Publication
Title
Digit ratios in two lacertid lizards : sexual dimorphism and morphological and physiological correlates
Author
Abstract
Digit length ratio (primarily 2D:4D) has become increasingly popular as a possible biomarker of intrauterine steroid exposure in the human medical, social and psychological literature. Human males tend to have lower digit ratios than females, and individuals with low ratios tend to excel in physical performance, especially in endurance-related sports. Because early limb development is evolutionarily conservative, it has been speculated that these trends should also be visible in other tetrapod vertebrates. However, studies on non-human vertebrates are scant, and their results suggest that sexual dimorphism in digit ratios and the associations with physical performance are much more intricate and taxon-specific than presumed. In this study, we compared digit ratios of two Podarcis lizards among sexes, colour morphs and species. We also tested for associations with three performance characteristics that are of ecological relevance. Both species examined exhibit male-larger sexual dimorphism in digit ratio. 2D:4D, 3D:4D and 2D:3D ratios are tightly correlated within the manus and the pes, but less so between manus and pes. In the colour polymorphic species P. melisellensis, the yellow morph exhibits higher dimorphism than the orange and white morphs. Digit ratios did not correlate with individual performance for sprint speed or endurance, but within males of P. melisellensis, individuals with higher digit ratios correlated positively with head size and bite force. We conclude that digit ratios in lizards deserve attention, because they exhibit sexual dimorphism and correlate with ecologically relevant morphological and performance variables. As lizard species differ widely in mating systems, reproductive mode, habitat use and locomotor behaviour, they seem excellent model animals for studying patterns in digit length ratios.
Language
English
Source (journal)
Zoomorphology : evolutionary, comparative and functional morphology. - Berlin
Publication
Berlin : 2015
ISSN
0720-213X
Volume/pages
134:4(2015), p. 565-575
ISI
000365186300006
Full text (Publishers DOI)
Full text (open access)
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UAntwerpen
Faculty/Department
Research group
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 27.11.2015
Last edited 23.05.2017
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