2007/04/10 by Yoel Rak, Avishag Ginzburg, Eli Geffen · 2 citations
Social Sciences · Psychology · Earth and Planetary Sciences · #Pleistocene-Era Hominins and Archaeology #Primate Behavior and Ecology #Evolution and Paleontology Studies #Morphology (biology) #Gorilla #Bipedalism #Australopithecus #Hominidae #Biology #Evolutionary biology #Anatomy #Human evolution #Phylogenetic tree #Biological evolution #Zoology #Paleontology #Gene #Genetics
paper · doi:10.1073/pnas.0606454104
openalex publication_date 2007/04/10 · openalex created_date 2016/06/24 · openalex updated_date 2026/06/11
Mandibular ramus morphology on a recently discovered specimen of Australopithecus afarensis closely matches that of gorillas. This finding was unexpected given that chimpanzees are the closest living relatives of humans. Because modern humans, chimpanzees, orangutans, and many other primates share a ramal morphology that differs from that of gorillas, the gorilla anatomy must represent a unique condition, and its appearance in fossil hominins must represent an independently derived morphology. This particular morphology appears also in Australopithecus robustus. The presence of the morphology in both the latter and Au. afarensis and its absence in modern humans cast doubt on the role of Au. afarensis as a modern human ancestor. The ramal anatomy of the earlier Ardipithecus ramidus is virtually that of a chimpanzee, corroborating the proposed phylogenetic scenario.