Homo erectus features used in cladistics and their variability in Asian and African hominids

Abstract

This paper focuses on morphological features which are suggested to be uniquely derived character states for East AsianHomo erectus. The assumed restricted occurrence of these features led to the far-reaching conclusion that AsianH. erectus might represent a different species from the African hominids generally attributed to it. In order to demonstrate whether these traits are in fact largely restricted to Asianerectus, we studied most of the African and Asianerectus fossils and representatives ofHomo habilis, Australopithecus africanus, and archaicHomo sapiens. To further contribute to the current assessment of these features, this study includes a large sample and variety of hominids, examines the extant variation of the character states and critically evaluates the definition of each characteristic. Our results show that a continuous variation can be assumed for all of the features studied and that simple determinations as discrete character states might lead to rather artificial lists of presence or absence. Moreover, it is shown that all of these features also occur in the African specimens attributed toerectus, and most of them even inH. habilis andA. africanus as well as in African and Asian archaicH. sapiens. Therefore, it appears rather unlikely that these features can continue to be considered as Asianerectus autapomorphies.