Climate Conditions Facilitated Ancient Human Interbreeding

Scientists argue that the intermingling of DNA between ancient human species, Denisovans and Neanderthals, was influenced by favorable climate conditions rather than just attraction. The presence of Neanderthal and Denisovan DNA in modern humans suggests that interbreeding occurred between these species and Homo sapiens. This finding challenges the notion that interspecies sex was uncommon among early humans.