It seems like the boom corresponded to the doubled population. I agree with that. But why, then, would they stop burying their dead after the neanderthals left? I get that there would be fewer dead, with less population pressure. But surely some homo sapiens died during those thousands of years. Why weren't they buried? Could the various groups have been protecting their dead from the other species? And once there was only one species, there was no need to protect the dead? Or could the burial phenomenon be related to some other stress, such as disease, that required separating the dead more carefully, and with honor, to pacify them and keep them from attacking the living? Once that stressor was removed, the homo sapiens did not need burial to stay safe.