Meeting Abstract

P1-100   -   Patterns of body elongation in carnivoran mammals Law, CJ; University of Washington and American Museum of Natural History cjlaw@ucsc.edu http://chrisjlaw.com

Although convergence is often recognized as a ubiquitous feature across the Tree of Life, whether the underlying traits also exhibit similar evolutionary pathways towards convergent forms continues to puzzle biologists. In carnivoran mammals, “elongate,” “slender,” and “long” are often used to describe and even to categorize civets, genets, martens, mongooses, polecats, and weasels together. But just how similar these carnivorans are and whether there is convergence in underlying morphologies that contribute to their body elongation has never been assessed. Using evolutionary models, I found that these species exhibited similarly elongate bodies compared to other terrestrial carnivorans. Analyses of the morphological components underlying body shape variation also indicated selection towards more elongate crania and vertebrae and a reduction in body depth. However, tests of convergence revealed nuanced patterns in convergence. The distance-based metric revealed that the morphological components contributing to body elongation are not significantly convergent. Although the frequency-based metric of convergence indicated that elongate carnivorans occupy a distinct region of morphospace relative to non-elongate carnivorans, the six elongate carnivoran groups do not overlap in morphospace and their disparity is not significantly less than non-elongate carnivorans as one would expect under complete convergence. Together, these results demonstrate that elongate carnivorans exhibit similarly elongate body shapes that may have been driven by the imperfect convergence of the underlying morphological components, particularly the elongation of the lumbar, cervical, and thoracic regions. Future work incorporating the fossil record is needed to distinguish whether body elongation in carnivorans evolved as a product of evolutionary statis or convergence.