During the Middle Paleolithic, it was the cooling of the climate associated with the last glacial advance that forced the Neanderthals to abandon their original territories in Europe and Asia and move southward. Their movement into the Levant was no tentative exploration of a new region, but part of an ongoing mass migration sparked by abrupt climate change. Under the circumstances, there no logical reason to assume Neanderthal migrants would have stopped their advance in the Levant, not when more warm and fertile territories still lay ahead.