Meeting Abstract

16.4  Saturday, Jan. 4 11:00  Spatial and temporal variation in phenotypic selection in the lizard Anolis sagrei WARNER, D.A.*; HARRISON, A.; REEDY, A.; University of Alabama at Birmingham; Harvard University; University of Virginia dawarner@uab.edu

Populations often experience substantial spatial and temporal variation in environmental and demographic features. This variation can impact the strength and form of natural selection on fitness-relevant phenotypes, and therefore could result in broad phenotypic variation through space and time. We performed a large-scale manipulative study on island populations of the invasive brown anole (Anolis sagrei) in Florida. We established nine experimental island populations and manipulated the adult sex ratio (an important demographic parameter that should affect the level of intra-sexual competition) on each island. Subsequent mark-recapture studies enabled us to quantify survival and assess the strength and form of viability selection on body size over the reproductive and non-reproductive seasons. Our results reveal substantial spatial variation in adult survival and reproduction across islands, with generally greater survival and reproduction on female-biased islands. The strength of selection operating on body size also varied spatially and differed between males and females, particularly on female-biased islands. Spatial variation in selection on body size was not due to island size, but preliminary analyses suggest that islands with greater shade cover favored relatively small body size. Our on-going research will assess selection on second-generation hatchling/juvenile phenotypes to enable robust evaluation of spatio-temporal variation in, and consistency of, natural selection.