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CONSTRAINTS ON MAMMALIAN FORELIMB DEVELOPMENT: INSIGHTS FROM DEVELOPMENTAL DISPARITY
Author(s) -
Ross Darcy,
Marcot Jonathan D.,
Betteridge Keith J.,
NasconeYoder Nanette,
Bailey C. Scott,
Sears Karen E.
Publication year - 2013
Publication title -
evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.84
H-Index - 199
eISSN - 1558-5646
pISSN - 0014-3820
DOI - 10.1111/evo.12204
Subject(s) - biology , limb development , heterochrony , forelimb , precocial , altricial , anatomy , evolutionary biology , vertebrate , morphometrics , ontogeny , tetrapod (structure) , zoology , embryo , paleontology , genetics , gene , biochemistry , microbiology and biotechnology
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.