Friday, 07 March, 2014
Bipedal locomotion defines hominins better than any other single behavioral or biological characteristic. There is evidence for some form of bipedality in the hominin fossil record as far back as 6-7 million years ago, but bipedalism may not have reached its modern form until much later, 1.5-2 million years ago, with the evolution of Homo erectus.
Interpreting the often mosaic changes in skeletal structure associated with this transition is made more difficult, however, by incomplete understanding of the functional significance of morphological variation, and the lack of modern-day analogues for early hominins. Both issues are addressed here, by examining structural characteristics of fossils that are directly related to behavior during life, and variation in morphology within a closely related group of modern primates (gorillas) who exhibit subtle differences in behavior and ecology. The use of ontogenetic models as "natural experiments" to investigate form-function relationships is also explored, again using gorillas as a model.