Where River Meets Sea

Recent genetic research suggests an expansion along the tropical coastline of the Indian Ocean, between 75,000 and 60,000 years ago, of the population which included the ancestors of all of the non‐African human mitochondrial DNA lineages known today. In view of the arid sections along this coastal stretch, irregularly punctuated by resource‐rich estuaries, and the crossings over open sea during the last leg to Australia/New Guinea, this expansion would necessarily have involved the features of watercraft, portage of potable water, and adaptation to estuaries. These features could well have been the cultural basis for the rapid tropical dispersal of Homo sapiens out of Africa to Australia/New Guinea.