  The Kets, an ethnic group in the Yenisei River basin, Russia, are considered
the last nomadic hunter-gatherers of Siberia, and Ket language has no
transparent affiliation with any language family. We investigated connections
between the Kets and Siberian and North American populations, with emphasis on
the Mal'ta and Paleo-Eskimo ancient genomes using original data from 46
unrelated samples of Kets and 42 samples of their neighboring ethnic groups
(Uralic-speaking Nganasans, Enets, and Selkups). We genotyped over 130,000
autosomal SNPs, determined mitochondrial and Y-chromosomal haplogroups, and
performed high-coverage genome sequencing of two Ket individuals. We
established that the Kets belong to the cluster of Siberian populations related
to Paleo-Eskimos. Unlike other members of this cluster (Nganasans, Ulchi,
Yukaghirs, and Evens), Kets and closely related Selkups have a high degree of
Mal'ta ancestry. Implications of these findings for the linguistic hypothesis
uniting Ket and Na-Dene languages into a language macrofamily are discussed.
