Ancient genomes show social and reproductive behavior of early Upper Paleolithic foragers

Present-day hunter-gatherers live in multilevel social groups essential to sustain a population structure characterized by limited levels of within-band relatedness and inbreeding. When these wider social networks evolved among hunter-gatherers is contentious. We test if the contemporary hunter-gatherer strategy is a later rather than a basal adaptation of anatomically modern humans (AMH) in Upper Paleolithic (UP) sites containing multiple contemporary AMH individuals, dated to ~34 thousand years BP (kya). Complete genome sequences demonstrate that these derive from a population of small effective size with limited kinship and inbreeding. Our findings reveal that UP social organization was similar to that of living hunter-gatherers, with limited relatedness within residential groups embedded in a larger mating network