An essay by Richard Corfield in Astrobiology Magazine points up the strange history of the Ediacarans, a group of anatomically diverse organisms that lived during the Ediacaran period (between 635 and 542 million years ago). These creatures, which predated nearly every form of animal life that exists today, stood rooted in bacterial bases on the seafloor, drawing nutrients from the water.

As best we can tell, the Ediacarans lacked mouths and recognizable digestive systems, and their bodies are thought to have looked like "sacks of mud, disks, hubcaps and mattresses." They were among the first complex life forms to appear on the planet, but they bear no discernible resemblance to anything else in the fossil record:

...they have none of the characteristics of the bilaterian animals, which evolved during the Cambrian explosion 542 million years ago. Since then, bilateral animals have provided the basic body plan for every animal that has occupied and dominated the Earth.

The Ediacarans came and went in a remarkably brief interval, geologically speaking. Corfield believes their population exploded when a mass-oxygenation of Earth's oceans coincided with the end of the Cryogenian ice age. Before long, Ediacarans had spread across the globe, as indicated by fossils everywhere from England to Australia. But the rise of mobile, bilaterian animals introduced too much competition to the oceans, and the Ediacarans died off almost as quickly as they'd flourished.

Guy Narbonne, a paleontologist at Queen's University in Ontario, recently told reporters that Ediacaran-descended life could still be with us today, in the form of certain worms and mollusks. For Corfield, though, the interesting thing about Ediacarans isn't whether they still have a presence on Earth, but what their evolutionary arc suggests about whether and how life might develop on other worlds:

the story of the Ediacarans... tells us that evolution can happen very quickly. The idea — first credited to Darwin — that vast amounts of deep time are required for evolution to occur may not be correct. The speed with which the Ediacarans arose in the aftermath of the final Cryogenian glaciation suggests strongly that the evolution of complex, multicellular organisms was on the blocks and just waiting for the starting pistol.

Fossils on the Edge of Forever [Astrobiology Magazine]

Image by Ryan Somma, used under Creative Commons license.

This was the decade of the first face transplant, the first extinct species brought back from the dead, and printable human tissue; a decade that brought us closer to synthetic life forms and the invisibility cloak. But we've whittled it down to ten of the decade's biggest science stories, with discoveries, advances, and topics that are sure to change our lives in the next ten years.

It's Full of Planets: This was a big decade for planets, and not just because Pluto got a downgrade. In 2005, astronomers discovered Eris, a dwarf planet larger Pluto (as well as smaller dwarf planets Haumea and Makemake). Eris' discovery prompted the International Astronomical Union to actually define the term planet, leading to Pluto's demotion to dwarf planet. But the discovery of Eris after all this time suggests there is still a lot to learn about our solar system.

We also got our first direct look at exoplanets, worlds outside our solar system, thanks to the Hubble Telescope. In 2008, astronomers at the Keck and Gemini captured the first images of planets orbiting distant stars. And the planetary discoveries just keep getting more exciting; just this week, astronomers announced that they had observed a super-Earth that might be made largely of liquid water.

Water, Water Everywhere: The world watched on as the Phoenix Lander dug through the Martian terrain for signs of water on the Red Planet. In the summer of 2008, NASA announced it had found definitive proof of water ice on Mars. More recently, scientists discovered that large deposits of water ice exist beneath the planet's surface. This fall, the moon became the center of our watery attention when astronomers found evidence of water throughout the moon's surface. Although the supervillainous plot to bomb the moon didn't seem as initially impressive as we had hoped, the probe did confirm researchers' suspicions that the moon does, in fact, contain a significant amount of frozen water. These discoveries not only reveal more about our solar system, they indicate that, should humans try to colonize Mars or the moon, there will be resources to make survival a little easier.

Shaking Up the Human Family Tree: Humanity got a new great-great-grandmother (or perhaps she's our great-great-great-aunt) in Ardi, a fossilized hominid skeleton found in Ethiopia. Granted, Ardipithecus ramidus was discovered in 1992, but it wasn't until 2009 that she was revealed as a significant addition to our family tree. Although there's technically no "missing link" because humans didn't evolve from chimpanzees, Ardi is, so far, our closest link to chimps, and brings us closer to the common human-chimp ancestor than ever before. Analysis of Ardi's skeleton and probably anatomy reveals just how unlike either chimps that common ancestor is bound to be. One of the Ardi researchers even quipped that when we find that common ancestor, it might look less like we evolved from a chimp-like creature and more like chimps evolved from creatures more like us.

The Book of Life Recorded: Our understanding of human genetics reached a new milestone with the mapping of the human genome. The Human Genome Project announced a rough draft of the human genome in 2000, followed by a more complete version in 2003; the sequence of the last chromosome was published in 2006. Though the genome hasn't been 100 percent mapped, the Human Genome Project has completed its mapping goals. We still have to interpret the sequences we have recorded, but hopefully as we translate the book of our genetic lives, we will get a better understand of how our genes interact and improve our treatment of genetic diseases. Plus, the project has paved the way for sequencing other critters and plants, and, just this week, the lung cancer and melanoma genomes were sequenced.

Changing Your Genes: The promises of genetic engineering have really begun to bear fruit in the last few years, in ways far beyond Alba, the glowing transgenic bunny that grabbed headlines in 2000. In 1999, an 18-year-old with a, inherited liver disease died during a gene therapy trial, after suffering an unanticipated immune reaction to a viral vector. But in more recent years, gene therapy and genetic engineering have shown their promise. In 2000, scientists reported the first gene therapy success, having provided a patient with severe combine immunodeficiency (commonly known as "Bubble Boy" syndrome), though SCID gene therapy treatments were halted when patients developed leukemia. This year, gene therapy successfully treated children with a congenital form of blindness, giving them the ability to see for the first time in their lives. Meanwhile, genetic engineering experiments on animals have cured color blindness in monkeys, created super-strong monkeys, created drug-producing rats, and enabled animals to pass their altered genes to their offspring.

Stem Cells Grow Up: Embryonic stem cells have been a source of contention for years, but in 2007, Shinya Yamanaka helped sidestep that issue when he found a way to reprogram adult skin cells into induced pluripotent stem cells. Stem cells themselves have continued to aid important medical advances. In 2008, researchers generated motor neurons from elderly patients with ALS, an advance that could help researchers better understand the disease. A newly released study has suggested that a mini stem cell transplant could reverse sickle cell disease, and stem cell research has lead to advances in HIV research and the treatment of heart disease.

Climate Change Takes Center Stage: One of the biggest science stories of the decade has been less about scientific advances than about how the public responds to scientific research. Reports that the glaciers are melting faster than expected, a decade of record warmth, and Al Gore's Nobel Prize have all been part of the conversation on climate change and to what extent humans are responsible.

Commercial Spacecrafts Prepare to Take Flight: Amidst NASA budget cuts, commercial spaceflight has come to the forefront. The Ansari X Prize, first offered in 1996 for the first private enterprise that could fly a three-passenger vehicle 100 kilopmeters into space twice in one week. In 2004, the prize was finally won by Mojave Aerospace Ventures' SpaceShipOne. That same year, Virgin Galactic was founded to further space tourism. The company recently unveiled SpaceShipTwo, the first commercial spacecraft. 2004 also saw the certification of the Mojave Air and Space Port, the first licensed facility for horizontal launches of reusable spacecraft in the US. In anticipation of the spaceflight business, one company claims it's readying a space hotel.

Our Cyborg Present: In the last decade, humans and machines have gotten closer than ever. We have machines that can read our memories, computers that let us type with our brains, and robotic arms controlled by monkey minds. Perhaps the most impressive cyborg advances have come in the last few months, with researchers hooking amputees up to robotic arms that not only respond to electrical signals from the human brain, but also provide tactile feedback.

The LHC Comes Online: The Large Hadron Collider has just begun colliding proton beams, but its construction represents one of the most ambitious scientific undertakings ever. The immense particle accelerator will hopefully give us first-hand observations of aspects of the universe that have been, thus far, the realm of theoretical physics. Despite fears from doomsayers that the LHC would destroy the world and a series of mishaps that led to claims that the device was being sabotaged from the future, the LHC came online this year and quickly got to smashing protons at record-breaking speeds.

Today PLoS Biology published a study of fruitflies, a species where the male flies show a marked preference for mating with larger females because they are more fecund. The problem is that the males show such aggressive preferences that they basically badger the females constantly to mate. What this means is that the females are so harried that they have less time to search for food, which degrades their health. Also, among fruitflies, the mating process is itself damaging to the health of the females - fruitfly sperm is toxic.

As a result, the most-desired females become far less capable of generating healthy offspring. And the smaller, less fit females wind up bearing as many offspring as the fitter ones. In the end, the males' aggressive mating with the fittest females ends up preventing their species from evolving into a much fitter group.

Tristan A. F. Long, one of the authors of the study, said:

These larger females are disproportionately harassed and harmed, by males attempting to obtain matings. When these males are ‘choosy' with their courtship, there may be negative consequences to the species' ability to adaptively evolve.

What's interesting about this study is that it's one of the few to point out how male mate choice affects evolution of a species. Usually female mate choice is emphasized, except in species where females are dominant. Here we can see clearly that male mate choice is having a profound and not very salutary affect on the future of fruitfly fitness. The issue here is obviously not attractiveness, but instead the kind of fitness associated with being larger and more fecund. If larger, "attractive" females are harrassed into reproductive uselessness by the males, then any traits they possess that make them healthier (a trait for metabolic efficiency, for instance) won't be able to spread through the population as quickly as it might if males chose mates randomly.

via PLoS Biology

The always excellent New Scientist has an article synthesizing much of the research into same-sex sexual behavior in animals and the possible evolutionary explanations. They spoke with University of California evolutionary biologists Marlene Zuk and Nathan Bailey, who recently published a paper examining same-sex behavior in various species. Zuk and Bailey note that same-sex sexual behavior in other animals can't necessarily be equated with sexual orientation in humans, researchers have come up with similar questions as to why certain animals have evolved to include members who expend energy on same-sex liaisons.

Evolutionary biologists have come up with various hypotheses for why same-sex behavior has evolved in various animals. In some cases, same-sex behavior has emerged as a result of specific adaptations, such as to foster social bonding, or because certain genes for same-sex attraction hold another survival benefit when only one copy is present. In some cases, though, the behavior is incidental, such as in certain fish that cannot easily tell male and female members apart.

Below, New Scientist charts several of the possible evolutionary explanations for same-sex sexual behavior in various species:

Bailey believes that exploring the evolution of sexual behavior will give us a better understanding of evolution, including the development of our own species:

"Given its persistence in species in many different animal groups, including humans, viewing it as an evolutionary force in its own right promises to provide a much richer understanding of the evolution of reproductive behaviour," Bailey says. He suggests we could make some fascinating comparisons. Might male-male copulation in species as diverse as flour beetles and dolphins have similar, even predictable, evolutionary consequences? More daringly, could understanding the evolutionary consequences of same-sex interactions in animals help us understand our own evolution?

Homosexual selection: The power of same-sex liaisons [New Scientist]

A group of researchers in the United States decided to do an experiment with water striders, in which they observed the mating success of prudent, "nice" males versus aggressive, "psychopathic" males. The latter group tried often to mate with the females very aggressively, and in previous experiments they had the most reproductive success. But these scientists discovered that the success of the psychopaths depended on very specific laboratory conditions

It turned out that other studies of sex among water striders had kept the population contained in a limited area, where females had access to very few males. When the researchers opened up the insects' habitat, allowing the females to roam freely, they discovered that the less aggressive males attracted the highest number of mates.

According to a release about the research, published yesterday afternoon in Science:

"The presence of psychopaths dramatically reduced the productivity of the population," [biologist David Sloan] Wilson said. "When all the males were gentlemen, the females laid about three times more eggs than they did when all the males were psychopaths. And yet within each group the psychopaths were doing better than the gentlemen. How do the gentlemen persist if they're disadvantaged within the group?"

Once the females could move between groups, the researchers had their answer. [Researcher Omar Tonsi] Eldakar and Michael J. Dlugos, then also a Binghamton graduate student, devised a wading pool equipped with special doors that could restrict movement between groups or allow the insects to move freely.

"When they opened the doors, the females would leave whenever a psychopath came around," Wilson said. "The whole thing resulted in a heterogeneity in which the females were clustered with the gentlemen. It's the movement of individuals that creates these differences between groups that favor nonaggressive males."

Who knows how much research into sexual selection has been flawed because researchers forgot the crucial ingredient of female freedom?

Ultimately, what's interesting about this study is that it shows why isolated populations might engage in a different mode of sexual selection than a free-ranging population that has a lot of contact with outside groups.

via Science

Researchers at the University of Leeds report that kissing plays an important role in human reproduction. It's not just that kissing can eventually lead to the reproductive act; it's the germs that come with that comes with swapping spit. Perhaps most importantly, when a man kisses a female partner, he passes a small amount of his cytomegalovirus to her. If the cytomegalovirus is introduced into a woman's system during pregnancy, it can damage or even potentially kill the fetus. But, if a woman kisses the same partner repeatedly, she eventually develops an immunity to his particular cytomegalovirus, decreasing the chances of infection during pregnancy. The study authors say that six months of kissing should yield optimum immunity.

It's just as well, then, that the whole cootie shot thing was a sham.

[Daily Mail via Popular Science]

Over at Astrobiology magazine, Aaron Gronstal describes new scientific work that led to the creation of this map. What you see here is the landmass which included a land bridge over the Bering Strait - the same bridge that allowed animals and humans to wander from Northern Europe into North America without being hindered by the Arctic Sea. The timeframe here is the Pleiocene and Pleistocene Eras - between 5.3 million to 12,000 years ago - when ice sheets and glaciers covered most of the northern hemisphere. And yet at the same time, some of the iciest parts of today's warmer world were at that time ice-free and full of life. How did that happen?

Gronstal sums up the research:

Temperatures were still low in Beringia during these epochs, but a lack of moisture due to the rainshadow of the surrounding mountain ranges prevented large-scale formation of ice. As the authors [of the new study] put it, "The interior of Yukon and Alaska was cold enough to support ice sheets but too dry for extensive glaciation." Because of this, Beringia was a key location for life during the Pleistocene, when the Earth's climate fluctuated between ice ages and glaciers often covered large portions of the globe.

As the Earth's climate varied, so did sea levels. This ebb and flow of the sea exposed a land-bridge across the Bering Straight between Alaska and Siberia. Not only was this an important route for the migration of animals between the continents of Asia and North America, it also expanded the ice-free land mass of Beringia. This provided a large area that was relatively rich in food – which was a lifesaver for those struggling to survive in the Earth's frozen North. Beringia was by no means a tropical paradise for life, but the cold, wind-swept desert was an important ecological refuge for plants and animals when glaciation of the Earth was at its peak.

This map is a perfect demonstration of how complicated the results are when we see massive weather shifts on Earth. Some areas that were uninhabitable become habitable in unforeseen ways.

via Astrobiology

Normally relocating bears is frowned on as a way of saving populations. Conventional environmental science says that a declining population should not be moved until the sources of its decline have been addressed. But this group of French biologists say that in this case, they have population models that prove the cause of the decline in the population has to do with a gender disparity.

While you might think this solution is obvious, it isn't. You see, the problem with these bears isn't that there aren't enough females to breed a new population - in fact, there are. Instead, the problem comes from the bears' practice of co-rearing their young, with the fathers sticking around to care for their offspring. Because the babies take a while to mature, there will be long stretches where some males are fathers and others aren't. The single bears will fight the fathers. When single bears win, they murder the father's offspring so they can parent their own children. As a result, even a slight gender imbalance between the bears can result in viable offspring being killed over and over.

The scientists' study was published yesterday in PLoS One. A release about the study explains:

The researchers analyzed field data collected from 1993 to 2005 and found that the western sub-population had much lower reproductive success than the central sub-population. They suggest this could be the consequence of the western sub-population being inbred or having a male-biased sex ratio. In species with extended parental care, a male-biased sex ratio can induce sexually selected infanticide, a behavior in which males attempt to kill unrelated cubs to induce estrous in females, maximizing their opportunity to breed.

[Researcher Guillaume] Chapron and his colleagues used a population model to compute how many bears should be released to ensure viability, and showed the population could recover provided an adequate number of new females are translocated.

via PLoS One

The article, published today in Science, looks at a microbe known as SUPO5, which lives in areas of the ocean which have low amounts of oxygen. These "dead zones" are created by climate change and nitrogen runoff. The microbes were found off the coast of British Columbia, in the Saanich Inlet, and use nitrates instead of oxygen as a source of energy. They remove sulfides from the water, fix carbon dioxide, and in turn produce nitrous oxide, a very potent greenhouse gas.

The dead zones, officially called oxygen minimum zones (OMZs), are expanding, and most marine life struggles to live in their low oxygen environments. You can find dead zones off the coasts of British Columbia, Oregon, Chile, and Namibia, among other locations. Their growth may have significant impact on fisheries and marine life, and the presence of SUPO5 seems to be one of the best indicators of the presence of dead zones - they are helping turn the zones into nitrogen sinks that pump out greenhouse gasses.

By creating dead zones, we my have inadvertently helped space-faring microbes evolve. SUPO5 can survive low oxygen environments, with otherwise deadly chemical makeups. The organism refines sulfur compounds, which on earth are only found in very exotic environments, such as hydrothermal vents, or these OMZs. On another planet, they could thrive.

Said Steve Hallam, the head researcher on the project:

I hesitate to use the word alien to describe [SMO5], as it's very much part of earth's system, but it's alien to us...it doesn't require the thin film of oxygenated atmosphere that we thrive in.

Possibly these microbes could be used in terraforming. They can survive starvation, too. When food supplies get low, the microbe goes dormant. That would make it ideal for putting into hibernation for a long trip.

Hallan says SMO5 also could be useful here on Earth in wastewater treatment or fuel production, where the microbes' unique biology could be used to remove sulfides.

via Science and the Joint Genome Institute

Image courtesy of Hallam Lab.

The spider was discovered in South Africa, and a group of researchers officially described the species in a paper published in PLoS One yesterday evening. Spiders in the Nephilia family all exhibit what's called extreme sexual size dimorphism - in other words, the females are a lot larger than the males, and usually eat the males after mating with them. You can see from these images that the males of N. komaci really are so small compared to the females that they could be mistaken for a post-coital snack.

The researchers also analyzed the evolution of these spiders, and concluded that what we're seeing is a tendency towards female gigantism rather than male dwarfism. Because the female spiders survive better the larger they get, they have evolved to be huge. The males, on the other hand, wind up passing along their sperm to the next generation if they mature early (i.e. when they are smaller) and can climb really well. And thus, you get tiny males and giant females.

via PLoS One

A team of researchers at Yale University, led by evolutionary biologist Stephen Stearns, studied 2238 post-menopausal women chosen from the Framingham Heart Study - which has tracked the medical history of the residents of Framingham, Massachusetts since 1948 - to see whether factors like height, weight or cholesterol impacted the number of children women had. Even with other, social, factors accounted for, the team found that on average, shorter, heavier women with lower cholesterol tended to have more children, and started having children earlier... and that they also tended to pass these traits onto their daughters. But what does this mean? According to Stearns, a lot:

If these trends continue for 10 generations, Stearns calculates, the average woman in 2409 will be 2 centimetres shorter and 1 kilogram heavier than she is today. She will bear her first child about 5 months earlier and enter menopause 10 months later.

2 centimeters in four hundred years? Natural selection may have an destination, but it's clearly not in any rush to get there.

Meet future woman: shorter, plumper, more fertile [New Scientist]

If Manthropology's theory can be believed, humanity is in pretty bad shape when compared with what's come before. As the opening of the book says,

If you're reading this then you - or the male you have bought it for - are the worst man in history. No ifs, no buts — the worst man, period...As a class we are in fact the sorriest cohort of masculine Homo sapiens to ever walk the planet.

Comparing the best of today's physical achievements with calculations on what past humans have been capable of, the book sets out the argument that everything used to be so much better in the olden days. According to McAllister, everything can be blamed on the industrial revolution:

We are so inactive these days and have been since the industrial revolution really kicked into gear. These people were much more robust than we were. We don't see that because we convert to what things were like about 30 years ago. There's been such a stark improvement in times, technique has improved out of sight, times and heights have all improved vastly since then but if you go back further it's a different story... The human body is very plastic and it responds to stress. We have lost 40 percent of the shafts of our long bones because we have much less of a muscular load placed upon them these days. We are simply not exposed to the same loads or challenges that people were in the ancient past and even in the recent past so our bodies haven't developed. Even the level of training that we do, our elite athletes, doesn't come close to replicating that.

While that may be true, it's worth pointing out that modern man may have been weakened by the industrial revolution, but that said industrial revolution has also enabled us to make machines to do all the hard work for us. And, as one very lazy modern man, I have to admit that that's perfectly fine with me.

Modern man 'a wimp', says anthropologist [Independent.co.uk]

A study published this week in PLoS One showed that chimps would share tools with each other, but usually only if requested. Which raises interesting questions about why humans are so easygoing, and free with our assistance.

The experiments focused on two chimps in adjoining cages. Either both apes had a tool the other needed, or just one had the object their neighbour required: a stick to get at a juice box, or a straw to drink from a container of juice. Even when there was no reciprocal trade, the chimpanzees gave the tool, but usually required a request. How does an ape signal that it wants what you have? Vocalizing, clapping, beating against the wall, and reaching through the barrier between walls.

Professor Shinya Yamamoto, of Kyoto University, and head of the experimental unit said:

Communicative interactions play an important role in altruism in chimpanzees. While humans may help others without being solicited, the chimpanzees rarely voluntarily offered an effective tool to a struggling partner. Indeed, simple observation of another's failed attempts did not elicit voluntary helping in chimpanzees.

Why do humans, and some other animals (like capuchin monkeys), offer help spontaneously, yet an animal we're so closely related to does not? As always, no one really knows, but there are a lot of theories.

Even though half the experimental couples were non-related chimps, they were just as likely to hand over the tool, so it's not a straight out family link. If food was at stake, then the chance one chimp would share with the other plummeted from 80-90% likelihood to down around 30%.

One significant factor may be the chimps' difficulty in understanding another being's point-of-view. But from a social perspective, requested altruism makes a huge amount sense. In a situation of limited resources, be they food, tools, or anything else, unnecessary assistance can lead to wasted goods. Evolving an "altruism on request" system is a way to ensure that the "help" offered is actually helpful, and minimizes unnecessary behaviour.

So why do humans behave differently? Chimpanzees function at a level very similar to a hunter-gatherer tribe. They make and modify tools to aid in their endeavours, getting most of their calories from gathering, but with the occasional hunting boost.

Humans, on the other hand, evolved into agricultural societies several thousand year ago. There's a huge body of literature based on the premise that, among humans, the food surpluses brought about by the shift to agriculture allowed for the creation of cities and complex hierarchical societies as we understand them. Could agriculture have made humans more altruistic than their hand-to-mouth chimp brethren?

If that were the cause of the change, then we would have developed our current style of offering help whenever we thought it appropriate in the last 10,000 years or so. Maybe the change happened when we shifted from the trees into the grasslands, a situation of higher predation which would require greater teamwork within a group. While this is purely speculation, further studies of altruism in apes will perhaps provide a better idea of why this discrepancy exists.

Charles Darwin, recognizing the similarities between humans and chimpanzees, postulated that we might someday find fossils of a "missing link," a creature that represented the evolutionary break between humans and chimps. The discovery of Ardi, however, suggests that when we do find that evolutionary break, the fossils we find will not be a blend of human and chimpanzee.

Researchers discovered Ar. ramidus near Aramis, Ethiopia, and have dated it as 4.4 million years old, considerably older than Lucy, who at 3.2 million years old was considered humanity's oldest relation. It's not clear whether humans are directly descended from this particular hominid, but it makes it clear that bipedal hominids are considerably older than previously thought.

The paleobiologists studying Ardi identify hers as an "intermediate" form, one that is bipedal, but at the same time capable of walking on all forms and traveling through trees. Still, although she represents a point past hominids' evolutionary break with gorillas and chimpanzees, she is very different from modern apes. For example, Ardi's had flat hands and feet and flexible wrists, and engaged in a form of locomotion called palmigrady, which is a trait of ancient apes and unlike gorillas and chimpanzees, which are stiff-wristed knuckle-walkers. This suggests that gorilla and chimp ancestors developed their knuckle-walking long after their evolutionary break with hominids.

In a paper in the upcoming issue of Science, which outlines the discovery, researchers will explain what Ardi's dissimilarity from modern apes means for our picture of human and chimp evolution:

Humans did not evolve from chimpanzees but rather through a series of progenitors starting from a distant common ancestor that once occupied the ancient forests of the African Micoene.

Paleontologists recently found the remains of the Raptorex in a lake bed in Northern China. Like the Tyrannosaurus Rex, Raptorex sports an over-sized head, itty bitty forearms, strong jaws, and a runner's build — "jaws on legs" as Paul Sereno of the University of Chicago described it — but it was only one hundredth the mass of the T-Rex and stood a mere 3 meters in length.

It's the combination of its small stature and its classically T-Rex features that has paleontologists excited. Other smaller relatives of the Tyrannosaurus have lacked that dinosaur's tiny forearms and comparatively large head, which has long caused paleontologists to suspect those adaptations were due to the Tyrannosaurus's large size. But finding them on a smaller relation means they will have to rethink the T-Rex's evolutionary development.

Raptorex – a prototype T. rex [New Scientist]

Raptorex Rendering
Raptorex Skeleton

T. Rex vs. Raptorex
Skull Comparison

Evolutionary biologist David Rollo and a team of scientists at McMaster University in Canada stumbled upon the universal death stench while studying how cockroaches avoid their dead. After observing that the insects would avoid fluid extracted from dead cockroaches, they surmised that smell is what allowed them to recognize and avoid these dead bodies. It turned out that they were right - after an animal or insect dies, its cells release fatty acids that carry a distinct odor. This same odor acts as a repellant in ocean-going crustacians too.

And the avoid this "death stench" of fatty acids goes back over 400 million years, around the time that insects and crustacians diverged. Rollo and his colleagues believe this because insects and crustacians share the aversion, which means it most likely evolved before the two families of species split off from one another. In fact, death stench avoidance probably evolved in the ocean.

Why would this be such an ancient trait?

Says Rollo:

Recognizing and avoiding the dead could reduce the chances of catching the disease, or allow you to get away with just enough exposure to activate your immunity . . . As explained in our study, fatty acids-oleic or linoleic acids-are reliably and quickly released from the cells following death. Evolution appears to have favoured such clues because they were reliably associated with demise, and avoiding contagion and predation are rather critical to survival.

Even if the death stench was emitted from a severed limb instead of a dead body, it is still useful as a warning. Rotting limbs could be diseased - or could be a sign that predators are nearby.

So does this mean that the fear of death evolved after the lust for sex? After all, there had been millennia of humping before the proto-crustacian-insects started avoiding the death stench.

via Evolutionary Biology

The discovery of the skulls in Tbilisi, Georgia, has led some scientists to believe that humanity's ancestors may have spent some time outside of Africa — or possibly have evolved parallel to the previously accepted history of humanity, according to the Georgia National Museum's general director, Professor David Lordkipanidze:

Before our findings, the prevailing view was that humans came out of Africa almost 1 million years ago, that they already had sophisticated stone tools, and that their body anatomy was quite advanced in terms of brain capacity and limb proportions. But what we are finding is quite different... The Dmanisi hominins are the earliest representatives of our own genus – Homo – outside Africa, and they represent the most primitive population of the species Homo erectus to date. They might be ancestral to all later Homo erectus populations, which would suggest a Eurasian origin of Homo erectus.

Lordkipanidze presented his theory during a speech at the British Science Festival, suggesting that it's possible that Homo erectus evolved in Eurasia before migrating to Africa... and also that actual evolution of the human body may also not have gone as we'd previously thought:

In regards to the question of which came first, enlarged brain size or bipedalism, maybe indirectly this information calls us to think that body anatomy was more important than brain size. While the Dmanisi people were almost modern in their body proportions, and were highly efficient walkers and runners, their arms moved in a different way, and their brains were tiny compared to ours.

A Skull That Rewrites The History of Man [Independent.co.uk]

The theme of this year's Burning Man was "Evolution," inspiring a great deal of art, vehicular and otherwise, centered around the animal kingdom. On the more retrofuturistic side of things, this year's Burning Man also featured the "Raygun Gothic Rocket" as an installation, which, contrary to festival rumors, didn't actually take off.

[Burning Man]

Photo by dko1960
Photo by Jon Sarriugarte
Photo by Jon Sarriugarte
Photo by juuuulllliiiieeeeeee
Photo by gir sushi
Photo by TWITA2005
Photo by Anamorphosis

The fibers were made from woven flax, which the paleolithic humans gathered in the wild outside their cave. You can see a few examples of the fibers, above, under the microscope. Some are twisted together, indicating they might have been used in ropes or string. Whatever woven items they were part of have long ago disintegrated, but they left behind distinct impressions in the cave's clay floor - and these impressions were what scientists saw when they examined the clay. Scientists could even discern the dyes used to color the fibers, which would have been created with colors derived from plants.

Says Harvard archaeologist Ofer Bar-Yosef, who worked on the excavation of the cave:

This was a critical invention for early humans. They might have used this fiber to create parts of clothing, ropes, or baskets-for items that were mainly used for domestic activities. We know that this is wild flax that grew in the vicinity of the cave and was exploited intensively or extensively by modern humans.

He added that the ability to weave cloth and ropes would have given the people who inhabited this cave many advantages. They could have sewn animal hides into shoes, or knitted cloth sacks to carry their belongings in. Either way, cloth would have aided them in staying warm and remaining mobile.

The people who lived in the Georgian cave, pictured here, occupied it for thousands of years over many generations. Along with the 34-thousand-year-old twine, researchers also discovered flax fibers in the cave dating back to 21 thousand and 13 thousand years ago. Bar-Yosef and his colleagues' research is published in Science this week.

via Science

BBC News explains:

One of the scientists, Dr Yali Xue from the Wellcome Trust Sanger Institute in Cambridgeshire, said: "The amount of data we generated would have been unimaginable just a few years ago.

"And finding this tiny number of mutations was more difficult than finding an ant's egg in an emperor's rice store."

New mutations can occasionally lead to severe diseases like cancer. It is hoped that the findings may lead to new ways to reduce mutations and provide insights into human evolution.

Joseph Nadeau, from the Case Western Reserve University in the US, who was not involved in this study said: "New mutations are the source of inherited variation, some of which can lead to disease and dysfunction, and some of which determine the nature and pace of evolutionary change.

"These are exciting times," he added.

I hope one of my 100 mutations includes the X-gene. I'm ready to grow wings now. Or, hey, I'd be satisfied with telekinesis.

via BBC