BIO342H5 Lecture Notes - Lecture 22: Melanesians, Multiregional Origin Of Modern Humans, Nuclear Dna
Document Summary
Four synapomorphies that make hominids different from other great apes: we started to walk on 2 legs, our brains got very big, we lost our hair, we started to use tools. 3 hypotheses for the origin of h. sapiens: multiregional model, african replacement model, leaky replacement model. Multiregional model: h. erectus migrated out of africa ca. 2 million years ago: diverging populations hybridized giving rise to h. sapiens. African replacement model: h. sapiens migrated out of africa 40-60 thousand years ago, replacing h. neanderthalensis and perhaps also h. erectus without hybridization. Evidence: ancient homo spp. dispersed out of african ca. Note: so far data suggests hypothesis 2, but. A new human population: siberian ancient humans were genetically distinct from european neandrethal (called. Denisovans), but perhaps their sister population: sequenced denisovan genome and compared with humans around the world, modern melanesians (e. g. papua new guinea) derive as much as 7. 4% (average 4-6%) of their dna from denisovans.
