Ancient Siberian Skeletons Confirm Native American Origins

[Buster's Uncle]

Ancient Siberian Skeletons Confirm Native American Origins
LiveScience.com
By Tia Ghose, Staff Writer  November 20, 2013 1:08 PM



A cross-section of a humerus bone from the 24,000-year-old skeleton found in Siberia.



The DNA gleaned from two ancient Siberian skeletons is related to that of modern-day Native Americans and western Eurasians, new research suggests.

The genetic material from the ancient Siberians provides additional evidence that the ancestors of Native Americans made the arduous trek from Siberia across the Bering Strait into the Americas.

But it also reveals there were multiple waves of migrations in Asia around this time, said Mark Hubbe, a biological anthropologist at The Ohio State University who was not involved in the study. [Top 10 Mysteries of the First Humans]

"This brings a new level of complexity to what we think happened in Asia," Hubbe told LiveScience.


Ancient migrations

Several genetic clues indicate that Native Americans came from a population that once inhabited Siberia and crossed the Bering Strait between 20,000 and 15,000 years ago.

Between 1928 and 1958, Russian scientists excavated a Siberian site in Mal'ta, Russia, near Lake Baikal, and unearthed a trove of Venus figurines along with the skeleton of a juvenile, all dating back approximately 24,000 years. The figurines were intriguing, because they were similar in style to ones made by European hunter-gatherers.



Lake Baikal, the region where the 24,000-year-old fossil skeleton was unearthed.


European relatives

To trace the ancestry of these ancient people, Maanasa Raghavan, a researcher at the University of Copenhagen in Denmark, and colleagues managed to extract DNA from the ancient skeleton.

The team found that the mitochondrial DNA, or genetic material carried in the cytoplasm of cells that is passed through the maternal line, came from a lineage known as U, which is rare or extinct now, but was once common in hunter-gatherers from Europe during the Paleolithic Period.

The team also sequenced the male sex chromosome (Y chromosome), which traces the paternal lineage of the skeleton. On the paternal side, the ancient boy came from a lineage known as R, which is now found in southern Siberia and western Eurasia. The R lineage is also a sister group to one common in Native Americans.

The researchers estimate that between 14 and 38 percent of Native American ancestry could come from this ancestral population, with the remaining portion coming from ancient East Asians.

DNA from a 17,000-year-old skeleton found in south central Siberia showed signs of being from the same genetic lineage as the Ma'lta specimen.

Previously, researchers had thought that people migrated from Europe into east Asia, and then entered Siberia from the south in a fairly linear expansion, Hubbe said. But the new results suggest the Siberian inhabitants may have come from the West, he said. That suggests Asia experienced multiple, crisscrossing waves of migration, he said.

However, because the skeletons are so old, it's important to rule out the possibility that the DNA was contaminated, Theodore Schurr, an anthropologist at the University of Pennsylvania who was not involved in the study, wrote in an email.

And having so few ancient samples paints a very limited picture of a complicated genetic history.

"Although these results are intriguing and important, we should be cautious in inferring too much from just two genomes," said Jennifer Raff, an anthropologist at the University of Texas at Austin who was not involved in the study. "I would certainly like to see a more geographically and temporally widespread sampling of Siberian genomes in order to better understand their population history."

The findings were published today (Nov. 20) in the journal Nature.


http://news.yahoo.com/ancient-siberian-skeletons-confirm-native-american-origins-180829272.html

[Buster's Uncle]

Research shows closer ties between Native Americans, Europeans
Reuters
By Jim Forsyth 4 hours ago



Travis Mazawaficuna of the Dakota Nation (Sioux) Native American tribe is photographed outside the United  Nations headquarters




SAN ANTONIO, Texas (Reuters) - Native Americans have closer genetic ties to people in Eurasia, the Middle East and Europe than previously believed, according to new research on a 24,000-year-old human bone.

Genome sequencing on the arm bone of a 3-year-old Siberian boy known as the "Mal'ta Boy," the world's oldest known human genome, shows that Native Americans share up to one-third of their DNA with people from those regions, said Kelly Graf, a research assistant professor at the Department of Anthropology at Texas A&M University and a member of the international research team.

The team is led by researchers at the University of Copenhagen in Denmark. The study was published in the journal Nature this week.

The results add a new dimension to earlier beliefs that Native Americans were mostly descended from East Asians who crossed the land bridge from Siberia to North America some 14,000 years ago, Graf said on Thursday.

Native Americans still have genetic connections to East Asians, Graf said, but the new sequencing shows that a "significant part" of their genome, as much as 35 percent, is linked to the Middle East, Eurasia and Europe.

"The Mal'ta people who had this DNA were part of a group that ranged anywhere from Lake Baikal (Siberia) into Central Europe," she said. "This is part of a group that is genetically related to each other."

They are not genetically related to the East Asians, however, so the question remains how DNA from these two peoples both ended up in the genetic code of Native Americans. "Native American ancestry is very complicated and very complex," Graf said.

One theory, she said, is that the two distinct peoples crossed the land bridge separately and met up in North America.

"There will, hopefully, be other sites between southern Siberia and Alaska to tell us when these people were available to colonize the Americas," Graf said.

Scientists have generally believed that the clearly European features of some Native Americans derived only from their intermingling with Europeans after the 15th century.

Several tribes living in what is now the United States, most notably the Mandan tribe that is native to the Dakotas, had strikingly European-looking features, including blond hair, when they were first met by French traders in the 18th century.

That has given rise to a range of theories, both scientific and fringe, including the idea that the Welsh, Scottish or Viking explorers, or even one of the Lost Tribes of Israel, had pre-Columbian contact with Native Americans.

But Graf said the new finding shows that those "European" traits are actually native to those tribes.

"What this study is telling us is that those Europoid-looking signatures, those features, came with them over the land bridge from Siberia, and were present in people who lived in Siberia 24,000 years ago," she said.


http://news.yahoo.com/research-shows-closer-ties-between-native-americans-europeans-211844248.html