Out of Africa: The Genus part 1

Our species Homo sapien was not the only upright ape to develop in Africa, so far around 13 different species belonging to the genus Homo have been discovered (although this number is still debated). The characteristics which link them to one another are complex and would take up more space than this one post, I will therefore be mainly mentioning what is thought of as the key developments: an increasing brain size and a reduction in size of teeth. Bipedalism, which many people suggest was the biggest development in making us who we are today, was actually adopted by an even earlier ancestor 4 mya (million years ago) - Australopithicus.

Australopithecines were a genus of ‘upright apes’ and would have had a brain size similar to that of the Chimpanzee and teeth which were still much larger than our more recent ancestors due to their mainly vegetarian diet. They were living in eastern Africa until around 1.8 mya.

Next on the scene were Homo habilis 2.4 mya, this species is widely agreed to be the first true Homo and is notable for its increased brain size and a regular use of stone tools, there is also evidence of an increasing meat orientated diet, a change which would have helped boost brain size.

Homo ergaster was another important species to have developed, they were one of our direct ancestors and lived in southern and eastern Africa from 1.8 until 1.3 mya. They show modifications in gait which suggested a more upright posture and the development of running. This change would have allowed them to become more efficient hunters, extra resources which in my opinion could have boosted population numbers from an increase in numbers of offspring able to be supported. It has been put forward that H. ergaster may have migrated from Africa 1.75 million years ago, a topic hotly contested which will be discussed more fully in a later post.