HUMAN EVOLUTION Vol. 8 - N. 4 (281-289) - 1993 B.M.E Galdikas J.B. Duffy H. Odwak C.M. Purss Department of Archaeology, Simon Fraser University, Burnab3; B.C., Canada, V5A 1S6 R Vasey Department d'Anthropologie, Universitd de Montreal, C.P. 6128, Succursale "A ", Montreal, Quebec, Canada, H3C M7 Key words: Hominids, Recognition Concept of Species, Specific Mate Recognition System, Postcrania. Postcrania and the specific mate recognition system The Recognition Concept of Species is examined for its potential usefnlness in discriminating speciation events in the hominid fossil record. Controversies over species-specific characteristics among Homo erectus and archaic Homo sapiens have centred on traits of the skull, largely because this element is most commonly preserved. Modern humans have an intuitive knowledge of their own Specific Mate Recognition System (SMRS), and therefore have the opportu- nity to compare their own SMRS to that of fossil hominids and the extant pongids. Such comparison suggests that our own skeletal SMRS may depend less on features of the skull than on the mor- phology of the postcranial anatomy. We propose that these compo- nents be further examined in this regard. We tentatively conclude that examination of the Recognition Concept of Species indicates that from late Homo erectus onwards, the same SMRS has been shared in common by all hominids, including modern Homo sapiens. This suggests that, following the SMRS criterion, none of these forms can be categorized as separate species. Introduction "An understanding of the nature of species is an indispensable prerequisite for the under- standing of the evolutionary process" (Mayr, 1970). The causal mechanism of speciation has recently been addressed at the theoretical level by Paterson (1976, 1980, 1981, 1982, 1985, 1986) under the rubric of the Recognition Concept of Species. The Concept's sine qua non for speciation is the breakdown of a taxon's fertilization signalling, termed the Specific Mate Recognition System (SMRS). According to this concept all members of a species are defined by a male-female co-adapted communication system evolved to facilitate fertilization through individual recogni- tion of potential mates. Extrapolation of the Recognition Concept to shed light on hominid speciation is facilitated by our intimate familiarity with our own SMRS. Our intuitive knowledge may give us some insight in discriminating speciation events in the hominid fossil record in a retrospective manner. In applying Paterson's hypothesis to the evolutionary record, we conclude that hominid postcrania deserve scrutiny for their SMRS traits. We also speculate on the possibility that our generalist behavioural repertoire mitigates against speciation events. Our intention in so doing is to open up the topic in the hope of stimulating further discussion. Paterson (1985), defines species as "the most inclusive population of individual biparental organisms which share a common fertilization system". He proposes that fertilization is a biologi- cal system of many components. The SMRS is considered to be a subset of adaptations involving