DNA taken from the skull of a baby girl unearthed in Alaska has provided a glimpse into the origins of the first people that populated the Americas.
The six-week-old girl, whose remains were untouched for 11,500 years in a burial pit, was named by the local indigenous community as "Xach'itee'aanenh t'eede gay" or "sunrise girl-child," an appropriate name for the light that she has shed upon ancient history.
Alaska's 'Sunrise' Girl Unearthed In 2013
In 2010, a team of archaeologists led by University of Alaska Fairbanks' Ben Potter discovered the ancient cremated remains of a three-year-old child at the Upward Sun River site in the Tanana River Valley of central Alaska.
Digging into the hearth, the archaeologists unearthed the remains of a pair of infants. One of these babies is "sunrise girl-child," and the other, possibly a fetus, was named "Yelkaanenh T'eede Gaa" or "dawn twilight girl-child."
An international team of scientists have now retrieved the genome of "sunrise girl-child" from her remains, which is the second-oldest human genome that has ever been acquired in North America.
What Does The Alaskan Baby's Genome Reveal?
The analysis on the infant's genome, published in the Nature journal, revealed that she belonged to a previously unknown population of Native Americans who were the descendants of the single wave of migrants who crossed a land bridge to travel from Siberia to Alaska during the Ice Age. The bridge, which is now submerged, spanned the Bering Strait.
"The study provides the first direct genomic evidence that all Native American ancestry can be traced back to the same source population during the last Ice Age," Potter explained.
The group that the baby belonged to, named the Ancient Beringians, is believed to have branched out from the original family tree about 20,000 years ago. While the Ancient Beringians lived in the north and later disappeared, the other branch moved south and split again about 15,000 years ago to form the populations of North and South America.
The analysis of the infant's genome debunked theories that the Ancient Beringian population split from the original population while still in Siberia. This would have meant that the two populations migrated separately across the land bridge into the Americas.
The findings brought about by the genome of "sunrise girl-child" show how even just one genome can provide a glimpse into ancient human history.
"It shows the power of ancient DNA - how much of our history is written in our DNA," said Princeton University evolutionary genomics professor Joshua Akey, who was not a participant in the study.