Dec 10, 2016

Butts Are to Chimps as Faces Are to Us

Chimpanzees can recognize each other from behind.

While chimps remember faces as well, new research has found that the primates recognize the buttocks of their kin just as well as humans recall familiar faces. Not only that, but our hairy relatives also seem to utilize the same type of brain processing for their neighbor's butt that humans use to spot a familiar face.

The ability to recognize one another is important for social animals. For humans, the face offers important information beyond identity, such as attractiveness and health. For chimpanzees, their buttocks can serve the same purpose . For instance, chimps can determine if the rump they see belongs to a relative or to a female that is ovulating.

 "Faces are enormously important for people, and all the features of our faces are optimally arranged to be seen and to communicate," study author Mariska Kret, a neuropsychologist at Leiden University, said in a statement. "In the course of evolution, our faces have acquired more contrast: red lips, the whites of our eyes, eyebrows and a smooth skin that makes everything more visible."

Color also plays an important role for chimps. Kret explained that female primates have hairless faces and buttocks, making the skin features, such as color, more visible. Female chimpanzees' bottoms are red, deepening in color and growing in size when the female is ovulating. Primates' eyes are also able to easily distinguish red tints, the researchers said.

In the study, the researchers tested chimpanzees' recognition abilities by using the "face inversion effect" — a phenomenon in which the brain recognizes human faces faster than other objects, but not if those faces are inverted. However, when people see an object such as a house, they recognize it just as rapidly (or slowly) whether or not it is inverted. The exact cause of this effect is unknown.

Researchers showed both humans and chimpanzees stimuli such as the faces, buttocks — and, as a control, feet — of both humans and chimpanzees. For instance, participants were shown an image of a pair of buttocks,and then they were shown some other photos and were tasked with tapping the original image on a touch screen to indicate recognition.

For humans, the "face inversion effect" was proven to only apply to faces, with inverted face images delaying humans' recognition. However, the humans recognized the buttocks quickly, whether the photos were upright or inverted.

When the chimpanzees were presented with images of buttocks, they were much faster to click on the buttocks image when it was upright rather than inverted.

Read more at Discovery News

This Fish Has Adapted to Toxic Waters That Should Kill It

Populations of Atlantic killfish living in highly polluted estuaries on the East Coast have found a way to make a living in waters that should normally kill them, according to researchers from the University of California, Davis.

Writing in the journal Science, the researchers say killfish living in long-polluted waters off Massachusetts, Connecticut, New Jersey, and Virginia were a whopping 8,000 times more resistant to the toxic industrial pollutants than other fish. In short: The fish should by all rights be dead, except they're not.

How do they do it? It's in their genes.

The researchers sequenced the complete genomes of close to 400 killfish from the sites (their waters sullied since more than half a century ago by industrial heavy metals and other pollutants) and found that a high degree of genetic variation – higher than any other vertebrate – let them evolve rapidly in response to a fast-changing environment that became contaminated.

Importantly, the fish made the changes in similar ways, genetically speaking, which told the researchers that the animals already carried within them the genetic variation necessary for life in the toxic water.

While the killfish doesn't have value to commercial fishermen, the UC Davis finding makes them important for people because of what might be learned from the fish's particularly hardened sensitivity to chemicals.

"If we know the kinds of genes that can confer sensitivity in another vertebrate animal like us, perhaps we can understand how different humans, with their own mutations in these important genes, might react to these chemicals," said Andrew Whitehead, lead author of the study, in a statement.

Read more at Discovery News

Dec 9, 2016

'Hyper-starburst' galaxy churns out stars, clues to universe’s evolution

The distorted galaxy in the simulation results from a collision between two galaxies, followed by them merging. Astronomers think such a merger could be the reason why SPT0346-52 is having such a boom of stellar construction. Once the two galaxies collide, gas near the center of the merged galaxy (shown as the bright region in the center of the simulation) is compressed, producing a burst of new stars. The composite inset shows X-ray data from Chandra (blue), short wavelength infrared data from Hubble (green), infrared light from Spitzer (red) at longer wavelengths, and infrared data from ALMA (magenta) at even longer wavelengths. (The light from SPT0346-52 is distorted and magnified by the gravity of an intervening galaxy, producing three elongated images in the ALMA data located near the center of the image. SPT0346-52 is not visible in the Hubble or Spitzer data, but the intervening galaxy causing the gravitational lensing is detected.) There is no blue at the center of the image, showing that Chandra did not detect any X-rays that could have signaled the presence of a growing black hole.
A recently discovered galaxy is undergoing an extraordinary boom of stellar construction, revealed by a group of astronomers led by University of Florida graduate student Jingzhe Ma using NASA's Chandra X-Ray Observatory.

The galaxy known as SPT 0346‐52 is 12.7 billion light years from Earth, seen at a critical stage in the evolution of galaxies about a billion years after the Big Bang.

Astronomers first discovered SPT 0346‐52 with the National Science Foundation's South Pole Telescope, then observed it with space and ground-based telescopes. Data from the NSF/ESO Atacama Large Millimeter/submillimeter Array in Chile revealed extremely bright infrared emission, suggesting that the galaxy is undergoing a tremendous burst of star birth.

However, an alternative explanation remained: Was much of the infrared emission instead caused by a rapidly growing supermassive black hole at the galaxy's center? Gas falling towards the black hole would become much hotter and brighter, causing surrounding dust and gas to glow in infrared light. To explore this possibility, researchers used NASA's Chandra X‐ray Observatory and CSIRO's Australia Telescope Compact Array, a radio telescope.

No X‐rays or radio waves were detected, so astronomers were able to rule out a black hole being responsible for most of the bright infrared light.

"We now know that this galaxy doesn't have a gorging black hole, but instead is shining brightly with the light from newborn stars," Ma said. "This gives us information about how galaxies and the stars within them evolve during some of the earliest times in the universe."

Stars are forming at a rate of about 4,500 times the mass of the Sun every year in SPT0346-52, one of the highest rates seen in a galaxy. This is in contrast to a galaxy like the Milky Way that only forms about one solar mass of new stars per year.

"Astronomers call galaxies with lots of star formation 'starburst' galaxies," said UF astronomy professor Anthony Gonzalez, who co-authored the study. "That term doesn't seem to do this galaxy justice, so we are calling it a 'hyper-starburst' galaxy."

The high rate of star formation implies that a large reservoir of cool gas in the galaxy is being converted into stars with unusually high efficiency.

Astronomers hope that by studying more galaxies like SPT0346‐52 they will learn more about the formation and growth of massive galaxies and the supermassive black holes at their centers.

"For decades, astronomers have known that supermassive black holes and the stars in their host galaxies grow together," said co-author Joaquin Vieira of the University of Illinois at Urbana‐Champaign. "Exactly why they do this is still a mystery. SPT0346-52 is interesting because we have observed an incredible burst of stars forming, and yet found no evidence for a growing supermassive black hole. We would really like to study this galaxy in greater detail and understand what triggered the star formation and how that affects the growth of the black hole."

Read more at Science Daily

Climate change is already causing widespread local extinction in plant and animal species

Local extinctions have already occurred in 47% of the 976 plant and animal species studied, report researchers.
Extinctions related to climate change have already happened in hundreds of plant and animal species around the world. New research, publishing on December 8th in the open-access journal PLOS Biology, shows that local extinctions have already occurred in 47% of the 976 plant and animal species studied.

Climate change is predicted to threaten many species with extinction, but determining how species will respond in the future is difficult. Dozens of studies have already demonstrated that species are shifting their geographic ranges over time as the climate warms, towards cooler habitats at higher elevations and latitudes. The new study, by Professor John J. Wiens from the University of Arizona, used these range-shift studies to show that local extinctions have already happened in the warmest parts of the ranges of more than 450 plant and animal species. This result is particularly striking because global warming has increased mean temperatures by less than 1 degree Celsius so far. These extinctions will almost certainly become much more widespread over time, because temperatures are predicted to increase by an additional 1 to 5 degrees in the next several decades. These local extinctions could also extend to species that humans depend on for food and resources.

The study also tested the frequency of local extinction across different regions, habitats, and groups of organisms. It found that local extinctions occurred in about half of the species surveyed across different habitats and taxonomic groups. However, the results showed that local extinctions varied by region and were almost twice as common among tropical species as among temperate species. This is important as the majority of plant and animal species live in the tropics. The results of this study contribute to our understanding of how plants and animals will respond to global climate change and highlight the need to slow and prevent further warming.

From Science Daily

'Vampire' Burials Have Been Uncovered in Poland

Polish archaeologists have uncovered the medieval remains of three "vampires" — individuals whose bodies were mutilated before interment to physically prevent any attempts to rise from the grave.

Dating to the 13th and 14th centuries, the deviant burials were unearthed in the village Górzyca in western Poland.

"They were found near a former bishop's residence. A Gothic cathedral once stood somewhere near the graves," Krzysztof Socha of the Museum of Fortress Kostrzyn in Poland, told Seeker.

Two skeletons, belonging to a woman and a man, bear the signs of various mutilations, carried out with sharp objects.

Both skeletons had holes in the spine, most likely from someone nailing the bodies into the ground.

Buried face down — a treatment aimed to impede the individual from rising from the grave — with her knees deliberately broken, the woman is believed to have suffered from kyphosis, an exaggerated rounding of the back.

A hole into the spine of a so-called "vampire". These individuals were staked to the ground to prevent them from rising from the grave.
The condition probably gave her a humped posture which may have scared the community. She was seen as a threat even after death.

The main, dismembered and decapitated, was also suspected to have had kyphosis.

The third skeleton, a male about 30-35 years of age, was buried with the head trapped between two stones. A hole into the spine showed an attempt to stake him to the ground.

"His bones look quite 'normal', without signs of diseases," Socha said.

Read more at Discovery News

Monkeys Have the Anatomy to Talk Like Us

There is little doubt that non-human primates like Koko the gorilla are very intelligent. Koko, for example, uses sign language to communicate with people, telling them that she loves her pet cats, Miss Black and Miss Grey. Koko, however, is noticeably the strong and silent type, at least when it comes to speaking our language. She doesn't say a word.

They may not always show it, but new research, published in the journal Science Advances, suggests that non-human primates, even monkeys down on the food chain, have the vocal anatomy to produce clearly intelligible human speech. The discovery negates a long-standing theory that monkeys, gorillas, chimps and the like do not talk as we do because they are incapable of creating the sounds required for the skill.

"I hope that this new data dispels forever the widespread myth that monkeys and apes cannot speak because of anatomical limitations of their vocal tract," lead author Tecumseh Fitch of the University of Vienna's Department of Cognitive Biology told Seeker.

Fitch, senior author Asif Ghazanfar, Bart de Boer and Neil Mathur investigated the range of movements that primate vocal anatomy could produce. Using X-ray videos, they captured and then traced the movements of a macaque's tongue, lips, larynx and more as the monkey vocalized, ate and made facial expressions. The researchers then used these X-rays to build a computer model of a monkey vocal tract, allowing them to answer the question: What would monkey speech sound like, if a human brain were in control?

You can hear the results, first with the monkey model saying, "Will you marry me?" and then, "Joyeux Noel (Merry Christmas in French)."

(Recordings courtesy of Asif Ghazanfar, Princeton Neuroscience Institute; Image 1 Credit: Paul Asman and Jill Lenoble, Flickr; Image 2, showing Tecumseh Fitch in his lab: University of Vienna)

The experiment worked out great, and yet we're still left with the fact that monkeys and apes do not talk as we do. The explanation turns out to be more complex, and controversial, than you might think.

First, Fitch and his team believe that most mammals possess flexible, speech-ready vocal tracts. He said, "It seems clear that this type of flexibility evolved early on, for reasons other than vocalization, probably initially for food processing—manipulating and swallowing food."

He suspects that humans evolved at least two important changes to our brains that give us a communication edge.

Fitch explained, "We have direct connections between our motor cortical neurons and the neurons that actually control the vocal tract musculature, particularly those in charge of the larynx; and we have much more substantial connections, within our cortex, between the auditory cortex—responsible for hearing sounds—and the motor cortex, responsible for making sounds."

Fitch says there are many theories attempting to explain how humans evolved both the brain and the vocal tract for speech. One of his favorites was formulated by famed British naturalist Charles Darwin, who theorized that our ancestors initially evolved to become "singing apes," or kind of a cross between gibbons and songbirds and being able to learn new songs. This musical ability, Darwin suspected, emerged first, and then later was put to use in speech.

X-ray of a macaque vocal tract.
Fitch thinks it is unlikely we could teach non-human primates to speak, save for the remote chance that genetic engineering in future might make this possible.

Laurie Santos, a psychology professor at Yale University, told Seeker the paper "opens whole new doors for finding the key to the uniqueness of humans' unparalleled language ability."

On the other hand, Constance Scharff, a professor in the Department of Animal Behavior at Free University Berlin, indicates we may undervalue the communicative skills of animals, many of which—like parrots—are clearly very vocal.

Scharff told Seeker that she is glad the new study "puts another nail in the coffin of the idea that the absence of speech in macaques cannot be explained by an unsuitable vocal tract." Scharff also agrees that monkeys "do not seem to have the same regions and neural connections in their brains that humans use."

But, she quickly added, "there are other ways imaginable to achieve speech." She pointed out that parrots, seals and elephants either use quite different brain regions to vocalize, or the underlying systems remain largely unknown.

Read more at Discovery News

Dying Star Offers Glimpse of Earth's Doomsday in 5B Years

Five billion years from now, our sun will die. After running out of hydrogen fuel, it will start burning heavier and heavier elements in its fusion core, causing its body to bloat, shedding huge quantities of material into space via violent stellar winds. During this time, our star will expand around 100 times bigger than it is now, becoming what is known as a "red giant." This dramatic expansion will engulf Mercury and Venus, the two closest planets to the sun.

But what is less clear is what will happen to Earth — will our planet go the way of Mercury and Venus and succumb to an ocean of superheated plasma? Or will our planet escape the worst of the sun's death throes to continue orbiting the tiny white dwarf star that will be left behind?

"We already know that our sun will be bigger and brighter [when entering the red giant phase], so that it will probably destroy any form of life on our planet," said Leen Decin, of the KU Leuven Institute of Astronomy, in a statement. "But will the Earth's rocky core survive the red giant phase and continue orbiting the white dwarf?"

With the help of the most powerful radio observatory on the planet, astronomers could soon have a clue by looking at a nearby star system that resembles how our solar system will look when the sun begins to die.

L2 Puppis is an evolved star located over 200 light-years from Earth. Though this seems far away, it's pretty much on our cosmic doorstep and well within the resolving power of the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. Through precise measurements of the star, astronomers have deduced its mass and age, realizing that it is (or was) a sun-like star that's now 10 billion years old. It's also a prime example of a planetary nebula in the making.

Like our sun five billion years in the future, L2 Puppis is ripping itself apart, blasting huge quantities of gas into space. This process creates a massive glowing cloud and this particular planetary nebula resembles a beautiful cosmic butterfly (pictured above by the ESO's Very Large Telescope).

A composite view of the L2 Puppis star system, including the location of the red giant star and probable exoplanet.
"We discovered that L2 Puppis is about 10 billion years old," said Ward Homan, also from KU Leuven. "Five billion years ago, the star was an almost perfect twin of our sun as it is today, with the same mass. One third of this mass was lost during the evolution of the star. The same will happen with our sun in the very distant future."

But that's not all. According to the new study published in the journal Astronomy & Astrophysics, L2 Puppis also appears to have a planet in tow, roughly 300 million kilometers from the star. Though this distance is around twice the distance that Earth orbits the sun, it provides a very privileged view of a world orbiting a dying sun-like star. It's also an ominous preview of what's in store for Earth in a few billion years and the researchers hope to study this unfortunate planet as it experiences the wrath of L2 Puppis.

Read more at Discovery News

Dec 8, 2016

John Glenn, American Hero and NASA Astronaut, Has Died

Former astronaut and U.S. Sen. John Glenn, 95, has died in his home state of Ohio after being hospitalized more than a week.

No further information on Glenn's cause of death was available.

"John Glenn is the last of the original seven American astronauts who truly had the 'right stuff.' On top of paving the way for the rest of us, he was also a first-class gentleman and an unabashed patriot," U.S. Sen. Bill Nelson, a Florida Democrat, said in a statement.

Glenn's 4-hour, 55-minute spaceflight on Feb. 20, 1962 marked a turning point in the tense race with the Soviet Union to develop missiles capable of precision strikes across the continents. Space was where the technology was showcased and until Glenn's flight, America was behind.

The Soviets had launched the first satellite, Sputnik, on Oct. 4, 1957, the first animal (a dog named Laika) on Nov. 3, 1957, and then the first person, cosmonaut Yuri Gagarin, on April 12, 1961.

"Sputnik was totally unexpected," historian Alan Marcus, now with Mississippi State University, said in an interview marking the 40th anniversary of Glenn's flight.

"Here were what we thought were these backward Russians putting up a satellite. Then came the Cuban missile crisis and we had this incredible tension between the Soviet Union and us. All these problems made Glenn's flight rewarding, but it was not the end-all be-all … It was a step on the way to winning the Cold War," he said.

Before Glenn strapped himself inside the Friendship 7 capsule and blasted off, two of his Mercury Seven brothers, Alan Shepard and Gus Grissom, had made short suborbital spaceflights. Wary of the Soviets and despite just 31 minutes of total U.S spaceflight experience, President John F. Kennedy issued a brash call for astronauts to land on the moon before the end of the decade.

Against that backdrop came Glenn, a straight-laced Marine Corps pilot from Ohio who had flown 59 combat missions during World War II and 100 missions in Korea before being selected as one of NASA's first astronauts.

In addition to Shepard, Grissom and Glenn, the Mercury Seven included Scott Carpenter, Gordon Cooper, Wally Schirra and Deke Slayton. Glenn, the eldest of the group, was the last surviving member.

Glenn made three orbits around Earth, reaching a maximum altitude of about 162 miles and a speed of about 17,500 mph before splashing down 800 miles southeast of Cape Canaveral, Florida, near Grand Turk Island. He returned home an instant hero, honored with a ticker-tape parade in New York City and a Congressional Medal of Honor from President Kennedy.

Read more at Discovery News

A Dinosaur's Bloody Feathered Tail Has Been Found Preserved in Amber

When paleontologist Lida Xing of the China University of Geosciences in Beijing visited an amber market two years ago in Myitkyina, Myanmar, one piece immediately caught the researcher's eye. Xing placed a flashlight under the amber chunk and noticed many slender feathers arranged in an elongated structure. Suspecting that it was an important object, Xing suggested that the Dexu Institute of Paleontology buy the amber.

When Xing and colleagues later CT scanned the amber and analyzed its chemistry, even they were surprised by what they found: a dinosaur tail, residue of dinosaur blood and insects that likely scavenged on the deceased dino, which died about 99 million years ago. The discovery is reported in the journal Current Biology.

Close-up of the 99-million-year-old dinosaur tail in amber. Scavenging insects can also be seen.
"Per pound, it is the most incredible fossil I have ever seen, and it is as close to Jurassic Park as we have ever gotten," co-author Scott Person of the University of Alberta told Seeker.

Co-author Ryan McKellar of the Royal Saskatchewan Museum added, "This is the first time that skeletal material from a dinosaur has been found in amber. Previous finds in amber have included isolated feathers that may have belonged to dinosaurs, but without an identifiable part of the body included, their source has remained open to debate."

The researchers believe that a juvenile carnivorous dinosaur belonging to the Maniraptora clade (dinos closely related to birds) could have become trapped in tree resin and died, or passed on for other reasons before resin dripped on it and hardened.

Recreation of a maniraptoran dinosaur that could resemble the individual whose tail became trapped in tree resin 99 million years ago.
"There are no struggle marks in the amber, so we cannot know for certain," McKellar told Seeker. "That said, there is milky amber around the tail that suggests at least a little bit of moisture remained in the tail when it was encapsulated. Some of the insects trapped alongside the tail also belong to groups that scavenge."

Persons added, "The little bit of tail comes from a dinosaur probably about the size of a robin. The shape of the tail vertebrae, which we can only see in X-ray images, indicates that the dinosaur was a two-legged carnivore. It may be a hatchling or possibly an extremely small species that's new to science. So little of the skeleton is preserved that we cannot tell."

The researchers could confirm that the tail comes from a dinosaur, and not a prehistoric bird, because of its structure. They explained that the tail is long and flexible, lacking a well-developed central shaft, known as a rachis. Keels of feathers run down each side. The structure of these feathers suggests that the two finest tiers of branching seen in modern feathers, called barbs and barbules, arose before a rachis formed.

"The development of the rachis allows feathers to form long, vaned shapes that are useful for more than just temperature, regulation, or visual signaling," McKellar said. "It provides feathers that are more useful in controlled flight."

Visible traces of pigmentation in the tail's plumage reveal that its upper surface was chestnut brown in color, while its underside was pale or white during the dinosaur's lifetime. The contrast must have been quite striking as the animal moved about.

Illustration showing what the maniraptoran dinosaur might have looked like when alive and hunting for food.
The amber also remarkably contains some of the original iron from dinosaur blood. If the specimen had been found just a few decades ago, there would have been great hope that it could contain DNA, but studies conducted over recent years suggest that remains degrade too quickly when preserved in amber as well as in related materials, such as copal.

The researchers are now eager to see how more finds from Myanmar and surrounding regions might reshape our understanding of plumage and soft tissues in dinosaurs and other prehistoric animals.

Read more at Discovery News

A 17th-Century Child Mummy Just Rewrote the History of Smallpox

An international team of researchers has identified the oldest known sample of the variola virus that causes smallpox in the mummified remains of a 17th-century child.

The findings, published in the journal Current Biology, raise new questions about the history of the pathogen, suggesting that smallpox, once thought to be an ancient disease, may have in fact emerged in rather recent times.

Smallpox remains the only human disease eradicated by vaccination — it was also the first disease to be combated with a vaccine when one was developed in 1796.

However, the history of this pathogen that caused millions of deaths worldwide remains mysterious.

"Scientists don't yet fully comprehend where smallpox came from and when it jumped into humans," said evolutionary geneticist Hendrik Poinar, director of the McMaster Ancient DNA Center and a researcher with Michael G. DeGroote Institute of Infectious Disease Research.

The disease had long been thought to have appeared in human populations thousands of years ago. Some researchers even diagnosed the pharaoh Ramses V with smallpox on the basis of visible pustular rashes and scars.

They may have been wrong, the study suggests.

New clues on the evolutionary history of the devastating viral disease came from the partial mummified remains of a child of undetermined sex. The mummy was found with no coffin or associated artifacts in the crypt of the Dominican Church of the Holy Spirit of Vilnius, Lithuania.

Once scheduled to be buried, the remains are now part of a project created in 2011 by anthropologist Dario Piombino-Mascali to study all the mummies in Lithuania, from the Egyptian mummies in the local museums, to the remains from the Holy Spirit crypt and 20th-century anatomical preparations.

"Those mummies revealed a number of diseases, such as arteriosclerosis, tuberculosis and bone pathologies. But this case has been really surprising," Piombino-Mascali, at the department of anatomy, histology, and anthropology of Vilnius University, told Seeker.

According to the researchers, the child died between the ages of 2 and 4 and in the years between 1643 and 1665, close to the time of several documented European epidemics.

Heavily fragmented DNA was extracted from the mummy's skin so the researchers were able to capture, sequence and reconstruct the complete genome of an ancient strain of variola virus. There was no indication of a live virus in the sample, so the mummy was not infectious.

"We believe this is the oldest smallpox genome sequenced to date," Ana Duggan, a postdoctoral fellow at the McMaster University Ancient DNA Center in Canada, told Seeker.

Duggan and colleagues compared the 17th-century strain to versions of the variola virus genome dating from 1946 up to 1977. The disease was declared eradicated by the World Health Organization in 1980.

"The results showed a very recent common ancestor for all available 20th-century variola strains and our 17th-century strain," Duggan said.

Indeed, the common viral ancestor originated sometime between 1588 and 1645, a date corresponding to a period of exploration, migration and colonization that would have helped the viral dissemination of smallpox around the globe.

Read more at Discovery News

First Animal to Walk on Land Traced to Scotland

The late Stan Wood, a self-taught paleontologist from Scotland, had an unwavering belief that the earliest animals to walk on land did so in his homeland. In 2011, just a year before he died of cancer, Wood discovered fossils of four-legged animals known as tetrapods at an unassuming place called Willie's Hole, located near Chirnside, Scotland.

The remains dated to between 360 and 345 million years ago, which is when most scientists believe vertebrates—animals with backbones—made the transition from sea to land.

A National Museums Scotland-organized excavation team returned to Willie's Hole in 2015 and unearthed evidence supporting Wood's long-held belief. They found the remains of five new fossil species, which date to about 355 million years ago and are thought to be the earliest known four-legged vertebrates to walk on terra firma. The fossils are described in the latest issue of the journal Nature Ecology & Evolution.

(Left) The late Stan Wood in 2010 pointing to Willie's Hole, Scotland. Credit: Jennifer A. Clack (Right) The National Museums Scotland-organised excavation of that site in 2015.
Once on land, tetrapods diverged into two groups: the ancestors of amphibians and the ancestors of reptiles, birds and mammals. This means that in a sense, as mammals, all humans can trace their ancestry back to Scotland.

Co-author Nick Fraser of National Museums Scotland admits the connection is a colossal stretch, but explained that the first literal animal step on land was "a pivotal step in the evolution of life on Earth." Without this moment, "the evolution of birds, crocodiles, pterosaurs, salamanders, dinosaurs, mammals—and, of course, ourselves—and birds could not have occurred."

What led to that important step, which Fraser likens to the "one giant leap for mankind" first step on the moon, appears to have been the aftermath of the late Devonian mass extinction that occurred 358 million years ago. The land masses that now form Scotland were then in very different locations, closer to the equator.

"We think the area was subject to quite a bit of change—low-lying ponds, lagoons and streams were being subjected to intermittent flooding and occasional inundation by the nearby sea," Fraser said, adding that there were also "periods of aridity."

The conditions were clearly demanding, he continued, so "it might well have been this dynamic changing environment that partly drove the transition to land by some of the early tetrapods."

The move happened gradually, such that the still fishy-looking animals had a semi-aquatic lifestyle, which at least involved returning to water to lay eggs, before later tetrapods evolved to become fully terrestrial. Those animals, "fully emancipated from water," as Fraser said, date to 345 million years ago in Scotland.

Artist's impression of the underwater environment of a swamp dating to about 355 million years ago.
This critical time in history has been murky due to a 15-million-year hole in the tetrapod fossil record known as Romer's Gap that extends between 345 and 360 million years ago. Wood's fossils, as well as those of Fraser and his colleagues, help to fill that gap.

Read more at Discovery News

Ancient Space Dust Washes Up in Rooftop Gutters

Through dogged determination, Jon Larsen has become driven to find space particles, which date back to when our sun was a baby, in the urban sediment that collects in the guttering of building rooftops. And, after he convinced a British planetary scientist to study his findings, years of work have finally paid off.

In 2011, Larsen reached out to Matthew Genge, of Imperial College London, with his plan to find dust particles in this seemingly unlikely place. Though distinguishing space particles from the zoo of man-made dust particles in a city environment was considered too difficult, the hurdle didn't deter Larsen.

"It was an amateur scientist, a chap called Jon Larsen who's actually quite a well-known jazz musician in Norway, who got interested in this and started collecting all the debris that ends up in the gutter," Genge told Seeker. After going through the debris found in the roof guttering from buildings in Oslo, Paris and Berlin, Larsen would send photos of interesting particles he'd find to Genge and, despite his pessimism that Larsen would ever uncover this unlikely quarry, he eventually struck gold.

Now, with Genge's assistance, the pair have identified hundreds of particles that fell from space and have origins dating back to the birth of the solar system. Larsen documents his micrometeorite discoveries as part of Project Stardust.

"Imagine somebody who has been sending you pictures every other week of something, and every time you look at them, you're like 'no, no, no, that's not it' and then after 5 years they send you a picture and it actually is the thing that you're looking for... that was the moment I went 'oh, my God! I should pay more attention to this guy!'" Genge added.

"He's put in so much work. He went through 300 kilograms [660 lb] of sediment from gutters. That's pretty incredible."

As described in research published in the journal Geology, the duo identified 500 particles of dust that originate from asteroids and comets. But finding these cosmic artifacts in the dirt was just the beginning; their research has revealed some profound science about the space dust that is falling onto our heads right at this moment and could add another layer to our understanding about the building blocks of planets.

Our solar system is filled with dust from collisions between asteroids and venting from comets. The most visible sign of this dust encountering Earth are the meteor showers that light up the upper atmosphere as Earth orbits though one of the many dusty trails left behind these interplanetary vagabonds. However, the tiny particles that rain through the atmosphere as "shooting stars" burn up completely, leaving only a bright flash in their wake. Their journey comes to an abrupt end as a blaze of super-heated glory.

"These particles [in gutter sediment] are almost definitely not coming from meteor showers as that dust comes in too fast — it comes in at maybe 30 kilometers per second [67,000 miles per hour] — and it completely evaporates in the Earth's atmosphere," said Genges.

The gutter particles are thought to enter the atmosphere at a speed of around 12 kilometers per second (27,000 miles per hour) where atmospheric heating does inevitably heat up the particles, but the dust survives the fall. Judging by their size of around 0.3 millimeters, these are likely the fastest dust particles to survive the hot atmospheric entry, noted Genges. Through analysis of the 500 specimens, the researchers found there to be a mix of particles that originate from asteroids and others that originate from comets.

"We have found dust particles that we think come from comets and they are subtly different from those that come from asteroids ... they are carbon rich. Whereas the ones from asteroids look similar to the material from meteorites, that are also from asteroids," he added.

Separating the cosmic particles from plain old gutter dirt is no easy task, but the researchers used an important trait found in these space particles to their advantage — they contain minerals that make them magnetic. So, by magnetically separating the dirt under the microscope, these particles could be found.

"These [particles] are very similar to the cosmic dust from deep sea sediments," said Genges. "The main difference is that these are very young. Because they've been largely collected from roofs on commercial buildings, those buildings have their gutters cleaned at least every 3-5 years, so we know these [particles] have landed on Earth at least in the last 5 years. Whereas the particles found on the seabed are up to 50,000 years old. These are a sample of what's landing on Earth, practically today."

As this dust has fallen to Earth within the last 5 years, the researchers could even deduce how the solar system dust falling on Earth has changed over the last million years. The dust found in city gutters contains fewer crystals than the dust that has been found in million-year-old ice Antarctica, for example, but the particles are remarkably similar to cosmic dust that fell onto Earth in medieval times.

According to an Imperial College London press release, the researchers think that the changes in dust particle structure could be down to very small orbital changes in the solar system's planets over millions of years. The slight gravitational disturbances likely change the trajectory of the interplanetary dust, causing it to hit the Earth's atmosphere at different speeds and angles. These slight changes can therefore influence how much heating is caused by atmospheric entry which, in turn, influences the size of the particles that make it to the ground and influence the shape of the crystals inside the microscopic grains.

Read more at Discovery News

Dec 7, 2016

Scientists shed new light on how the brain processes, maintains what we don't see

A team of scientists has mapped out how our brains process visuals we don’t even know we’ve seen, indicating that the neuronal encoding and maintenance of subliminal images is more substantial than previously thought.
A team of scientists has mapped out how our brains process visuals we don't even know we've seen, indicating that the neuronal encoding and maintenance of subliminal images is more substantial than previously thought.

"Our results indicate that what is 'invisible' to the naked eye can, in fact, be encoded and briefly stored by our brain," observes Jean-Rémi King, a postdoctoral fellow in NYU's Department of Psychology and one of the researchers.

The co-authors of study, which appears in the journal Neuron, also include Niccolo Pescetelli, a doctoral student at the University of Oxford, and Stanislas Dehaene, a professor at Collège de France.

In their study, human subjects viewed a series of quickly flashed images, and reported which ones they saw and which they could not see, while their brain activity was monitored using magnetoencephalography (MEG) -- a non-invasive neuroimaging technique which makes, at every millisecond, multiple measurements of the tiny magnetic fields generated by the neuronal activity. Critically, the authors developed machine learning algorithms to decode the content of these images directly from these large and complex neuroimaging data.

These new algorithms allowed the authors to confirm a series of theoretical predictions. In particular, they reveal a striking dissociation between the dynamics of "objective" (i.e. the visual information presented to the eyes) and "subjective" neural representations (i.e. what subjects report having seen). However, and contrarily to theoretical predictions, the authors also showed that invisible images can be partially maintained within high-level regions of the brain.

"Undoubtedly, these results suggest that our current understanding of the neural mechanisms of conscious perception may need to be revised," notes King, who also holds an appointment at the Frankfurt Institute for Advanced Studies (FIAS). "However, beyond our empirical findings, this study demonstrates that machine learning tools can be remarkably powerful at decoding neuronal activity from MEG recordings -- a preview of what we can uncover about the workings of the brain.

From Science Daily

Overwhelming evidence of malaria's existence 2,000 years ago

An analysis of 2,000-year-old human remains from several regions across the Italian peninsula has confirmed the presence of malaria during the Roman Empire, addressing a longstanding debate about its pervasiveness in this ancient civilization.

The answer is in mitochondrial genomic evidence of malaria, coaxed from the teeth of bodies buried in three Italian cemeteries, dating back to the Imperial period of the 1st to 3rd centuries Common Era.

The genomic data is important, say researchers, because it serves as a key reference point for when and where the parasite existed in humans, and provides more information about the evolution of human disease.

"Malaria was likely a significant historical pathogen that caused widespread death in ancient Rome," says evolutionary geneticist Hendrik Poinar, director of McMaster's Ancient DNA Centre where the work was conducted.

A serious and sometimes fatal infectious disease that is spread by infected mosquitoes, malaria and its parasite Plasmodium falciparum, is responsible for nearly 450,000 deaths every year, the majority of them children under the age of five.

"There is extensive written evidence describing fevers that sound like malaria in ancient Greece and Rome, but the specific malaria species responsible is unknown," says Stephanie Marciniak, a former post doctoral student in the Ancient DNA Centre and now a postdoctoral scholar at Pennsylvania State University.

"Our data confirm that the species was likely Plasmodium falciparum, and that it affected people in different ecological and cultural environments. These results open up new questions to explore, particularly how widespread this parasite was, and what burden it placed upon communities in Imperial Roman Italy," she says.

Marciniak sampled teeth taken from 58 adults and 10 children interred at three Imperial period Italian cemeteries: Isola Sacra, Velia and Vagnari. Located on the coast, Velia and Isola Sacra were known as important port cities and trading centres. Vagnari is located further inland and believed to be the burial site of labourers who would have worked on a Roman rural estate.

Using techniques developed at McMaster and abroad, researchers mined tiny DNA fragments from dental pulp taken from the teeth. They were able to extract, purify and enrich specifically for the Plasmodium species known to infect humans.

It was a difficult and painstaking process, complicated by the very nature of the disease.

Usable DNA is challenging to extract because the parasites primarily dwell within the bloodstream and organs, including the spleen and liver, which decompose and break down over time -- in this instance, over the course of two millennia.

Read more at Science Daily

Look Into the Eyes of a Neolithic Man in This Reconstruction

The face of a man who lived 9,500 years ago in the Biblical city of Jericho has been reconstructed based on extensive new analysis of the "Jericho Skull," which is the oldest portrait in The British Museum.

The Jericho Skull is a face modeled in plaster over the man's actual skull, which has now come to life in the vivid reconstruction described in the latest issue of British Archaeology.

The man's identity remains unknown, but researchers think he could have held elite status, perhaps as a revered community elder. The Jericho Skull was one of seven discovered together by famed British archaeologist Kathleen Kenyon (1906–1978) during excavations in 1953 at Jericho, a city now located in the Palestinian Territories near the Jordan River in the West Bank. The other skulls are distributed at museums across the globe.

The Jericho Skull. Tell es-Sultan, Jericho, Palestinian Authority. Human bone, plaster, shell, soil. About 8200-7500 BC, Middle Pre-pottery Neolithic B period.
"He was certainly a mature individual when he died, but we cannot say exactly why his skull, or for that matter the other skulls that were buried alongside him, were chosen to be plastered," Alexandra Fletcher, the Raymond and Beverly Sackler Curator for the Ancient Near East at The British Museum, told Seeker. "It may have been something these individuals achieved in life that led to them being remembered after death."

Fletcher added that the individuals might have also been related, since each of the skulls in the same burial were missing their second and third molars, which she said could be an inherited trait.

The Imaging and Analysis Center at the Natural History Museum completed a micro-CT scan of the Jericho Skull, which led to the construction of a 3-D digital model of the object, complete with bones inside. For the first time, hidden areas were revealed, such as the shape of his palate, cheekbones, brow ridge and eye sockets.

The researchers determined that the skull lacked a jaw. They could also see that the man had broken and decayed teeth, and that he had broken his nose during his adult life, but that it had healed before he died.

Notably, there is evidence he had undergone tight head binding from early infancy that changed the shape of his skull.

"Head binding is something that many different peoples have undertaken in various forms around the world until very recently," Fletcher explained. She said the practice of head binding in some modern cultures are intended to "make an individual appear more beautiful. In this case, the bindings have made the top and back of the head broader—different from other practices that aim for an elongated shape. I think this was regarded as a 'good look' in Jericho at this time."

The head binding adds to evidence that the man and other individuals found with him were of an elite status.

Jericho is featured prominently in the Bible. Fletcher said that in the Book of Joshua, Jericho is the first city the Israelites came to after their return from Egypt. With Joshua as their leader, they marched around the city, shouting and blowing horns, causing Jericho's walls to collapse.

"Most scholars agree that this is not an historically accurate account, but that it relates to the political situation in the Iron Age, when the territories around Jericho were vassal states of Assyria and Babylon," Fletcher said. "During this period, huge numbers of people were forcibly moved from their homes to live in different areas."

Since that Iron Age event happened around 900–500 B.C., Fletcher thinks it is unlikely that the Jericho Skull man could have been mentioned in the Bible.

Side view of the reconstruction. The effect of the head binding is just visible.
When Biblical texts were written, however, remains a heated topic for debate. Hebrew writing dating to the 10th century B.C. has led some scholars to believe that portions of the Bible were crafted during what would have been the man's lifetime.

What is clear is that when he died, his remains received special care. Someone cut a hole in his cranium. Soil was packed inside the space, to prevent the plaster applied outside of the skull from collapsing.

Human remains to this day are treated with special care, respect and dignity at The British Museum, which has a strict policy concerning how they must be handled. Because of the regulations, the researchers have not yet been able to determine the man's eye and hair color.

Read more at Discovery News

Ice Age Clues Help Explain Mysterious Slowdown of Earth's Rotation

Measurements of Earth's rotation from 720 B.C. to 2015, confirm prior research that our planet is slowing down, causing each day to become progressively longer by about two thousandths of a second per century.

While that is just a blip in time, the moments are adding up and can no longer fully be explained by tidal friction, according to the new study, published in the journal Proceedings of the Royal Society A.

"Several geophysical factors have also operated over the past 2,700 years," co-author Leslie Morrison of the International Astronomical Union told Seeker. "The reduction in the loading from the polar ice caps following the last Ice Age, which alters the shape of the Earth slightly (and its rotation), the electro-magnetic interaction between the core and mantle of the earth — and changes in mean sea level, which affect the speed of rotation."

Big earthquakes are additionally believed to have an impact, albeit minor, on Earth's rotation.

Such dynamic factors operate outside of human activities, of course, but numerous other researchers have linked man-made global warming to melting ice at the poles as well as to sea level changes, our actions could impact Earth's rotation, though very slightly, and may be doing so now.

The new paper presents the most comprehensive assembly and analysis of historical data on the rotation of Earth before the introduction of the Atomic Time scale in 1962. Morrison explained, "The Atomic Time scale is very accurate, but it covers a relatively short time span."

To study the years before 1962, Morrison and colleagues Richard Stephenson and Catherine Hohenkerk combined data from the fields of astronomy, archaeology, history and geophysics. Using gravitational theories about the orbital motion of the Earth around the sun and the moon around our planet, they computed when and where solar and lunar eclipses should have been in the past.

They next studied archaeological and historical records related to the eclipses. These records included everything from China's "Chunqiu: Spring and Autumn Annals" to translations of the Babylonian cuneiform script on thousands of clay tablets stored in the British Museum.

According to the paper's authors, the historical observations show a consistent discrepancy between the gravitational calculations and where and when the eclipses were actually seen.

"This discrepancy," Morrison explained, "is a measure of how the earth's rotation has been varying since 720 B.C., which is where the extant, reliable and accurate observations of eclipses in ancient civilizations begin."

Nevertheless, Morrison's team and other scientists are keen to understand what is driving variations in Earth's rotation. Our planet's movement, after all, affects nearly every aspect of life, from the seasons to the tides.

This image of Earth's northern hemisphere shows, via black and grey-colored areas, where polar ice used to be during the Ice Age.
Duncan Agnew, a geophysicist from the University of California at San Diego and Scripps Institution of Oceanography, told Seeker he agrees with Morrison that the primary rate differences are "probably caused by Earth's gradual change in shape caused by the end of the Ice Age. Understanding this change in shape is important in measured changes in sea level, something very important in this age of global warming. Should global warming cause major amounts of melting and a large rise in sea level, this will certainly change the earth's rotation, though by an amount that will be very small."

However small, such an additional human-caused change to Earth's rotation could affect life on our planet in ways that have yet to be determined. Richard Holme, a professor of geomagnetism at the University of Liverpool, told Seeker that "all sorts of other human effects can also influence LOD (Length of Day)."

Read more at Discovery News

Dec 6, 2016

Plants Are Even Smarter Than We Thought

Can plants learn by forming associations? They can, if you ask researchers from The University of Western Australia (WA), who say they've shown for the first time that plants can link events to learn more about their surroundings and use the associations to better their chances of survival.

The researchers focused their study on the garden pea Pisum sativum, seedlings of which they placed at the base of a Y-shaped maze. Then, in a series of training sessions, they put a fan and a light source at the end of either the same arm or opposing arms of the Y.

According to the scientists, the seedlings became better seekers of precious light by learning to associate the breeze of the fan with the location where the light would shine, growing toward that location even when the light was removed.

"The ability of seedlings to anticipate both the imminent arrival of light ('when') and its direction ('where') based on the presence and position of the fan indicates that plants are able to encode both temporal and spatial information and modify their behavior under the control of environmental cues," the scientists wrote.

The team suggested that the type of learning demonstrated by the seedlings should no longer be considered exclusive to the animal kingdom: "Our results show that associative learning is an essential component of plant behavior. We conclude that associative learning represents a universal adaptive mechanism shared by both animals and plants."

"Whilst the possibility that plants also learn by association has been considered by earlier studies," the scientists added, "our current study provides the first unequivocal evidence."

The WA scientists said they're aware of how their "smart plant" discoveries might be interpreted.

"Because our findings are unexpected, we anticipate that this study will stir a lively and exciting debate on the origin and properties of memory, learning and ultimately intelligent behavior in biological systems," said study lead Monica Gagliano, in a statement.

The researchers say their study was inspired by Russian scientist Ivan Pavlov's famed research on conditioned responses in dogs, which explored how behavior could be modified through conditioning.

Gagliano and her team have documented their findings in the online journal Scientific Reports.

From Discovery News

Madame Tussaud's Mysterious Cause of Death Has Just Been Revealed

Marie Tussaud, the wax modeler behind one of London's most popular attractions, likely died of pneumonia, says a new study published in the journal Lancet Respiratory Medicine.

One of the first successful businesswomen of 19th century Europe and a pioneer of the cult of celebrity, Tussaud died in 1850 at the age of 89. Her death certificate only vaguely recorded "old age" as the cause of her demise.

According to her two sons, until a few days before her death, Madame Tussaud sat at the entrance of her exhibition — which now has branches in dozens of locations worldwide — to collect the public's shillings.

But this image of a strong, healthy woman in charge of her business until the very end is likely false.

"It was a family concern to depict a very efficient Madame Tussaud," first author Francesco Galassi, at the Institute of Evolutionary Medicine at the University of Zurich, Switzerland, said.

"However, a re-analysis of the correspondence of her youngest son Francis tells a different story," he added.

A letter written by Francis to his father in 1848, two years before Madame Tussaud's death, reveals that Marie was "growing very feeble."

"At times she is very ill and she suffers from asthma which allows her no rest at night ... Her legs are bad like yours, and she has bunions that hurt her when she walks," Francis wrote.

 According to Galassi and colleagues Louise Baker, archivist at Madame Tussauds, Roberta Ballestriero, at the University of the Arts, London, and Frank Rühli, at the Institute of Evolutionary Medicine at the University of Zurich, a cardiorespiratory disease can explain fatigue and weakness, asthma and varicose veins.

"Heart failure, primary or secondary to pulmonary or systemic disease (eg. hypertension) would account for all of these symptoms," the researchers wrote.

They noted that an alternative diagnosis could be progressive lung diseases including emphysema, chronic bronchitis, and asthma, which could still have had consequences on the heart.

Further help with the diagnosis came from historical sources, which report that Tussaud's final illness lasted five days.

"This is suggestive of an infection, such as pneumonia, which is still common today with patients with chronic obstructive pulmonary disease," Galassi said.

Read more at Discovery News

Mammoth Fossils Found at Site of LA Subway Dig

Fossils from giant, ice age-beasts were uncovered while workers were digging an extension to the Los Angeles subway system.

The finds include a 3-foot-long (1 meter) section of mammoth tusk, as well as a skull and partial tusks from a much younger animal, which might have been either a mammoth or a mastodon, according to The Source, a transportation blog about the L.A. Metro.

Though the ice-age fossils (whose exact age has not yet been determined) are certainly treasures that are rarer to unearth under the subway than rat "fossils" and "coprolites," old chicken wings or discarded coffee cups, the finds actually aren't all that surprising. The area around the site of the fossil discovery, near the La Brea/Wilshire station, is not too far from the La Brea Tar Pits, an area of central Los Angeles where natural asphalt has been seeping up from the ground for the last 40,000 years.

Over the eons, this constant ooze of asphalt has created sticky pits in valleys that would often become obscured by leaves, branches and other ground cover. As a result, unwary animals stepped into the sticky death traps. The viscous ooze trapped small animals and insects immediately, while larger beasts like mammoths sank inches into the tar, struggling to get out before becoming stuck, researchers have noted. The dead or dying animals attracted predators as well — some of which also became stuck in the asphalt. All told, more than 1 million fossils have been found in the tar pits, according to the La Brea Tar Pits & Museum.

Mammoths and mastodons are both Proboscideans. Though both were majestically large and had shaggy coats and impressively curved tusks, mammoths are much more closely related to modern-day elephants, having arisen about 5 million years ago in Africa. By contrast, mastodons arose about 27 million to 30 million years ago.

During the Pleistocene epoch, between 1.8 million and 11,700 years ago, mammoths and mastodons roamed over the part of North America that was not covered by ice sheets, including coastal California.

Read more at Discovery News

'Fluffy' Seeds Grow Into Baby Planets

How do baby planets form? This question would seem to have a simple answer: You take a huge quantity of dust in orbit around a young star, compress it and — hey presto! — the seed of a planetary newborn is formed, around which its gravity pulls in more and more material to bulk it up into a full-blown protoplanet.

Though this makes logical sense, many puzzles remain and astronomers still aren't quite sure how the gas and dust around young stars really forms planets. This issue is the basis of a decades-long mystery underlying planetary formation models, but we are closing in on some answers.

Now, the largest radio observatory on the planet has studied the light coming from a young star in an effort to understand the initiation of planet building and astronomers think they've added an important clue to the mystery surrounding the evolution of planets.

The Atacama Large Millimeter/submillimeter Array in Chile was used to study a specific type of polarization of radio waves coming from the 5-million-year-old star HD 142527. The star, which is approximately double the mass of our sun and located 500 light-years away, possesses a ring of dust and gas that astronomers believe forms the building blocks of a planetary system. But how this dust will turn from microscopic specks into huge rocky planets measuring thousands of miles across is a quandary.

ALMA observation of the dust ring surrounding HD 142527
As these grains of dust surrounding HD 142527 are basically the "seeds" of future exoplanets, Akimasa Kataoka, of Heidelberg University and the National Astronomical Observatory of Japan (NAOJ), and his team used ALMA's precise instrumentation to study the orientation of the polarization of radio waves coming from the dusty ring.

Radio waves are emitted by the star and then scattered by particles in the ring. By looking at this scattered emission, information about the particles within the ring leave a "fingerprint." In this case, Kataoka was able to discern the size of the dust particles from their polarization fingerprint and he stumbled upon a surprise: The individual dust particles were a lot smaller than previous studies assumed. It turns out that the basic dusty grains from which planets will form are only 150 micrometers wide — that's roughly half the size of a grain of table salt and 10 times smaller than previous estimates.

This presents a problem with previous planetary formation models and also, possibly, points to a tantalizing planetary formation mechanism.

"In the previous studies, astronomers have estimated the size based on radio emissions assuming hypothetical spherical dust particles," said Kataoka in a statement.

The dust particles that form the building blocks of planets are not simple spherical particles, they are complex structures composed of many smaller dust particles according to new research
This new research suggests that far from being simple spherical particles, the dust particles are "fluffy"; many small 150 micrometer-size particles clump together to form larger and more complex dust particles. Therefore, previous astronomical studies that have detected larger particles are actually fluffy agglomerations of smaller particles. And the mechanism by which these particles clump together could form the fundamental mechanism that triggers the initiation of planet birth.

Read more at Discovery News

Dec 5, 2016

Extreme downpours could increase fivefold across parts of the US

The figure shows the expected increase in the number of summertime storms that produce extreme precipitation at century's end compared to the period 2000 - 2013.
At century's end, the number of summertime storms that produce extreme downpours could increase by more than 400 percent across parts of the United States -- including sections of the Gulf Coast, Atlantic Coast, and the Southwest -- according to a new study by scientists at the National Center for Atmospheric Research (NCAR).

The study, published in the journal Nature Climate Change, also finds that the intensity of individual extreme rainfall events could increase by as much as 70 percent in some areas. That would mean that a storm that drops about 2 inches of rainfall today would be likely to drop nearly 3.5 inches in the future.

"These are huge increases," said NCAR scientist Andreas Prein, lead author of the study. "Imagine the most intense thunderstorm you typically experience in a single season. Our study finds that, in the future, parts of the U.S. could expect to experience five of those storms in a season, each with an intensity as strong or stronger than current storms."

The study was funded by the National Science Foundation (NSF), NCAR's sponsor, and the Research Partnership to Secure Energy for America.

"Extreme precipitation events affect our infrastructure through flooding, landslides and debris flows," said Anjuli Bamzai, program director in NSF's Directorate for Geosciences, which funded the research. "We need to better understand how these extreme events are changing. By supporting this research, NSF is working to foster a safer environment for all of us."

A year of supercomputing time

An increase in extreme precipitation is one of the expected impacts of climate change because scientists know that as the atmosphere warms, it can hold more water, and a wetter atmosphere can produce heavier rain. In fact, an increase in precipitation intensity has already been measured across all regions of the U.S. However, climate models are generally not able to simulate these downpours because of their coarse resolution, which has made it difficult for researchers to assess future changes in storm frequency and intensity.

For the new study, the research team used a new dataset that was created when NCAR scientists and study co-authors Roy Rasmussen, Changhai Liu, and Kyoko Ikeda ran the NCAR-based Weather Research and Forecasting (WRF) model at a resolution of 4 kilometers, fine enough to simulate individual storms. The simulations, which required a year to run, were performed on the Yellowstone system at the NCAR-Wyoming Supercomputing Center.

Prein and his co-authors used the new dataset to investigate changes in downpours over North America in detail. The researchers looked at how storms that occurred between 2000 and 2013 might change if they occurred instead in a climate that was 5 degrees Celsius (9 degrees Fahrenheit) warmer -- the temperature increase expected by the end of the century if greenhouse gas emissions continue unabated.

Prein cautioned that this approach is a simplified way of comparing present and future climate. It doesn't reflect possible changes to storm tracks or weather systems associated with climate change. The advantage, however, is that scientists can more easily isolate the impact of additional heat and associated moisture on future storm formation.

"The ability to simulate realistic downpours is a quantum leap in climate modeling. This enables us to investigate changes in hourly rainfall extremes that are related to flash flooding for the very first time," Prein said. "To do this took a tremendous amount of computational resources."

Impacts vary across the U.S.

The study found that the number of summertime storms producing extreme precipitation is expected to increase across the entire country, though the amount varies by region. The Midwest, for example, sees an increase of zero to about 100 percent across swaths of Nebraska, the Dakotas, Minnesota, and Iowa. But the Gulf Coast, Alabama, Louisiana, Texas, New Mexico, Arizona, and Mexico all see increases ranging from 200 percent to more than 400 percent.

The study also found that the intensity of extreme rainfall events in the summer could increase across nearly the entire country, with some regions, including the Northeast and parts of the Southwest, seeing particularly large increases, in some cases of more than 70 percent.

A surprising result of the study is that extreme downpours will also increase in areas that are getting drier on average, especially in the Midwest. This is because moderate rainfall events that are the major source of moisture in this region during the summertime are expected to decrease significantly while extreme events increase in frequency and intensity. This shift from moderate to intense rainfall increases the potential for flash floods and mudslides, and can have negative impacts on agriculture.

The study also investigated how the environmental conditions that produce the most severe downpours might change in the future. In today's climate, the storms with the highest hourly rainfall intensities form when the daily average temperature is somewhere between 20 and 25 degrees C (68 to 77 degrees F) and with high atmospheric moisture. When the temperature gets too hot, rainstorms become weaker or don't occur at all because the increase in atmospheric moisture cannot keep pace with the increase in temperature. This relative drying of the air robs the atmosphere of one of the essential ingredients needed to form a storm.

Read more at Science Daily

A watershed moment in understanding how water conducts electricity

Scientists have taken spectroscopic snapshots of nature's most mysterious relay race: the passage of extra protons from one water molecule to another during conductivity.

The finding represents a major benchmark in our knowledge of how water conducts a positive electrical charge, which is a fundamental mechanism found in biology and chemistry. The researchers, led by Yale chemistry professor Mark Johnson, report their discovery in the Dec. 1 edition of the journal Science.

For more than 200 years, scientists have speculated about the specific forces at work when electricity passes through water -- a process known as the Grotthuss mechanism. It occurs in vision, for example, when light hits the eye's retina. It also turns up in the way fuel cells operate.

But the details have remained murky. In particular, scientists have sought an experimental way to follow the structural changes in the web of interconnected water molecules when an extra proton is transferred from one oxygen atom to another.

"The oxygen atoms don't need to move much at all," Johnson said. "It is kind of like Newton's cradle, the child's toy with a line of steel balls, each one suspended by a string. If you lift one ball so that it strikes the line, only the end ball moves away, leaving the others unperturbed."

Johnson's lab has spent years exploring the chemistry of water at the molecular level. Often, this is done with specially designed instruments built at Yale. Among the lab's many discoveries are innovative uses of electrospray ionization, which was developed by the late Yale Nobel laureate John Fenn.

Johnson and his team have developed ways to fast-freeze the chemical process so that transient structures can be isolated, revealing the contorted arrangements of atoms during a reaction. The practical uses for these methods range from the optimization of alternative energy technologies to the development of pharmaceuticals.

In the case of the proton relay race, previous attempts to capture the process hinged on using infrared color changes to see it. But the result always came out looking like a blurry photograph.

"In fact, it appeared that this blurring would be too severe to ever allow a compelling connection between color and structure," Johnson said.

The answer, he found, was to work with only a few molecules of "heavy water" -- water made of the deuterium isotope of hydrogen -- and chill them to almost absolute zero. Suddenly, the images of the proton in motion were dramatically sharper.

"In essence, we uncovered a kind of Rosetta Stone that reveals the structural information encoded in color," Johnson said. "We were able to reveal a sequence of concerted deformations, like the frames of a movie." Johnson's lab was assisted by the experimental group of Knut Asmis at the University of Leipzig and the theory groups of Ken Jordan of the University of Pittsburgh and Anne McCoy of the University of Washington.

One area where this information will be useful is in understanding chemical processes that occur at the surface of water, Johnson noted. There is active debate among scientists regarding whether the surface of water is more or less acidic than the bulk of water. At present, there is no way to measure the surface pH of water.

Read more at Science Daily

How Humans Lost Their Tail, Twice

Humans can't seem to keep a tail, suggests new research that finds our early ancestors lost tails not just once, but twice.

The findings, published in the journal Current Biology, not only help explain why people don't wag dog-like tails, but they also shed light on why we all have a tailbone and begin life with an actual tail that gradually disappears.

"Fleshy tails go all the way back to the earliest vertebrate ancestors and are found in very young embryos, so it would be very difficult to get rid of them entirely without causing other problems," author Lauren Sallan told Seeker. "As a result, both fishes and humans have had to stunt growth instead, leaving a buried, vestigial tail much like the legs of whales."

The origins of this mysterious vestigial tail go back to fish. For the study, Sallan, an assistant professor in the University of Pennsylvania's Department of Earth and Environmental Science, analyzed 350-million-year-old hatchlings of the fossil fish Aetheretmon. This jawed fish distant ancestor of terrestrial animals today had both a scaly, fleshy tail and a flexible tail fin, sitting one atop the other.

Sallan found these structures were entirely separate. By comparing the Aetheretmon hatchlings with those of living fish, she found that the two "tails" started out one atop the other and then grew on their own. This discovery overturns at least two centuries of scientific belief that the modern adult fish tail fin was simply added to the end of an ancestral tail shared with land animals.

The early double-tailed fish Aetheretmon swimming alongside a singled-tailed modern pufferfish and an early tetrapod in a 350-million-year old river.
The disconnect means that the two tails went on their own evolutionary paths. Fish lost the fleshy tail and kept the flexible one to improve their swimming. Having just the back fin, she explained, "allows for more refined movements, which a muscular tail (originally present for power swimming) would disrupt."

Fish that evolved to become semi-aquatic and then land-dwelling animals lost the flexible back fin, but kept the fleshier one that over time became the familiar appendage we now see on dogs, cats, cows and many other animals. As dogs show, tails are useful for visual communication, slapping away flying insects and other functions.

Read more at Discovery News

'Mythical' Sea Blob Finally Spotted a Century After Its Discovery

A mysterious sea blob that looks like a psychedelic Slinky has finally been spotted, more than a century after it was first described.

The translucent, sea-dwelling invertebrate, called Bathochordaeus charon, was identified recently off the coast of Monterey, California, by scientists using a remotely operated vehicle (ROV). Though B. charon was first discovered a century ago, no one had managed to confirm its existence in all those years, Rob Sherlock, a scientist at the Monterey Bay Aquarium Research Institute who found the creature, told Live Science in an email.

B. charon belongs to a group of sea creatures known as larvaceans — normally teensy, millimeter-size creatures whose bodies resemble a tadpole's, with a large "head" (actually a trunk) and a tail, Sherlock said.

A giant larvacean, Bathochordaeus charon, that has discarded its mucus feeding filters and is swimming freely in the open ocean.
Though the sea is teeming with tiny larvaceans, the larger versions, which can have bodies extending up to 3.9 inches (10 centimeters), are much less common. To eat, the sea blob filters food through its shimmering, parachute-like mucus "house" almost 3.3 feet (1 m) in length. By waving its tail, it stirs the water and pulls particles directly into its house. Large particles get trapped and form a fine dusting of marine "snow" on the house, while the smaller particles pass through, concentrating and then funneling into a feeding tube that goes into the mouth, Sherlock said. (The tiny larvaceans also don mucus homes, but they're smaller.)

If a passing squid or fish crashes through the house, or big particles clog the feeding tube, larvaceans simply move on and build another house. Without their houses, they cannot eat, Sherlock said.

The first report of B. charon's existence came in 1899, when professor Carl Chun of Leipzig University came across one in the south Atlantic Ocean while leading the Valdivia Expedition, a German mission aimed at exploring the deep sea. Chun believed the creature welled up from the deepest depths of the ocean, so he named the larvacean after Charon, who in Greek mythology ferries the souls of the dead across the river Styx, the researchers reported Aug. 16 in the journal Marine Biodiversity Records.

In the decades that followed, several other naturalists reported spotting giant larvaceans, though only a few were captured alive and described thoroughly. In 1936, for instance, British marine biologist Walter Garstang collected a set of giant larvaceans that differed from Chun's, and they were classified as a new species, Bathochordaeus stygius.

Because the two sets of specimens were similar and Chun's originals were lost to history, scientists eventually began to wonder whether Chun's originally described B. charon was actually the same species as B. stygius. One famous larvacean expert even suggested combining the two species names, Sherlock said. Part of the difficulty in capturing these creatures is that they don't fare well in the trawling nets typically used to collect specimens, Sherlock said.

Sherlock and his colleagues happened upon the new species when the team's ROV, called Doc Ricketts, was exploring the waters of Monterey Bay. As soon as they saw it, the crew carefully collected it in a sealed, thermally insulated container.

"Since the vehicle was recovered some tens of minutes later, the animal was alive, in fantastic shape, and we preserved it right away in order to send it to the Smithsonian," Sherlock said. "We had no idea, until we looked more closely at the specimen, that we had actually found B. charon, the species first described over a hundred years ago."

Genetics and analysis of physical features confirmed the find, Sherlock said. It was official: There really were two distinct species of giant larvacean — B. stygius and B. charon.

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