Read moreThe genetic ancestry of the earliest Europeans survived the ferocious Ice Age that took hold after the continent was initially settled by modern people.
That is the suggestion of a study of DNA from a male hunter who lived in western Russia 36,000 years ago.
His genome is not exactly like those of people who lived in Europe just after the ice sheets melted 10,000 years ago.
But the study suggests the earliest Europeans did contribute their genes to later populations.
Europe was first settled around 40,000 years ago during a time known as the Upper Palaeolithic.
But conditions gradually deteriorated until ice covered much of the European landmass, reaching a peak 27,000 years ago.
The ice melted rapidly after 10,000 years ago, allowing populations from the south to re-populate northern Europe – during a time known as the Mesolithic. But the genetic relationships between pre- and post-Ice Age Europeans have been unclear.
Some researchers have in the past raised the possibility that pioneer populations in Europe could have gone extinct some time during the last Ice Age.
And one recent study looking at the skull features of ancient Europeans found that Upper Palaeolithic people were rather different from populations that lived during the later Mesolithic period.
In the latest study, an international team of researchers sequenced the genome (the genetic “blueprint” for a human) of a man buried in Kostenki, Russia.
They discovered a surprising genetic “unity” running from the first modern humans in Europe, through to later peoples. This, they claim, suggests that a “meta-population” of Palaeolithic hunter-gatherers managed to survive the Ice Age and colonise the landmass of Europe for more than 30,000 years.
“That there was continuity from the earliest Upper Palaeolithic to the Mesolithic, across a major glaciation, is a great insight into the evolutionary processes underlying human success,” said co-author Dr Marta Mirazón Lahr, from Cambridge’s Leverhulme Centre for Human Evolutionary Studies (LCHES).
“For 30,000 years ice sheets came and went, at one point covering two-thirds of Europe. Old cultures died and new ones emerged – such as the Aurignacian and the Gravettian – over thousands of years, and the hunter-gatherer populations ebbed and flowed.
“But we now know that no new sets of genes are coming in: these changes in survival and cultural kit are overlaid on the same biological background.”
She added: “It is only when farmers from the Near East arrived about 8,000 years ago that the structure of the European population changed significantly.”
genetics
Read moreGenetic data on 27 Easter Island natives indicated that interbreeding between the Rapa Nui and native people in South America occurred roughly between 1300 and 1500.
“We found evidence of gene flow between this population and Native American populations, suggesting an ancient ocean migration route between Polynesia and the Americas,” said geneticist Anna-Sapfo Malaspinas of the Centre for GeoGenetics at the University of Copenhagen, who led the study.
The genetic evidence indicates either that Rapa Nui people traveled to South America or that Native Americans journeyed to Easter Island. The researchers said it probably was the Rapa Nui people making the arduous ocean round trips.
“It seems most likely that they voyaged from Rapa Nui to South America and brought South Americans back to Rapa Nui and admixed with them,” said Mark Stoneking, a geneticist with Germany’s Max Planck Institute for Evolutionary Anthropology who collaborated on a related study of Brazil’s indigenous Botocudo people. “So it will be interesting to see if in further studies any signal of Polynesian, Rapa Nui ancestry can be found in South Americans.”
In making their way to South America and back, the Rapa Nui people may have spent perilous weeks in wooden outrigger canoes.
The researchers concluded that the intermixing occurred 19 to 23 generations ago. They said Rapa Nui people are not believed to have started mixing with Europeans until much later, the 19th century. Malaspinas said the genetic ancestry of today’s Rapa Nui people is roughly 75 percent Polynesian, 15 percent European and 10 percent Native American.
A second study, also published in Thursday’s issue of Current Biology, illustrates another case of Polynesians venturing into South America. Two ancient human skulls from Brazil’s indigenous Botocudo people, known for the large wooden disks they wore in their lips and ears, belonged to people who were genetically Polynesian, with no detectable Native American ancestry.
“How the two Polynesian individuals belonging to the Botocudos came into Brazil is the million-dollar question,” said University of Copenhagen geneticist Eske Willerslev of the Centre for GeoGenetics, who led the study on the Botocudos.
The findings suggest these Polynesians reached South America and made their way to Brazil, either landing on the western coast of the continent and crossing the interior or voyaging around Tierra del Fuego and up the east coast, Stoneking said.
[1404.7766] Genome-wide Scan of Archaic Hominin Introgressions in Eurasians Reveals Complex Admixture History
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We found that detected introgressions shared more archaic-specific mutations with Altai Neanderthal than they shared with Denisovan, and 60.3% of archaic hominin introgressions were from Neanderthals. Furthermore, we detected more introgressions from two unknown archaic hominins whom diverged with modern humans approximately 859 and 3,464 thousand years ago. The latter unknown archaic hominin contributed to the genomes of the common ancestors of modern humans and Neanderthals. In total, archaic hominin introgressions comprised 2.4% of Eurasian genomes. Above results suggested a complex admixture history among hominins.
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* translation: not only are we the product of cross breeding with Neanderthals and Denisovans, but two far older branches of the hominid tree.
The natural state of hominids has been expansion then separation into subspecies… like say from an Ice Age, or other heavy weather event or catastrophe… then hooking up again later and swapping genes. This is how it’s been done for millions of years.
Statistically, there being just one species of human on the planet has been “unnatural”. Remember, our current count for the end of the last Ice Age now stands at four.
Who knows what more genetic data mining will reveal? Our complex origins.
Extrapolate forwards for Mars and other off-world colonies at your leisure. (And sideways for cryptozoological fun times.)
Read more "[1404.7766] Genome-wide Scan of Archaic Hominin Introgressions in Eurasians Reveals Complex Admixture History"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
The Committee to Nuke Elysium 