Evolutionary relationships between morphology, performance and habitat openness in the lizard genus Niveoscincus (Scincidae : Lygosominae)

Correlations between an animal's morphology and ecological parameters such as habitat characteristics emphasize the intimate link between phenotype an d the environment, but are often difficult to interpret because the functio nal consequences of morphological variation are frequently unknown. We prov ide one of the few studies relating limb morphology, functional capabilitie s, and habitat in reptiles. We tested the hypothesis that species occupying open microhabitats would possess relatively longer limbs and faster sprint speeds than those occurring in more closed microhabitats. A number of morp hological characteristics relevant to locomotion were quantified, including the length of the bones of the fore- and hindlimbs and body size. A phylog enetic analysis was then used to examine the evolutionary relationships bet ween morphology, locomotor performance and microhabitat openness in seven s pecies of Niveoscincus and one species of the closely related genus Pseudem oia. A significant evolutionary relationship was established between sprint ing ability, morphology, and the openness of the microhabitat occupied by a species. The phylogenetic analysis demonstrated an evolutionary trend in N iveoscincus of species occupying open microhabitats (e.g. N. greeni, N. oce llatus) being large with long limbs and high sprinting ability, while those occupying closed microhabitats (e.g. N. coventryi, P entrecasteauxii) are smaller with short limbs and much slower maximum sprint speeds. (C) 2000 Th e Linnean Society of London.