The girl’s remains were unearthed at the Upward Sun River archaeological site in the Tanana River Valley in central Alaska. Ben A. Potter, an archaeologist at the University of Alaska, discovered the site in 2006.
It was apparently home to short-lived settlements that appeared and disappeared over thousands of years. Every now and then, people arrived to build tent-like structures, fish for salmon, and hunt for hare and other small game.
In 2010, Dr. Potter and his colleagues discovered human bones at Upward Sun River. Atop a hearth dating back 11,500 years were the cremated bones of a 3-year-old child. Digging into the hearth itself, archaeologists discovered the remains of two infants.
The two infants were given names: the baby girl is Xach’itee’aanenh T’eede Gaay (“sunrise girl-child,” in Middle Tanana, the dialect of the local community), and the remains of the other infant, or perhaps a fetus, is Yełkaanenh T’eede Gaay (“dawn twilight girl-child”).
The Healy Lake Village Council and the Tanana Chiefs Conference agreed to let scientists search the remains for genetic material. Eventually, they discovered mitochondrial DNA, which is passed only from mother to child, suggesting each had different mothers. Moreover, each infant had a type of mitochondrial DNA found also in living Native Americans.
That finding prompted Dr. Potter and his colleagues to begin a more ambitious search. They began collaborating with Dr. Willerslev, whose team of geneticists has built an impressive record of recovering DNA from ancient Native American bones.
Among them are the 12,700-year-old Anzick Child, the oldest genome ever found in the Americas, and the Kennewick Man, an 8,500-year-old skeleton discovered in a riverbank in Washington State. Questions over his lineage provoked a decade-long legal dispute between scientists, Native American tribes and the Army Corps of Engineers.
Living Native Americans descend from two major ancestral groups. The northern branch includes a number of communities in Canada, such as the Athabascans, along with some tribes in the United…