Mysterious MigrationsOur prehistoric ancestors journeyed out of Africa on contested roads Bruce Bower It was the most momentous immigration ever, a population realignment that marked a startling departure for our species, Homo sapiens. After emerging in eastern Africa close to 200,000 years ago, anatomically modern people stayed on one continent for roughly 140,000 years before spreading out in force around the world. Then, from 40,000 to 35,000 years ago, our forerunners advanced into areas stretching from what is now France to southeastern Asia and Australia. DIGGING THE PAST. Workers excavate deep into a site near the Russian village of Kostenki,...