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

Authors

Jessica L. Joganic
Katherine E. Willmore
Joan T. Richtsmeier
Kenneth M. Weiss
Michael Mahaney, The University of Texas Rio Grande Valley
Jeffrey Rogers
James M. Cheverud

Document Type

Article

Publication Date

2-2018

Abstract

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 (VP) and additive genetic (VA) 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 to selection on body mass alone.

Results

Covariates account for 1.2%–91% of craniofacial VP. EID VA decreases across models as more covariates were 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 VA is shared with body mass variation, different methods of correcting for allometry by statistically controlling for size can alter residual VP patterns. 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.

Comments

Original published version available at https://doi.org/10.1002/ajpa.23349

Recommended Citation

Joganic, J. L., Willmore, K. E., Richtsmeier, J. T., Weiss, K. M., Mahaney, M. C., Rogers, J., & Cheverud, J. M. (2018). Additive genetic variation in the craniofacial skeleton of baboons (genus Papio) and its relationship to body and cranial size. American journal of physical anthropology, 165(2), 269–285. https://doi.org/10.1002/ajpa.23349

Publication Title

American journal of physical anthropology

DOI

10.1002/ajpa.23349

Academic Level

faculty

Mentor/PI Department

Office of Human Genetics