Genomic Insights into Cold Adaptation and Demographic History of Amur-Heilong River Basin Populations

Human adaptation to extreme cold has been studied predominantly in Arctic populations, leaving the genetic basis of cold resilience in non-Arctic high-latitude regions insufficiently understood. The Amur-Heilong River Basin (AR) in Northeast Asia represents one of the coldest inhabited regions in East Asia, yet its long-term resident populations remain underexplored at the genomic level. Here, we compiled high-coverage whole-genome sequences for 78 individuals representing three indigenous AR populations (Daur, Evenki, and Oroqen) to investigate their demographic history and genetic adaptation to cold environments. Population genomic analyses revealed distinct ancestral compositions, with Evenki and Oroqen showing closer genetic ties to Siberian populations, while Daur exhibited greater admixture with northern East Asians. Demographic reconstructions identified shared and prolonged bottlenecks across AR populations between ∼ 10,000 and 3000 years ago. Genome-wide selection scans uncovered candidate loci associated with cold adaptation, including SORBS2, PRKAG2, KCNMA1, PRKG1, NTM, CHST11, OCA2, RYR3, OTOA, and PKIG, many showing strong correlations between allele frequency and cold-related climatic variables. Notably, a Neanderthal-derived allele at CHST11 (rs11112181) likely contributed to cold-adaptive variation. Functional enrichment analyses suggest that cold adaptation in AR populations may preferentially involve neuro-sensory regulation and tissue integrity, rather than the classical metabolic thermogenesis pathways emphasized in Arctic populations. Integrating population history, selection signals, and archaic introgression, our results indicate that cold resilience in the AR reflects a composite of ancestral adaptation, demographic processes, and limited archaic contributions. These findings expand current understanding of human cold adaptation beyond the Arctic and highlight alternative evolutionary strategies in extreme environments.