Aug 16, 2012

Humans, Neanderthals Did Not Have Babies

Anthropologists have dealt a blow to theories that humans and Neanderthals interbred, according to a new study.

Over the last two years, several studies have suggested that Homo sapiens got it on with Neanderthals, an hominid who lived in parts of Europe, Central Asia and the Middle East for up to 300,000 years but vanished more than 30,000 years ago.

The evidence for this comes from fossil DNA, which shows that on average Eurasians and Asians share between one and four per cent of their DNA with Neanderthals, but Africans almost none.

But a new study by scientists at Britain's University of Cambridge says the shared DNA came from a shared ancestor, not from "hybridization" or reproduction between the two hominid species.

Reporting in the journal Proceedings of the National Academy of Sciences, Andrea Manica and Anders Eriksson at the university's Evolutionary Ecology Group devised a computer model to simulate a genetic odyssey.

Common ancestor

It begins with a common ancestors of Neanderthals and H. sapiens who lived around half a million years ago in parts of Africa and Europe.

Around 300,000 to 350,000 years ago, the European population and the African population of this hominid became separated.

Living in genetic isolation, the European range evolved bit by bit into Neanderthals, while the African range eventually became H. sapiens, which expanded in waves out of Africa from around 60,000 to 70,000 years ago.

Communities of H. sapiens that were geographically closer to Europe - possibly in North Africa - retained a relatively larger share of the ancestral genes, according to the theory.

They also became the first colonizers of Eurasia during the progressive 'Out of Africa' migration.

This could explain why modern-day Europeans and Asians but not Africans have the tiny bit of genetic similarity with Neanderthals.

"Our work shows clearly that the patterns currently seen in the Neanderthal genome are not exceptional, and are in line with our expectations of what we would see without hybridization," says Manica.

"So, if any hybridization occurred - it's difficult to conclusively prove it never happened - then it would have been minimal and much less than what people are claiming now."

Earlier split

One of the great questions of anthropology is what happened to the Neanderthals.

Hybridization would have answered that, at least partly. By interbreeding with humans, the Neanderthals were not wiped out by H. sapiens or by climate change as some contest. Instead, Neanderthal genes were merged into the genome of the dominant strain of Homo.

Read more at Discovery News

How Long Until We Learn Animal Languages?

Koko the gorilla can comprehend roughly 2,000 words of spoken English. She doesn't have a vocal tract suitable for responding verbally, so the 40-year-old ape signs her thoughts using a modified form of American Sign Language. Counting her native gorilla tongue, she is, therefore, trilingual.

And she doesn't just talk about food. Over the 28 years that gorilla researcher Penny Patterson has worked with Koko, the ape has expressed a whole range of emotions associated with humans, Patterson says, including happiness, sadness, love, grief and embarrassment.

Alex the African grey parrot could utter some 150 English words by the time of his death in 2007. The wordy bird demonstrated that he could count up to six objects, distinguish between numerous colors and shapes, combine words to create new meanings and understand abstract relational concepts such as "bigger," "smaller," "over" and "under." On the night of his death, at age 31, Alex's last words to his handler, animal psychologist Irene Pepperberg, reportedly were: "You be good. See you tomorrow. I love you."

From Chaser the border collie and Kanzi the bonobo to Akeakamai the dolphin, lab animals of many stripes have excelled at learning the rudiments of human languages. But despite the great strides these animals have made in crossing the species divide and communicating with humans in human terms, people have seldom ventured the other way.

Surely, as the most intelligent species, humans could learn to understand dolphin-speak better than dolphins learn sign language. Instead of trying to teach human communication systems to animals, why don't people decode theirs?

As it turns out, many scientists are trying. They hope to someday learn dolphin, elephant, gorilla, dog and all the other animal tongues. One scientist has already decoded a great deal of prairie dog. But researchers are off to a slow and late start down this road, because they're having to overcome a major obstacle of their own making: the idea that animals don't actually have languages.

"It's a hotly debated area, because there are still people who want to separate humans from other animals," said Marc Bekoff, professor emeritus of ecology and evolutionary biology at the University of Colorado, Boulder, and co-founder (with primatologist Jane Goodall) of Ethologists for the Ethical Treatment of Animals. "So if you're doing fieldwork and you see something in the animal's communication system that looks like syntax, they're going to say it isn't."

Prairie dog prattle

Constantine Slobodchikoff may have ventured further beyond this barrier than anyone. A professor emeritus of biology at Northern Arizona University, he has spent decades decoding the communication system of Gunnison's prairie dogs, a species native to the Four Corners region of the U.S. Southwest. Prairie dogs are rodents. They aren't particularly renowned for their smarts. And yet, in dozens of books and articles over the past three decades, Slobodchikoff and his colleagues have laid out extensive evidence that prairie dogs have a complex language. And he can understand a lot of it.

When they see a predator, prairie dogs warn one another using high-pitched chirps. To the untrained ear, these chirps may all sound the same, but they aren’t. Slobodchikoff calls the alarm calls a "Rosetta stone" in decoding prairie-dog language, because they occur in a context people can understand, enabling interpretation.

In his research, Slobodchikoff records the alarm calls and subsequent escape behaviors of prairie dogs in response to approaching predators. Then, when no predator is present, he plays back these recorded alarm calls and films the prairie dogs' escape responses. If the escape responses to the playback match those when the predator was present, this suggests meaningful information is encoded in the calls.

And indeed, there seems to be. Slobodchikoff has discovered the rodents have distinct calls pertaining to different potential predator species, such as coyotes, humans or domestic dogs. Their calls even specify the color, size and shape of the predator; for example, they'll differentiate between an overweight, tall human wearing a blue T-shirt and a thin, short human wearing green.

Remarkably, the prairie dogs even create new alarm calls in response to foreign objects introduced by the researchers, such as a picture of a large black oval. Although the prairie dogs never would have had cause to discuss such an object previously, they all generate an identical alarm call in response to it, suggesting they are describing the oval’s size, shape and color in a standard way.

And just like different groups of humans, different species of prairie dogs have distinct dialects. The Gunnison's prairie dogs that Slobodchikoff studies are unlikely to understand the calls of Mexican prairie dogs, Slobodchikoff said.

Their communication goes beyond alarm calls. “Prairie dogs also have what I call social chatters, where one prairie dog will produce a string of vocalizations, and another prairie dog across the colony will respond with a different string of vocalizations,” Slobodchikoff told Life’s Little Mysteries. "I can show that there seems to be some syntax in these strings, but since nothing about the behavior of the prairie dogs changes, I can't say anything about the context, and so I have no way of decoding the possible information contained in these [social] chatters."

In his new book, "Chasing Doctor Dolittle: Learning the Language of Animals" (St. Martin's Press), scheduled for release on Nov. 27, Slobodchikoff lays out his and other scientists' latest efforts to learn animal tongues.


If animals seemingly as simple as rodents have a language replete with nouns, adjectives, syntax and dialects, think what higher-order animals might be saying.

Elephants hold funerals for their dead and have been known to orchestrate raids on human villages in retaliation for poaching. Chimps wage wars. Complex animal behaviors like these necessitate complex languages, Bekoff said. "People wonder, 'How do wolves coordinate their hunts?' It's by having really complex communication systems."

Consider dolphins. They form strong social bonds, and a recent study found they even display culture, preferring to socialize with other dolphins that use the same simple tools as they do. Dolphins also make a variety of vocalizations, such as clicks and whistles. Those aren't likely to be meaningless. So will people ever learn what they're saying?

It turns out scientists have been trying to do so for over half a century. "We know a lot more than we knew a few decades ago, but we're still a long way from two-way communication," said Stan Kuczaj, director of the Marine Mammal Behavior and Cognition Laboratory at the University of Southern Mississippi.

Kuczaj said the major stumbling block has been figuring out what the units of dolphin communication are.

Monosyllabic sounds and other "phonemes are the building blocks of human languages," Kuczaj told Life’s Little Mysteries. "We don't know what the building blocks of dolphin communication systems are. Are they whistles, clicks? We now know they use touch and posture as well. My guess is we'll learn more about the units by studying the development of communication in dolphin calves. And then the next level is, what do the combinations of the units mean?"

Denise Herzing and colleagues at the Wild Dolphin Project have discovered that dolphins seem to address each other with names — vocalizations that the researchers call "signature whistles." These would suggest the whistles are units of communication, but how dolphins' clicks and postures enter in remains to be determined.

Kuczaj thinks we may eventually crack the code, but not everyone agrees there's a code to be cracked. Justin Gregg, a researcher with an international dolphin research organization called the Dolphin Communication Project, thinks dolphins may not have units of language at all.

Read more at Discovery News

Ancestor of Sharks, Humans Had Sixth Sense

The common ancestor of sharks and humans -- and all jawed animals with a backbone for that matter -- possessed a sixth sense: the ability to detect electrical fields under water.

The anatomical tools for this ability, called electroreceptors and electrosensory ampullary organs, arose from the same cell population in both cartilaginous fishes (such as sharks and skates) and bony fishes (such as sturgeons and paddlefish) along with some salamanders, concludes the study, published in the journal Development.

Humans, even aquatic wonders like swimmer Michael Phelps, unfortunately lost this sixth sense a long time ago.

"There are absolutely no remnants of electrosensory ampullary organs in humans," lead author Andrew Gillis told Discovery News. "In fact, human embryos no longer possess the embryonic structures that give rise to the ampullary organs of our fishy ancestors. ... So we (meaning our overall ancestral line) have not possessed the ability to detect electric fields underw ater using ampullary organs for a very long time."

Gillis, a Dalhousie University biologist, and his colleagues made the determinations after using long-term cell tracing techniques to study live skate embryos as they developed over a period of up to 70 days. The investigation revealed that the basic electrosensory system of this fish represents a more elaborate form of what was present in the last common ancestor of jawed animals with a backbone, vertebrates.

Amazingly, scientists have a pretty good idea of what this ancient relative of both sharks and humans looked like.

"The last common ancestor of jawed vertebrates was a fish that lived approximately 450 million years ago, and we can infer certain aspects of its anatomy based on features that are present in both of its descendant lineages," Gillis said.

These lineages all "possess jaws, teeth and paired fins," he explained, features that aren't seen in living jawless vertebrates, such as lampreys and hagfishes. Researchers can therefore reasonably conclude that these same features were present in that key last common ancestor.

Prior research further suggests that this prehistoric marine dweller looked more like a shark than another type of fish.

The electrosensory abilities passed down from this ancestor allow marine predators to hunt live prey in water. When prey, such as a smaller fish, swim or move their gills, they create changes to the surrounding electrical field, which the predators can detect.

When our distant ancestors left the water thousands of years ago, they evolved other ways of hunting, so this natural ability to detect electrical fields under water was lost over time.

Certain mammals, however, such as dolphins and the semi-aquatic platypus, later independently evolved modified nerve endings that provide them with their own way of detecting underwater electrical fields.

Read more at Discovery News

Future Violent Space Weather a Key Concern

A new report based on input from the science community outlines the most pressing objectives over the next decade for studying the sun and the far-reaching effects of solar activity. The report, which was released on Wednesday (Aug. 15) by the National Research Council, identifies specific science goals and provides recommendations for how to maintain robust and effective programs despite budgetary constraints.

The study is the council's second decadal survey for solar and space physics. The committee that wrote the 454-page report, led by Daniel Baker of the University of Colorado in Boulder, pinpointed the top research priorities in heliophysics for the decade spanning 2013 to 2022.

 More than 85 scientists and space system engineers contributed to the study, which aims to guide the ongoing and future initiatives of government agencies, including NASA, the National Science Foundation and the National Oceanic and Atmospheric Administration.

The report emphasizes the need for research to better understand the sun, how it interacts with Earth and other bodies in the solar system, and the origins of potentially harmful space weather, said University of Michigan professor Thomas Zurbuchen, vice chairman of the decadal survey.

"We really have a feeling that the next decade is one that really moves us from a decade focusing to understand drivers of space weather to one that is focused on the responses of that," Zurbuchen told reporters in a news briefing in Washington today.

The decadal survey's recommendations focus on the types of missions that should be pursued, and how mission planners can keep these endeavors cost-effective without sacrificing their potential scientific return.

The report also suggests establishing a new line of midsize missions -- ones with price tags between $4 million to $9 million -- and encourages cooperation internationally and between agencies as a way to take advantage of available resources.

"The proposed strategy directed at NSF, NASA, and also NOAA is one that recognizes the increased societal importance of solar and space physics, and how important it is to tackle these new opportunities with a diverse set of tools -- from miniature satellites like cubesats to moderate and large missions," Zurbuchen said.

Read more at Discovery News

Aug 15, 2012

Previously Unknown Cleaning System in Brain

A previously unrecognized system that drains waste from the brain at a rapid clip has been discovered by neuroscientists at the University of Rochester Medical Center. The findings were published online August 15 in Science Translational Medicine.

The highly organized system acts like a series of pipes that piggyback on the brain's blood vessels, sort of a shadow plumbing system that seems to serve much the same function in the brain as the lymph system does in the rest of the body -- to drain away waste products.

"Waste clearance is of central importance to every organ, and there have been long-standing questions about how the brain gets rid of its waste," said Maiken Nedergaard, M.D., D.M.Sc., senior author of the paper and co-director of the University's Center for Translational Neuromedicine. "This work shows that the brain is cleansing itself in a more organized way and on a much larger scale than has been realized previously.

"We're hopeful that these findings have implications for many conditions that involve the brain, such as traumatic brain injury, Alzheimer's disease, stroke, and Parkinson's disease," she added.

Nedergaard's team has dubbed the new system "the glymphatic system," since it acts much like the lymphatic system but is managed by brain cells known as glial cells. The team made the findings in mice, whose brains are remarkably similar to the human brain.

Scientists have known that cerebrospinal fluid or CSF plays an important role cleansing brain tissue, carrying away waste products and carrying nutrients to brain tissue through a process known as diffusion. The newly discovered system circulates CSF to every corner of the brain much more efficiently, through what scientists call bulk flow or convection.

"It's as if the brain has two garbage haulers -- a slow one that we've known about, and a fast one that we've just met," said Nedergaard. "Given the high rate of metabolism in the brain, and its exquisite sensitivity, it's not surprising that its mechanisms to rid itself of waste are more specialized and extensive than previously realized."

While the previously discovered system works more like a trickle, percolating CSF through brain tissue, the new system is under pressure, pushing large volumes of CSF through the brain each day to carry waste away more forcefully.

The glymphatic system is like a layer of piping that surrounds the brain's existing blood vessels. The team found that glial cells called astrocytes use projections known as "end feet" to form a network of conduits around the outsides of arteries and veins inside the brain -- similar to the way a canopy of tree branches along a well-wooded street might create a sort of channel above the roadway.

Those end feet are filled with structures known as water channels or aquaporins, which move CSF through the brain. The team found that CSF is pumped into the brain along the channels that surround arteries, then washes through brain tissue before collecting in channels around veins and draining from the brain.

How has this system eluded the notice of scientists up to now?

The scientists say the system operates only when it's intact and operating in the living brain, making it very difficult to study for earlier scientists who could not directly visualize CSF flow in a live animal, and often had to study sections of brain tissue that had already died. To study the living, whole brain, the team used a technology known as two-photon microscopy, which allows scientists to look at the flow of blood, CSF and other substances in the brain of a living animal.

While a few scientists two or three decades ago hypothesized that CSF flow in the brain is more extensive than has been realized, they were unable to prove it because the technology to look at the system in a living animal did not exist at that time.

"It's a hydraulic system," said Nedergaard. "Once you open it, you break the connections, and it cannot be studied. We are lucky enough to have technology now that allows us to study the system intact, to see it in operation."

First author Jeffrey Iliff, Ph.D., a research assistant professor in the Nedergaard lab, took an in-depth look at amyloid beta, the protein that accumulates in the brain of patients with Alzheimer's disease. He found that more than half the amyloid removed from the brain of a mouse under normal conditions is removed via the glymphatic system.

"Understanding how the brain copes with waste is critical. In every organ, waste clearance is as basic an issue as how nutrients are delivered. In the brain, it's an especially interesting subject, because in essentially all neurodegenerative diseases, including Alzheimer's disease, protein waste accumulates and eventually suffocates and kills the neuronal network of the brain," said Iliff.

"If the glymphatic system fails to cleanse the brain as it is meant to, either as a consequence of normal aging, or in response to brain injury, waste may begin to accumulate in the brain. This may be what is happening with amyloid deposits in Alzheimer's disease," said Iliff. "Perhaps increasing the activity of the glymphatic system might help prevent amyloid deposition from building up or could offer a new way to clean out buildups of the material in established Alzheimer's disease," he added.

Read more at Science Daily

Virus Causes Mad Snake Disease

Until now, no one knew why pythons and boa constrictors would sometimes tie themselves up in knots, stare into space and appear drunk.

Now scientists believe the fatal condition, known as inclusion body disease (IBD), is caused by a rodent virus. It can hit aquariums hard by infecting a large number of snakes before it's identified, and, with no treatment available, sick snakes must be euthanized.

Researchers from the University of California at Irvine noticed signs of the virus in DNA samples of snakes during an outbreak of IBD at the Steinhart Aquarium in San Francisco, according to a study published in mBio. When they tested the samples, they found a virus never seen before.

The virus appears to belong to a family of arenaviruses usually seen in rodents, and before now, only in mammals. But the snake virus doesn't fit into the two categories (called New World and Old World) previously known.

"This is one of the most exciting things that has happened to us in virology in a very long time," University of California at Irvine professor Michael Buchmeier said in a press release. "The fact that we have apparently identified a whole new lineage of arenaviruses that may predate the New and Old World is very exciting."

With the new findings, aquariums should be able to test snakes for the virus before exposing them to other snakes.

Researchers became interested in the problem when a San Francisco Bay Area woman named Taryn Hook wrote a letter after becoming worried about her snake, a 7-foot-long boa constrictor named Larry, NPR reports.

"So I wrote him a letter with a picture of myself and Larry in our backyard," Hook told NPR. "And I pled with him, explaining that he was my last hope."

Read more at Discovery News

CT Scans Reveal Mysteries Of Shark's Teeth

Shark teeth are the longest-lasting piece of the animal -- their bones are cartilage and usually decompose quickly when a shark dies. But despite the longevity of shark teeth, marine biologists were unable to draw substantial conclusions about the animal because there was no good way to look at teeth structure.

That's all changed, using the technology of X-ray computed tomography, otherwise known as CT ("cat") scans.

At Cornell University evolutionary biologist Willy Bemis, graduate student Josh Moyer and director of the Micro CT facility, Mark Riccio, decided to use CT scanner and the latest imaging software to look deep into the structure of shark's teeth. The images showed structural patterns that weren't visible before and allowed them to compare lots of teeth, answering questions about a sharks' growth, development and evolutionary history -- some of which had been lingering for at least a century.

"The thing is we can compare fossil and living shark's teeth," Bemis told Discovery News. "Because the technology is now cheaper, we can survey a large number of species in ways that were impractical in the past."

And shark teeth they do have: there are specimens that have been sitting around on shelves for years. One big advantage of the CT scan is that it's possible to see the teeth forming in the (dead) shark's head, without taking apart the specimen. The CT scan also shows an individual tooth's internal structure, which also changes as a shark ages. That reveals a lot about a shark's development, and doesn't require a scientist to slice up each tooth individually to peer inside.

CT scans were once a cumbersome business. Not only were the machines huge, but the computers and software needed to tease out images were expensive and the calculations for generating the images took a lot of time. But in the last decade, a combination of small CT machines and fast computers has made this kind of research feasible.

Read more and see video at Discovery News

Only Humans Care About Fairness

Humans could be the only animals that are sensitive to fairness, suggests a new Royal Society Biology Letters study.

It's not that other animals are unfair. They just don't seem to care as much about fairness as we do, or so this and other research concludes.

Ingrid Kaiser of the University of Heidelberg and colleagues focused their investigations on bonobos and chimpanzees. Chimps have long been regarded as the closest living relatives of humans.

For the study, the researchers presented their hairy participants with "the ultimatum theft game."
The below illustration and text from the paper illustrate how the game worked.

Instead of making offers, the chimp and bonobo subjects created the outcomes by stealing (or leaving) a portion of their partner’s share of grapes. Neither chimpanzees nor bonobos seemed to care whether food was stolen or not, or whether outcomes were fair or not, as long as they got something.

"Bonobos and chimpanzees in this study were equally insensitive to inequity," the researchers concluded.

They continued, "This finding is very different from what is found in humans, including children. While humans are strongly affected by concerns for fair allocations and fair intent, chimpanzees and bonobos do not appear to be."

Read more at Discovery News

Aug 14, 2012

Skeletal Remains of Hundreds of Warriors Unearthed

A fractured skull and a thighbone hacked in half. Finds of damaged human bones along with axes, spears, clubs and shields confirm that the bog at Alken Enge was the site of violent conflict.

"It's clear that this must have been a quite far-reaching and dramatic event that must have had profound effect on the society of the time," explains Project Manager Mads Kähler Holst, professor of archaeology at Aarhus University.

For almost two months now, Dr Holst and a team of fifteen archaeologists and geologists have been working to excavate the remains of a large army that was sacrificed at the site around the time of the birth of Christ. The skeletal remains of hundreds of warriors lie buried in the Alken Enge wetlands near Lake Mossø in East Jutland, Denmark.

The remains will be exhumed from the excavation site over the coming days. Then an international team of researchers will attempt to discover who these warriors were and where they came from by performing detailed analyses of the remains.

"The dig has produced a large quantity of skeletal remains, and we believe that they will give us the answers to some of our questions about what kind of events led up to the army ending up here," explains Dr Holst.

Forty hectares of remains

The archaeological investigation of the site is nearing its conclusion for this year. But there are many indications that the find is much larger than the area archaeologists have excavated thus far.

"We've done small test digs at different places in the 40 hectare Alken Enge wetlands area, and new finds keep emerging," says Field Director Ejvind Hertz of Skanderborg Museum, who is directing the dig.

In fact, the find is so massive that researchers aren't counting on being able to excavate all of it. Instead, they will focus on recreating the general outlines of the events that took place at the site by performing smaller digs at different spots across the bog and reconstructing what the landscape might have looked like at the time of the birth of Christ.

New geological insights

At the same time as the archaeological dig, geologists from the Department of Geoscience at AU have been investigating the development of the bog.

"The geological survey indicates that the archaeological finds were deposited in a lake at a point in time when there was a a smaller basin at the east end of Lake Mossø created by a tongue of land jutting into the lake," explains Professor Bent Vad Odgaard, Aarhus University.

Read more at Science Daily

Remaking History: A New Take On How Evolution Has Shaped Modern Europeans

Investigators reporting in the Cell Press journal Trends in Genetics say that new analytical techniques are changing long-held, simplistic views about the evolutionary history of humans in Europe. Their findings indicate that many cultural, climatic, and demographic events have shaped genetic variation among modern-day European populations and that the variety of those mechanisms is more diverse than previously thought.

Recent advances in paleogenetics are providing never-before-seen glimpses into the complex evolution of humans in Europe, helping researchers piece together the events that ultimately created what is now known as modern man. Following the period when ice sheets were at their maximum extension across Earth (between 27,000 and 16,000 years ago), hunter-gatherer populations re-colonized most parts of Europe. Then around 8,000 years ago, the first farming populations appeared on the continent during the so-called Neolithic transition. For several thousand years, two separate modes of life coexisted in Europe: hunter-gatherer populations continued to rely on wild food resources, while farming populations had an entirely different demographic profile and lifestyle that consisted of domesticated crops and livestock, pottery, housing, and storage technology.

For some decades, it was assumed that the genetic diversity of contemporary Europeans was shaped mainly during the Neolithic transition; however, it now appears that it was also affected both before and after this key event. Moreover, the spread of farming is likely to have varied to a great extent by region, leading to varying impacts of migrating farmers' and local hunter-gatherers' genetic contributions to future populations.

"We are currently at a stage in which next-generation sequencing technologies, ancient DNA analyses, and computer simulation modeling allow us to obtain a much more accurate and detailed perspective on the nature and timing of major prehistoric processes such as the colonization of Europe by modern humans, the survival of human populations during the ice age, the Neolithic transition, and the rise and fall of complex societies and empires," says first author Dr. Ron Pinhasi, of Trinity College Dublin, in Ireland.

Read more at Science Daily

Could Escaped Animals Account for Bigfoot Reports?

Last weekend a chimpanzee was seen rampaging through a Las Vegas neighborhood. It wasn't a hoax, nor a hallucination -- and it wasn't the first time.

The Associated Press reported,

A chimpanzee who rampaged through a Las Vegas neighborhood last month made a second escape from her backyard enclosure this weekend, but her caretaker thinks she had human help this time. Timmi De Rosa says the 13-year-old chimp, CJ, didn't get loose Saturday by bending steel bars without help. She thinks someone let CJ out of her cage. De Rosa says the 180-pound animal was captured quickly and was never a threat to neighbors. On July 12, CJ and her mate Buddy broke free and roamed the neighborhood, pounding on vehicles and climbing in an unoccupied car. An officer shot and killed Buddy when the animal frightened bystanders.

What might this sort of bizarre and scary incident have to do with Bigfoot and other mysterious creatures? Plenty.

The field of cryptozoology doesn't merely include unknown animals like Bigfoot, but also those "out of place" -- animals known to exist but rarely if ever reported outside of their natural habitats.

If a person walking in the woods sees a large, hairy bipedal creature, he or she is likely to assume it's Bigfoot. But Bigfoot is of course not the only large hairy animal that can stand on two legs; bears, for example, can stand and even briefly walk on two legs, as can chimpanzees, bonobos, baboons and other animals.

Other large animals such as moose or elk, when seen from behind and/or in near-darkness, can also appear to be standing on two legs and therefore Bigfoot-like.

In these cases the reason that an eyewitness rules out a known animal in favor of an unknown one is that he or she assumes that there are no wild animals in the area that could look like that. Clearly, that is not always the case.

As wild animals lose more and more of their native habitats they are drawn closer to cities and towns. Coyotes and bears, for example, have become an increasingly common sighting in many areas. And that's only the tip of the iceberg.

Exotic Animal Escapes

In 2010, two camels and a tiger were found in the woods in Canada. The animals were among several being moved from Nova Scotia to a private zoo outside of Toronto, and they escaped when the truck carrying them was stolen by thieves in Quebec.

In 2009 an Oklahoma couple driving home from church on U.S. 81 about an hour north of Oklahoma City swerved to avoid an eight-foot-tall, 4,500-pound elephant on the highway. It had escaped earlier that day from a circus at the Garfield County Fairgrounds, and amazingly no one had been able to track or find it.

Then of course there was the bizarre and tragic case in October 2011 when an Ohio man released his private menagerie of exotic animals into the wild before killing himself. In all nearly 60 animals including wolves, grizzly bears, lions, Bengal tigers, leopards and monkeys scattered into the woods outside of Columbus. All were (apparently) eventually recovered, though many had to be killed.

There are many other cases similar to these, and likely even more that go unreported. Some people whose exotic pets escape may not want to report it to police for fear that they will be fined or jailed (either for illegally keeping them in the first place, or for allowing them to escape), or that their animal will be shot and killed.

These misplaced animals don't always escape from private zoos or circuses. Last year a 140-pound cougar was killed on a highway in Connecticut, far outside its natural habitat. As the New York Times noted,

 So where had this cougar come from? Now we know the answer, and it couldn't be more astonishing. Wildlife officials, who at first assumed the cat was a captive animal that had escaped its owners, examined its DNA and concluded that it was a wild cougar from the Black Hills of South Dakota. It had wandered at least 1,500 miles before meeting its end at the front of an S.U.V. in Connecticut.

One wonders how many people saw the cougar during its journey halfway across the United States; did anyone see the elusive creature and think it might be an unknown creature or monster?

Read more at Discovery News

Nuke Disaster Spawns Mutant Butterflies

Japan may have a real-life Mothra on its hands. Like the giant moth that often battled Godzilla, the butterflies near the site of the 2011 Fukushima disaster may have been mutated by exposure to radiation. But Tokyo is in no danger of being demolished by these butterflies.

To the contrary, the butterfly's mutations, such as small wings and irregular eyes, seem like handicaps and the malformations are getting worse with succeeding generations, say a team from the University of the Ryukyus, Okinawa in the journal Scientific Reports. The team has been studying the species, known as the pale grass blue butterfly (Zizeeria maha) for more than 10 years, reported BBC News.

The fluttering freaks were found by the Japanese entomologists. The insects were part of a group of 144 of their kind collected from 10 different parts of Japan in May 2011, two month after the earthquake/tsunami/nuke disaster combination struck the Land of the Rising Sun. Only near the site of the damaged Fukushima Dai-ichi nuclear power plant did the scientists find abnormal butterflies.

To test the long term fallout of the possible radiation-induced mutations, the scientists raised some of the butterflies from the site in a lab far from the on-going effects of radiation exposure near the nuclear plant. The next generation was even more malformed that the first, even though they were raised far from any radioactive contamination. Field studies in September 2011 found that subsequent generations of wild butterflies were more warped as time went on as well.

Read more at Discovery News

Aug 13, 2012

100,000 DPI Image Pushes Limits of Resolution

A method of printing nanometer-tall pillars has been used to create full-colour images with a resolution pushing up against the maximum theoretical limit.

The Singapore-based team, who describe their work in a paper in Nature Nanotechnology, created pixels using tiny nanoscale posts, with silver and gold nanodiscs on top. The distance between these structures, and their diameter, sets the colour of light that they reflect.

As proof of concept, the researchers, based at Singpore’s Agency for Science, Technology and Research, printed a 50 x 50 micrometer image of Lena Söderberg, a Swedish model from a 1972 issue of Playboy magazine, often used in image processing experiments.

They used electro-beam lithography to cover a silicon wafer with pillars made from an insulating material, then deposited the nanodiscs on top and coated the surface of the wafer with metal to reflect the coloured light and make the image brighter. The resulting image came in at an impressive 100,000 DPI resolution.

That’s right up at the maximum possible resolution that can be achieved. Even under the best microscope, a limit can be reached due to the wavelength of visible light. If two objects are too close together, light reflecting off them will diffract and they’ll blur together. In the case of visible light, in the centre of the colour spectrum, that distance is 250 nanometers — exactly the distance between the pixels in the created image.

The other benefit of using nanostructures to create colour is that they’ll never fade. So long as the pillars don’t corrode and change shape, the image won’t change over time.

Read more at Wired Science

Prehistoric Shark Species Found in Ariz.

The remains of several new toothy shark species, with at least three dating to 270 million years ago, have been unearthed in Arizona, according to a new study.

The research, published in the latest issue of Historical Biology, suggests that Arizona was home to the most diverse collection of sharks in the world during the pre-dinosaur Middle Permian era. The researchers have discovered many other new shark species from the area, with papers in the works to document them.

For now, lead author John-Paul Hodnett described the three mentioned in the latest study:

Nanoskalme natans ("swimming dwarf blade") was a small (about 3.2-foot- long) shark with blade-like cutting teeth. It was probably a scavenger and predator on small fish.

Neosaivodus flagstaffensis ("new Saivodus from Flagstaff") was a medium-sized shark (about 6.6 feet) with gripping teeth that might have been a specialist on nautiloids as a juvenile, but a more generalist feeder as an adult.

Kaibabvenator swiftae ("Swift's Kaibab hunter") was a large (around 19.7 feet ) shark with big serrated cutting teeth. It was presumably an active apex predator on large prey including other sharks, similar to the modern great white shark.

Hodnett, a researcher in the Museum of Northern Arizona's Geology and Paleontology Department, analyzed the shark remains with colleagues David Elliott, Tom Olson and James Wittke. The sharks were unearthed at what is known as the Kaibab Formation of northern Arizona.

Elliott told Discovery News that a shallow, warm sea covered this part of Arizona at the time. Today, this same area is a high plateau region supporting a Ponderosa Pine forest. Although hard to imagine, the region was once home to a bustling shark-eat-shark ecosystem.

"At this time, sharks were the main vertebrate predators in marine environments world wide, and they were very numerous and diverse, filling niches that were occupied later by bony fish and even mammals, such as cetaceans (a group that includes whales and dolphins)," Hodnett said. "The main predators on sharks would have been other sharks."

According to the researchers, the new species are all ctenacanthiformes, an extinct order of primitive sharks characterized by two ornamental dorsal fin spines, and teeth in which the central cusp is large and well-developed, with smaller lateral cusps. The sharks' tails were symmetrical, unlike the asymmetrical tails of most modern sharks, and their heads were short-snouted.

The findings reveal how rich and diverse marine life was at the time, some 45 million years before the first dinosaurs even appeared.

Elliott shared that on land during this period, "the most important vertebrates were the synapsids (pre-mammals) that included animals such as Dimetrodon." That was a lizard-like beast with a large sail on its back.

Sharks, however, clearly ruled Arizona back in the day.

Read more at Discovery News

Seeing the Milky Way Spiral in a Coffee Cup

Coffee is a funny thing.

I seem to have been tempted away from tea by the seductive smell of coffee -- it feels like I've cheated on my beloved Earl Grey. Spending most of my time in coffee shops writing about all things space, I find myself looking at the top of my skinny peppermint latte (really, you should try it!) and notice how the pattern on the top resembles the Milky Way as seen from above.

The fact that I know it resembles the Milky Way is pretty clever given that no one has ever come remotely close to getting such a stunning view of the galaxy we live in. It's a testament to human logic that has granted us the knowledge of the shape of our galaxy and it's a story that starts back at the beginning of civilization.

We can even go back to prehistoric times when man first looked at the sky and had a view that was completely unrestricted by artificial lighting. To our ancestors, the view would have been stunning with the ghostly glow of thousands of visible stars arching overhead.

It wasn't until invention of the telescope in 1608 and the curiosity of Galileo Galilei that things started to change. Galileo found that under magnification, the band of light separated out into thousands of individual stars.

Not much changed until the 18th century when another astronomer, William Herschel who was working from his own observatory in England, turned one of his large telescopes on the Milky Way to try and measure the distance to as many stars as possible.

Making the rather rash, yet incorrect assumption that all stars give off the same amount of light, he estimated their distance based on apparent brightness in the sky, fainter ones being further away than the brighter ones. We now know that stars vary considerably in the amount of light they give off, so his distance estimates would have been quite wrong even though he was just working on relative distances rather than absolute.

That said, Herschel correctly drew the conclusion that we are located inside a giant disk of stars with the Milky Way representing the plane of the disk.

Other than Herschel's disk-shaped view of our galaxy, very little was known about the actual size and shape until 1914 when another astronomer called Harlow Shapley started to study clusters of stars with the 60 inch (1.5 meter) reflecting telescope at Mount Wilson observatory in California. He found that these clusters seemed to contain a type of variable star whose actual light output was directly linked to how long it took the star to brighten from from minimum to maximum brightness.

By observing these very special Cepheid variable stars in distant clusters, Shapley could time how long it took for them to change in brightness and therefore deduce how much light they really produced. Comparing this to how bright they appeared in the sky would allow him to calculate their distance and hence our distance to the cluster.

When Shapley plotted the positions of some of the clusters, a remarkable picture emerged. Their distribution seemed to be centered on a point a staggering 60,000 light-years away and the Galaxy itself was about 300,000 light-years in diameter. We now know that the diameter is about a third of Shapley's figure at around 100,000 light-years and galactic center is around 30,000 light-years away in the direction of the constellation Sagittarius.

Read more at Discovery News

Mystery Rock Shelf Floating in Pacific

An "island" of floating pumice rocks bigger in area than Israel has been spotted in the South Pacific, New Zealand's Royal Navy said.

Officers on a Royal New Zealand Air Force ship saw the rock raft southwest of Raoul Island on Aug. 9. It measures an astounding 300 miles (482 kilometers) in length and more than 30 miles (48 km) in width, the Navy said.

Lieutenant Tim Oscar, of the Royal Australian Navy, described the rocks as "the weirdest thing I've seen in 18 years at sea," according to the Australian Associated Press.

"The rock looked to be sitting two feet above the surface of the waves, and lit up a brilliant white color in the spotlight," Oscar told AAP. "It looked exactly like the edge of an ice shelf."

Pumice forms when lava from a volcano cools rapidly. Trapped gas in the hardening lava creates pores in the rocks, which allow them to float. The Navy said scientists believe these chunks off New Zealand's coast were likely spewed to the surface by an underwater volcano, possibly the Monowai seamount, which has been active along the Kermadec arc.

Officials said the phenomenon is probably not related to the eruption at New Zealand's Mout Tongariro, which sent ash 20,000 feet (6,100 meters) into the air earlier this week.

A group of researchers from GNS Science, a government-owned firm, were traveling nearby on another military ship. That group changed course to collect samples of the pumice, which will be analyzed to determine where the rocks came from, the Navy wrote on its Facebook page.

Read more at Discovery News

Aug 12, 2012

Mutations Disrupt Cellular Recycling, Cause a Childhood Genetic Disease

Genetics researchers have identified a key gene that, when mutated, causes the rare multisystem disorder Cornelia deLange syndrome (CdLS). By revealing how mutations in the HDAC8 gene disrupt the biology of proteins that control both gene expression and cell division, the research sheds light on this disease, which causes intellectual disability, limb deformations and other disabilities resulting from impairments in early development.

"As we better understand how CdLS operates at the level of cell biology, we will be better able to define strategies for devising treatments for CdLS, and possibly for related disorders," said study leader Matthew A. Deardorff, M.D., Ph.D., a pediatric genetics clinician and scientist at The Children's Hospital of Philadelphia. Deardorff also is in the Perelman School of Medicine at the University of Pennsylvania.

Deardorff and co-corresponding author Katsuhiko Shirahige, Ph.D., of the Research Center for Epigenetic Disease at the University of Tokyo, published their study online August 12 in Nature.

The current findings add to previous discoveries by researchers at The Children's Hospital of Philadelphia. A group led by Ian Krantz, M.D., and Laird Jackson, M.D., announced in 2004 that mutations in the NIPBL gene are the primary cause of CdLS, accounting for roughly 60 percent of the "classical" cases of the disease. In 2007, Deardorff joined them to describe mutations in two additional genes, SMC1A and SMC3. First described in 1933, CdLS affects an estimated 1 in 10,000 children.

The CdLS research team at Children's Hospital has focused on the cohesin complex, a group of proteins that form a bracelet-like structure that encircles pairs of chromosomes, called sister chromatids. "Cohesin has two roles," said Deardorff. "It keeps sister chromatids together during cell division, and it allows normal transcription -- the transmission of information from DNA to RNA."

Deardorff added that mutations that perturb normal cohesin function can interfere with normal human development. Such is the case in CdLS, which exemplifies a newly recognized class of diseases called cohesinopathies.

In the current study, the scientists investigated both acetylation -- how an acetyl molecule is attached to part of the cohesin complex¬ -- and deactylation, the removal of that molecule. Normally, deactylation helps recycle cohesin to make it available during successive rounds of cell division. The study team found that mutations in the HDAC8 gene threw off normal cellular recycling of cohesin.

Mutations in the gene cause loss of HDAC8 protein activity, and consequently decrease the amount of "recharged" cohesin available to properly regulate gene transcription. This, in turn, the researchers suggest, impairs normal embryonic development and gives rise to CdLS.

The researchers showed in cell cultures that mutations in HDAC8 lead to a decrease in cohesin binding to genes, similar to that seen for cells deficient in the NIPBL gene. They also identified HDAC8 mutations in approximately 5 percent of patients with CdLS.

Because mothers of children with CdLS may carry mutations in the HDAC8 gene, identifying these mutations will be very useful in accurately counseling families of their recurrence risk -- the likelihood of having a subsequent child with CdLS.

Furthermore, added Deardorff, by providing biological details of the underlying defect in CdLS, the current research suggests future approaches to treating the genetic disease. "By concentrating downstream on the biological pathway in the cohesin cycle rather than focusing on the defective gene, we may be able to eventually screen for small-molecule drugs that could be used to intervene in CdLS."

Deardorff and colleagues will continue investigate CdLS and possible therapies. Last month, the Doris Duke Charitable Foundation chose Deardorff to receive a Clinical Scientist Development Award. This three-year award, totaling $486,000, is directed to further studies of cohesin abnormalities in human disease. Deardorff is a member of Children's Hospital's Center for Cornelia deLange Syndrome and Related Diagnoses, one of the world's leading programs in studying and treating CdLS.

Read more at Science Daily

World's Most Powerful X-Ray Laser Beam Refined to Scalpel Precision

'Self-seeding' promises to speed discoveries, add new scientific capabilities.

With a thin sliver of diamond, scientists at the U.S. Department of Energy's (DOE) SLAC National Accelerator Laboratory have transformed the Linac Coherent Light Source (LCLS) into an even more precise tool for exploring the nanoworld. The improvements yield laser pulses focused to higher intensity in a much narrower band of X-ray wavelengths, and may enable experiments that have never before been possible.

In a process called "self-seeding," the diamond filters the laser beam to a single X-ray color, which is then amplified. Like trading a hatchet for a scalpel, the advance will give researchers more control in studying and manipulating matter at the atomic level and will deliver sharper images of materials, molecules and chemical reactions.

"The more control you have, the finer the details you can see," said Jerry Hastings, a SLAC scientist and co-author on the research, published this week in Nature Photonics. "People have been talking about self-seeding for nearly 15 years. The method we incorporated at SLAC was proposed in 2010 by Gianluca Geloni, Vitali Kocharyan and Evgeni Saldin of the European XFEL and DESY research centers in Germany. When our team from SLAC and Argonne National Laboratory built it, we were surprised by how simple, robust and cost-effective the engineering turned out to be." Hastings added that laboratories around the world are already planning to incorporate this important advance into their own X-ray laser facilities.

Self-seeding has the potential to produce X-ray pulses with significantly higher intensity than the current LCLS performance. The increased intensity in each pulse could be used to probe deep into complex materials to help answer questions about exotic substances like high-temperature superconductors or intricate electronic states like those found in topological insulators.

The LCLS generates its laser beam by accelerating bunches of electrons to nearly the speed of light and setting them on a zig-zag path with a series of magnets. This forces the electrons to emit X-rays, which are gathered into laser pulses that are a billion times brighter than any available before, and fast enough to scan samples in quadrillionths of a second.

Without self-seeding these X-ray laser pulses contain a range of wavelengths (or colors) in an unpredictable pattern, not all of which experimenters can use. Until now, creating a narrower wavelength band at LCLS meant subtracting the unwanted wavelengths, resulting in a substantial loss of intensity.

To create a precise X-ray wavelength band and make the LCLS even more "laser-like," researchers installed a slice of diamond crystal halfway down the 130-meter bank of magnets where the X-rays are generated.

Producing the narrower wavelength band is just the beginning. "The resulting pulses could pack up to 10 times more intensity when we finish optimizing the system and add more undulators," said Zhirong Huang, a SLAC accelerator physicist and co-author, who has been a major contributor to the project.

LCLS has already begun accepting proposals to use self-seeding for future experiments.

The first tests of the LCLS self-seeding system have generated intense excitement among scientists the world over. Representatives from other X-ray laser facilities, including Swiss FEL, SACLA in Japan and the European XFEL, came to help, and also learn how to implement it at their own sites.

Read more at Science Daily