60,000 years ago, our ancestors left Africa. After about 50,000 years, our behavior changed completely. We started to make art, music, and we started to found culture. The oldest rock art ever found was found by a scientist named Randy White. At 34,000 years old, this was quite a discovery. The art may have been made to teach future generations about themselves (which it did, 34,000 years later). Another possibility was that it was used to mark territories. Scientist Richard Klein believes that there was a big change in brain capacity of the modern human. He says, however, that it was not just one immediate change, but a series of small mutations that added up to a large result. This change constitutes what we are today.