The DNA from a single infant is shining a light on the true origins of the first Americans. The headline-generating research relies on the DNA of a child buried roughly 12,600 years ago, and establishes that the first North Americans were born to humans who came to the New World from Asia. The origins of the Clovis people, who fashioned distinctive stone tools, had been contested, with some believing they were descendants of southwestern Europeans. "This shows very clearly that the ancestry of the very first Americans can be traced back to Asia," says Michael Waters, a co-author of the study, which also indicates that the Clovis people are direct ancestors of today's Native Americans.
The Clovis skeleton was uncovered in 1968 in the Anzick burial site in western Montana and belongs to a boy between 12 and 18 months; it's "the only known Clovis burial," Waters tells LiveScience. National Geographic reports that the process of collecting the DNA was no simple feat: Bone shavings from the skull were used to reconstruct the genome, but no more than 2% of the collected DNA was human. "The rest of it came from bacteria that invaded the skeleton after death," explains another researcher. The eventual genome was similar to those of ancient Siberian people and East Asians' ancestors, which seems "to fit quite nicely with an early occupation of the Americas about 2,000 years before the onset of Clovis," says Waters. But there were also similarities between it and that of 52 Native American populations from Canada and South America. One challenge in establishing whether Native Americans from the US are direct descendants of the Clovis: They've been hesitant to share their DNA, and that of their ancestors, with scientists. LiveScience notes that the child's remains will be reburied. (Read more Clovis people stories.)