SREL Reprint #2093

Quantitative genetic and optimality analysis of life-history plasticity in the eastern mosquitofish, Gambusia holbrooki

Stephen C. Weeks and Gary K. Meffe

Savannah River Ecology Laboratory, University of Georgia, Aiken, South Carolina 29802

Conclusions: Overall, the mosquitofish in the current study appeared to exhibit adaptive phenotypic plasticity in response to food stress. Patterns of plasticity in age at maturity, reproductive allotment, and investment in offspring were consistent with optimality models for these traits. Further studies, both comparative and experimental, are required before we can claim the observed plasticity is the optimal response to the feeding environments imposed (Orzack and Sober 1994). In this regard, visualizations of the fitness surface for life-history variants in the two feeding environments (Schluter 1988) would potentially help to understand the different selective regimes in the two environments. Nevertheless, we can claim that the average responses of these fish were in the directions predicted by several optimality models, and thus suggest adaptive phenotypic plasticity has been selected in this Pond C mosquitofish population.

Keywords: additive genetic variance, food limitation, genotype by environment interaction, norms of reaction, phenotypic plasticity

SREL Reprint #2093

Weeks, S.C. and G.K. Meffe. 1996. Quantitative genetic and optimality analysis of life-history plasticity in the eastern mosquitofish, Gambusia holbrooki. Evolution 50:1358-1365.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).