Sunrise child-girl, or Xach’itee’aanenh t’eede gay, lived for a month around 11,500 years ago. Her remains, discovered and genetically sequenced in Alaska, have been able to shed light on the first settlers of America, with implications that reach far beyond the river her remains were found near.
The findings from Elke Willerslev from the University of Copenhagen and his team confirmed the existence of a previously unknown Native American ancestor, now referred to as Ancient Beringians.
While the bodies of two infants were originally found at Upward Sun River in Alaska in 2013, only the girl’s was viable for further research. Researchers gathered DNA from the petrosa bone in the skull of the child, and were able to extract high quality genomes which they compared to the genomes of existing ethnic groups, such as contemporary Native Americans.
Common understandings of the biological origins of Native Americans says that there are two groups of Native Americans – one group in the North, and one in the South, which share some similar genetic material but are different otherwise. After researchers compared the girl’s genomes to the gene sequences of contemporary and ancient Native Americans, they found that she possessed DNA from the two broad genetic groups of Native Americans, which had never been discovered before.
It allowed the scientists to infer that the child was a previously unknown ancestor of Native Americans, the “Ancient Beringian” mentioned above. The findings also cast further light on population movement. Between 20,000 and 15,000 years ago, it is roughly estimated, Native Americans diverged into two genetic branches, north and south (not to be confused with the geographical and cultural divergences of Native Americans in more recent history). What has happened to Ancient Beringians remains unknown – they seem to have been absorbed into Native Americans in the north of America, as evidence shows that they were not isolated and maintained contact with this group.
Victor Moreno-Mayar, who co-authored the paper alongside Willerslev, emphasises that these results are genetic conjecture, and many of the team’s conclusions would be strengthened by archeological evidence which remains amiss. “There is no archaeological site that is found in Alaska that predates 15,000 years ago, and this is something that requires more research. All of this is from a genetic standpoint,” he tells me.
“There is this saying in archaeology – you will never find the oldest archaeological artefact,” he adds.”One problem with archaeology in North America is that the archaeological record is very sparse, and it is very hard to find archaeological sites that predate 10,000 years ago – this site was found in 2006 when they were planning a railway expansion in Alaska. During this project, we were working with two archaeologists as well and we tried to make our best to integrate the genetic results with archaeology and paleo-climatic studies, but the conclusions will always be limited by the number of data points.”
Archaeologists, historians and scientists have been asking questions (and proposing wildly different theories) about the origins of the first peoples in America for many years, but their questions have remained broadly unresolved for a variety of reasons. Generally, there is a broad consensus that a land bridge, Beringia, stretched between northwest North America and northeast Asia, and that the original people of Asian descent used it to cross into Alaska. But much more remains uncertain, from when this occurred, to how many other populations were involved in the founding of Native Americans, or when the “basal split” between the North Native Americans and South Native Americans occurred. They remain uncertain becuse there is a lack of concrete archaeological evidence – such as the remnants of a corpse – that can be adequately analysed to provide evidence against of for dominant ideas. Even if there is evidence, time and natural processes will have altered its viability for analytical processes like genome sequencing, such as in this study and others like it.
This paper provides some further evidence for the theory that Native Americans are directly descended from the Asians the crossed the land bridge, at least from a genetic view point. “If you’re looking at a map from Asia into America, the first and oldest branch, the Ancient Beringians is found in Alaska,” says Morano-Mayar. “And then the next branch is somewhere south of the ice which had formed over most of North America.”
However, this work has some wide-reaching implications far beyond the scope of the study itself. In 2014, Willerslev and another team had sequenced the genome of a young boy’s remains found in Montana, who bore genetic similarities to various genome sequences from North, Central and South America, making him one of the first humans to be sequenced. This was first genetic confirmation of the existence of a land bridge, Beringia, between Siberia and Alaska, which has now been further substantiated by this paper.
It also demonstrates how much of humanity’s history is unknown – being able to identify an entirely unknown group of people is an extremely rare occurrence, and these results indicate that other unknown groups could have existed around the world, but we just don’t have the evidence to support these claims yet.
Within America, this particular issue – that of who was the first to populate America – has been a contentious issue. Moreover, Native Americans and the scientists studying their origins have had a difficult history too – many Native American tribes have asserted their rights to reburial in the event of new remains being discovered, while scientists have emphasised the value of carrying out such work. Some tribes around the continent have asserted their belief, passed from generation to generation, that they have been here, as a people, since the beginning of time, and don’t need a scientific body to confirm that. In America, the most effective methods of establishing the human history of the continent often require processes like excavation, but these can cause issues with indigenous communities because of the Native American Graves Protection and Repatriation Act of 1990, which asserts the rights of indigenous Americans to leave their corpses undisturbed.
The well-publicised case of the Kennewick Man in 2004 (also carried out by Willeslerv and his team) was quite typical of the debate – the bones of a skeleton, now identified as one of the oldest humans in America, were dug up in Washington. The Army Corps of Engineers, who were guardians of the land where it was found, claimed ownership. But so, too, did a coalition of Native American tribes, concerned about scientists and anthropologists who dug up skeletons without a care for indigenous burial customs. Eventually, a court case gave the Army Corps rights over the body, enabling scientists to continue with their research, but the relationship between Native Americans and the scientific community soured further.
Even so, this paper has sent ripples through the scientific community and has generated public interest in further work along these lines. It could be that people around the world are curious about what this could mean for us as a species, genetically and socially. As for now, it seems that the way forward is just to collect more data points. “The more information you have, the more that you know,” says Morano-Mayer. “That’s just how science works.”