Pritzker Lecture: 'Lucy and Selam' Climbed Trees, So What?!

Lucy and Selam are famous skeletons that belong to Australopithecus afarensis, a direct ancestor of humans that lived between 4 and 3 million years ago. When the Lucy skeleton was discovered in 1974, it helped establish that this creature was an upright walking species pushing the then accepted date for bipedalism by a million years. Lucy's foot, the knee and pelvis are all very human-like. However, the upper body told a different story. The features were much more ape-like, including long arms, curved fingers. At the time, scientists split into two groups. One group argued, Yes, A. afarensis has ape-like features, but the species didn't need them for survival, it's just ancestral retention or evolutionary baggage.  The second group interpreted the ape-like characters for their function: they saw the lower body for bipedalism and the upper body for climbing.  This discussion went on for the following 35 years. In this presentation Alemseged discusses the evidence for climbing behavior in A. afarensis based on new evidence coming from his own find "Selam", currently the most complete and earliest skeleton of a juvenile human ancestor.

Speaker: Zeray Alemseged, Irvine Chair of Anthropology