Pygmies and the bushmen of Africa are the most genetically diverse people on Earth. For some genetic traits they have as many as 17 variations, where the rest of the peoples of Earth have only two or three. A possible explanation is that our oldest ancestors came from these regions, perhaps 200,000 years ago, and that not all of them left to spread around the world. Therefore the pygmies and bushmen represent the survivors of the original human population.