Additive genetic variation in the craniofacial skeleton of baboons (genus Papio) and its relationship to body and cranial size.

TitleAdditive genetic variation in the craniofacial skeleton of baboons (genus Papio) and its relationship to body and cranial size.
Publication TypeJournal Article
Year of Publication2018
AuthorsJoganic, JL, Willmore, KE, Richtsmeier, JT, Weiss, KM, Mahaney, MC, Rogers, J, Cheverud, JM
JournalAm J Phys Anthropol
Date Published2018 Feb

OBJECTIVES: Determining the genetic architecture of quantitative traits and genetic correlations among them is important for understanding morphological evolution patterns. We address two questions regarding papionin evolution: (1) what effect do body and cranial size, age, and sex have on phenotypic (V) and additive genetic (V) variation in baboon crania, and (2) how might additive genetic correlations between craniofacial traits and body mass affect morphological evolution?

MATERIALS AND METHODS: We use a large captive pedigreed baboon sample to estimate quantitative genetic parameters for craniofacial dimensions (EIDs). Our models include nested combinations of the covariates listed above. We also simulate the correlated response of a given EID due to selection on body mass alone.

RESULTS: Covariates account for 1.2-91% of craniofacial V. EID Vdecreases across models as more covariates are included. The median genetic correlation estimate between each EID and body mass is 0.33. Analysis of the multivariate response to selection reveals that observed patterns of craniofacial variation in extant baboons cannot be attributed solely to correlated response to selection on body mass, particularly in males.

DISCUSSION: Because a relatively large proportion of EID Vis shared with body mass variation, different methods of correcting for allometry by statistically controlling for size can alter residual Vpatterns. This may conflate direct selection effects on craniofacial variation with those resulting from a correlated response to body mass selection. This shared genetic variation may partially explain how selection for increased body mass in two different papionin lineages produced remarkably similar craniofacial phenotypes.

Alternate JournalAm. J. Phys. Anthropol.
PubMed ID29154459