The persistence of environmentally-induced phenotypic variation in western fence lizards


Meeting Abstract

52.5  Jan. 6  The persistence of environmentally-induced phenotypic variation in western fence lizards BUCKLEY, C.R.*; IRSCHICK, D.J.; ADOLPH, S.C. ; University of Massachusetts crcbuck@gmail.com

Developmental plasticity is known to have profound effects on the phenotypes of young organisms, especially ectotherms. Evolutionary biologists have demonstrated changes in phenotype that include neonates� morphology, behavior, physiology and performance in response to proximate environmental influences (e.g. temperature, humidity) during incubation. However, to date, few studies have examined the persistence of these traits� environmentally induced variation through ontogeny. We studied the importance of developmental plasticity to the quality of lizard hatchlings over time. We hypothesized that whereas incubation would noticeably affect hatchling traits, these effects will become weaker as animals are raised in a common post-hatching environment, and that as a result traits will converge on an intermediate phenotype. We collected pregnant female Sceloporus occidentalis from two high-elevation (approximately 2200m) and two low-elevation (approx. 1350m) populations in California and subjected their eggs to two incubation environments representative of the extreme conditions experienced by these eggs in the wild (warm and cool). We raised the hatchlings for at least 11 weeks in the laboratory and measured their morphology (limb and head dimensions), growth rate, thermal preference, and sprinting performance at biweekly intervals. Our data reveal that although source population and incubation environment have significant effects on these animals� phenotypes, in some cases, these differences do not persist over time. We discuss the ecological relevance of developmental plasticity in comparison to the rearing environment in these lizards, and caution that studies of developmental plasticity should include a post-hatching component.

the Society for
Integrative &
Comparative
Biology