Evolution of H. sapiens and Species of Genus Homo: Genetic Effects of Warfare

Ancient DNA Genomics has recently provided evidence for more than ten admixture/hybridization events within and among the three Homo species: Sapiens, Neandertals, and Denisovans, including those that, in our opinion, give rise to them as distinct species. We explore the idea that all admixtures were adversarial, governed by two behavioral instincts carried by all Homo species: group violence and constant migration. If genetically based, these instinctive behaviors of the genus Homo may explain why Homo survived as a biological lineage, while all other hominin branches perished. An evolutionary biology consideration shows how the “Rape of Sabines” instinct shared with the Pan and Homo ancestors is transformed into a hunter-gatherer predatory lifestyle in Homo. This drive progressed from Habilis to Erectus and culminated in Sapiens as the overarching planetary apex predator. The genetic mechanism in Homo species, invariably consisting of isolated tribes, ensures that warfare is the response to every intertribal encounter, resulting in minority DNA from kidnapped females being incorporated through mating into the genomes of subsequent generations of victorious tribes, populations, and species. This process allows the genetic/phenotypic gains of victims to be used as a selective advantage for future generations, instead of being lost like their lives. Warfare and ensuing gene flow between Sapiens and its minority parent, Archaics, happened for 100000 years in Africa, from Sapiens' origin to its conquest of Eurasia. This explains the patchy and puzzling paleoanthropological and archaeological record for that period. Our synthesis of the genomic history of the three Homo species covers about 800 kya and ends no later than 30 kya. After this point, biological rules no longer governed human history. Since 20kya, our species has shown the ability to create civilizations, managing the violent and migratory instincts of individuals, groups, and peoples at the cultural level.