Tuesday, 29 June 2010

Johnald's Fantastical Daily Link Splurge

Johnald's Fantastical Daily Link Splurge

6 Super Close-Ups of Crazy Bug Eyes

Posted: 28 Jun 2010 04:30 PM PDT

<< previous image | next image >>

They may not seem like creatures worth admiring when they are buzzing around your head or landing on your lunch, but under the microscope, bugs can be truly spectacular. Especially their eyes.

Saturday, 26 June 2010

Johnald's Fantastical Daily Link Splurge

Johnald's Fantastical Daily Link Splurge

Sperm Whale Voices Are Personal

Posted: 25 Jun 2010 12:02 PM PDT

A new technique for deciphering the calls of sperm whales allows the magnificent, mysterious creatures to be studied in unprecedented detail.

Researchers identified subtle variations caused by differences in the shape of individual whales' heads. It's the first time that sperm whale vocalizations have been linked to specific individuals.

"This is the just the first step in answering a lot of questions about their vocal and social complexity," said Shane Gero, a Dalhousie University biologist. "It's the first time that we're getting to the level of knowing these animals as individuals, as families — as personalities, really. It's a whole new step."

Vocalizations are used by every cetacean species, but only a few, such as bottlenose dolphins and humpback whales, have been studied in detail. Even those fields of research are still young, however, and it's not always possible to extrapolate findings between species that are different both physically and socially.

Sperm whales have been particularly difficult to study, as their family groups tend to be large, with a proclivity for long-distance roaming. Only snatches of communication are usually heard. It's been enough for researchers to learn that each sperm whale family has a distinctive repertoire of sounds, but the sounds have been so mixed together that they can't be consistently attributed to a individuals — a first step in understanding what the whales might be saying.

The latest study, currently in press at the journal Marine Mammal Science, focuses on a seven-member sperm whale family who live in waters around the Caribbean island nation of Dominique. Caribbean sperm whales have unusually small home ranges. This allowed the researchers to spend more time with them than is usually possible. Because the group was small, there were more opportunities to identify and record individual whales when they were alone.

The researchers could then analyze whales' vocalizations, which take the form of high-frequency clicks made by pushing air through structures in their skulls.

"The whales communicate by patterns of clicks. The clicks reverberate in the head. If you listen to it carefully, there are these pulses. The time between pulses reflects the time it takes for sounds to reverberate, to go from one end of the head and back. Because the heads are all different length, they have different reverberation times," study co-author Hal Whitehead, also a Dalhousie University biologist. Until now, "just figuring out who makes which sound underwater was tough," he said.

Analysis of the whales' vocalizations are still in their early stages, but the results are already intriguing. While the whales tended to possess the same basic repertoire of "codas" — the technical name for each distinctive series of clicks — one female had a completely different set. She happened to be a mother. The distinctive sounds could be what she used to communicate with her calf.

Apart from the mom, the researchers found that half of each individuals' vocalizations followed one of two patterns.

One pattern is formed by two consecutive, slowly-paced clicks, followed by three faster clicks. It has been found only in the Caribbean. While the pattern varies slightly between groups, this study suggests that it's consistent within the group. According to Gero, it could function as a family identifier, letting other whales know who is around. "It says, I belong to this family, I belong to this vocal clan," he said.

The other common pattern is composed of five regularly-spaced clicks, and has been heard in sperm whales all over the world. Preliminary research suggests that the pattern may vary slightly between each individual, said Gero. If so, the pattern could function as an individual identifier — or, from another perspective, a name.

The question of whether it's appropriate to think of sperm whales as having names is a controversial one. Some scientists think that many cetaceans should be considered persons, at least on par with non-human great apes. There's considerable evidence to support the notion: cetacean brains are extraordinarily sophisticated, especially in areas associated with cognition and communication, and many social behaviors can be explained only as culture rather than instinct. In captivity, dolphins pass tests of self-recognition and self-awareness that were once considered markers of personhood.

Questions of consciousness and personhood are difficult to answer in another species in scientifically quantifiable ways, said Gero. But techniques like those used in this study should help.

"I use the word 'personality' very carefully. It's hard to quantify. But they undoubtedly have them," said Gero. "It may take years and years to understand them, to translate their behaviors and nuances, to understand things like fear or happiness. But it's time that the assumption was made that these animals are individuals, and have a concept of self."

Images: Above, sperm whale mother and her calf; below, a juvenile whale the researchers nicknamed "Can Opener."/Shane Gero.

See Also:

Citation: "Individual vocal production in a sperm whale (Physeter macrocephalus) social unit." By Tyler M. Schulz, Hal Whitehead, Shane Gero & Luke Rendell. Marine Mammal Science, in press.

Brandon Keim's Twitter stream and reportorial outtakes; Wired Science on Twitter. Brandon is currently working on a book about ecological tipping points.

Giant, Tilted Exoplanets Like It Hot

Posted: 25 Jun 2010 11:30 AM PDT

Giant planets with wonky orbits mostly circle blistering-hot stars, two new studies find. This pattern could explain why some "hot Jupiters" — planets from a third to 12 times the mass of Jupiter that sit scorchingly close to their stars — orbit the way their star spins, while others tilt so far that they orbit backward.

"It's a possible resolution of what would otherwise be a weird fluke," said astronomer Joshua Winn of MIT, a co-author of one of the new studies.

Originally, astronomers thought planets formed from a swirling disk of gas and dust that revolved around a central star like a record. When the disk's material cooled and congealed, the resulting planets all marched in line with the star's equator. Hot Jupiters were supposed to have formed around where Jupiter sits in our solar system, then spiraled calmly inward by exchanging gravitational energy with the disk, a process called migration. The first batch of extrasolar planets discovered fit this picture, reassuring astronomers that their model was right.

But in 2008, astronomers started finding giant planets whose orbits lay at jaunty angles with respect to their stars. A recent study declared that so many hot Jupiters have cock-eyed orbits — about half of the 28 whose angles have been directly measured — that scientists should throw out the disk-migration theory altogether. Instead, most hot Jupiters probably got where they are through a violent encounter with a sibling planet.

Whether a single process could have formed both regular and wrong-way hot Jupiters — and why the first batch of planets looks so different from the second — remained a puzzle. In a paper posted on arXiv.org and submitted to Astrophysical Journal Letters, astronomers propose an answer to both questions: Wonky hot Jupiters orbit hot stars.

Winn and his colleagues took 19 of the planets whose angles have been measured, and plotted their angles against the temperature of their star. Only two of 11 planets orbiting cool stars were misaligned, while six out of eight planets orbiting stars with temperatures hotter than 6,250 Kelvin (10,790 degrees Fahrenheit) had tilted orbits.

The team pointed out that the first hot Jupiters were found by observing how the star moved in response to the planet's gravitational tug. This method, called Doppler spectroscopy, has an easier time finding planets around relatively cool stars.

The second group was found in transit surveys, where the planet announces its presence by passing in front of the star and blocking some of the star's light. This method works better with hotter, brighter stars, because the contrast is greater.

"That's why the first bunch of stars we looked at showed well-aligned orbits, and the second batch showed misaligned orbits: because the second batch were mainly hot stars," Winn said.

A second paper accepted to the Astrophysical Journal came to the same conclusion by a different route. Kevin Schlaufman, a graduate student at the University of California, Santa Cruz, noted that current techniques measure only the angle between the star and the planet's orbit, but the angle between the star and the Earth is also needed to draw a complete picture in three-dimensional space.

One way to estimate this angle is to check how fast the star seems to spin. Astronomers can tell how fast a star should spin based on its age and its mass. If the star apparently spins too slowly, that's a clue that it's not facing the Earth edge-on. Planets that cross in front of their stars must have edge-on orbits from the Earth's point of view, or we wouldn't see them. So if a star spins too slowly but has a transiting planet, that means the planet is at a wonky angle.

Schlaufman did a statistical study of 75 exoplanet systems, and found that 10 of them should have tilted orbits. Several of the planets his computations picked out were already known to have funny orbits. And all of them circled large, hot stars.

"I find that encouraging, and a signal that we're onto something good," Winn said. "We have these two pretty much totally independent ways of checking, and they give the same result."

Winn suggested that the transition temperature could explain why only hot stars have tilted planets. Stars that burn cool have thick outer layers called convective zones that respond strongly to the gravitational pull of the planet. The friction from the planet and the star yanking each other around robs energy from the planet's orbit. The orbit slowly becomes circular and settles into alignment with the star's equator, a position that takes less energy to maintain.

Stars hotter than 6,250 Kelvin have thin or even nonexistent convective zones, Winn said, so their hot Jupiters stay wherever their violent histories parked them.

"It struck us as interesting that this transition from well-aligned planets to misaligned planets happens to be at about the same temperature as convective zones," Winn said.

The theory still has some kinks to work out, like keeping the planet from getting swallowed up by the star. Astronomer Andrew Collier-Cameron of the University of St. Andrews in Scotland, who was not involved in the new study, calls for more observations.

"It's early days yet, and we're still working with a grand total of only about 28 planets," Cameron said. "Until we go do the legwork and measure more of them, there's still plenty of wriggle room for theorists."

Cameron also noted that, though "rampaging hot Jupiters" could knock any other planets out of their systems, most of the galaxy's Earth-like planets are probably safe. Hot Jupiters are "rare beasts," he said. "By and large, although they may mess up their own systems, they don't really harm the chances of us finding terrestrial type planets."

Image: ESO/L. Calçada

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Friday, 25 June 2010

Johnald's Fantastical Daily Link Splurge

Johnald's Fantastical Daily Link Splurge

Sense of Touch Shapes Snap Judgments

Posted: 25 Jun 2010 03:00 AM PDT

Sitting in a hard chair can literally turn someone into a hardass. Holding a heavy clipboard leads to weighty decisions. Rubbing rough surfaces makes us prickly. So found researchers studying the interaction between physical touch and social cognition.

The experiments included would-be car buyers who, when seated in a cushy chair, were less likely to drive a stiff bargain. The findings don't just suggest tricks for salesman, but may illuminate how our brains develop.

"The way people understand the world is through physical experiences. The first sense they develop is touch," said study co-author Josh Ackerman, a Massachusetts Institute of Technology psychologist. As they grow up, those physical experiences shape how people conceptualize abstract, social experience, he said. "Later on, you can do what we did — trigger different physical experiences, and produce changes in people's thoughts."

Published June 24 in Science, the study is the latest addition to a booming field of embodied cognition, which over the last decade has scientifically eroded the notion that mind and body are distinctly separate.

Other studies have shown that kids are better at math when using their hands while thinking. Actors recall lines more easily while moving. People tend towards generosity after holding a warm cup of coffee, and are more callous after holding a cold drink.

The drink temperature study was co-authored by Yale University psychologist John Bargh, also a co-author of the latest paper. His group is especially interested in touch, which is one of the first senses to develop.

Other research shows that the brain doesn't always have different structures for different functions, but often uses the same systems in a variety of ways. And given the importance of touch, it's easy for developing brains to use tactile associations — heaviness requires effort, roughness leads to friction, hard objects are inflexible — in understanding social situations.

"Those connections that people have, between physical experience and mental understanding, don't ever disappear," said Ackerman.

To test the connection, the researchers conducted a variety of experiments simulating real-world social interactions. In one, test participants played the part of employers interviewing job applicants. When holding a heavy clipboard, they were more likely to consider candidates to be serious, and thought of their own judgements as especially important.

In another test, passerby asked to complete surveys on government funding of social programs were more likely to support increases while holding heavy clipboards. The problems seemed more significant.

After hearing stories about an ambiguous social interaction, test participants tended to consider it uncoordinated and harsh if they'd just handled a rough-surfaced jigsaw puzzle. After assembling a smooth puzzle, those ambiguous stories didn't seem so awkward.

Test subjects who touched a block of wood subsequently judged job applicants to be more strict in character than when they'd touched a blanked. And in the car negotiations, people sitting in stiff chairs rather than soft held out for an extra $350 price cut.

"The tactile sensation is extremely important early in devleopment. The idea that other associations would be built on that makes intuitive sense," said Franklin & Marshall College psychologist Michael Anderson, who was not involved in the study. "Brain regions that may initially have been dedicated to one particular task, turn out ot contribute to multiple tasks."

It's not only people curious about brain development who will be interested in the findings. Manipulations "used in the studies might have important implications for a host of social situations such as job interviews, buyer/seller interactions, and the collection of signatures for petitions," said Gettysburg University psychologist Brian Meier.

For those fearing exploitation by marketers, Ackerman noted that tactile suggestion's effects diminish when people pay attention. "It's when you're distracted, thinking in a shallow fashion, that you get hit by these cues," he said.

The researchers want to further study how tactile-social interactions form during infancy and adolescence, and whether certain types of people are susceptible than others. They're are curious whether tactility affects hormone balances and, in the short term, personality type.

Ackerman said the connection isn't one-way. "Once you have the connections, the process works both ways," he said. "There is some evidence that you can change people's sensations by changing their thoughts."

Image: Taber Andrew Bain/Flickr.

See Also:

Citation: "Incidental Haptic Sensations Influence Social Judgments and Decisions." By J.M. Ackerman, C.C. Nocera, J.A. Bargh. Science, Volume 328 No. 5987, June 22, 2010.

Brandon Keim's Twitter stream and reportorial outtakes; Wired Science on Twitter. Brandon is currently working on a book about ecological tipping points.

New Form of Gene Regulation Hints at Hidden Dimension of DNA

Posted: 24 Jun 2010 03:00 PM PDT

An entire class of seemingly useless genetic components may actually regulate gene activity, suggests a study that — though preliminary — has potentially transformative implications for biology.

The findings involve apparently redundant copies of genes, called "pseudogenes," and RNA molecules that would normally carry out genetic instructions, but appear to be disabled.

When it comes to altering the activity of PTEN, a cancer tumor-regulating gene, these components are neither redundant nor broken. Instead they help turn PTEN on and off.

The same might happen for thousands of other genes. If so, the findings have revealed an entire new class of operators in the programming language of life.

"This is a completely new way by which genes can be regulated. It's something that up to this point has been undiscovered," said Leonardo Salmena, a Harvard Medical School geneticist and co-author of the study, published June 23 in Nature.

The implicit question is whether the process is unique to PTEN and its decoys, or applies to the human genome's other 19,000 pseudogenes. If so, the junk may actually be vitally important to development and disease.

"There's a huge domain of non-coding RNAs. Until now, we couldn't make sense of them," said study co-author Pier Paolo Pandolfi, also a Harvard Medical School geneticist. "Now we have a way to understand them. We're not in the dark."

Scientists have been aware of RNA since the 1960s, when they learned that genes code for what's now known as messenger RNA, which carry instructions to protein-manufacturing cellular factories. But the straightforward messenger model proved simplistic.

Other types of RNA, called microRNA and small interfering RNA, can bind to messenger RNA. This prevents gene instructions from reaching their destinations, and allows for fine-tuned gene control. Gene activity can be quickly shut off, and just as quickly allowed to proceed.

So-called RNA interference is now considered essential for coordinating the ultra-fast, ultra-complicated mixing-and-matching of proteins that takes place in every single cell, all the time. In 2006, the discoverers of RNA interference received a Nobel Prize. Researchers anticipated an RNA revolution.

In the latest study, the researchers flipped the standard script of RNA interference. Inspired by MIT geneticist Phil Sharp's discovery that synthetic messenger RNA could be used to trap microRNA — interfering with the interferer, so to speak — they wondered if cells might not already do that.

Indeed, each human genome has many pseudogenes, or near-perfect copies of functional genes. These pseudogenes produce RNA that doesn't seem to do anything, but simply floats in cellular space. Scientists have long assumed pseudogenes and their RNA to be so much cruft, the biological equivalent of leftover code that's yet to be excised from a program. But the researchers in this study, whose specialty is a tumor-suppressing gene called PTEN, noticed that RNA produced by PTEN's pseudogenes was shaped exactly like the real thing.

They hypothesized that PTEN's pseudogene RNA should work like a decoy, pulling in microRNA and small interfering RNA, allowing PTEN's messenger RNA to proceed unobstructed. Experiments showed that their guess was right.

To test their proposition, the researchers first amplified the expression of PTEN pseudogenes in laboratory cell cultures. As predicted, this increased PTEN protein production: The decoys did their job. When the researchers decreased PTEN pseudogene expression, PTEN protein levels fell. In mice, decreased PTEN expression often leads to cancer.

The researchers then studied expression levels of PTEN and its pseudogenes in samples of cancerous tissue, and found the patterns duplicated. It wasn't only PTEN that helped suppress tumors, but supposed junk. In their absence, would-be interfering RNA was unleashed.

The researchers dubbed the decoys "competitive endogenous RNA," or ceRNA. They speculate that regular messenger RNA could also function as ceRNA, as could non-coding RNA that's not produced by pseudogenes but hasn't yet been functionally identified.

According to Pandolfi, if the findings truly represent a widespread new class of RNA, they will double the known number of functional genetic elements.

"This brings into play thousands of RNAs that we previously had no idea what they did," said Salmena. "We think we've only hit the tip of the iceberg with this phenomena."

In two accompanying Nature commentaries, Thomas Jefferson University geneticist Isidore Rigoutsos and University of California, San Diego geneticist Frank Furnari lauded the work's immediate implications for cancer.

Furnari noted that altered PTEN gene expression patterns are seen in Cowden's disease and Bannayan-Zonana syndrome, raising the possibility that ceRNA is involved in those rare diseases. Rigoutsos agreed that the findings "could have broader implications beyond PTEN regulation."

"They made a very exciting observation. It raises the question of whether there's another level of regulation of gene expression," said Dinah Singer, a geneticist at the National Cancer Institute, which helped fund the research. "Having made this observation, you can now look anywhere for it."

Singer declined to speculate on whether the newly described mechanism might eventually account for the so-called missing heritability, a term used by scientists to describe genetic risk factors that clearly exist but can't be linked to standard gene mutations.

"To what extent this is going to be a general mechanism, the onus is now on the scientific community to begin looking in other systems," said Singer. "I presume they will."

Image: Intensity of PTEN gene expression in normal and cancerous prostate tissue./Nature.

See Also:

Citations: "A coding-independent function of gene and pseudogene mRNAs regulates tumour biology." By Laura Poliseno, Leonardo Salmena, Jiangwen Zhang, Brett Carver, William J. Haveman & Pier Paolo Pandolfi. Nature, Vol. 465 No. 7301, June 23, 2010.

"Decoy for microRNAs." By Frank Furnari and Isidore Rigoutsos. Nature, Vol. 465 No. 7301, June 23, 2010.

Brandon Keim's Twitter stream and reportorial outtakes; Wired Science on Twitter. Brandon is currently working on a book about ecological tipping points.

Baby Red Panda Born at National Zoo

Posted: 24 Jun 2010 02:21 PM PDT

A baby red panda was born at the National Zoo in Washington, DC on June 16. The newborn is the first red panda to be born at the zoo in 15 years.

The proud parents, two-year-old Shama and three-year-old Tate, first met in February 2009, and got busy immediately. But because red pandas mate only once a year, and "because the two were inexperienced," it took them a few tries to get Shama pregnant, the National Zoo said in a press release.

"This birth indicates that the animals are comfortable and well adjusted in their home here," said Tony Barthel, curator of the Zoo's Asia Trail. "We are excited about the opportunity we'll have to watch and learn from the interactions between the red pandas as Shama raises the cub."

Despite their name, red pandas (Ailurus fulgens, also called "lesser panda," "bear cat" and "firefox") are more closely related to raccoons than to giant pandas. They live in cool bamboo forests in the Sichuan and Yunnan provinces in China, in the Himalayas and in Burma. Fewer than 2,500 red pandas remain in the wild, making this birth a victory for conservationists worldwide as well as for its first-timer parents.

The red pandas' enclosure at the zoo is closed to the public to let Shama and her baby bond, but these early pictures are high-pitched-squeal-inducingly cute.

Images: Smithsonian

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Thursday, 24 June 2010

Johnald's Fantastical Daily Link Splurge

Johnald's Fantastical Daily Link Splurge

Citizen Science: Count the Gulf’s Ghost Crabs

Posted: 23 Jun 2010 11:35 AM PDT

While the oil disaster's terrible toll on birds and turtles will at least be measured, less charismatic creatures tend to be ignored. That's why conservationists are organizing a citizen science project to count the Gulf Coast's ghost crabs.

Also known as sand crabs, they're not classically cute, but they're an important part of coastal food webs. Because the crabs are relatively easy to spot, it's possible for people to help scientists estimate their numbers, providing baseline counts for comparison against future surveys.

"A lot of people are speculating that this spill could have severe effects on marine invertebrates," said Drew Wheelan, a conservation coordinator for the American Birding Association, who came up with the idea for a ghost crab count. "Ghost crabs are conspicuous and easy to count."

Wheelan modeled his project after an ongoing Gulf Coast bird count organized by the Audubon Society and Cornell Lab of Ornithology. Since early May, birders have submitted approximately 150,000 observations from Gulf states. That data will be invaluable to scientists trying to quantify the oil's impacts, especially in areas where precise population counts didn't previously exist.

University of Florida zoologist Sea McKeon designed the ghost crab-counting methodology, which is described on Wheelan's blog, along with instructions for submitting data. It involves measuring distances between tideline crab burrows at a specific time and place each day for as long as possible, and requires little more than a measuring tape, notebook and pen, GPS reading and some sunscreen.

Wheelan said counts need to start as soon as possible in areas where oil hasn't yet come ashore. Pre-disaster data is needed, and BP — which is trying to bar journalists and citizens from many affected areas — may close beaches as oil approaches.

Wheelan is still counting birds, too. During an ABA film project, Wheelan was interrogated by a policeman who appeared to take orders from BP.

But for now, "at least in Florida and Alabama and Mississippi, people are still able to travel on beaches" and count crabs, said Wheelan.

Image: Drew Wheelan

See Also:

Brandon Keim's Twitter stream and reportorial outtakes; Wired Science on Twitter. Brandon is currently working on a book about ecological tipping points.

Fishy Gene Hints at How Limbs Evolved From Fins

Posted: 23 Jun 2010 08:47 AM PDT

Two genes found only in fish may be a key piece in the puzzling evolution of limbs.

The genes' removal from zebra-fish embryos resulted in the loss of actinotrichia — a basic fin component — and made their proto-fins resemble appendages seen in ancient fossils of the first four-legged creatures.

"The loss of actinotrichia may have contributed to the evolutionary transition from fin to limb," wrote researchers led by University of Ottawa biologists Jing Zhang and Marie-Andrée Akimenko in a study published June 23 in Nature.

During early embryonic development, fins and limbs look strikingly alike. In fish, however, some cells form a pattern of fine fibers. These are the actinotrichia, which form the scaffold on which fin rays are assembled.

In their study, Zhang and Akimenko noticed that two genes, actinodin 1 and 2, are especially active during zebra-fish fin development. These proved to code for previously unknown proteins that mix with collagen to form actinotrichia.

Subsequent searches of animal-genome databases found the actinodin genes in other bony fishes (including whale sharks, living fossils little changed in the 400 million years since the Devonian, before limbs evolved) but not in mammals, birds or amphibians.

When the researchers knocked actinodin genes out of zebra-fish embryos, actinotrichia didn't form in the resulting fishes' pectoral fins. Their tails, however, were unaffected. That fits with the evolutionary narrative suggested by fossils of the earliest known four-limbed creatures, which kept their fishy tails even as legs started to form.

Similar general patterns of gene expression are also found in embryonic chickens and mice with extra toes, a condition known as polydactyly.

"This is also in agreement with the fossil record, which indicates that the earliest primitive aquatic tetrapods of the late Devonian were polydactylous," wrote the researchers.

Image: Left: A zebra-fish–embryo fin. Right: The paw of an embryonic mouse.
Jing Zhang

Citation: "Loss of fish actinotrichia proteins and the fin-to-limb transition." By Jing Zhang, Purva Wagh, Danielle Guay, Luis Sanchez-Pulido, Bhaja K. Padhi, Vladimir Korzh, Miguel A. Andrade-Navarro & Marie-Andree Akimenko. Nature, Vol. 465, No. 7301, June 23, 2010.

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Brandon Keim's Twitter stream and reportorial outtakes; Wired Science on Twitter. Brandon is currently working on a book about ecological tipping points.

Wednesday, 23 June 2010

Johnald's Fantastical Daily Link Splurge

Johnald's Fantastical Daily Link Splurge

EPA Reverses Controversial ‘Human Guinea Pig’ Rule

Posted: 22 Jun 2010 01:50 PM PDT

Under proposed changes to federal research ethics standards, the Environmental Protection Agency will no longer accept studies that use people as guinea pigs in chemical tests.

In 2006, under chemical-industry pressure, and over arguments that the studies were scientifically and ethically bankrupt, the EPA declared such data acceptable. On June 16, the EPA reversed its decision.

"What we were really concerned about is toxicity studies, where they're trying to do a study on humans to determine the dose response of a chemical," said Jennifer Sass, a senior scientist at the Natural Resources Defense Council, a liberal nonprofit. "If the EPA stops accepting them, there's no motivation for companies to conduct them."

Almost every standard code of medical ethics — including the Nuremberg Code, written in response to Nazi doctors' nightmare studies — forbid human tests of drugs or chemicals that may cause harm, but can provide no direct benefit.

The chemical industry, however, has long argued that the EPA should accept data from tests in which healthy volunteers are paid for exposing themselves to pesticides and other known toxins. The industry says such data provide a more accurate picture of chemical effects than animal studies.

Critics say the resulting science is worthless, with companies running tests on small, non-representative groups of people, such as healthy young men, in order to create a false impression of safety. More importantly, the tests put people at potentially grave physical risk, with no benefit but a cash payment.

"These pesticides are intentionally designed to be toxic. Their whole purpose is to kill insects and invasive plants," wrote senator Barbara Boxer (D-CA) and representative Henry Waxman (D-CA) in a 2005 report (.pdf) on the industry's tests. "Yet in the experiments, test subjects swallowed insecticide tablets, sat in chambers with pesticide vapors, had pesticides applied to their skin, had pesticides shot into their eyes and noses, and were even exposed in their homes for six months at a time."

Continued Waxman and Boxer: "The subjects were not told of the dangers of exposure to the pesticides. Sometimes, they weren't even told the substances being tested were pesticides. They were misled into believing that they were participating in 'drug' trials, not pesticide experiments."

Nevertheless, the Bush-era EPA — led by Stephen Johnson, a former tobacco-industry scientist — said they'd accept data from those studies. The NRDC, along with liberal nonprofits Pesticide Action Network and Earthjustice, filed suit in federal court.

Proposed rule changes announced by the EPA on June 16are the result of negotiations that accompanied the legal battle. They extend protections from the Common Rule (a widely accepted set of medical ethics that forbid intentional-dosing studies that have no benefit) to all people involved in EPA-accepted studies. Extra protections are given to children and pregnant women.

"EPA expects its tougher new rules will decrease the number of systemic intentional dosing toxicity studies conducted for pesticides," reads the EPA website. "We expect the number of systemic toxicity studies to drop to as few as zero or one per year."

The rules will be opened to public comment in January of 2011, and will need court approval to finally become law.

The American Chemistry Council, the major chemical industry trade group and an advocate of expanded human testing, did not respond to requests for comment.

According to Sass, Some data on human exposures to chemicals may still be used. Reports from accidental poisonings, worker exposures and other unintentional dosing exist, and "EPA could incorporate a lot of that unfortunate, real-world data," she said.

"Pesticide companies should not be allowed to take advantage of vulnerable populations by enticing people to serve as human laboratory rats," said Pesticide Action Network senior scientist Margaret Reeves in a press release.

Image: Flickr/Michelle Tribe

See Also:

Brandon Keim's Twitter stream and reportorial outtakes; Wired Science on Twitter. Brandon is currently working on a book about ecological tipping points.

‘Lucy’s Grandfather’ Fossil Makes Humanity’s Ancestor Seem More Like Us

Posted: 22 Jun 2010 11:28 AM PDT

A 3.6 million-year-old fossil from one of humanity's earliest ancestors is more human-like than expected — and much taller.

The discovery makes Lucy, the best-known fossil of all, appear to be exceptionally short by comparison. Lucy and the new skeleton are both Australopithecus afarensis, the first fully bipedal primate and a direct ancestor of humanity. Unlike Lucy and every other A. afarensis fossil, the new skeleton has complete forelimb and hindlimb bones, allowing researchers to estimate its size more accurately.

The new A. afarensis specimen stood a full six feet tall, or almost twice Lucy's height. Other fossil fragments suggested that Lucy was an unreliable measuring stick for A. afarensis, but the new fossil is the most conclusive evidence yet. Dubbed "Kadanuumuu," or Big Man, it is described June 21 in the Proceedings of the National Academy of Sciences.

Big Man's limbs also appear well-suited for running, in contrast to the shambling gait implied by Lucy's skeleton. The proportions compare to those found two million years later in Homo erectus, and would not be out of place in a modern human, said study co-author Owen Lovejoy, a Kent State University paleoanthropologist.

"The difference between Australopithecus and humans is much less than everyone expected," said Lovejoy. "Upright walking and running were pretty advanced at 3.6 million years ago, and they didn't change much over the next two million years. Most of the changes in that period of time took place elsewhere."

Lovejoy was also part of the team that discovered Ardipithecus ramidus, a 4.4 million-year-old possible human ancestor that was officially described last October. Ardipithecus was far less chimp-like than expected.

That raises the possibility that it's the other Great Apes, rather than humans, whose bodies have evolved the most over the last few million years.

Big Man, with a rib cage shaped more like our own than that of a chimpanzee or gorilla, reinforces that notion.

"Chimps and gorillas are again the unusual form. Hominids and ourselves bear many primitive traits that haven't been specialized like they have in gorillas," said Lovejoy.

"The classic cartoon of the ape turning into the human doesn't work at all."

Image: Yohannes Haile-Selassie/PNAS.

See Also:

Citation: "An early Australopithecus afarensis postcranium from Woranso-Mille, Ethiopia." By
Yohannes Haile-Selassie, Bruce M. Latimer, Mulugeta Alene, Alan L. Deino, Luis Gibert, Stephanie M. Melillo, Beverly Z. Saylor, Gary R. Scott, C. Owen Lovejoy.

Brandon Keim's Twitter stream and reportorial outtakes; Wired Science on Twitter. Brandon is currently working on a book about ecological tipping points.

Not for Public Display: Backstage at the American Museum of Natural History

Posted: 21 Jun 2010 04:30 PM PDT

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NEW YORK CITY — You could spend three or four days in the American Museum of Natural History and still not see all the dinosaur fossils, meteorites, butterflies, lizards, diamonds and historical artifacts it has to offer. But even if you could, you would only have seen one face of the museum. In the basement, attic, turrets, back hallways and closets there's an equally dizzying array of awesome stuff.

Wired Science recently took a tour of the museum-behind-the-museum to learn about the science, art, construction and collection that make up the heart of the 140-year-old institution. From cutting-edge cryogenic tissue storage to decades-old, handmade, fossil-preparation equipment to the Big Bone Room, we learned how the museum helps discover, advance and preserve the knowledge it is best known for putting on display.

Frozen Tissue Laboratory

Getting to the various labs and back rooms of the museum involves navigating a confusing agglomeration of large spaces lined with tall cabinets containing all manner of beetle, bird and badger specimens; riding in oversized elevators; and walking down long, cluttered hallways with exposed pipes and a strange mix of outdated, faded science and safety posters on the walls. So entering the sterile, spare, high-tech frozen-tissue laboratory is like stepping into another world.

The Ambrose Monell Cryo Collection consists of eight nearly indestructible liquid-nitrogen–fueled cryogenic tanks. Three are already online, preserving 70,000 tissue samples from reptiles, amphibians, mammals, insects, fish and birds. The space can fit four more vats, and at full capacity could store and catalog a million samples.

"We have all taxa. It's one of the things that makes this collection unique," said Julie Feinstein, collections manager for the tissue lab. "All of the collections from the museum have samples here."

The cryovats take the place of the many individual collections that used to be kept in freezers in labs all over the museum. Those samples were vulnerable to power outages and even when they managed to stay frozen, they were kept between minus 4 and minus 112 Fahrenheit, which is not cold enough to prevent all damage and degradation over time. The bottom of the vats are filled with liquid nitrogen that is below minus 300, always keeping the tissue colder than minus 230.

"And the freezers don't fail," Feinstein said. Even in the event of a catastrophic power failure, the vats will stay cold for five weeks on their own. And they are on wheels, so the samples can be moved without taking them out of the freezers. There's also a dedicated staff just for the frozen collection. "So the freezers are not alone."

The tissue library is also protected against loss and misplacement by a meticulous computer tracking system that involves bar codes and human-readable numbers.

The cryostorage supports the museum's genetic-analysis and conservation studies, but the lab will store samples for any scientist with a need who is willing to relinquish ownership and share. The types of samples range from mammal blood to bird liver to whale skin. The lab recently received some samples of bats with White Nose syndrome, which threatens bat populations in the eastern United States, and is already receiving requests from other researchers to study them.

It is the premier tissue storage facility in the world, and the Smithsonian, Harvard and Yale natural history museums are hoping to model their own collections after it, Feinstein said.

Photos: Jonathan Snyder/Wired.com

Cassini Skims Through Titan’s Upper Atmosphere

Posted: 21 Jun 2010 01:39 PM PDT

The Cassini spacecraft made its deepest dip ever into the atmosphere of Titan, Saturn's largest moon, at 8:28 p.m. Eastern time on June 20. The data it collected will help determine whether the moon has its own magnetic field.

"For Titan scientists, this is one of the most anticipated flybys of the whole mission," wrote space physicist Cesar Bertucci of the Institute of Astronomy and Space Physics in Buenos Aires, Argentina in a blog post. That's saying something, as Cassini has already orbited Saturn for six years and may last seven more.

The flyby took Cassini within 547 miles of Titan's surface, about two and a half times the altitude of the International Space Station. Although this distance shaved only 43 miles off the next nearest approach, the flyby was the first to take the spacecraft below Titan's ionosphere, a layer of charged particles in the upper atmosphere. The ionosphere shielded the spacecraft from Saturn's much larger magnetic field, allowing scientists the first hints of whether Titan has a magnetic field of its own.

Earlier measurements by the Voyager spacecraft and an earlier Cassini flyby at 590 miles showed that Titan's magnetic field is weak at best, and certainly no match for Saturn's. But that doesn't mean it's not there, Bertucci said. "We'd like to know what the internal field might be, no matter how small."

Measuring the field will provide insight into the moon's internal structure. In planets like Saturn or Earth, long-lived magnetic fields are driven by currents in a metallic, liquid core. These currents arise as the planet rotates. With its thick atmosphere of nitrogen and methane and its liquid hydrocarbon lakes, Titan resembles the early Earth more than any other body in the solar system, making the moon an ideal natural laboratory for studying the origins of life. If Cassini picks up a magnetic field, it might mean that Titan, like Earth, has a liquid core.

But it might not. There are two other explanations for a magnetic Titan, Bertucci wrote. Like Mars, Titan may once have had a liquid core that has since frozen, leaving behind residual magnetism in the crust. Or, if a conducting layer like an ocean lies on or below the crust, part of the surface could have temporarily picked up some of Saturn's magnetism before Cassini got there.

The data should finish its downlink to Earth by the end of today, and a preliminary report on all the measurements from the flyby should be available by the end of the week, Bertucci told Wired Science.

Image: NASA/Cassini

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Video: How Leaping Fish Species Left the Water — For Good

Posted: 21 Jun 2010 12:28 PM PDT

Using high-speed video, researchers have revealed the biomechanical tweaks that allow a little-known fish called the leaping blenny to thrive on land.

Propelled by a twisting motion that turns their tails into springboards, leaping blennies have colonized rocky intertidal areas across the South Pacific. Closely related species still live in the ocean, but leaping blennies only go back by accident.

"None of the blennies were observed voluntarily entering the water during low or high tide," wrote Temple University biomechanicist Tonia Hsieh in a study published June 18 in Public Library of Science One.

Tsieh is one of a handful of researchers to study leaping blennies, formally known as Alticus arnoldorum. They've escaped scientific attention in part because blennies live among rocks buffeted by large, violent waves. It's a niche shared only with limpets and crabs, which could explain the evolutionary pressures favoring A. arnoldorum's terrestrial migration.

In the latest study, Hsieh studied leaping blennies and five closely-related species. Each can breathe through blood vessel-rich skin while out of water, allowing them to survive indefinitely if intermittently splashed, but only A. arnoldorum and one other blenny, Praealticus labrovittatus, venture onto land.

Hsieh used high-speed video and force-measuring plates to compare the locomotion of the different species. She found that A. arnoldorum and P. labrovittatus begin their leaps by curling their bodies into a C-shape. It's a shape seen often in the aquatic fish world as a reflexive response to danger, preceding a burst of escaping speed. The two blennies have brought it under intentional control.

Hsieh also found that A. arnoldorum has literally added a twist, rotating its tail fin sideways for extra push. This added boost likely explains its wholly terrestrial tendencies; P. labrovittatus, with its basic C-shape, is merely amphibious, and still returns regularly to the ocean.

"The terrestrial blennies have co-opted this for movement on land," Hsieh said.

Hsieh next plans to study the genetic relationships between the species, determining how the terrestrial blennies evolved and perhaps guessing how they'll evolve in the future. She also wants to study the blennies' impressive climbing abilities, which seem to involve adhesive mucus and suction-forming fins, allowing them to climb slippery, vertical surfaces.

"People say that a fish out of water is a dead fish, and that's not necessarily true," said Hsieh.

Videos: 1) Lateral view of jumping in the terrestrial blenny./Tonia Hsieh. 2) Ventral view of a terrestrial blenny, Alticus arnoldorum, climbing up a vertical piece of Plexiglas./Tonia Hsieh.

See Also:

Citation: "A Locomotor Innovation Enables Water-Land Transition in a Marine Fish." By Shi-Tong Tonia Hsieh. Public Library of Science ONE, Vol. 5 No. 6, June 18, 2010.

Brandon Keim's Twitter stream and reportorial outtakes; Wired Science on Twitter. Brandon is currently working on a book about ecological tipping points.