The phenotypic plasticity displayed by most phenotypes is thought to potentially buffer populations from novel environmental changes, or to even guide subsequent evolutionary responses. Behavior is often thought to be the most plastic phenotype, and the first phenotype to change or respond to sudden environmental changes. Thus, the degree of a population’s behavioral plasticity should be under intense selection during environmental change. The threespine stickleback (Gasterosteus aculeatus) populations residing in southcentral Alaska are currently experiencing an invasion from the predatory Northern pike (Esox lucius). Multiple stickleback populations have potentially gone extinct following pike invasion; thus, stickleback populations are likely to be under intense selection pressures following pike invasion. In this experiment, we asked how the developmental, and activational plasticity of threespine stickleback behavior has evolved following invasion by northern pike. We did this by exposing stickleback from three populations with and without northern pike to chronic artificial predation events during the first year of development and asked how their behavior differed to those that were not exposed. Our results suggest that long-term predation exposure does not influence stickleback behavior. Furthermore, we found that the degree of behavioral plasticity in stickleback antipredator behavior was much more variable among populations with invasive pike, than those without invasive pike, with the both the most plastic and least plastic populations being pike-invaded populations. In this talk we will discuss these results in the context of how phenotypic plasticity evolves, and how likely it is that populations of the same species evolve, and evolve in the same manner, in response to novel environmental changes.