In order to understand fully Plio-Pleistocene hominid migrations, a whole gamut of interacting factors must be examined. It has been hypothesised that the most important variables affecting hominid migrations out of Africa would have been environmental, since in most respects hominids would have acted in the same manner as any other large land mammal of the time. For this work, therefore, as far as language barriers permitted, as many published sources as could be traced from palynological and palaeontological sites from the Late Pliocene and Early Pleistocene within east and northern Africa...