Interbreeding between archaic and modern humans

There is evidence for interbreeding between archaic and modern humans during the Middle Paleolithic and early Upper Paleolithic. The interbreeding happened in several independent events that included Neanderthals and Denisovans, as well as several unidentified hominins. In Eurasia, interbreeding between Neanderthals and Denisovans with modern humans took place several times. The introgression events into modern humans are estimated to have happened about 47,000–65,000 years ago with Neanderthals and about 44,000–54,000 years ago with Denisovans. Neanderthal-derived DNA has been found in the genomes of most or possibly all contemporary populations, varying noticeably by region. It accounts for 1–4% of modern genomes for people outside Sub-Saharan Africa, although estimates vary, and either none or possibly up to 0.3% — according to recent research — for those in Africa. It is highest in East Asians, intermediate in Europeans, and lower in Southeast Asians. According to some research, it is also lower in Melanesians compared to both East Asians and Europeans. However, other research finds higher Neanderthal admixture in Melanesians, as well as in Native Americans, than in Europeans (though not higher than in East Asians). Denisovan-derived ancestry is largely absent from modern populations in Africa and Western Eurasia. The highest rates, by far, of Denisovan admixture have been found in Oceanian and some Southeast Asian populations. An estimated 4–6% of the genome of modern Melanesians is derived from Denisovans, but the highest amounts detected thus far are found in the Negrito populations of the Philippines. While some Southeast Asian Negrito populations carry Denisovan admixture, others have none, such as the Andamanese. In addition, low traces of Denisovan-derived ancestry have been found in mainland Asia, with an elevated Denisovan ancestry in South Asian populations compared to other mainland populations. In Africa, archaic alleles consistent with several independent admixture events in the subcontinent have been found.