物種分化歧異度是否與形態演化的速率有關?

photo by cotinis

Are rates of species diversification correlated with rates of morphological evolution?
Dean C. Adams, Chelsea M. Berns, Kenneth H. Kozak and John J. Wiens

作者在此以190個無肺螈科山椒魚物種的形態與親緣關係資料測試此關係。出乎意料地，作者發現物種分化速率與形態分化速率沒有顯著相關，這些快速分化可以與 少量的形態改變共同發生，反之亦然。作者也發現大多數支系發生明顯相似的形態演化(雖然廣泛的共域)，且那些相對較新的表型並未與快速演化相關。最後，作 者發現體型和形狀的演化之間有強烈的關係，此關係在前人研究中並未驗證過。

Abstract
Some major evolutionary theories predict a relationship between rates of proliferation of new species (species diversification) and rates of morphological divergence between them. However, this relationship has not been rigorously tested using phylogeny-based approaches. Here, we test this relationship with morphological and phylogenetic data from 190 species of plethodontid salamanders. Surprisingly, we find that rates of species diversification and morphological evolution are not significantly correlated, such that rapid diversification can occur with little morphological change, and vice versa. We also find that most clades have undergone remarkably similar patterns of morphological evolution (despite extensive sympatry) and that those relatively novel phenotypes are not associated with rapid diversification. Finally, we find a strong relationship between rates of size and shape evolution, which has not been previously tested.

(本篇文字作者為Enya)