods such as Tyrannosaurus rex. Other research showed that feathers weren’t always ϐ Ǥ ǯ scales might have evolved into elaborate, multicolored ǡ ϐ Ǥ ϐ ǡ ϐ ǡ remains a mystery. There are several theories about it, and many begin on the ground. For instance, the University of Montana’s Ken Dial uses high-‐speed digital ϐ ϐ Ǧ Ǥ proposed this “wing-‐assisted incline running” as an intermediate evolutionary step that may have helped birds eventually go from the ground to the air—not the other way around. By Daniel Engber

planes, using skills he picked up from his repairman father. Two decades later, he’s still assembling machines—only they’re now a billionth the size, made from DNA, and designed to destroy cancer cells. Other labs have worked with DNA to build distinct shapes—a process colloquially known as DNA origami—but most have produced nonfunctional objects. At the University of California at San Francisco, Ǥ ǲ ϐ have realized the dream of a truly programmable container for delivering therapies to cells in a targeted way,” says Paul Rothemund, a biochemical engineer at Caltech. Douglas’s nanomachine looks like a clamshell, its halves clasped together by two sets of entwined Ǧ ϐ antibodies or drug molecules. When the DNA binds to proteins on target cells, such as cancer, the two double strands unzip and the clamshell swings open to unleash its cargo. Such targeted drug treatment would require lower doses of disease-‐killing chemicals—and thus produce fewer unpleasant side effects. Douglas hopes nanotechnology will attract new generations of tinkerers. “I want to get college students to come with new ideas and do all sorts of exciting stuff,” he says. Last year, he launched BioMod, a competition in which students build their own nanomachines. So far 25 teams have already signed up By Lauren Aaronson.

Evolve Magazine, November 2012

Clever Ways Female Animals Control Reproduction Sexual reproduction in the animal kingdom is often a tenuous alliance between male and female. Both parents want (in an evolutionary sense) to pass on their genes, but that's all they really agree on. Females of most species invest more energy in caring for babies, so they are more picky about when and with whom they mate. To get their wishes, males sometimes turn to strategies like forced matings or "traumatic insemination" (read on...), but their female counterparts have quite a few reproductive tricks up their hoo-hahs too.

8 Clever Ways

There are up to three kangaroo babies in this tableau: the "young-‐at-‐foot" hopping out in front, another joey hidden inside its mother's pouch, and a third-‐-‐a tiny embryo-‐-‐lurking in the womb. Female kangaroos, you see, are permanently pregnant, but they can halt development of embryos through a strategy called diapause. Although joeys can be born after less than a month of gestation, they spend nearly eight more months suckling on a teat in their mother's pouch. The female red kangaroo can mate and become pregnant again during this time, but the new embryo will grow no larger than a clump of 70 to 100 cells. When the nursing joey reaches 200 days old, development of the embryo restarts; a day before birth, the mother kicks the older joey of out her pouch to make space for its younger sibling. But the new young-‐at-‐foot isn't quite gone yet. It sticks around and continues nursing up to one year of age. Female kangaroos' teats produce different types of milk tailored to the different nutritional needs of a joey in the pouch and at-‐foot

Arrested (Embryonic) Development

http://discovermagazine.com shuttershock

"I'll Have What He's Having"

Evolve Magazine, November 2012

Female primates, and only females, are known for especially loud noises during sex. Scientists have long speculated that these "female copulatory calls" aren't just a pointless quirk-‐-‐they might have an evolutionary function. Female primates aren't just overcome with passion, according to this hypothesis-‐-‐they're telling all the other males nearby what they're up to. Attracting more mates during copulation is a way of inciting male-‐male competition, so that she's more ϐ Ǧ Ǥ ǡ mating with multiple males, some researchers have argued, paternity becomes confused. That may not sound obviously desirable, but it decreases infanticide by males: Male primates are less likely kill young they did not father if they can't tell which babies are theirs. One other idea for why female primates (potentially including humans) vocalize during sex: to get their mates to climax faster. In either case, it seems to be a way for the female to assert reproductive control

Clockwise Vaginas v. Counterclockwise Penises

Unlike most birds, male ducks have penises. And not just your garden-‐variety penises: corkscrew-‐shaped phalluses that are over a foot long and capable of "explosive eversion" They often use these large penises to forcibly mate with unwilling females. Both sides have evolved some pretty bizarre anatomy in this evolutionary battle of the sexes. Female ducks may not ϐ ǡ ways of keeping out their sperm. Unlike nearly any other species on the planet, female ducks have exceedingly complicated vaginas to keep unwanted phalluses out. And while the males penises spiral counterclockwise, the females' vaginas wind clockwise, making it harder for the males to get in a ϐ Ǥ ̵ ǡ anatomical blind alleys in their vaginas: Unwanted males that can't get very far in end up ejaculating into shallow pouches that keep sperm far away from any eggs. A willing female, on the other hand, can relax her muscles to let the male further in, increasing the chances of conception. Female ducks are doing something right: While a third of duck sex is the forced kind, only 3% of all offspring are born out of these matings. Sławek Staszczuk / Wikimedia Commons

ebaetscher

Due to a chromo-‐ somal quirk, female birds may have special control over the sex of their offspring. Female birds have the one Z chromosome and one W chromosome, while males have 2 Z's, which means a chick always inherits a Z from its father and either a Z or a W from its mother. For birds, the sex chromosome passed mother determines the sex of the offspring, the reverse of how it works in all mammals. (In case you're wondering, the "male" designation always goes to the sex that makes sperm, or the smaller gamete.) So by preferentially keeping eggs with either a Z or W chromosome, female birds can bias the offspring sex ratio. When a female blue tit mates with a high-‐quality male, for example, she tends to have more male offspring. High-‐quality males can pass on their desirable traits, like good singing ability, to their sons. This becomes particular-‐ ly important because a high-‐quality son will mate with many females, so the best way for a female to insure her own genes will spread is to hitch them to the desirable genes of a high quality male.

Boy or Girl? Lady's Choice

Evolve Magazine, November 2012

8 Clever Ways

A human who wants to store sperm to use it another day would need a trip to the cryogenic sperm bank, but a number of female animals can pull off the same feat without a deep freezer. It's a common strategy taken to different lengths by queen ants (30 years), snakes (seven years), chickens (30 days), and bats (six months), to name just a few. In comparison, human sperm survives in a woman's upper genital tract for a mere 3 to 5 days. Crickets have one of the better-‐stud-‐ ied mechanisms of storage: A biomechanical trick in the female cricket's sperm storage organ somehow slows down sperm metabolism, extending their viability to several weeks. A study earlier this year found that sperm stored in female crickets have fewer free radicals, hydrogen-‐hungry molecules that cause cell damage. Free radicals are a normal byproduct of metabolism, but their accumulation may be a molecular cause for aging. By keeping sperm around for longer, a female can mate once, and then fertilize her eggs and give birth at her convenience

A Personal Sperm Bank

Photo: Jess Dittmar

nycgeo / Flickr

Danny Steaven / Wikimedia Commons

In the simple view of inheritance, it doesn't matter whether a gene comes from your mother or your father. But itin real life, it does matter-‐-‐especially in mammals. Genomic imprinting means that some genes are silenced if inherited from one parent but not the other. From placenta to milk, baby mammals are especially good at extracting nutrients from their mothers. For a male fathering children with many mates, it's in the interest of his genes that the baby suck as much out of the mother as it can. Mothers, on the other hand, want to save resources for their future offspring. Genes are often imprinted according to these battle lines. Take, for example, insulin-‐like growth factor 2 (Igf2) and its receptor (Igf2r) in mice. Igf2 promotes growth of the fetus, while Igf2r restricts growth by binding and inactivating Igf2. In order to limit how much the fetus can draw from its mother, the maternal version of Igf2 is silenced, while Igf2r is activated. For the father, who "wants" the fetus to grow as big as possible, the situation is exactly reversed (Igf2 activated; Igf2r silenced). Several other genes that control embryo growth and suckling behavior follow this same pattern. Genomic imprinting is epigenetic, meaning that the underlying DNA sequence doesn't change. Instead, specially placed methyl groups-‐-‐a carbon atom surrounded by three hydrogens-‐-‐turn a gene on or off. Methylation and thus imprinting generally reset in each generation, so that an imprinted gene can be active in a man's daughter but then inactive her offspring.

You Definitely Have Your Father's Igf2

Evolve Magazine, November 2012

As hermaphrodites, banana slugs having sex gets a little complicated. Both parties have penises-‐-‐large, body-‐length penises-‐-‐that have to be inserted into each other's female tract. And then things can get a little sticky. Sometimes, it seems that one banana slug is stuck in the other, so it chews off the other guy/gal's stuck penis before they can go their separate ways. That's one theory. Apophallation, or amputation of the penis, is still a somewhat mysteri-‐ ous behavior in banana slugs. An alternative theory ̵ ǣ ̵ ϐ behavior explained by sperm competition. By chewing off the other slug's penis, the chewer insures that its partner is unlikely to mate again. (Sure, the once-‐hermaphrodite chewee slug can still mate as a female, but a banana slug missing half its sexual organs is less desirable.) That ensures that all of the chewee's eggs were fertilized by chewer, who is free to mate with more slugs and spread its sperm farther and wider.

Apophallation, or: I'm Biting Off Your Penis

Richard Ignell / Wikimedia Commons Andy.gorachev / Wikimedia Commons

If You Can't Beat 'Em...

Female bed bugs have perfectly intact and straightforward reproductive tracts, but male bedbugs aren't into that. No, they opt instead for traumatic insemination, which is just as grisly as it sounds. The male's needle-‐like paramere-‐-‐the bug equivalent of a penis-‐-‐pierces the female's body, and he ejaculates directly into her abdominal cavity. For obvious reasons, traumatic insemination is not so great for the female bedbug; one estimate says it cuts their lifespan by a quarter. Female bedbugs haven't exactly fought back, but they have, in a way, adapted to the trauma of bedbug sex. Off to one side of her abdomen is a small pale groove called the spermalege. If the female is pierced in the spermalege, specialized tissue helps the wound heal and scar. Scientists have suggested the specialized organ evolved to prevent post-‐insemination infection, especially important since blood-‐sucking bedbugs don't live in the cleanest of habitats. O

Evolve Magazine, November 2012

10 1

Photo: Â Jess Â Dittmar

Interview with:

Bacteria found in gold mines and frozen caves show the extreme flexibility of life, and hint at where else we might find it in the solar system.

Evolve Magazine, November 2012

“

The radiation keeps on recharging the battery for the bacteria that then do their thing. Those bacteria could then sustain other deep organisms.

ϐ ǡ ͳͻͻ͸ǡ African mines—for instance, microbes similar to those previously had no idea what to expect. What was that trip like? seen only at the bottom of the ocean. The miners took me into the stopes, the tunnels where they mine gold, to sample the rocks. We were looking at an organic rock layer just millimeters ǡ ϐ carbon was a good place to look for life. The stopes are a meter high and they tilt downward at a steep angle, so you go down them almost like a slide, passing from one tunnel to the next. I basically slipped into a rabbit hole and got this big chunk of rock. I put it in an autoclave bag [normally used for sterilizing equipment], stuffed it in my knapsack, and then I went down the stope further until I came out the bottom into another, deeper tunnel.

What did you do with the sample you collected? We measured the rock’s radioactivity. The Geiger counter showed it was hot ǡ ϐ argon gas, which pushed out all the oxygen. Organisms that live deep down are not normally exposed to oxygen, and in fact it could be toxic to them. So we sealed the rock away until we could get it back into the lab. I checked this radioactive rock inside a steel thing as baggage on a plane. This was 1996. Airport security was not like it is today.

ǡ ϐ ǫ ϐ hot spring in New Mexico. But the surprise was that this particular species could do something the other hot spring organisms could not: reduce [i.e., transfer electrons to] iron, which is present in minerals that are abundant in the mine’s rocks, and uranium, part of soluble compounds found in water in the mine. That helped us understand how they got their energy.

That’s right. We went back to South Africa in 1998, this time to Driefontein Mine, located about 40 miles southwest of Johannesburg, and took water samples, which are easier to work with than rock and less likely to be Ǥ ϐ Ǧ ȏ ǡ Ǧ ϐ ϐ ȐǤ don’t know how the same organisms got to be in both places, because South African crust has not seen ocean water in two-‐and-‐a-‐half billion years. It’s very much a mystery. We published the data, and the National Science Foundation gave us more money to go back again in 2000.

What happened on your third deep excursion in South Africa? The next time, we purchased a house in one of the villages near the gold mines and set up a semipermanent lab there. Over two years, a rotating team from my lab and six other institutions collected most of the samples that ǯ Ǥ ϐ ϐ and look at more radioactive samples. We began developing an idea that radiation in the rock provides energy for microorganisms. Wherever we had radiation, we tended to see hydrogen gas forming. It made me realize that radiation should produce hydrogen by breaking water bonds. Hydrogen is the key component the bacteria need to make ATP, the molecule they use for Ǥ Ǧ ϐ ǡ Ǧ ecosystem. Such things aren’t supposed to exist.”

That’s amazing, since we usually think of radioactivity as deadly—but these organisms were actually living on radiation?

Then you found still more perplexing discoveries in other South Well, not just radiation, but radiation, water, and rock were all that was needed to support life at depth. You don’t need light, food, or anything else

Evolve Magazine, November 2012

Tullis Onstott from the surface. Plus, it’s a renewable energy source. It turns water into hydrogen and hydrogen peroxide, which helps make the metals that the organisms consume. It is like recharging an electric battery. The radiation keeps on recharging the battery for the bacteria that then do their thing. Ǥ ϐ really important to NASA because you can imagine any body in the solar system that has liquid water beneath the surface—like Jupiter’s moon Europa, probably—will have energy for organisms as well.

Can we observe these organisms at work in the lab? The rule of thumb is that when you get back to the lab, you can grow less than 0.1 percent of what actually exists down there. We tried all sorts of ways to grow them, gave them all sorts of nutrients we thought they might want, and we failed miserably.

Since you couldn’t grow the bacteria that you found deep down, how did you learn just how they functioned? ǡ ϐ ǡ ϐ Ǥ

Organisms so far underground, reliant on so few resources, must live a pretty limited existence, right?

Photo by Jess Dittmar

“

Candidatus Desulforudis audaxviator is entirely self-sufficient. It has its energy source, radiation. It contains everything it needs to exist, and it requires nothing from another organism.

Since the population of cells down there is small, most people thought they would just barely be able to eke out a living, that they were organisms with very few capabilities. But it turns out that was totally wrong. We did a full analysis of Candidatus Desulforudis audaxviator, an organism we found again and again in different mines in South Africa at the greatest depths—never above 2 kilometers (1.2 miles)—that made up 99.9 percent of the DNA in some of our samples. This thing had everything. It could take nitrogen directly from its environment, something we did not expect subsurface organisms to do because it takes so much energy. But the real ϐ ǡ themselves, which basically means it could be swimming around in the environment. It had genes for gas vesicles, which means it can adjust its buoyancy in the environment. And it had genes for chemoreception, which tells us it’s sensing something. The genome is saying it’s a very adaptable organism, and it has the capability of moving around. The idea that organisms down there might be moving around and interacting with the environment—that was really surprising. The only tip-‐off from the genome that this is a subsurface organism is that it has no protection against oxygen. As soon as it hits air, it’s dead.

And does that microbe interact with other species down deep? Ǧ ϐ Ǥ energy source, radiation. It contains everything it needs to exist, and it requires nothing from another organism. The fact that we’ve found it almost by itself tells us that it’s a one-‐species ecosystem. Such things aren’t supposed to exist. We thought all organisms depended on others, but this one doesn’t. We’ve found a whole new way to live.

In addition to bacteria you also discovered more complex, multicel-‐ lular organisms living 1.5 kilometers down—almost a mile under-‐ Ǥ ǡ ϐ ǫ In 2006 I was contacted by Gaetan Borgonie, a Belgian scientist who had found microscopic roundworms, or nematodes, in caves in Central America. ǡ ϐ ǡ up of bacteria, in a mine in South Africa, too. So we went down together into ϐ Ǥ ϐ Ǥ about 1,000 cells, so it’s not exactly a big guy, but still—I never would have ϐ Ǥ

The deepest organisms you have found so far are from 3.8 kilome-‐ ters (2.4 miles) underground—the farthest that it’s been possible to explore until now. How much deeper might life go? At Mponeng mine, a company is now drilling a tunnel to explore for gold ϐ Ǧ Ǧ Ǧ Ǥ ǡ ǯ economically feasible. For us, we think, “Yay!” The deeper, the hotter, the better. Down that far, it’ll be 90 degrees centigrade, about 195°F. That’s Ǥ ǯ ϐ ǡ ǯ what the next several years will turn up.

Evolve Magazine, November 2012

What will going that deep into the planet tell us about life and evolution up here on the surface? We’re trying to see what the base of the biosphere, of all life on Earth, looks like. If DNA organisms exist down that far and at such high temperatures, we ϐ ǡ ǯ ǡ understand why. And if there are no DNA organisms, are there other types of organisms that might occur there in very small concentrations? There may exist a shadow biology—very, very primitive organisms that may have come into existence very early on our planet but were completely replaced by DNA organisms everywhere else.

So far you’ve talked only about hot environ-‐ ments, but what about the other extreme? Many of the places elsewhere in the solar system where we’re looking for life, like Mars, are intensely cold. Have you explored any analogous low-‐temperature environments on Earth? Mars has this very thick cryosphere, or permanently frozen rock layer, on its surface. So we went to a gold mine deep beneath the permafrost in the high Arctic, in the Nunavut territory in Canada. The mine has a helical tunnel that goes a kilometer and a half down. All this warm air comes up from below, and as soon as it hits the permafrost layer, where the ground is permanently frozen, all the moisture in the air ϐ ǡ feet wide. You get ice stalactites and ice stalagmites all over. It looks like Superman’s sanctuary. It’s easy to imagine there might be something like this on Mars as well. I had an epiphany within these ice caves: This is the kind of environment you’d want to explore if you ever went to Mars; send your rover inside the caves and have a look around. There’s moisture there. There’s plenty of room for life in these environments. Unfortunately, we never really had a chance to explore and look for life in those caves before that mine shut down.

Could we pick out signs of microbial life on Mars even before we go digging around in caves there? http://www.camse.org On parts of Mars, there’s methane gas that may be seasonal. It seems to appear and then go away. That means something unusual is happening: There has to be something that makes the methane and something that consumes it. The Arctic regions where those microbes live are warming rapid-‐ The question is, are life-‐forms making and consuming the methane? If life ly. What impact might that have on the Earth? is generating and consuming that methane, its chemical signature will There’s a concern that those microorganisms will all of a sudden kick on change because of those biological processes. So as a project with NASA, and start chewing up organic matter, making carbon dioxide and ǯ ϐ methane. That could cause a runaway greenhouse effect in the later part Ǥ ϐ of the century. Our mission is to try and understand whether that will seasonal cycle and its composition is changing, that’s a very good indica-‐ happen. We collected 40 ice cores from the island. We’re gradually tion that there’s something alive on Mars. But whatever that something is, thawing them to study which microorganisms are doing what, and which it’s going to be something quite different from anything we’ve seen on gases are being released and how quickly. Then we’re comparing this to Earth because the surface conditions on Mars are pretty inhospitable to ϐ ǡ -‐ life as we know it. ment seems to be doing the same things as the permafrost in the lab. A lot You’ve looked at other extremely cold environments to learn more of groups are doing similar studies across the Arctic. We don’t know the ǡ ϐ about life here on Earth, too. What was that like? We’ve gone up to Axel Heiberg Island, a Canadian island high in the Arctic to expect over the next 100 years. Ocean, to do some work there at the McGill Arctic Research Station, a.k.a. Has studying these various kinds of extreme, deep-‐dwelling Mars. It’s one of the largest uninhabited islands in the world, and very microbes changed your thinking about what’s necessary for life? beautiful. It has enormous mountain glaciers, almost like a little Swiss The more I learn, the more it seems that the requirements for life are Alps, so it’s a nice change from the mines. We went up there to study pretty minimal. The niches that life can occupy never cease to amaze me. microbes living in the permafrost that have been frozen for millennia. A place may look terrible to us, but to something else, that’s their Eden. O

Evolve Magazine, November 2012

The

Language of the Brain interactive-biology.com

Our brains are better than Google or the best robot from iRobot. We can instantly search through a vast wealth of experiences and emotions. We can immediately recognize the face of a parent, spouse, friends or pet, whether in daylight, darkness, from above or sideways—a task that the computer vision system built into the most sophisticates robots can accomplish only haltingly. We can also multitask effortlessly when we can extract a handkerchief from a pocket and mop our brow while striking up a conversation with an acquaintance. Yet designing an electronic brain that would allow a robot to perform this simple combination of behaviors remains a distant prospect.

umich.edu

How does that brain pull all this off, given that the complexity of the networks inside our skull—trillions of connections among billions of brain cells—rivals that of ǫ ϐ ǣ a nerve cell communicates with another, the brain uses just a millionth of the energy that a digital computer expends to perform the equivalent operation. Evolution, in fact, may have played in important role in pushing the three-‐pound organ ϐ Ǥ Parsimonious energy consumption cannot be the full explanation, though, given that the brain also comes with many built-‐in limitations. One neuron in the cerebral cortex, for instance, can respond to an ϐ ǡ “spike,” in thousandths of a second—a snail’s pace compared with the transistors that serve as switches in computers, which take billionths of a second to switch on. The reliability of the neuronal network is also low: a signal traveling from one cortical call to another typically has only a 20 percent possibility of arriving at its ultimate destination and much less of a chance of reaching a distant neuron to which it is not directly connected. Neuroscientists do not fully understand how the brain manages to extract meaningful information from all the signaling that goes on with it. The two of us and others, however, have recently made exciting progress by focusing new attention on how the brain ϐ ϐ -‐ al problems. This is because a group of spikes that ϐ more information than can a comparably sized groups that activates in an unsynchronized fashion. Beyond offering insight to the most complex known machine in the universe, further advances in this research could lead to entirely new kinds of computers. Already scientists have built “neuromorphic” electronic circuits that mimic aspects of the brains signaling network. We can build devices today with a million electronic neurons, and much larger systems are planned. Ultimately investiga-‐ tors should be able to build neuromor-‐ phic computers that function much faster than modern computers but require just a fraction of the power.

CELL CHATTER Like many other neuroscientists, we often use the visual systems as our test bed, in part because its basic wiring diagram is well understood. Timing of signals

Evolve Magazine, November 2012

there and elsewhere in the brain has long been suspected of being a key part of the code that the brain uses to decide whether information passing through the network is meaningful. Yet for many decades these ideas were neglected because timing is only important when compared between different parts of the brain, and it was hard to measure activity of more that one neuron at a time. Recently, however, the practical development of computer models of the nervous system and new results from experimental and theoretical neuroscience have spurred interest in timing as a way to better understand how neurons talk to one another. Brain cells receive all kinds of inputs on different timescales. The microsecond-‐quick signal from the right ear must be reconciled with the slightly out-‐of-‐sync input from the left. These rapid responses contrast with the sluggish stream of hormones coursing through the blood stream. The signals most important for this discussion, though, are the spikes, which are sharp rises in voltage that course through and between neurons. For cell-‐to-‐cell communication, spikes lasting a few milliseconds handle immediate Ǥ ϐ number of inputs urging it to switch on outweigh the number telling it to turn off. When the decision is made, a spike travels down the cell’s axon (somewhat akin to a branched electrical wire) to its tips. Then the signal is relayed chemically through junctions, called synapses, that link the axon with recipient neurons. In each eye, 100 million photoreceptors in the retina respond to changing patterns of light. After the incom-‐ ing light is processed by several layers of neurons, a million ganglion cells at the back of the retina convert these signals into a sequence of spikes that are relayed by axons to other parts of the brain, which in turn send spikes to still other regions that ultimately give rise to a conscious perception. Each axon can carry up to several hundred spikes each second, though more often just a few spikes course along the neural wiring. All that you perceive of the visual world-‐the shapes, colors and movements of everything around you—is coded into these rivers of spikes with varying time interval separating them. Monitoring the activity of many individual neurons at once is critical for making sense of what goes on in the brain but has been extremely challenging. In 2010, though, E.J. Chichilnisky of the Salk Institute for

Biological Studies in La Jolla, Calif., and his colleagues reported in Nature that they had achieved the monumental task of simultaneously recording all the spikes from hundreds of neighboring ganglion cells in monkey retinas. This achievement made it possible to ϐ ganglion cell. The growing ability to record spikes form many neurons will assist in deciphering meaning from these codelike brain signals. For years investigators have used several methods to interpret, or decode, the meaning in the stream of spikes coming from the retina. One method counts spikes from each axon separately over some period: ϐ ǡ Ǥ ϐ ǡ code, relays features of visual images, such as location in space, regions of differing light contrast, and where motion occurs, with each of these features represent-‐ ed by a given group of neurons. Information is also transmitted by relative Ȅ ϐ when another cell spikes. Ganglion cells in the retina, for instance, are exquisitely sensitive to light intensity and can respond to a changing visual scene by transmitting spikes to other parts of the brain. When ϐ instant, the brain suspects that they are responding to an aspect of the same physical object. Horace Barlow, a leading neuroscientist at the University of Cambridge, characterized this phenomenon as a set of “suspicious coincidences.” Barlow referred to the observation that each cell in the visual cortex may be ϐ (say, its color or its orientation within a scene). When several of these cells switch on at the same time, their combined activation constitutes a suspicious ϐ a unique object. Apparently the brain takes such synchrony to mean that the signals are worth noting because the odds of such a coordination occurring by chance are slim. Electrical engineers are trying to build on this ϐ incorporates the principals of spike timing when Evolve Magazine, November 2012

recording visual scenes. One of us has built a camera that emits spikes in response to changing a scenes brightness, which enables tracking of very fast moving objects with minimal processing by the hardware to capture images.

INTO THE CORTEX New evidence adds proof that the visual cortex attends to temporal clues to make sense of what the eye sees. The ganglion cells in the retina do not project directly to the cortex but relay signals through neurons in the thalamus, deep within the brain’s midsection. This region in turn must activate 100 million cells in the visual cortex in each hemisphere at the back of the brain before the messages are sent to higher brain area for conscious interpretation. We can learn something about which spike patterns are most effective in turning on cells in the visual cortex by examining the connections from relay neuron in the thalamus to cells known as spiny stellate neurons in a middle layer of the visual cortex. In 1994 Kevan Martin, now at the Institute if Neuroinformatics at the University of Zurich, and his colleagues reconstructed the thalamic inputs to the cortex and found that they account for only 6 percent of the all the synapses on each spiny stellate cell. How, then, everyone wondered, does this relatively weak visual input, a mere trickle, manage to reliably communi-‐ cate with neurons in all layers of the cortex? ϐ inputs and can respond to them by emitting a spike in a matter of a few milliseconds, In 2010 one of us, along with Hsi-‐Ping Wang and Donald Spencer of the Salk Institute and Jean Marc Fellous of the University of Arizona, developed a detailed computer model of a spiny stellate cell and showed that even though a single spike from only one axon cannot cause one of these ϐ ǡ will respond reliably to inputs from as few as fours axons projecting from the thalamus if the spikes from all four arrive within a few milliseconds of one another. Once inputs arrive from the thalamus, only a sparse subset of the ϐ to represent the outline and texture of an object. Each spiny stellate neuron has a preferred visual stimulus from the eye that produces a ϐ ǡ particular angle of orientation. In the 1960s David Hubel of Harvard Medical School and Torsten Wiesel, now at the Rockefeller University, discovered that each neuron in the relevant section of the cortex responds strongly to its preferred stimulus ϐ ϐ ǯ ϐ Ǥ responding to stimulation in the fovea, the central region of the retina, have the smallest receptive ϐ Ȅ Ǥ them as looking at the world through soda straws. In the 1980s John All man of the California Institute of Technology showed that visual stimulation form outside ϐ ϐ ϐ Ǥ “surround” input puts the feature that a neuron responds to into the context of the broader visual environment.

Evolve Magazine, November 2012

http://drpinna.com Nicolás Cuenca

Stimulating the region surrounding a neuron’s ϐ of spike timing. David McCormick, James Mazer and their colleagues at Yale University recently recorded the responses of single neurons in the cat visual cortex to a movie that was replayed many times. When they narrowed the movie image so that neurons triggered by ϐ ϐ ȋ the surrounding area), the timing of the signals from these neurons had a randomly varying and imprecise pattern. When they expanded the movie to cover the ϐ ǡ ϐ rate of each neuron decreased, but the spikes were precisely timed. The timing of spikes also matters for other neural processes. Some evidence suggests that synchronized timing—with each spike representing one aspect of an object (color or orientation)—functions as a means of assembling an image from component parts. A spike for ǲ ǳ ϐ ǲ contour,” enabling the visual cortex to merge these ϐ Ǥ

ATTENTION AND MEMORY Our story so far has tracked visual processing from the photoreceptors in the cortex. But still more goes into forming a perception of a scene. The activity of cortical ϐ by those inputs but also by excitatory and inhibitory interactions between cortical neurons. Of particular importance for coordinating the many neurons responsi-‐ ble for forming a visual perception is the spontaneous, ϐ ϐ ͳͲͲ Ǥ Attention—a central facet of cognition—may also have physical underpinnings in sequences of synchronized spikes. It appears that such synchrony acts to emphasize the importance of a particular perception or memory passing through conscious awareness. Robert Desimone, now at Massachusetts Institute of Technology, and his colleagues have shown that when monkeys pay attention to a given stimulus, the number of cortical neurons that ϐ -‐ ǡ ϐ well. Pascal Fries of the Ernst Strungmann Institute for Neuroscience in cooperation with the Max Planch Society in Frankfurt found evidence for gamma-‐band signaling between distant cortical areas. Neural activation of the gamma-‐frequency band has also attracted the attention of researchers who have found that patients with schizophrenia and autism show decreased levels of this type of signaling on electroen-‐ cephalographic recordings. David Lewis of the University of Pittsburgh, Margarita Behrens of the Salk Institute and ϐ called a basket cell, which is involved in synchronizing spikes in nearby circuits. An imbalance of either inhibition or excitation of the basket cells seems to reduce synchronized activity in the gamma band and may thus explain some of the physiological underpin-‐ nings of these neurological disorders. Interestingly, patients with schizophrenia do not perceive some visual illusions, such as the tilt illusion, in which a person typically misjudges the tilt of a line because of the tilt of nearby lines. Similar circuit abnormalities in the prefron-‐ tal cortex may be responsible for the thought disorders that accompany schizophrenia.

When it comes to laying down memories, the relative timing of spikes seems to be as important as the rate of ϐ Ǥ ǡ ϐ the cortex is important for increasing the strengths of synapses—an important process in forming long term memories. A synapse is said to be strengthened when ϐ neuron on the other side of the synapse to register a stronger response. In 1997 Henry Markham and Bert Sakmann, then at the Max Planck Institute for Medical Research in Heidelberg, discovered a strengthening process known as spike-‐timing-‐dependent plasticity, in which and input as a synapse is delivered at a frequency in the gamma range and in consistently followed within milliseconds by a spike from the neuron on the other side of the synapse, a pattern that leads to enhanced ϐ Ǥ ǡ ϐ ͳͲ ϐ ǡ the cells decreases. Some of the strongest evidence that synchro-‐ nous spikes may be important for memory comes from research by Gyorgy Buzsaki of New York University and others on the hippocampus, a brain area that is import-‐ ant for remembering objects and events. The spiking od neurons in the hippocampus and the cortical area that it ϐ oscillations of brain waves in a range of frequencies from four to eight hertz, the type of neural activity encoun-‐ tered, for instance, when a rat is exploring its cages in a laboratory experiment. These theta-‐band oscillations can coordinate the timing of spikes and also have a more permanent effect in the synapses, which results in Ǧ ϐ Ǥ

GRAND CHALLENGE AHEAD Neuroscience is at a turning point as new methods for simultaneously recording spikes in thousands of neurons help to reveal key patterns in spike timing and produce massive databases for researchers. Also, optogenics—a technique for turning on genetically engineered neurons using light—can selectively activate or silence neurons in the cortex, and essential step in establishing how neural signals control behavior. Together, these and other techniques will help us eavesdrop on neurons in the brain and learn more and more about the secret code that the brain use to talk to itself. When we decipher the code, we will not only achieve an understanding of the brain’s communication system, we will also start building machines that ϐ Ǥ O Evolve Magazine, November 2012

Physicians struggle to curb the growing number of lethal overdoses. serret.deviantart.com

Evolve Magazine, November 2012

he two young men who showed up retching and wild-‐eyed in an emergency room in Portland, Ore., last summer insisted they had swallowed nothing but an ordinary soft drink before one collapsed. Yet their odd coloring suggested otherwise. Fifteen minutes after they had downed their drink, their lips and skin turned startling blue. Their blood was as dark as chocolate. Eventually one of the men confessed: they had spiked their soda with a bitter liquid they bought online. They meant to order “2C-‐E,” a man-‐made hallucinogen that they heard was similar to Ecstasy or LSD. What they received instead from a chemical company in China was an aniline, an industrial solvent that ruptured their red blood cells, starved their tissues for oxygen and nearly killed them. Whether the substitu-‐ tion was their mistake or the company’s, no one knew. “For quite a while after they got to the ER,” says Zane Horowitz, medical director of the Oregon Poison Center, “we didn’t know what exactly they had taken, and neither did they.” Horowitz and other toxicologists say the range of legal and illegal drugs now available to anyone with a credit card or well stocked family medicine chest in broader and, in some ways, more dangerous than ever before. Bored teens seeking the latest high are only part of the

livingstingy.blogspot.com

89%

of accidental poisonings result from drugs

problem. Patients who double down on long-‐acting prescription narcotics or mix some medicines with one another or with alcohol are vulnerable, too. The escalating death toll from drug use in the U.S. is startling, as a recent overview from the Centers for Disease Control and Prevention has ϐ Ǥ leading cause of fatal injury, and 89 percent of the poisonings result from drugs. The magnitude of the problem has legislators, doctors and public health experts searching for solutions. Last July, President Barack Obama signed into law the Synthetic Drug Abuse Prevention Act of 2012, nationally outlaw-‐ ing the manufacture, sale and possession of 2C-‐E and 25 other “designer” recreational drugs. To try to reign in prescription drug abuse, at least 49 states have authorized funding for electronic databases that ultimately aim to identify physicians who overprescribe narcotics, as well as addicts who “doctor shop” to load up on pain relievers or stimulants. Meanwhile medical toxicologists have surprising advice for emergency room teams treating overdoses: rely less on standard blood and urine tests when trying to identify drug abuse because those lab tests can be grossly misleading. Instead, these medical sleuths say, asking sharper questions will likely save more patients.

Evolve Magazine, November 2012

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NEW NARCOTICS

Despite the recent increase in deaths from designer drugs-‐ recreational compounds that are chemically tweaked to stay ahead of the law-‐ a less exotic threat accounts for the more common type of drug poisoning. In the most recent analysis of all overdose deaths in the U.S., more than 40 percent involved prescription narcotics. Sales of these strong painkill-‐ ers, including oxycodone, hydrocodone and methadone, have climbed, too, jumping by 300 percent between 1998 and 2008, according to the CDC, as doctors have prioritized alleviating the severe pain of cancer, surgery, and serious injury. ϐ course of prescription narcotics can safely reduce suffering. But the abuse of these potentially addictive drugs, alone or in combination, in particularly deadly. A 2008 study in the Journal of the American Medical ϐ ǣ ͷ͸ ʹ͹ͷ people who overdosed on prescription narcotics had not been prescribed the medication that killed them. Another 21 percent had ϐ year before they died, a pattern that suggests they had doctor shopped to obtain more pills than anyone physician would supply. National statistics underscore the risk: legal narcotics now kill more people every year than heroine and cocaine combined. Not only are prescription narcotics more widely available than ever before, some also stay in the body longer. High-‐dose, extended-‐release pills are convenient for patients seeking uninterrupted relief from severe pain throughout the night, for example, but they also make overdose more likely if taken incorrectly. Some recreational abusers pulverize long acting 60-‐milligram pills of oxycodone to snort or smoke it, thereby sending a potentially toxic quantity into the blood stream all at once. Well-‐meaning pain patients run afoul of the pills, too. “I get patients who tell me, ‘I ran out of my medicine, so my neighbor gave me some of his,’” Horowitz says. “But it turned out the neighbor was taking a much higher dose.”

Evolve Magazine, November 2012

“

For quite a while after they got to the ER, we didn’t know what exactly they had taken, and neither did they.

”

The greater availability of prescription drugs also makes it dangerously easy to mix medications. In the JAMA overdose study, nearly 80 percent of those who died were on a medley of drugs that usually included benzodi-‐ azepines (commonly prescribed for anxiety or insomnia) and had sometimes imbibed alcohol as well. That pattern of mixing often bespeaks an underlying addiction, the researchers say. In high-‐enough doses, each of those drugs can slow breathing, and the combination is particularly dangerous, says Jane Prosser, an emergency medicine physician at Weill Cornell Medical Center in New York City. “This is one of those cases where one plus one equals four.” An overdose in an older patient, who is more likely to be undergoing treatment for multiple chronic conditions, can be especially tough to diagnose in the emergency room, Prosser says. “A confused elderly person comes to the ER and says, ‘I feel very weak and dizzy.’ Is that their cancer? The chemo? The pain meds? The fact that they’re dehydrated because they’ve been vomiting and have diarrhea? It can be very hard to tell.”

WHEN LAB TESTS GO WRONG

Although advanced analytical techniques can selectively identify any drug, they are too expensive and slow to be useful in a medical emergency, says Mark B. Mycyk, a medical toxicologist at John H. Stroger, Jr., Hospital of Cook County in Chicago. And the standard panels of quicker screening tests for drugs in blood and urine have not kept up with shifts in the types of drugs people abuse.

“Those core (toxicology) screens were developed for the war on drugs in the workplace in the mid-‐1970s and are designed mostly to pick up heroine, cocaine and marijuana use,” Mycyk says. The tests will not detect the increasing number of barely legal or illegal recreational drugs such as 2C-‐E that come on many slightly rejiggered versions because of creative chemists looking to make a buck. Even many legitimate medicines, includ-‐ ing the anti-‐anxiety pills Ativan and Xanax and the painkillers methadone and oxycodone, do not show up in the standard hospital drug-‐screening tests. Relying on lab results, Prosser says, can, in this case, foil diagnosis and misguide treatment. Say a man addicted to methadone comes into the emergency room unconscious after also taking a hefty dose of Xanax. The doctor, trying to ϐ ǡ narcotics. The results come back negative because the screen will pick up neither methadone nor Xanax. Misled by the test results, the doctor does not prescribe a medicine that would blunt symptoms of withdrawal as the narcotic wears off—and that decision has fatal consequences. “Suddenly [the patient] starts vomiting from opiate withdrawals but doesn’t wake up, because he has OD’d on benzodiazepines,” Prosser says. Inhaling that vomit could kill him. Improved testing is not necessarily the answer, Mycyk says. When times is critical, taking note of a telltale constellation of symptoms typically

triggered by a certain class of drugs—and treating those Ȅ ϐ Ǥ Federal organizations have started to work on solutions as well. Last July the Food and Drug Administration began requiring drug companies to start educating doctors about the special risks of such prescription drugs. The CDC has called on states to consider monitoring Medicaid or worker’ compensation claims “for signs of inappropriate use of controlled prescription drugs.” To help reduce doctor shopping, the CDC says, these state programs might in some cases consider restricting reimbursement for controlled drug to scripts that come through only one designated prescriber per patient and one designated pharmacy. Mycyk has started telling the ER physicians he trains that they might ϐ learned to ask in medical school. “Don’t ask, ‘Do you abuse illegal drugs?’” He says. “Most of the drug people are using today are not illegal. A lot of them are overdosing on drugs that were prescribed by their doctor.” Instead, Mycyk says, asking questions such as “Have you ever gotten high on cough syrup?” or “Have you ever taken a friend or relative’s pill?” will put you on the right track to more helpful responses. “Most [patients] will do all they can to help you,” he says. “In most cases, landing in the ER was an accident. They don’t want to die.” O

Other source

7.1%

Get drug from dealer or stranger

4.4%

Took from friend or relative without asking

4.8%

Obtained free from friend or relative

55%

11.4%

Bought from friend or relative

17.3% Prescibed by one doctor

People who abuse prescription painkillers get drugs from a variety of sources.

Evolve Magazine, November 2012

NEXT ISSUE THE RECIPE FOR IMMORTALITY

An expert in synthetic biology explains how people could soon live for centuries.

THE END OF AIDS Beyond the drug cocktail. Beyond a vaccine. Scien-‐ tists are talking about total cure.

THE WORLD IN 50 YEARS What will the world be like in 50 years? We explore the trends of that vibrant and worrisome time.

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