Author: m1k3y

Ancient native boy’s genome reignites debate over first Americans   

A new analysis challenges the out-of-Europe hypothesis, which has figured in a political debate over the rights of present-day Native American tribes. Scientists announced on Wednesday that they had, for the first time, determined the full genome sequence of an ancient American, a toddler who lived some 12,600 years ago and was buried in western Montana. His DNA, they report, links today’s Native Americans to ancient migrants from easternmost Asia.

The study, published in the journal Nature, “is the final shovelful of dirt” on the European hypothesis, said anthropological geneticist Jennifer Raff of the University of Texas, co-author of a commentary on it in Nature.

The idea that the first Americans arrived millennia earlier than long thought and from someplace other than Beringia – which spans easternmost Russia and western Alaska – has poisoned relationships between many Native Americans and anthropologists. Some tribes fear that the theory that the continent’s first arrivals originated in Europe might cast doubt on their origin stories and claims to ancient remains on ancestral lands.

Despite the new study, other experts say the debate over whether the first Americans arrived from Beringia or southwestern Europe, where a culture called the Solutrean thrived from 21,000 to 17,000 years ago, is far from settled.

“They haven’t produced evidence to refute the Solutrean hypothesis,” said geneticist Stephen Oppenheimer of Oxford University, a leading expert on using DNA to track ancient migrations. “In fact, there is genetic evidence that only the Solutrean hypothesis explains.”

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“The genetic data from Anzick confirms that the ancestors of this boy originated in Asia,” said Eske Willerslev of the Natural History Museum of Denmark, who led the study. The DNA shows that the child belonged to a group that is a direct ancestor to as many as 80 percent of the Native Americans tribes alive today, he said: “It’s almost like he is a missing link” between the first arrivals and today’s tribes.

The most likely scenario, said Texas’s Raff, is that humans reached eastern Beringia from Siberia 26,000 to 18,000 years ago. By 17,000 years ago, receding glaciers allowed them to cross the Bering Strait. Some migrated down the Pacific coast, reaching Monte Verde in Chile by 14,600 years ago, while others – including the ancestors of Anzick-1 – headed for the interior of North America.

The genetic analysis found that the boy is less closely related to northern Native Americans than to central and southern Native Americans such as the Maya of Central America and the Karitiana of Brazil. That can best be explained, the scientists say, if he belonged to a population that is directly ancestral to the South American tribes.

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Genetic analysis is also keeping the out-of-Europe idea alive.

One variant of DNA that is inherited only from a mother, called mitochondrial DNA, and is found in many Native Americans has been traced to western Eurasia but is absent from east Eurasia, where Beringia was before the sea covered it, Oppenheimer explained. For the variant, called X2a, to have such a high frequency in Native Americans “it must have got across the Atlantic somehow,” he said. The new study “completely ignored this evidence, and only the Solutrean hypothesis explains it.”
Ancient native boy’s genome reignites debate over first Americans   

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“For about two years, I had the coolest job title in NASA: manager of the interstellar propulsion research project.”

Johnson’s team determined that the most practical path to the stars was via solar sails, which required fewer scientific breakthroughs than fusion-powered nuclear engines or exotic propulsion methods like warp drive. Ultra-thin sails would use the faint but constant pressure of sunlight or high-powered lasers to propel them to a few percent of the speed of light. (NASA plans to launch a 124-foot solar sail, called Sunjammer after a sail in an Arthur C. Clarke novel, in 2015, although it will stay well within the bounds of the solar system.) “Sailships are the only way we know to get to velocities that are anywhere close to the speed of light,” Gregory Benford, another physicist/sci-fi author, tells the Starship Congress attendees.

Yet even with this relatively reasonable-sounding technology, the problems are so vast that we won’t be sailing to the stars anytime soon. Johnson says that to propel a craft to Alpha Centauri, the nearest star system, a solar sail would have to be as big as the state of Alabama, and would need a millennium to travel the 4.3-light-year distance. Change the power source from solar radiation to terawatt-scale lasers and you could cut the travel time to a century. The big drawback? Such a system would require power “equivalent to the total output of humanity today,” Johnson says.

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Lubin acted as conference contrarian, frequently asking presenters pointed questions about their proposed technologies. But he also offered up his own sci-fi-sounding project: a planetary defense system that could double as a solar sail’s power source, using beamed energy to propel an unmanned probe to the stars.

The system would collect sunlight with miles-wide solar arrays in Earth orbit and convert it to a beam of energy, similar to a giant laser. Lubin says that over a year, such a beam could completely vaporize a threatening asteroid a third of a mile (1,760 feet) wide at a range of one astronomical unit—the distance from Earth to the sun (93 million miles)—and deflect much larger ones. “It wouldn’t require any miracles, just a lot of hard work,” he says. Such a system could start on a much smaller scale—big enough to zap space debris, perhaps—then be expanded as engineering and funding allow.

If used to propel starships, the energy beam could boost probes to substantial speeds, Lubin says. A 100-kilogram (220-pound) probe with a 100-foot reflector to catch the beam could reach Mars in three days; with a much larger reflector, such a probe could hit three percent of lightspeed—up to 20 million mph—by the time it reached the edge of the solar system in less than a month.

http://www.airspacemag.com/space/going-interstellar-180947759/
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The Collapse Will be Televised and Live Tweeted

wolvensnothere: http://WAGA.images.worldnow.com/interface/js/WNVideo.js?rnd=559772;hostDomain=www.myfoxatlanta.com;playerWidth=645;playerHeight=363;isShowIcon=true;clipId=9829106;flvUri=;partnerclipid=;adTag=Weather;advertisingZone=;enableAds=true;landingPage=;islandingPageoverride=false;playerType=STANDARD_EMBEDDEDscript;controlsType=fixed If I might be allowed to paraphrase Moz: This joke isn’t funny anymore. FOX 5 News Atlanta: Winter Ice Storm Warning (Direct link to video, in case it decides not to work). Here in the Southern Archonic Protectorate days after the five year anniversary of the last great burnening of the Victorian countrycide, […]

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aleskot:

“That’s Peter Freuchen and his wife Dagmar Freuchen-Gale, in a photo taken by Irving Penn. Freuchen is a top candidate for the Most Interesting Man in the World. Standing six feet seven inches, Freuchen was an arctic explorer, journalist, author, and anthropologist. He participated in several arctic journeys (including a 1000-mile dogsled trip across Greenland), starred in an Oscar-winning film, wrote more than a dozen books (novels and nonfiction, including his Famous Book of the Eskimos), had a peg leg (he lost his leg to frostbite in 1926; he amputated his gangrenous toes himself), was involved in the Danish resistance against Germany, was imprisoned and sentenced to death by the Nazis before escaping to Sweden, studied to be a doctor at university, his first wife was Inuit and his second was a Danish margarine heiress, became friends with Jean Harlow and Mae West, once escaped from a blizzard shelter by cutting his way out of it with a knife fashioned from his own feces, and, last but certainly not least, won $64,000 on The $64,000 Question.”

More here.

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“Alien Electromagnetic Signals Will Be Discovered by 2040” –SETI’s Chief Astronomer

Writing in Acta Astronautica, Shostak says that the odds favour detecting such alien AI rather than “biological” life. Seti researchers have long argued that nature may have solved the problem of life using different designs or chemicals, suggesting extraterrestrials would not only not look like us, but that they will not be carbon based life forms, but be bound to follow “at least some rules of biochemistry, live for a finite period of time, procreate, and above all be subject to the processes of evolution.”

“If you look at the timescales for the development of technology, at some point you invent radio and then you go on the air and then we have a chance of finding you,” he told BBC News.“But within a few hundred years of inventing radio – at least if we’re any example – you invent thinking machines; we’re probably going to do that in this century. So you’ve invented your successors and only for a few hundred years are you… a ‘biological’ intelligence.”

From a probability point of view, if AI-powered machines evolved, we would be more likely to spot signals from them than from the “biological” life that invented them.

“But having now looked for signals for 50 years, Seti is going through a process of realizing the way our technology is advancing is probably a good indicator of how other civilisations – if they’re out there – would’ve progressed. Certainly what we’re looking at out there is an evolutionary moving target.”

Dr Shostak says that artificially intelligent alien life would be likely to migrate to places where both matter and energy – the only things he says would be of interest to the machines – would be in plentiful supply. That means the Seti hunt may need to focus its attentions near hot, young stars or even near the centers of galaxies.

“I think we could spend at least a few percent of our time… looking in the directions that are maybe not the most attractive in terms of biological intelligence but maybe where sentient machines are hanging out.” Shostak thinks SETI ought to consider expanding its search to the energy- and matter-rich neighborhoods of hot stars, black holes and neutron stars.

Data centers like this generate a lot of heat, and keeping them cool is a major challenge for modern computing. Intelligent computers would likely seek out a low-temperature habitat. Bok globules (image at top of page) are another search target for sentient machines. These dense regions of dust and gas are notorious for producing multiple-star systems. At around negative 441 degrees Fahrenheit, they are about 160 degrees F colder than most of interstellar space.

This climate could be a major draw because thermodynamics implies that machinery will be more efficient in cool regions that can function as a large “heat sink”. A Bok globule’s super-cooled environment might represent the Goldilocks Zone for the AI powered machines, says Shostak. But because black holes and Bok globules are not hospitable to life as we know it, they are not on SETI’s prime target list.

“Machines have different needs,” he says. “They have no obvious limits to the length of their existence, and consequently could easily dominate the intelligence of the cosmos. In particular, since they can evolve on timescales far, far shorter than biological evolution, it could very well be that the first machines on the scene thoroughly dominate the intelligence in the galaxy. It’s a “winner take all” scenario.”

“Alien Electromagnetic Signals Will Be Discovered by 2040” –SETI’s Chief Astronomer

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science-junkie:

Information Destruction Through History

Information the most valuable commodity in the world. All human progress depends on the accumulation and preservation of information. When information is lost, human progress suffers. This infographic displays some of the most significant loses of information human civilization has suffered.

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