Out of Africa, but When?

Writing for IO9, Annalee Newitz summarizes a recent discussion at New Scientist about when people first migrated out of Africa. Catherine Brahic writes:

A closer look at the genetics also suggests there was an earlier migration. Recently, Katerina Harvati of the University of Tubingen in Germany and her colleagues tested the classic “out of Africa at 60,000 years ago” story against the earlier-exodus idea. They plugged the genomes of indigenous populations from south-east Asia into a migration model. They found that the genetic data was best explained by an early exodus that left Africa around 130,000 years ago, taking a coastal route along the Arabian peninsula, India and into Australia, followed by a later wave along the classic route.

We’re all Africans ultimately; the question is how far back did our various ancestors leave Africa?