A world of categones devmd of spirit waits for life to return. Saul Bellow, Humboldt's Gift The stock-in-trade of communicating hypotheses about the historical path of evolution is a graphical representation called a phylogenetic tree. In most such graphics, pairs of branches diverge from other branches, successively marching across abstract time toward the present. To each branch is tied a tag with a name, a binominal symbol that functions as does the name given to an individual human being. On phylogenetic trees the names symbolize species. What exactly do these names signify? What kind of information is communicated when we claim to have knowledge of the following types? "Tetonius mathewzi was ancestral to Pseudotetonius ambiguus. " "The sample of fossils attributed to Homo habzlis is too variable to contain only one species. " "Interbreeding populations of savanna baboons all belong to Papio anubis. " "Hylobates lar and H. pileatus interbreed in zones of geographic overlap. " Whilethere is nearly universal agreement that the notion of the speczes is fundamental to our understanding of how evolution works, there is a very wide range of opinion on the conceptual content and meaning of such particular statements regarding species. This is because, oddly enough, evolutionary biolo­ gists are quite far from agreement on what a species is, how it attains this status, and what role it plays in evolution over the long term.

Springer Book Archives

What, If Anything, Is a Species; N. Eldridge. Species Concepts; F.S. Szalay. Primates and Paradigms; J. Masters. Species, Subspecies, and Baboon Systematics; C.J. Jolly. Speciation in Living Hominoid Primates; C.P. Groves. Geographic Variation in Primates; G.H. Albrecht, J.M.A. Miller. Speciation and Morphological Differentiation in the Genus Lemur; I. Tattersall. Squirrel Monkey; (Genus Saimiri) Taxonomy; R.K. Costello, et al. Measures of Dental Variation as Indicators of Multiple Taxa in Samples of Sypatric Cercopithecus Species; D.A. Cope. Catarrhine Dental Variability and Species Recognition in the Fossil Record; J.M. Plavcan. Multivariate Craniometric Variation in Chimpanzees; B.T. Shea, et al. Species Concepts and Species Recognition in Eocene Primates; K.D. Rose, T.M. Brown. Anagenetic Angst; L. Krishtalka. Cladistic Concepts and the Species Problem in Hominoid Evolution; T. Harrison. 7 additional articles. Index.