"Homo sapiens" has lived from about 250,000 years ago to the present. Between 400,000 years ago and the second warm period in the Middle Pleistocene, around 250,000 years ago, its skull grew and more sophisticated technologies based on stone tools developed. One possibility is that a transition between "H. erectus" to "H. sapiens" occurred. The evidence of Java Man suggests there was an initial migration of "H. erectus" out of Africa. Then, much later, a further development of "H. sapiens" from "H. erectus" in Africa. Then a subsequent migration within and out of Africa eventually replaced the earlier "H. erectus".