A proper study for mankind: Analogies from the Papionin monkeys and their implications for human evolution

• Published in: American journal of physical anthropology 2001, Vol.116 (S33), p.177-204
• Main Author: Jolly, Clifford J.
• Format: Article
• Language: English
• Subjects: Animals; Anthropology; Anthropology, Physical - trends; baboons; Biological Evolution; Ecology; Evolution; evolutionary analogies; Genetic Variation; Hominidae - physiology; Hominids; hominins; human evolution; Human paleontology; Humans; Mankind origin and evolution; Methodology and general studies; Models, Theoretical; Monkeys & apes; Papio - physiology; Papionini; Phylogeny; Physiology, Comparative; Prehistory and protohistory
• ISSN: 0002-9483; 0096-848X; 1096-8644; 2331-1371
• DOI: 10.1002/ajpa.10021

This paper's theme is that analogies drawn from the cercopithecine tribe Papionini, especially the African subtribe Papionina (baboons, mangabeys, and mandrills), can be a valuable source of insights about the evolution of the human tribe, Hominini, to complement homologies found in extant humans and/or African apes. Analogies, involving a “likeness of relations” of the form “A is to B, as X is to Y,” can be usefully derived from nonhomologous (homoplastic) resemblances in morphology, behavior, ecology, or population structure. Pragmatically, the papionins are a fruitful source of analogies for hominins because they are phylogenetically close enough to share many basic attributes by homology, yet far enough that homoplastic modifications of these features are easily recognized as such. In “The Seedeaters,” an analogy between Theropithecus among baboons and Australopithecus africanus among hominines was the source of a widely discussed (and often misrepresented) diet‐based scenario of hominin origins that explained previously unassociated hominin apomorphies, interpreted basal hominins as nonhuman rather than prehuman primates, and accommodated a basal hominin adaptive radiation of at least two lines. Current usage recognizes an even more extensive evolutionary radiation among the basal hominins, originating no earlier than about 7 ma, with multiple lineages documented or inferred by 2.5 ma. Although multilineage clades (especially the Paranthropus clade) within this complex are widely recognized, and emerge from sophisticated, parsimony‐based analyses, it is suspected that in many cases, developmental or functional homoplasies are overwhelming the phylogenetic signal in the data. The papionin analogy (specifically the splitting of the traditional, morphology‐based genera Cercocebus and Papio mandated by molecular evidence) illustrates the power of these factors to produce erroneous cladograms. Moreover, the rapid deployment of basal hominins across varied African habitats was an ideal scenario for producing morphologically undetectable homoplasy. There seems to be no foolproof way to distinguish, a priori, homologous from homoplastic resemblances in morphology, but one pragmatic strategy is to severely censor the datset, retaining only resemblances or differences (often apparently trivial ones) that cannot be reasonably explained on the basis of functional resemblance or difference, respectively. This strategy may eliminate most morpological data, and leav