Child’s genes shed new light on first Americans

A BABY girl who died in Alaska about 11 500 years ago belonged to a formerly unknown population group whose discovery has shed light on the peopling of the Americas, a study of her genome has revealed.

By decoding the child’s genetic fingerprint, scientists could look back on the history of the first people to conquer the New World, and conclude that they likely arrived from Siberia 20 000 years ago.

Researcher Ben Potter, of the University of Alaska, said: “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 and a team analysed the DNA of an infant whose remains were unearthed at the Upward Sun River archaeological site in Alaska in 2013.

She was named Xach’itee’aanenh T’eede Gaay (Sunrise Girlchild) by the indigenous community, and her genome provided an unprecedented window into the history of her people, Potter said.

The team had expected the girl’s genetic profile to match that of known Native American groups.

Instead, it showed she belonged to a completely new group, which they named Ancient Beringians.

Critically, the girl’s genome also revealed the identity of a common ancestor her people shared with Native Americans.

This common forebear, or source population, which the team dubbed Ancestral Native Americans, emerged some 36 000 years ago in Siberia, splitting from East Asians.

What is still not sure is whether the common ancestor group was the first to make the crossing, splitting only afterwards, or whether the Beringians and their cousins’ group made the journey to America together. – AFP