DNA from the 8,500-year-old skeleton of an adult man found in 1996, in Washington, is more closely related to Native American populations than to any other population in the world, according to an international collaborative study conducted by scientists at the University of Copenhagen and the Stanford University School of Medicine. The finding challenges a 2014 study that concluded, based on anatomical data, that Kennewick Man was more related to indigenous Japanese or Polynesian peoples than to Native Americans. The study is likely to reignite a long-standing legal dispute regarding the skeleton's provenance and its eventual fate.

"Using ancient DNA, we were able to show that Kennewick Man is more closely related to Native Americans than any other population," said postdoctoral scholar Morten Rasmussen, PhD. "Due to the massive controversy surrounding the origins of this sample, the ability to address this will be of interest to both scientists and tribal members."

Rasmussen is the lead author of the research, published online June 17 in Nature. The senior author of the study is Eske Willerslev, PhD, from the University of Copenhagen's Centre for GeoGenetics. Rasmussen initiated the study at the Centre for GeoGenetics and completed the analysis of the DNA sequences at Stanford, working with Carlos Bustamante, PhD, professor of genetics.

The skeleton, known as Kennewick Man, is called the Ancient One by Native American groups, which believe the bones are those of a long-ago ancestor. In 2004, five Native American tribes of the Pacific Northwest requested repatriation of the remains for reburial, but the proceedings were halted to allow further investigation into the skeleton's origins.