TESTING FOR DIFFERENCES IN RATES OF SPECIATION, EXTINCTION, AND MORPHOLOGICAL EVOLUTION IN FOUR TRIBES OF CICHLIDS ENDEMIC TO LAKE TANGANYIKA, EAST AFRICA
Article first published online: 8 JUL 2011
© 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.
Volume 65, Issue 12, pages 3398–3412, December 2011
How to Cite
Hoerner, M. E. (2011), TESTING FOR DIFFERENCES IN RATES OF SPECIATION, EXTINCTION, AND MORPHOLOGICAL EVOLUTION IN FOUR TRIBES OF CICHLIDS ENDEMIC TO LAKE TANGANYIKA, EAST AFRICA. Evolution, 65: 3398–3412. doi: 10.1111/j.1558-5646.2011.01390.x
- Issue published online: 1 DEC 2011
- Article first published online: 8 JUL 2011
- Accepted manuscript online: 16 JUN 2011 04:29AM EST
- Received November 9, 2010, Accepted May 18, 2011, Data Archived: Dryad doi:10.5061/dryad.1ps0t
- Adaptive radiation;
- East Africa;
- morphological evolution
Patterns of morphological disparity yield important insight into the causes of diversification and adaptive radiation in East African cichlids. However, comparisons of cichlid disparity have often failed to consider the effects that differing clade ages or stochasticity may have on disparity before making interpretations. Here, a model of branching morphological evolution allows assessment of the relative contributions of differing turnover and morphological change rates, clade ages, and stochastic variation to the observed patterns of disparity in four endemic tribes of Lake Tanganyika cichlids. Simulations compare the likelihood of generating the observed disparity of the four tribes using 200-parameter combinations and four model conditioning variations, which allows inference of evolutionary rate differences among clades. The model is generally robust to model conditioning, the approach to data analysis, and model assumptions. Disparity differences among the first three cichlid tribes, Ectodini, Lamprologini, and Tropheini, can be explained entirely by stochasticity and age, whereas the fourth tribe, Cyprichromini, has likely experienced lower rates of turnover and morphological change. This rate difference is likely related to the low dietary diversity of the Cyprichromini. These results highlight the importance of considering both clade age and stochastic variation when interpreting morphological diversity and evolutionary processes.