EAPSI:Discerning human from non-human great ape in the southern Chinese fossil dental record

Avalos Toby, Iowa City IA

Investigators

Abstract

A handful of scientists consider a collection of two million year old fossil teeth from China to be the earliest evidence for humans outside of Africa. However, many scientists disagree, believing instead that humans left Africa around 1.5 million years ago, and consider this collection of teeth to belong to extinct orangutans. This research, conducted in collaboration with Dr. Changzhu Jin from the Chinese Academy of Sciences (CAS), applies state of the art statistical methods, called geomorphometrics, to assess whether these teeth are in fact human or ape. Dr. Jin has been involved with the excavation of many of these fossils firsthand and is China?s authority on extinct apes. After photographs of tooth surfaces are taken, the positioning of their shared features relative to one another is recorded, providing distance data between specimens. The group with which they cluster more closely will determine whether they belong to living or extinct humans or orangutans. If these teeth are confirmed to be human, the research will provide evidence that the earliest remains for humans outside of Africa are not only found in China, but also half a million years older than previously thought. Recent publications posit evidence for early humans in southern China two million years ago based on disassociated fossil dentition. Such controversial taxonomic assignments have resulted from an overreliance on simple linear tooth crown measurements and traditional qualitative analysis. The results of these types of studies often produce dental dimensions that overlap with early African hominins. To determine a more precise phylogeny for these specimens, a geomorphometric analyses on 2-D digital photographs of the occlusal surfaces of posterior dentition attributed to the following hominid taxa will be performed: Lufengpithecus, extinct Pongo, Hominoid indeterminate, Hominin indeterminate, H. erectus, and teeth historically assigned to Chinese early Homo or Australopithecus; all housed at the CAS, Beijing. This NSF EAPSI award is funded in collaboration with the Ministry of Science and Technology of China.