Paths of Human Migration

Scientists are now able to trace the routes taken by the ancestors of modern humans as they migrated out of Africa by tracking small changes in fossil DNA. The route maps are surprisingly complete - it almost seems as if prehistoric humans were walking on superhighways at super-slow speeds. In actual fact, they stopped and established colonies along the way, staying in one place for generations when conditions were right for human habitation. Modern humans finally reached South America roughly 40,000 years after their ancestors first left Africa - that's an average speed of less than 1/2 mile per year. The route took them across the Arabian peninsula, over Asia to Siberia, across a narrow land bridge to Alaska, and then south across North and Central America.

The techniques for tracing human migrations and the various routes taken are documented in “Traces of a Distant Past” (Scientific American, July 2008, pp. 56-63.) This would be a great paper to share with your students when you're discussing human evolution.