Conflicts of interest: None.
Macroevolutionary diversity of amniote limb proportions predicted by developmental interactions
Article first published online: 1 AUG 2013
© 2013 Wiley Periodicals, Inc.
Journal of Experimental Zoology Part B: Molecular and Developmental Evolution
Volume 320, Issue 7, pages 420–427, November 2013
How to Cite
2013. Macroevolutionary diversity of amniote limb proportions predicted by developmental interactions. J. Exp. Zool. (Mol. Dev. Evol.) 320B:420–427..
- Issue published online: 7 OCT 2013
- Article first published online: 1 AUG 2013
- Manuscript Accepted: 10 MAY 2013
- Manuscript Received: 30 APR 2013
- Alberta Ingenuity Fund. Grant Number: #200300516
Mammals, birds, and reptiles exhibit a remarkable diversity of limb proportions. These evolved differences are thought to reflect selection for biomechanical, postural, and locomotor requirements primarily acting on independent variation in later fetal and postnatal segmental growth. However, earlier conserved developmental events also have the potential to impact the evolvability of limb proportions by limiting or biasing initial variation among segments. Notably, proximo-distal patterning of the amniote limb through activation–inhibition dynamics predicts that initial proportions of segments should exhibit both tradeoffs between stylopod and autopod and a diagnostic reduction in variance of the zeugopod. Here it is demonstrated that this developmental “design rule” predicts patterns of macroevolutionary diversity despite the effects of variation in segmental growth over ontogeny, lineage-specific differences in phylogenetic history, or functional adaptation. These results provide critical comparative evidence of a conserved Turing-like mechanism in proximo-distal limb segmentation, and suggest that development has played a previously unrecognized role in the evolvability of limb proportions in a wide range of amniote taxa. J. Exp. Zool. (Mol. Dev. Evol.) 320B: 420–427, 2013. © 2013 Wiley Periodicals, Inc.