Jade Finnecy 4th October 2012
The Evolution of Man

In his 1871 book entitled The Descent of Man, and Selection in Relation to Sex, Charles Darwin speculated that fossils of the earliest humans and their immediate progenitors ultimately would be found somewhere in Africa. He based this on the fact that the natural range of our nearest living relatives, chimpanzees and gorillas, is limited to Africa. He concluded that we ultimately must have shared a now extinct common ancestor with those apes in Africa. This view was mostly rejected by the scientific world of the time (http://anthro.palomar.edu/hominid/australo_1.htm). It would be some 50 years and the unearthing of Australopithicus africanus in 1924, before advances would be made in understanding our ancestors.

In 1974 an exciting discovery was made in the finding of ‘Lucy’ (Australopithecus afarensis) by Professor Johanson and his student Gray in northern Ethiopia. We discovered the most complete specimen of A afarensis ever found (Boyle and Senior 2008). They are one of the first of our ancestors to stand and walk upright on two legs, this is referred to as ‘bipedalism’. It is believed that A aferensis would not have walked straight legged as we do, though are more likely to have walked with bent knees and hips, not unlike chimps.
Diagram sourced from http://humanorigins.si.edu
Diagram sourced from http://humanorigins.si.edu A aferensis, is dated around 3.2million years ago, it was 5 million years prior to this, that there was huge ecological changes. The dense rain forest that covered the majority of Africa began to die and the land began to dry out leaving only a scattering of trees and grasses. At this point it became more energy efficient for A aferensis to walk upright and would also allow females to