When the researchers compared MA-1’s autosomal genome against a large panel of modern and ancient human populations, they found something that no model of Native American ancestry had clearly predicted.

MA-1 showed a specific and statistically significant genetic relationship to modern Native American populations.

The genome of a 24,000-year-old boy from south-central Siberia was more closely related to the genomes of contemporary Native Americans than to the genomes of contemporary East Asians.

At the same time, MA-1 also showed genetic relatedness to some western Eurasian populations — a relationship that did not appear in modern Native American genomes at the same level.

The interpretation the researchers offered was this: MA-1 represented a population that contributed material ancestry to the founding population of the Americas, but that was not the same as the East Asian populations also represented in Native American ancestry.