The remains of
a six-week-old infant cast new light upon the Native American founding
Scientists divided the ancient American populations into two
categories: the Southern and the Northern Native Americans. The
two groups are related, but a link between them and an ancient Siberian
population was missing, until now.
were taken at Upward Sun River site. Credit: Ben Potter
"It's the first time that we have had direct genomic evidence
that all Native Americans can be traced back to one source population,
via a single, founding migration event." said evolutionary geneticist
Willerslev from the University of Cambridge in the UK, the
research team leader, in a press
Researchers named this population "Ancient Beringians" after
Beringia, the land bridge that connected northeast Asia with northwestern
North America, during the Pleistocene
epoch sometimes called the Ice Age.
The girl was named Xach'itee'aanenh t'eede gaay, or Sunrise
Child-girl, by the local Native community. Her skeleton was discovered
at the Upward Sun River archaeological site in Alaska in 2013. Scientists
say the child lived 11,500 years ago, long after the first wave
of migration occurred, but her genome was consistently different
from the two types of ancient Native Americans.
"The Ancient Beringians diversified from other Native Americans
before any ancient or living Native American population sequenced
to date. It's basically a relict population of an ancestral group
which was common to all Native Americans, so the sequenced genetic
data gave us enormous potential in terms of answering questions
relating to the early peopling of the Americas," Eske Willerslev
excavation site from Alaska. Credit: Ben Potter
This is the first ancient skeleton ever discovered in Alaska
acidic soils make bone tissue and DNA preservation very difficult.
"We were able to show that people probably entered Alaska
before 20,000 years ago. It's the first time that we have had
direct genomic evidence that all Native Americans can be traced
back to one source population, via a single, founding migration
event." said Professor Willerslev.
The Northern and the Southern branches are thought to have separated
somewhere between 17,000-14,000 years ago. The two groups probably
went separate ways as they passed through or around the Cordilleran
and Laurentide ice sheets that covered present-day Canada and a
part of northern United States.
Scientists believe that the Ancient Beringians were left behind
the ice sheets and remained in Alaska. Next, the population was
absorbed by other Native groups derived from the Northern branch,
that migrated back after the ice had melted away.
"One significant aspect of this research is that some people
have claimed the presence of humans in the Americas dates back
earlier to 30,000 years, 40,000 years, or even more. We
cannot prove that those claims are not true, but what we are saying,
is that if they are correct, they could not possibly have been
the direct ancestors to contemporary Native Americans", added
The paper was published in the Nature journal on the 3rd of
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