A scientific illustration of the Upward Sun River camp in what is now Interior Alaska ILLUSTRATION BY ERIC S. CARLSON IN COLLABORATION WITH BEN A. POTTERAt the end of the last ice age, about 11,500 years ago, ancient people buried two infants at a residential campsite called Upward Sun River (USR) in what is currently central Alaska. Now, the whole genome sequence of one of the infants—a six-week-old named Xach’itee’aanenh T’eede Gaay, or Sunrise Child-girl by local Native Americans and USR1 by researchers—has revealed that she was part of a distinct and previously unknown group descended from the same founding population as all other Native Americans. The findings were published today (January 3) in Nature.
“USR1 really provides the most definitive evidence for all Native American populations in North and South America deriving from a single population,” says University of Florida geneticist Connie Mulligan, who did not participate in the study. “In other words, there was only one wave of migration over to the New World to settle both continents until much more recent times. It’s the final data in support of a single migration.”
Researchers usually agree that humans arrived in the Americas through Beringia—the area encompassing parts of present-day East Asia and North America, connected by what was the Bering Land Bridge. But the scientists must rely on inferences from both archaeological and genomic data to figure out how and when this migration occurred.
“These are only the ...