The discovery of Lucy toppled the theories of the established scientific community. Lucy was a small brained, bipedal hominid, this was contrary to the established theory that “brain enlargement came before bipedality” (Johanson 1981, pg. 181), that only large brain hominid had the ability to walk on two legs. To make the case for Lucy’s inclusion into the human family, Johanson traveled back to the US for further analysis of his findings. Johanson’s support for the Lucy’s relation to the human family laid primarily on her bipedal ability with the evidence of: Lucy’s knee joint; Lucy’s pelvis; and Mary Leakey’s Laetoli footprints.
