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Ontogeny and phylogeny in papionin primates
Steven R Leigh1, Natasha F Shah, Laurel S Buchanan
1Department of Anthropology, 109 Davenport Hall, University of Illinois, Urbana, IL 61801, USA. sleigh@uiuc.edu
Journal of Human Evolution
|October 31, 2003
Summary
Papionin primate cranial diversity is explained by developmental changes in growth timing and rate. Larger species like Papio exhibit peramorphic development, driven by heterochrony, influencing skull shape and size.
Area of Science:
- Evolutionary biology
- Developmental biology
- Primate paleontology
Background:
- Papionin primates (Macaca, Cercocebus, Mandrillus, Lophocebus, and Papio) exhibit significant cranial size and shape variation.
- Understanding the developmental mechanisms underlying this diversity is crucial for evolutionary studies.
Purpose of the Study:
- To investigate the developmental bases of cranial size and shape variation in papionin primates.
- To test hypotheses that heterochronic changes in ontogeny explain cranial diversity and allometric scaling.
Main Methods:
- Analysis of large developmental samples of extant papionin crania.
- Application of bivariate allometric methods to test heterochronic hypotheses.
Main Results:
- Larger papionins (Mandrillus, Papio) display peramorphic cranial development, exceeding the size and shape ranges of smaller species.
- Heterochronic processes, including acceleration and hypermorphosis, contribute to observed patterns.
- Cranial region growth decoupling and size shifts characterize ontogenetic changes.
- Allometric scaling has complex developmental underpinnings, with size changes being critical for facial comparisons.
Conclusions:
- Papio exhibits derived brain growth patterns influencing postnatal cranial size and shape.
- These derived growth patterns may result from early ontogeny selection, leading to unique life history traits.