In the spring of 2006, a team of divers descended into the turquoise waters of the Red Sea, just offshore of one of the limestone islands in the Farasan Islands archipelago. Outfitted with cameras, measuring tapes and special deep-sea scuba gear, the team wasn’t there to admire the colorful corals or vibrant fish that attract most divers to the island chain located 40 kilometers off Saudi Arabia’s southwestern coastline. Instead, they were searching for a rare treasure: submerged traces of our ancestors’ journey out of Africa.
The human fossil record and studies of human genetic diversity agree on the origins of our species: Sometime nearly 200,000 years ago, Homo sapiens emerged in Africa. Then, by 50,000 years ago, a group of these modern humans ventured from their African homeland into the unknown. Descendants of these early explorers eventually made their way across the entire globe, yet the oldest-known successful human population outside of Africa comes from an unlikely place — Australia, where human fossils show our ancestors reached the island continent by at least 45,000 years ago. This fossil evidence and studies of genetics together suggest that humans headed to India and the isolated islands of the Indian Ocean before migrating into Europe or northern Asia tens of thousands of years later. The exact route these early humans used to leave Africa, however, is debated.