The Ancient Beringian (AB) is a human archaeogenetic lineage, based on the genome of an infant found at the Upward Sun River site (dubbed USR1), dated to 11,500 years ago.
The modern Athabaskan populations are derived from an admixture of this NNA back-migration and a Paleo-Siberian (Early Paleo-Eskimo) lineage before about 2,500 years ago.
[5] The discovery was made from archaeogenetic analyses on the remains of two female infants discovered in 2013 at the Upward Sun River site (USR).
The genomic analysis of nuclear DNA of the older of the two infants (USR1) was done at the Centre for Geogenetics at the University of Copenhagen's Natural History Museum of Denmark.
The "Ancient Beringian" (AB) lineage derived from ANA and persisted without significant admixture in Alaska until the time of USR1, some 8,000 years later.