Ontogeny and homoplasy in the papionin monkey face

Citation
M. Collard et Po. O'Higgins, Ontogeny and homoplasy in the papionin monkey face, EVOL DEV, 3(5), 2001, pp. 322-331
Citations number
70
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biology,"Experimental Biology
Journal title
EVOLUTION & DEVELOPMENT
ISSN journal
1520-541X → ACNP
Volume
3
Issue
5
Year of publication
2001
Pages
322 - 331
Database
ISI
SICI code
1520-541X(200109/10)3:5<322:OAHITP>2.0.ZU;2-8
Abstract
Recent molecular research has provided a consistent estimate of phylogeny f or the living papionin monkeys (Cercocebus, Lophocebus, Macaca, Mandrillus, Papio, and Theropithecus). This phylogeny differs from morphological phylo genies regarding the relationships of the mangabeys (Cercocebus and Lophoce bus) and baboons (Mandrillus, Papio, and Theropithecus). Under the likely a ssumption that the molecular estimate is correct, the incongruence between the molecular and morphological data sets indicates that the latter include numerous homoplasies. Knowledge of how these homoplasies emerge through de velopment is important for understanding the morphological evolution of the living papionins, and also for reconstructing the phylogenetic relationshi ps and adaptations of their fossil relatives. Accordingly, we have used geo metric morphometric techniques and the molecular phylogeny to investigate t he ontogeny of a key area of morphological homoplasy in papionins, the face . Two analyses were carried out. The first compared allometric vectors of C ercocebus, Lophocebus, Macaca, Mandrillus, and Papio to determine which of the facial resemblances among the genera are homoplasic and which are plesi omorphic. The second analysis focused on early post-natal facial form in or der to establish whether the facial homoplasies exhibited by the adult papi onins are to some degree present early in the post-natal period or whether they develop only later in ontogeny. The results of our analyses go some wa y to resolving the debate over which papionin genera display homoplasic fac ial similarities. They strongly suggest that the homoplasic facial similari ties are exhibited by Mandrillus and Papio and not by Cercocebus and Lophoc ebus, which share the putative primitive state with Macaca. Our results als o indicate that Mandrillus and Papio achieve their homoplasic similarities in facial form not through simple extension of the ancestral allometric tra jectory but through a combination of an extension of allometry into larger size ranges and a change in direction of allometry away from the ancestral trajectory. Thus, the face of Mandrillus is not simply a hypermorphic versi on of the face of its sister taxon, Cercocebus, and the face of Papio is no t merely a scaled-up version of the face of its sister taxon, Lophocebus, L astly, our results show that facial homoplasy is not restricted to adult pa pionins; it is also manifest in infant and juvenile papionins. This suggest s that the homoplasic facial similarities between Mandrillus and Papio are unlikely to be a result of sexual selection.