ECOLOGICAL CAUSES OF DECELERATING DIVERSIFICATION IN CARNIVORAN MAMMALS
Article first published online: 3 MAY 2013
© 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.
Volume 67, Issue 8, pages 2423–2433, August 2013
How to Cite
Machac, A., Storch, D. and Wiens, J. J. (2013), ECOLOGICAL CAUSES OF DECELERATING DIVERSIFICATION IN CARNIVORAN MAMMALS. Evolution, 67: 2423–2433. doi: 10.1111/evo.12126
- Issue published online: 26 JUL 2013
- Article first published online: 3 MAY 2013
- Accepted manuscript online: 12 APR 2013 03:14PM EST
- Manuscript Accepted: 3 APR 2013
- Manuscript Received: 23 NOV 2012
- Agency of the Czech Republic. Grant Number: P505/11/2387
Clade diversification is a central topic in macroevolutionary studies. Recently, it has been shown that diversification rates appear to decelerate over time in many clades. What causes this deceleration remains unclear, but it has been proposed that competition for limited resources between sympatric, ecologically similar species slows diversification. Employing carnivoran mammals as a model system, we test this hypothesis using a comprehensive time-calibrated phylogeny. We also explore several conceptually related explanations including limited geographic area and limited rates of niche evolution. We find that diversification slowdowns are strong in carnivorans. Surprisingly, these slowdowns are independent of geographic range overlap between related species and are also decoupled from rates of niche evolution, suggesting that slowdowns are unrelated to competition and niche filling. When controlling for the effects of clade diversity, diversification slowdowns appear independent of geographic area. There is a significant effect of clade diversity on diversification slowdowns, but simulations show that this relationship may arise as a statistical artifact (i.e., greater clade diversity increases the ability of the gamma statistic to refute constant diversification). Overall, our results emphasize the need to test hypotheses about the causes of diversification slowdowns with ecological data, rather than assuming ecological processes from phylogenies alone.