Literaturdatenbank
Literaturdatenbank |
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Lindeman, P. V., & Sharkey, M. J. (2001). Comparative analyses of functional relationships in the evolution of trophic morphology in the map turtles (emydidae: graptemys). Herpetologica, 57(3), 313–318.
Added by: Admin (17 Aug 2008 17:23:53 UTC) |
| Resource type: Journal Article BibTeX citation key: Lindeman2001b View all bibliographic details  |
Categories: General Keywords: Emydidae, Graptemys, Habitat = habitat, Nordamerika = North America, Schildkröten = turtles + tortoises, Systematik = taxonomy Creators: Lindeman, Sharkey Collection: Herpetologica |
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| Abstract |
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Variation in relative width of the head and alveolar surfaces of the jaws in map turtles (Graptemys) is associated with the degree of molluscivory in adult females. Adult males are substantially smaller in body size and are primarily insectivorous, and they take few mollusks regardless of their relative head width or alveolar width. We assessed functional relationships within and between the sexes using comparative analyses (independent contrasts and squared-change parsimony) of the residuals of regressions of head width on plastron length and alveolar width on head width. Residuals of head width and alveolar width were significantly correlated within females but not within males in all comparative analyses. Residuals of each regression were significantly correlated between males and females for a subset of analyses. Our results suggest that evolutionary changes in relative head width have been correlated with changes in relative alveolar width in females of Graptemys due to a functional relationship that is related to the tendency to feed on mollusks. Males have exhibited changes in the two characters similar to changes in females over evolutionary time, probably as a result of genetic covariation, but due to males' primarily insectivorous nature, changes in the two characters have not shown significant correlation with one another.
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