One Migration from Siberia Peopled the Americas: Study

Native American ancestors reached the New World in a single, initial migration from Siberia at most 23,000 years ago, only later differentiating into today’s distinct groups, DNA research revealed Tuesday.

Most scientists agree the Americas were peopled by forefathers who crossed the Bering land and ice bridge which connected modern-day Russia and Alaska in Earth’s last glacial period.

And it is known through archaeological finds that humans were already present in the Americas 15,000 years ago.

But there was a long list of outstanding questions.

When did the migration take place? In one or several waves? And how long did these early pioneers spend in Beringia — the then-raised land area between Asia and America?

On Tuesday, analysis of Native American and Siberian DNA, present-day and ancient, sought to fill in some of the blanks with two studies carried simultaneously in the journals Science and Nature.

The first, led by the Center for GeoGenetics at the University of Copenhagen and published in Science, found there was only one initial migration, no more than 23,000 years ago.

This ancestral pool split into two main branches about 13,000 years ago, coinciding with glacier melt and the opening of routes into the North American interior, researchers found.

These became the groups which anthropologists refer to as Amerindians (American Indians) and Athabascans (a native Alaskan people).

Previous research had suggested that Amerindian and Athabascan ancestors had crossed the strait independently.

“Our study presents the most comprehensive picture of the genetic prehistory of the Americas to date,” said Maanasa Raghavan, one of the study’s lead authors.

“We show that all Native Americans, including the major sub-groups of Amerindians and Athabascans, descend from the same migration wave into the Americas.”

This was distinct from later waves which gave rise to the Paleo-Eskimo and Inuit populations, she added.

Given that the earliest evidence for the presence of humans in the Americas dates to 15,000 years ago, the first ancestors may have remained in Beringia for about 8,000 years before their final push into the New World, the team said.

This is much shorter than the tens of thousands of years of isolation theorized by some earlier research.

But diversification into the distinct tribes we know today, happened only after arrival in the Americas, not before.

Read more at Discovery News

New Horizons Zooms-in on Pluto's Tiny Moons Nix and Hydra

Since their discovery by the Hubble Space Telescope in 2005, Pluto’s tiny moons Nix and Hydra have been mere distant specks of reflected light. But with new observations transmitted back to Earth by NASA’s New Horizons mission, that has all changed.

Blasting through the Pluto system at around 31,000 miles per hour on July 14, New Horizons was able to quickly image the dwarf planet’s moons as it made its rapid close encounter, coming within 7,750 miles of Pluto’s surface. By now, we are becoming very familiar with Pluto’s and largest moon Charon’s beautifully detailed geology, but the smaller moons have yet to be so well defined.

However, that’s beginning to change, in new imagery showcased on Tuesday.

Shown here are Nix and Hydra, the second and third Pluto moons to be discovered after Charon. Nix’s color has been enhanced and an intriguing region has been revealed, appearing reddish. According to NASA, the moon is “jelly bean-shaped,” around 26 miles (42 kilometers) long and 22 miles (36 kilometers) wide.

This reddish region has piqued mission scientists’ interest, and they already speculate that this region may be the site of a large impact crater, but they have to be patient for the spacecraft to send more data.

“Additional compositional data has already been taken of Nix, but is not yet downlinked. It will tell us why this region is redder than its surroundings,” said Carly Howett, New Horizons mission scientist with the Southwest Research Institute, in Boulder, Colo. “This observation is so tantalizing, I’m finding it hard to be patient for more Nix data to be downlinked.”

In addition to Nix, New Horizons also sent an observation of Hydra made by the spacecraft’s Long Range Reconnaissance Imager (LORRI) from a distance of 143,000 miles (231,000 kilometers). This observation reveals an irregularly-shaped moon around 34 miles (55 kilometers) long and 25 miles (40 kilometers) wide with what appear to be two large craters and some variation in surface composition.

Read more at Discovery News

Massive Search Will Scour Cosmos for Intelligent Aliens

The most far-reaching search for extraterrestrial intelligence (SETI) is now underway: A new $100 million initiative invites the world’s top minds to scour the universe for signals from distant planets, scientists announced Monday.

Yuri Milner, a billionaire particle physicist and investor, announced the 10-year “Breakthrough” initiatives at the Royal Society in London with other top scientists, including physicist Stephen Hawking and SETI pioneer Frank Drake.

“Somewhere in the cosmos, perhaps, intelligent life may be watching these lights of ours, aware of what they mean,” said Hawking, according to Space.com, a sister site to Live Science. “Or do our lights wander a lifeless cosmos — unseen beacons, announcing that here, on one rock, the universe discovered its existence?”

“Either way, there is no bigger question,” Hawking said. “It’s time to commit to finding the answer — to search for life beyond Earth.”

Incredible initiatives

The SETI Institute and previous SETI projects have spent the past few decades scanning the cosmos with radio dishes, looking for non-random signals that could be created by intelligent civilizations beyond Earth. The SETI Institute will be involved in the new initiative, and talks are ongoing about how the Institute’s Allen Telescope Array, located in northern California, may be a part of the project, said Pete Worden, former director of NASA’s Ames Research Center in Moffett Field, California.

The first of the new initiatives, dubbed Breakthrough Listen, will be the most comprehensive SETI search to date, using two of the world’s most powerful telescopes: the 328-foot-diameter (100 meters) Robert C. Byrd Green Bank Telescope in West Virginia, and the 210-foot-diameter (64 m) Parkes Telescope in New South Wales, Australia.

The new search will be 50 times more sensitive and will search an area 10 times larger than earlier SETI programs, the researchers said. It will also scan at least five times more of the radio spectrum, and 100 times faster, project officials said in a statement.

“This new SETI program will be deeper, more sensitive and superior to past programs,” veteran planet hunter Geoff Marcy, a professor of astronomy at the University of California, Berkeley, said at a news conference today.

The researchers will have access to each of the two telescopes for between one and two months every year, Marcy said.

“With all of the telescope time that we are going to acquire, we can achieve longer dwell times on the targets, so we can sense weaker, fainter radio signals,” Marcy added. The increased telescope time will also help researchers survey about 1 million stars at about 100 galaxies in addition to the Milky Way galaxy, the researchers said.

Laser locator

Breakthrough Listen will also use the Automated Planet Finder Telescope at the Lick Observatory, located on the summit of Mount Hamilton in California, to commence the deepest and broadest search for optical laser transmissions, the researchers said.

Optical laser communication is becoming more common, whether it’s air-to-air communication or ground-to-satellite laser communication, Marcy said.

Advanced alien civilizations may realize that lasers are a good communication means, as humanity has, Marcy said. “There could therefore be a sort of galactic Internet not born of copper wire, not born of fiber optics, but carried by laser beams crisscrossing the galaxy,” Marcy said. “And we, here on the Earth, may serendipitously just happen to fall on those laser beams.”

The Lick Telescope will measure the spectra of stars and galaxies, “looking for specific, single wavelengths of which there’s a lot of light, which would be best interpreted as lasers from some other civilization,” Marcy said.

The search will be so powerful that Breakthrough Listen’s optical search will be able to detect a 100-watt laser — the energy equivalent of a typical light bulb — from a “nearby” star 25 trillion miles (40 trillion kilometers) away, the researchers said.

If an intriguing signal is found, the researchers said, they will spend several months verifying it within the scientific community before publishing the detailed results in a scientific journal.

“It must be reproducible,” Marcy said. “We must be able to point other radio telescopes at the same coordinates, verify that the radio waves really are coming at the radio [or laser] frequencies that we thought.”

Public invitation

The public will have access to the enormous data trove collected by Breakthrough Listen, the researchers said. In fact, experts invite the public to join them as they use open-source software to sift through the vast amounts of data.

Furthermore, Breakthrough Listen’s software and hardware will be compatible with other telescopes, so people around the world can join the quest to find intelligent alien life, possibly developing their own methods to analyze the data, the researchers said.

At the University of California, Berkeley, 9 million volunteers from around the world will be able to use a supercomputer platform to search the data for possible extraterrestrial life, they added.

Enthusiasts can also contribute in other ways. A second initiative, Breakthrough Message, asks people around the world to create digital messages that represent humanity and Earth that could one day be sent to advanced alien civilizations.

Read more at Discovery News

Rhino-Cam Could Help Catch Poachers in the Act

If a new camera-driven anti-poaching system works as well as hoped, rhinoceros poachers may soon find themselves caught in the act on video, the Independent reports.

The system has been dubbed "Rapid" -- Real-Time Anti-Poaching Intelligence Device -- and is driven by a camera embedded in the animal's horn (a painless procedure, according to this BBC News video showing the drilling in action).

Along with the spy camera, the rhino will be outfitted with a heart-rate monitor and a location tracker.

The Rapid system will alert authorities if the heart-rate monitor on the rhino is triggered by an attack. The tracking device will capture the location of the attack, to within a few meters.

Attack location in hand, rangers can quickly head to the scene via truck or helicopter and stop the poachers. The camera, meanwhile, will have collected visual evidence to use against them.

According to the Independent, the Rapid system was developed by Chester University's Dr. Paul O'Donoghue, a specialist who has worked extensively with endangered black rhinos.

"You can’t outrun a helicopter," O'Donoghue told the Independent. "Rapid renders poaching a pointless exercise.”

Officials hope to have the system up and running in trials in South Africa, where the vast majority of the world's remaining rhinoceroses live, early in 2017.

From Discovery News

Surf Pro Fights Off Shark Attack on Live TV

Johannesburg (AFP) - An Australian surfing champion fought back against a shark attack on live television during a competition in South Africa on Sunday, escaping from the terrifying scene without injury.

Mick Fanning, 34, was competing in the final heat of a world tour event at Jeffrey's Bay in the country's Eastern Cape province when a looming black fin appeared in the water behind him.

In a churn of water and spray, Fanning could be seen battling to fend off the shark.

"It came up and got stuck in my leg rope," he said in a television interview afterwards.

"I was kicking and screaming. I just saw a fin. I didn't see teeth. I was waiting for the teeth to come at me as I was swimming. I punched it in the back."

Fanning, a triple world champion nicknamed White Lightning, was sitting on his board in the water when the shark lunged at him, tipping him off the board.

He was taken out of the water by safety crews, and said he had only lost his leg rope.

"We've never seen anything that dramatic and that frightening," commentator Joe Turpel was quoted as saying.

The competition was abandoned after the incident.

From Discovery News

Deep-Diving Dolphins Avoid 'Bends' with Strong Lungs

When dolphins dive deep below the water's surface, they avoid succumbing to decompression sickness, or "the bends," likely because the massive sea creatures have collapsible lungs, a new study finds. These lungs allow dolphins to inhale and exhale two to three times quicker than humans.

Understanding how dolphins breathe rapidly and maintain lung functionality under immense pressure could help scientists keep humans safe when they are in similarly extreme situations, such as under anesthesia during surgeries, the researchers said.

Unlike humans, dolphins do not need to be strapped to an oxygen tank to achieve their impressive diving feats. This is because dolphins have compressible lungs that help them withstand high pressures deep in the ocean.

"The deeper go into the ocean, the smaller the volume of gas or air in the lungs gets," said study lead author Andreas Fahlman, a professor of biology at Texas A&M University in Corpus Christi. Fahlman found that dolphins can replace as much as 95 percent of the air in their lungs in a single breath. For comparison, humans are capable of replacing only as much as 65 percent. Dolphins exhale and then inhale above water before diving back down with lungs filled with air — each breath consumes and releases a certain amount of oxygen that energizes the animals as they swim the ocean.

The researchers studied six male bottlenose dolphins at Dolphin Quest Oahu, a dolphin training facility in Hawaii that is open to the public. The dolphins were free to swim away from the researchers whenever they wished, Fahlman said, though the animals were trained to sit still and breathe into a mask, called a pneumotachometer. This device essentially functioned as a "speedometer for the lungs," Fahlman said. The mask covered the dolphins' blowholes at the backs of their necks.

When trainers had dolphins breathe as hard as they could, in breaths researchers called "chuffs," the animals could inhale 8 gallons (30 liters) of air in one second, and exhale 34 gallons (130 liters) of air per second. A human's strongest exhale moves at a rate of 4 gallons (15 liters) per second, and human coughs range from about 10 to 16 gallons (40 to 60 liters) per second. In other words, dolphins move air two to three times faster than humans could ever do, Fahlman said.

Part of the reason dolphins are expert divers is because they can collapse their alveoli, the little sacks on the lungs that monitor air flow, and then open them up again, "but humans can't do that," Fahlman said.

This has implications for humans who are exposed to similarly extreme conditions, such as patients who undergo emergency operations.

"f you're in the hospital and you're undergoing surgery, oftentimes what they do is put a tube down your throat and put a positive pressure to prevent a collapse from happening," Fahlman said.

Putting positive pressure on the lungs keeps them open, but can also be dangerous, he added. "This is a clinically relevant issue for people in emergency care, for people undergoing surgery, because we cannot as easily open up the alveoli."

Fahlman said it's possible that dolphins' lungs look completely different from humans' or that dolphins have a very different biochemical composition in their lungs, which could explain their impressive exhalation abilities. Lungs typically contain a compound called surfactant, or pulmonary surfactant, that helps with breathing. Previous research found that surfactant in some seals and sea lions can keep the alveoli more lubricated so they open up easily.

All mammals use surfactant while breathing; it's a "way of trying to reduce the number of calories that it costs inhale and exhale," Fahlman said, adding that animals developed differences in surfactant to adapt to their environments.

Prematurely born babies benefit from surfactant manufactured from cows, Fahlman said, because the babies can't produce enough of the substance at such a young age.

Surfactant from dolphins and other sea mammals could be beneficial under different circumstances, he added. "We can learn about the structure of the surfactant [that animals] have and replicate it for humans," Fahlman said.

Studying animal breathing rhythms and capacities can also help scientists better understand respiratory disease in marine animals, which is a major cause of morbidity and mortality among marine animals in the wild and under human care, Fahlman said.

Humans are exposed to pollen, debris and other airborne pollutants that many dolphins and other mammals are unable to remove from their blowholes. This can make some animals susceptible to certain diseases like lung disease.

Fahlman said he plans to expand his research to beluga whales and porpoises to investigate their breathing patterns. He said there is especially high concern around mammals living in waters near oil rigs. Researchers are planning to travel to Alaska and the Arctic to study the mammals before oil reserves there are exploited, to establish a baseline for animal health, he added.

Read more at Discovery News

Hawking Spearheads New Hunt for Intelligent Aliens

On Monday, famed theoretical physicist Stephen Hawking announced the launch of a new $100 million effort to track down an alien civilization within the next decade.

Funded by US-based tech billionaire Yuri Milner, the initiative, called “Breakthrough Listen,” will take a “Silicon Valley approach” to discovering aliens, using two powerful radio telescopes and leveraging the problem-solving power of social networks. Frank Drake, the father of modern SETI who started the hunt for alien transmissions with "Project Ozma" in 1960, was also in attendance at the announcement with Hawking and other participating astronomers.

“Somewhere in the cosmos, perhaps, intelligent life may be watching these lights of ours, aware of what they mean,” said Hawking. “Or do our lights wander a lifeless cosmos — unseen beacons, announcing that here, on one rock, the Universe discovered its existence. Either way, there is no bigger question. It’s time to commit to finding the answer — to search for life beyond Earth.

“We are alive. We are intelligent. We must know.”

According to Breakthrough Listen, this will be the biggest scientific search for intelligent extraterrestrial life, a survey that will cover 10 times more of the sky than previous programs, monitoring 5 times more of the radio spectrum, 100 times faster, reports BBC News.

Breakthrough Listen is the first half of the group's mission. The second, "Breakthrough Message," will consist of an international competition to compile a global message that will one day be transmitted to another civilization.

Breakthrough Listen will take observational data from the Green Bank Telescope in West Virginia and the Parkes Telescope in New South Wales, Australia, and the public will be asked to participate in the SETI@home project, the stalwart alien-hunting software that first appeared in 1999 to leverage the distributed computer power of computers connected to the internet all over the world.

But will it be successful at eking out an alien radio signal? Well, that’s anybody’s guess. Searching for extraterrestrial intelligence(s) is a minefield of unknowns, some of which are explored by Trace and myself during this very special TestTube Plus+ video. Check it out:

From Discovery News

Red Planet, Icy World? New Picture of Ancient Mars Emerges

This image paints two very different views of ancient Mars: one warm and wet (top left), and the other a frozen, icy world.

Ancient Mars might have looked more like an icy snowball than the warmer, wetter planet that many researchers have suggested, according to a new study. The study suggests that channels seen on the Red Planet’s surface are better explained by erosion from ice and snow runoff — and not by flowing water — in the ancient past.

But if ancient Mars was, indeed, an icy wasteland, that would have made it harder for potential life to take hold 3 billion or 4 billion years ago, researchers behind the study say.

“I’m still trying to keep an open mind about this,” Robin Wordsworth, the study’s lead author and an assistant professor at the Harvard School of Engineering and Applied Sciences, said in a statement. “There is lots of work to be done.”

Wordsworth and his collaborators arrived at this conclusion after running 3-D atmospheric models to see how water moved between Mars’ surface and its atmosphere billions of years ago.

The first scenario envisioned Mars as a temperate place, with an average global temperature of 50 degrees Fahrenheit (10 degrees Celsius). The second scenario then cast the Red Planet into ice-ball conditions, with an average global temperature of minus 54 F (minus 48 C).

The results showed that the “cold” model did a better job of eroding features on the planet’s surface similar to those observed by spacecraft currently on and orbiting Mars. Further, the researchers said the “cold model” was based on a more accurate representation of the sun’s history (it was 25 percent dimmer at the time) and the way Mars’ axis was tilted 3 billion to 4 billion years ago.In that scenario, Mars’ poles would have been pointed at the sun, which would have caused a buildup of ice along the planet’s equator.

There also would have been a thicker atmosphere that would have exaggerated the effect: The equator highlands would have been cold, and the lower lands at the poles would have been warm.So, is it possible that Mars was warm and wet? The scientists said that scenario is more unlikely, as previous work shows that carbon dioxide, dust and clouds are still not quite enough to make the planet that way.

After adding more effects to their model, however, the scientists came up with a scenario where rainfall changed greatly across the planet. Arabia and the Hellas basin, where there are few erosion features spotted today, would have been the wettest areas, the researchers said.

Read more at Discovery News

Amateur astronomers spot one in a billion star

The Gaia satellite has discovered a unique binary system where one star is 'eating' the other, but neither star has any hydrogen, the most common element in the Universe. The system could be an important tool for understanding how binary stars might explode at the end of their lives.

An international team of researchers, with the assistance of amateur astronomers, have discovered a unique binary star system: the first known such system where one star completely eclipses the other. It is a type of two-star system known as a Cataclysmic Variable, where one super dense white dwarf star is stealing gas from its companion star, effectively 'cannibalising' it.

The system could also be an important laboratory for studying ultra-bright supernova explosions, which are a vital tool for measuring the expansion of the Universe. Details of the new research will be published in the journal Monthly Notices of the Royal Astronomical Society.

The system, named Gaia14aae, is located about 730 light years away in the Draco constellation. It was discovered by the European Space Agency's Gaia satellite in August 2014 when it suddenly became five times brighter over the course of a single day.

Astronomers led by the University of Cambridge analysed the information from Gaia and determined that the sudden outburst was due to the fact that the white dwarf -- which is so dense that a teaspoonful of material from it would weigh as much as an elephant -- is devouring its larger companion.

Additional observations of the system made by the Center for Backyard Astrophysics (CBA), a collaboration of amateur and professional astronomers, found that the system is a rare eclipsing binary, where one star passes directly in front of the other, completely blocking it out when viewed from Earth. The two stars are tightly orbiting each other, so a total eclipse occurs roughly every 50 minutes.

"It's rare to see a binary system so well-aligned" said Dr Heather Campbell of Cambridge's Institute of Astronomy, who led the follow-up campaign for Gaia14aae. "Because of this, we can measure the system with great precision in order to figure out what these systems are made of and how they evolved. It's a fascinating system -- there's a lot to be learned from it."

Using spectroscopy from the William Herschel Telescope in the Canary Islands, Campbell and her colleagues found that Gaia14aae contains large amounts of helium, but no hydrogen, which is highly unusual as hydrogen is the most common element in the Universe. The lack of hydrogen allowed them to classify Gaia14aae as a very rare type of system known as an AM Canum Venaticorum (AM CVn), a type of Cataclysmic Variable system where both stars have lost all of their hydrogen. This is the first known AM CVn system where one star totally eclipses the other.

"It's really cool that the first time that one of these systems was discovered to have one star completely eclipsing the other, that it was amateur astronomers who made the discovery and alerted us," said Campbell. "This really highlights the vital contribution that amateur astronomers make to cutting edge scientific research."

AM CVn systems consist of a small and hot white dwarf star which is devouring its larger companion. The gravitational effects from the hot and superdense white dwarf are so strong that it has forced the companion star to swell up like a massive balloon and move towards it.

The companion star is about 125 times the volume of our sun, and towers over the tiny white dwarf, which is about the size of the Earth -- this is similar to comparing a hot air balloon and a marble. However, the companion star is lightweight, weighing in at only one percent of the white dwarf's mass.

AM CVn systems are prized by astronomers, as they could hold the key to one of the greatest mysteries in modern astrophysics: what causes Ia supernova explosions? This type of supernova, which occurs in binary systems, is important in astrophysics as their extreme brightness makes them an important tool to measure the expansion of the Universe.

In the case of Gaia14aae, it's not known whether the two stars will collide and cause a supernova explosion, or whether the white dwarf will completely devour its companion first.

"Every now and then, these sorts of binary systems may explode as supernovae, so studying Gaia14aae helps us understand the brightest explosions in the Universe," said Dr Morgan Fraser of the Institute of Astronomy.

"This is an exquisite system: a very rare type of binary system in which the component stars complete orbits faster than the minute hand of a clock, oriented so that one eclipses the other," said Professor Tom Marsh of the University of Warwick. "We will be able to measure their sizes and masses to a higher accuracy than any similar system; it whets the appetite for the many new discoveries I expect from the Gaia satellite."

"This is an awesome first catch for Gaia, but we want it to be the first of many," said the Institute of Astronomy's Dr Simon Hodgkin, who is leading the search for more transients in Gaia data. "Gaia has already found hundreds of transients in its first few months of operation, and we know there are many more out there for us to find."

Read more at Science Daily

Bilinguals of two spoken languages have more gray matter than monolinguals

A new study published in the journal Cerebral Cortex suggests people who speak two languages have more gray matter in the executive control region of the brain.

In past decades, much has changed about the understanding of bilingualism. Early on, bilingualism was thought to be a disadvantage because the presence of two vocabularies would lead to delayed language development in children. However, it has since been demonstrated that bilingual individuals perform better, compared with monolinguals, on tasks that require attention, inhibition and short-term memory, collectively termed "executive control."

This "bilingual advantage" is believed to come about because of bilinguals' long-term use and management of two spoken languages. But skepticism still remains about whether these advantages are present, as they are not observed in all studies. Even if the advantage is robust, the mechanism is still being debated.

"Inconsistencies in the reports about the bilingual advantage stem primarily from the variety of tasks that are used in attempts to elicit the advantage," says senior author Guinevere Eden, DPhil, director for the Center for the Study of Learning at Georgetown University Medical Center (GUMC). "Given this concern, we took a different approach and instead compared gray matter volume between adult bilinguals and monolinguals. We reasoned that the experience with two languages and the increased need for cognitive control to use them appropriately would result in brain changes in Spanish-English bilinguals when compared with English-speaking monolinguals. And in fact greater gray matter for bilinguals was observed in frontal and parietal brain regions that are involved in executive control."

Gray matter of the brain has been shown to differ in volume as a function of people's experiences. A prominent finding of this type was a report that London taxi drivers have more gray matter in brain areas involved in spatial navigation.

What about being bilingual leads to these advantages? To address this question the team went one step further. "Our aim was to address whether the constant management of two spoken languages leads to cognitive advantages and the larger gray matter we observed in Spanish-English bilinguals, or whether other aspects of being bilingual, such as the large vocabulary associated with having two languages, could account for this," explains Olumide Olulade, PhD, the study's lead author and post-doctoral fellow at GUMC.

The researchers compared gray matter in bilinguals of American Sign Language (ASL) and spoken English with monolingual users of English. Both ASL-English and Spanish-English bilinguals share qualities associated with bilingualism, such as vocabulary size. But unlike bilinguals of two spoken languages, ASL-English bilinguals can sign and speak simultaneously, allowing the researchers to test whether the need to inhibit the other language might explain the bilingual advantage.

"Unlike the findings for the Spanish-English bilinguals, we found no evidence for greater gray matter in the ASL-English bilinguals," Olulade says. "Thus we conclude that the management of two spoken languages in the same modality, rather than simply a larger vocabulary, leads to the differences we observed in the Spanish-English bilinguals."

Read more at Science Daily