Journal Article

Evolution and ecology of lizard body sizes

Meiri, Shai

2008

Overview

Body size is instrumental in influencing animal physiology, morphology, ecology and evolution, as well as extinction risk. I examine several hypotheses regarding the influence of body size on lizard evolution and extinction risk, assessing whether body size influences, or is influenced by, species richness, herbivory, island dwelling and extinction risk. World-wide. I used literature data and measurements of museum and live specimens to estimate lizard body size distributions. I obtained body size data for 99% of the world's lizard species. The body size-frequency distribution is highly modal and right skewed and similar distributions characterize most lizard families and lizard assemblages across biogeographical realms. There is a strong negative correlation between mean body size within families and species richness. Herbivorous lizards are larger than omnivorous and carnivorous ones, and aquatic lizards are larger than non-aquatic species. Diurnal activity is associated with small body size. Insular lizards tend towards both extremes of the size spectrum. Extinction risk increases with body size of species for which risk has been assessed. Small size seems to promote fast diversification of disparate body plans. The absence of mammalian predators allows insular lizards to attain larger body sizes by means of release from predation and allows them to evolve into the top predator niche. Island living also promotes a high frequency of herbivory, which is also associated with large size. Aquatic and nocturnal lizards probably evolve large size because of thermal constraints. The association between large size and high extinction risk, however, probably reflects a bias in the species in which risk has been studied.

• Publisher: Oxford, UK : Blackwell Publishing Ltd,Blackwell Publishing,Blackwell Publishing Ltd,Blackwell
• Subject: Amphibia. Reptilia / Animal and plant ecology / animal physiology / Animal, plant and microbial ecology / Biogeography / Biological and medical sciences / Biological taxonomies / Body size / description dates / diurnal activity / diversification rates / Ecological genetics / Extinct species / extinction / extinction risk / Fundamental and applied biological sciences. Psychology / General aspects / Herbivores / insularity / islands / Lacertilia / lizard diets / Lizards / mammals / niches / Population ecology / predation / predators / risk / size–frequency distributions / snout–vent length / Species / species diversity / Species extinction / species richness / Synecology / Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution / zoogeography