human prehistory: out of (eastern) africa

For tens of thousands of years, Homo sapiens lived throughout Africa. By 60,000 years ago, they had expanded into nearly every corner of the continent. As their descendants moved into new environments they became more isolated from one another, setting the stage for the high level of genetic diversity we see in Africa today.

During this time people also started to make more sophisticated tools, and soon after began creating art. Did new language abilities spark this burst of innovation? A genetic change in the population could have allowed some people to express more complex concepts through language, out-competing those who could not.

Around 50,000 years ago, a small group of travelers crossed into Asia - possibly as few as a hundred. Everyone alive today who has any non-African ancestors is probably descended from this group.

The intrepid travelers and some of their descendants followed a coastal route along the Indian Ocean, reaching present day Malaysia within a few millennia. Along the way, they might have come in contact with other hominids such as Homo erectus, a cousin of ours who had been living in Asia for hundreds of thousands of years. By 45,000 years ago, people had reached parts of present day Australia. This is an amazing feat, considering they had to cross nearly 60 miles of open water just to get there.

As humans moved into Europe, they faced cold climates and tough terrain. They also ran into Neanderthals, our short, stocky relatives who had been living there for over half a million years. Though the Neanderthals may have acquired some of their new neighbors' advanced technologies, they soon found it hard to keep up. By 35,000 years ago, Neanderthals were confined to the southwest corner of Europe. Soon after, they had disappeared.