What type of characteristic feature you will be looking for in order to called it Homo? So, let’s define the genus .
We all belong to the genus Homo. Genus Homo is characterized by having
- enlarged brain case compared to Australopithecine group.
- a less projecting and flat face with reduced teeth and jaw size.
- Their body size was large and they were perfectly biped, meaning striding bipedalism.
- a shift to a more animal based diet
- dependence on manufacturing and use of stone tools and technology for gathering and processing food instead.
- However, earlier members of Homo were less different from the Australopithecines as compared to later members, making it difficult to distinguish between them. Hence, the first Homo is not much different from some of the Australopithecines at all.
Plio-Pleistocene climatic condition favorable for evolution of Homo
Shifting from Australopithecine to Homo implies some set of adaptive strategy which was compelled by the changing climatic condition. So, we need to have some idea about the climatic condition during the time when the first Homo appeared. The first species of Homo appeared around 2.5 million year ago, say in late Pliocene and early Pleistocene. This period coincided with greatest climatic variability.
Ice sheets became permanent features at North and South Pole during the early Pliocene. Cyclic glaciations began about 3 million year ago and became increasingly intensed throughout the Pleistocene. The glaciations became so severe that it lowered the sea levels enough to connect Islands of Southeast Asia to mainland Asia for the first time. This phenomenon is important because Homo started to move out of Africa. This severity in climate may also be the reason for enlargement in brain size and increased intelligence among Homo. Adapting to such hazardous environment may have honed human intelligence (Potts, 1996).