February 13, 2014
America’s Short-Lived Clovis People Genetically Mapped For First Time
April Flowers for redOrbit.com - Your Universe Online
The Clovis people lived in America around 13,000 years ago. They hunted mammoth, mastodons and giant bison with big spears. Though they were not the first humans in America, they did represent the first humans with a wide expansion on the North American continent. That is, until the culture mysteriously disappeared only a few hundred years after it emerged.
Who the Clovis people were, and what present day humans they are related to has been a major scientific debate. This issue is key in understanding how the Americas were populated. Currently, only one human skeleton—Anzick-1—has been found in association with Clovis tools. The small boy, between 1 and 1.5 years of age, is among the oldest human skeletons found in the Americas. It was discovered in a 12,600-year-old burial site, called the Anzick Site, in Wilsall, Montana. An international team of researchers has now mapped the genome of this ancient child, reviving the scientific debate about the colonization of the Americas.
As Reuters reports, the debate has raged for over 20 years between two major theories. The first, as every school child is taught, is that the first Americans walked over a land bridge across the Bering Strait. The second theory is that they arrived by sea, perhaps in animal-skin kayaks, a theory which has played into the political debate over the rights of present-day Native Americans.
The findings, published in Nature, reveal that roughly 80 percent of all present-day Native American populations on the two American continents are direct descendants of the Clovis boy's family. According to Lundbeck Professor Eske Willerslev, of the Centre for GeoGenetics at the Natural History Museum of Denmark, University of Copenhagen, the remaining 20 percent are more closely related with the Clovis family than any other people on Earth.
"It is almost like finding the 'missing link' to the common ancestor of the Native Americans. The Clovis boy's family is the direct ancestor to roughly estimated 80 percent of all present day Native Americans. Although the Clovis culture disappeared its people are living today. Put simply it is a sensation that we succeeded in finding an approximately 12,600 year old boy whose closest relatives can be regarded as the direct ancestor to so many people," Willerslev says.
"This also means that Clovis did not descend from Europeans, Asians or Melanesians, a theory that a number of scientists have advocated. They were Native Americans – and the Native American ancestors were the first people in America. This is now a fact," Willerslev adds.
Shane Doyle, a historian from the Apsaalooke (Crow) tribe and a professor at Montana State University, who helped the team with consultations to the Montana tribes agrees.
"This discovery by Eske and his team proves something that tribal people have never doubted - we've been here since time immemorial and all the ancient artifacts located within our homelands are remnants from our direct ancestors," says Doyle. "But the discovery is only part of the importance of this study. The other part being Eske and his team's respectful commitment to interacting face to face with tribal communities and listening to Native American leaders, which has lead directly to the reburial of this little boy."
Sarah Anzick, a molecular biologist in the study and the steward of the remains that were found on private land is excited, saying,"After 46 years since the discovery on my family land, we are finally hearing this child's story through his genetic legacy. I find it remarkable that the descendants of the Clovis culture, which seemed to have vanished 12,600 years ago, are still alive and thriving today."
The researchers found that the Native American ancestors coming in from Siberia split into two groups. The first group are ancestors to the Native American, or First Nations, people presently living in Canada. The second group, represented by the Clovis boy, are the ancestors to virtually all Native peoples in South America and Mexico. So far, the US is still a white spot on the genome-wide map of Native American data—though the team hopes to access such data in the future to understand the full picture.
The researchers say the most likely scenario is that humans reached eastern Beringia from Siberia 26,000 to 18,000 years ago. Receding glaciers, 17,000 years ago, allowed them to cross the Bering Strait, where 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 findings of this study validate the concept of continuity in the history of Native populations, suggesting that modern Native peoples are direct descendants of the first people occupying this land, according to Rasmus Nielsen, a Professor at UC Berkeley, who developed the method used for determining that many modern native Americans are direct descendants of the Clovis boy's family.
The initial wave of immigrants came to the Americas from Siberia via the Beringia Land Bridge, which connected Siberia with North America during the last Ice Age. They did not bring the Clovis culture with them, rather the Clovis culture emerged after the arrival in America. The boy from Anzick was a descendant of these first immigrants.
Michael Waters, the key archaeologist connected to the study and who has worked on many Clovis and older sites in North America elaborates, "The genetic findings mesh well with the archaeological evidence to confirm the Asian homeland of the First Americans, more clearly define their genetic heritage, and is consistent with occupation of the Americas a few thousand years before Clovis. The findings do not support a western European origin of the First Americans as suggested by the Solutrean hypothesis. The genetic information provided by the Anzick boy is part of the larger story of modern human dispersal across the Earth and is shedding new light on the last continent to be explored and settled by our species."
"Then who were the first immigrants? We don't know. Yet. Maybe a Native American, maybe an ancestor related to the Mal'ta boy from Siberia and another one who was East Asian. We don't know. But our results eliminate all other theories about the origins of the first people in America. The first people in America were the direct ancestors of Native Americans," says Professor Willerslev.
He adds, "We can see that the Clovis boy shares about 1/3 of his genes with the 24,000 year old child from Mal'ta at the Siberian Lake Baikal who we have analyzed previously. The same goes for all present day Native Americans. Therefore the encounter between East Asians and the Mal'ta group happened before Clovis."
The boy's remains will be reinterred at the Anzick site sometime later this year in cooperation with Native American tribes in Montana. In connection with the genome work on the Clovis boy, Willerslev has visited several of Montana's Native American tribes with Crow historian Shane Doyle to discuss the findings. The researchers hope that this study leads to more enhanced cooperation between Native peoples and scientists. To that end, an international press conference to discuss the findings will be held on the Crow tribe reservation in Montana, close to where the boy's remains were found.
Although Jennifer Raff, an anthropological geneticist from the University of Texas, says these findings are "the final shovelful of dirt" on the European hypothesis, not everyone is convinced that the Clovis remains conclusively prove that the first immigrants came from Beringia rather than 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."
Part of this evidence is found in the 125 artifacts found with the boy's body. These included stone spear points and elk antlers centuries older than the boy's bones, according to Prof Michael Waters, of Texas A&M University's Center for the Study of the First Americans.
That suggests that the antler artifacts "were very special heirlooms handed down over generations," Waters said. It is unclear why they were buried with the boy, but the distinctive tools show that the boy was definitely part of the Clovis culture.
"We definitely have some stuff here in the east of the United States that is older than anything they have in the west," said anthropologist Dennis Stanford of the Smithsonian Institution, a proponent of the out-of-Europe model. "They've been reliably dated to 20,000 years ago," too early for migrants from Beringia to have made the trek, he said, and strongly resemble Solutrean artifacts.
The out-of-Europe idea is also being kept alive by genetic research.
Mitochondrial DNA is only inherited from a mother. In many Native American tribes, mDNA has been traced to western Eurasia, but is absent from eastern Eurasia, where Beringia was before the sea covered it. Oppenheimer said that for the variant, 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."