What was Lucy’s impact on our understanding of other australopith relatives?

Session Date: 
Apr 6, 2024

This talk begins by considering what the fossil and molecular evidence for early hominin evolution looked like in 1974, when conventional wisdom suggested that what were then called hominids and pongids had a relatively ancient divergence. It also predated the acquisition of the most compelling evidence that chimpanzees and bonobos were more closely-related to modern humans than to gorillas. The talk considers separately the impact of Lucy and the impact of Lucy’s ilk (i.e., the impressive hypodigm of Australopithecus afarensis). In 1974, aside from the relatively fragmentary and poorly preserved associated skeletons of Australopithecus africanus, little to nothing was known about the body size and limb proportions of the creatures that linked later hominins with what we now know would have been the common ancestor of hominins and panins. Lucy provides exceptional information about an individual early hominin, but it is the quantity, quality, and temporal resolution of the overall hypodigm of A. afarensis—Lucy’s ilk—that has helped put the other australopiths recovered from sites in southern and eastern in sharper context. Lucy’s ilk sheds light on important topics such as taxic diversity, phylogenetic relationships, and the tempo and mode of evolution within the hominin clade. It is, in many ways, the key that has the potential to unlock the secrets of hominin evolutionary history that both preceded, and came after, A. afarensis.