CONSTRAINTS ON MAMMALIAN FORELIMB DEVELOPMENT: INSIGHTS FROM DEVELOPMENTAL DISPARITY
Article first published online: 12 SEP 2013
© 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.
Volume 67, Issue 12, pages 3645–3652, December 2013
How to Cite
Ross, D., Marcot, J. D., Betteridge, K. J., Nascone-Yoder, N., Bailey, C. S. and Sears, K. E. (2013), CONSTRAINTS ON MAMMALIAN FORELIMB DEVELOPMENT: INSIGHTS FROM DEVELOPMENTAL DISPARITY. Evolution, 67: 3645–3652. doi: 10.1111/evo.12204
- Issue published online: 2 DEC 2013
- Article first published online: 12 SEP 2013
- Accepted manuscript online: 2 JUL 2013 01:26PM EST
- Manuscript Accepted: 11 JUN 2013
- Manuscript Received: 15 FEB 2013
- National Science Foundation. Grant Numbers: 0104927, 125873
- National Institutes of Health. Grant Number: HD050042-01
- North Carolina State University College of Veterinary Medicine
Tetrapod limb development has been studied extensively for decades, yet the strength and role of developmental constraints in this process remains unresolved. Mammals exhibit a particularly wide array of limb morphologies associated with various locomotion modes and behaviors, providing a useful system for identifying periods of developmental constraint and conserved developmental mechanisms or morphologies. In this study, landmark-based geometric morphometrics are used to investigate levels and patterns of morphological diversity (disparity) among the developing forelimbs of four mammals with diverse limb morphologies: mice, opossums, horses, and pigs. Results indicate that disparity among the forelimbs of these species slightly decreases or stays the same from the appearance of the limb ridge to the bud stage, and increases dramatically from the paddle through tissue regression stages. Heterochrony exhibited by the precocial opossum limb was not found to drive these patterns of morphological disparity, suggesting that the low disparity of the middle stages of limb development (e.g., paddle stage) is driven by processes operating within the limb and is likely not a result of embryo-wide constraint.