Open AccessThe role of habitat shift in the evolution of lizard morphology: evidence from tropical Tropidurus
Author(s) -
Laurie J. Vitt,
Janalee P. Caldwell,
Peter A. Zani,
Tom A. Titus
Publication year - 1997
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.94.8.3828
Subject(s) - lizard , biology , ecology , morphology (biology) , habitat , outcrop , population , panama , sauria , zoology , paleontology , demography , sociology
We compared morphology of two geographically close populations of the tropical lizardTropidurus hispidus to test the hypothesis that habitat structure influences the evolution of morphology and ecology at the population level.T. hispidus isolated on a rock outcrop surrounded by tropical forest use rock crevices for refuge and appear dorsoventrally compressed compared with those in open savanna. A principal components analysis revealed that the populations were differentially distributed along an axis representing primarily three components of shape: body width, body height, and hind-leg length. Morphological divergence was supported by a principal components analysis of size-free morphological variables. Mitochondrial DNA sequences of ATPase 6 indicate that these populations are closely related relative to otherT. hispidus , the rock outcrop morphology and ecology are derived withinT. hispidus , and morphological and ecological divergence has occurred more rapidly than genetic divergence. This suggests that natural selection can rapidly adjust morphology and ecology in response to a recent history of exposure to habitats differing in structure, a result heretofore implied from comparative studies among lizard species.