PT - JOURNAL ARTICLE AU - Annat Haber TI - Phenotypic Covariation and Morphological Diversification in the Ruminant Skull AID - 10.1101/017533 DP - 2015 Jan 01 TA - bioRxiv PG - 017533 4099 - http://biorxiv.org/content/early/2015/04/06/017533.short 4100 - http://biorxiv.org/content/early/2015/04/06/017533.full AB - Differences between clades in their diversification patterns result from a combination of extrinsic and intrinsic factors. In this study I examined the role of intrinsic factors in the morphological diversification of ruminants in general, and in the differences between bovids and cervid in particular. Using skull morphology, which embodies many of the adaptations that distinguish bovids and cervids, I examined 132 of the 200 extant ruminant species. As a proxy for intrinsic constraints I quantified different aspects of the phenotypic covariation structure within species, and compared them with their among-species divergence patterns, using phylogenetic comparative methods. My results show that bovids have dispersed into a wider range of directions in morphospace than cervids, and that their overall disparity is higher. Within both bovids and cervids, most species divergence is well aligned with their phenotypic covariance matrices, and those that are better aligned have diverged further away from their ancestor. Bovids’ greater disparity and broader dispersion is associated with a lower eccentricity of their within-population covariance matrices. These results are consistent with the role of intrinsic constraints in determining amount, range, and direction of dispersion, and demonstrate that intrinsic constraints can influence macroevolutionary patterns even as the covariance structure evolves.Online Appendix A: Additional details on methods and resultsOnline Appendix B: Simulations exploring the relationship between Average flexibility and rSDEDryad files: Data, phylogenetic hypotheses, and annotated R codes for all analyses