Wednesday, August 8, 2018: 9:50 AM
335-336, New Orleans Ernest N. Morial Convention Center
Background/Question/Methods
Intraspecific trait variation is ubiquitous in natural systems and can have substantial impacts on the eco-evolutionary dynamics of populations and communities (Schreiber et al, 2011). The fitness and ecological function of a trait (such as mediating interactions among species or adapting to local environmental conditions) can be influenced by its degree of phenotypic variation, while its genetic variance determine its evolutionary trajectory. We examined how the genetic and phenotypic variance of a trait affect a community's eco-evolutionary feedbacks. To do this, we developed a theoretical model in which body size affects each population's trophic interactions and suitability to the environment. We simulated the simultaneous invasion of two species that are identical except for their phenotypic variance and examined the effects on the ecological and evolutionary dynamics of all species in the system.
Results/Conclusions
Our results show that in communities with unimodal resource distributions, the invader with lower phenotypic variance will be establish successfully when the initial distance between the trait mean and the optimal value is small. The high variance invader is initially grows to aa high population density when the initial distance to the optimal trait value is larger; however, the low-variance invader will ultimately succeed if it is able to avoid extinction. Initial simulations with more complex resource distributions or environmental fluctuations have suggested circumstances in which the higher variance invader is unambiguously successful. When environmental conditions (and thus trait optima) fluctuated, our preliminary analysis suggest higher phenotypic variance was successful when heritability was low but became less beneficial with higher heritability. Better understanding the interactions of intraspecific variation and environmental change on community dynamics could provide greater insight into community responses to anthropogenic disturbances.