Migration et prehistoire

Human migration has been occurring for at least 2 million years, both within and beyond the African homeland, and humans have become the world's most dominant and universal mammalian species. Our patterns of biological and cultural diversity exist in large part due to this remarkable human ability to migrate into and through all landscapes capable of sustaining life, as well as across sea. However, while migration has been a continuous activity throughout human prehistory, it has also been cyclical in its intensity and significance. There have been periods in the past when concentrated bouts of migration, especially into new and previously uninhabited landscapes, have determined major segments of subsequent human history. Here I focus on 3 such fundamental phases of hominin/human expansion. The first involved the archaic hominins[1] who migrated out of Africa to settle previously uninhabited Eurasia around 21.5 million years ago, ultimately reaching Java and Flores in Indonesia, the latter presumably by crossing sea. The second involved the ancestors of all modern living humans (Homo sapiens), who migrated out of Africa during the Late Pleistocene, perhaps initially around 100,000 years ago into the previously inhabited Levant, but much later into the colder northern latitudes of Eurasia. Modern humans reached the uninhabited continents of Australia about 50,000 years ago and the Americas about 16,000 years ago. The third and most recent episode involved the migrations of farmers and the ancestral speakers of many of the world's largest modern language families, consequent upon the several developments of food production and improved technology (e.g. in boat construction) during the Holocene, after 11,500 years ago. These food producer migrations mostly took place into territories occupied previously by hunters and gatherers, but this phase also saw the colonization of many of the major uninhabited islands of the world, previously unreachable without boats