OVIPOSITION SITE CHOICE AND LIFE-HISTORY EVOLUTION

Studies of life history evolution, as well as much of life history the ory, have typically focused on ''hard'' components of life histories; phenotypic characteristics that can be readily observed, quantified, a nd ultimately, connected rather directly to fitness. Typical of these are propagule size, propagule number, and age and size at maturity. Wh at is largely missing from the study of life history evolution is cons ideration of the role of behavior, principally female oviposition site choice, in the evolution of life histories. For oviparous organisms, natural selection cannot produce locally optimized ''hard'' components of life history phenotypes without a consistent environmental context (whether invariant or variable); in a variable environment, that cons istent environmental context can be most effectively provided by inter active oviposition site choice. I present a model of selection on ovip osition site choice in the context of the evolution of ''hard'' compon ents of life history phenotypes, along with some experimental data ill ustrating oviposition site choice in response to predators. The model and data are then related to the overall question of the role of ovipo sition site choice in life history evolution. The conclusion is that o viposition site choice must be under equally strong selection with egg size, egg number and the other hard components of life histories in o rder to generate and optimize locally adapted or ecologically speciali zed life history phenotypes, and must therefore, play a significant ro le in the evolution of life histories.