Wednesday, August 6, 2008: 1:30 PM-5:00 PM
102 C, Midwest Airlines Center
Organizer:
Casey P. terHorst
Co-organizer:
Thomas E. Miller
Moderator:
Thomas E. Miller
Community patterns are strongly affected by the evolutionary history of the species in the community. While concepts such as character displacement, niche divergence, and species packing are widely-used heuristics, studies of evolutionary mechanisms rarely focus on more than two species and little is known about how species evolve in a community context. As the number of species in a community increases, the number of direct and indirect interactions between species increases exponentially, as does the number of potential selective forces. However, not all direct and indirect interaction pathways between pairs of species generate selection in the same direction; considering evolution in response to multiple species may result in an increase or decrease in the rate of evolution relative to evolution in response to a single species. The goal of this session will be to explore the diversity of approaches and existing evidence on the mechanisms and patterns of evolution in a community context. The first half of the session will examine how considering evolution in a community context changes how we view evolution. Presenters will examine evolution in response to multiple other species or in response to an indirect effect from another species. These examples come from a variety of assemblages, including plant-pollinator-herbivore interactions, trophic cascades, and predator-prey interactions with multiple competing prey. More importantly, each presenter will take different experimental and theoretical approaches in addressing evolution in these communities. The second half of the symposium will focus on how incorporating evolution influences our understanding of broader community patterns. One presentation will address this topic by examining the relationship between phylogeny and community structure. Another will integrate evolution and the neutral theory of biodiversity to determine when species might converge or diverge over evolutionary time. One presentation will focus on evolution in metacommunities and how evolution affects dispersal and heterogeneity patterns, and ultimately, community structure. Finally, one presentation will focus on the burgeoning field of community genetics, or how the evolution of one species dramatically affects the community associated with that species. Talks will incorporate theory and experimental work at several scales, while bringing together previously disparate areas to discuss common questions.