The primary goal of this symposium is to examine the generality and significance of evolutionary effects in populations, communities, and ecosystems. This symposium will feature speakers working on questions at the interface of ecology and evolution. It will focus primarily on empirical data from studies conducted in nature. The introductory talk will frame the question addressed in the symposium – should ecologists care about eco-evolutionary dynamics? The goal of the introduction is to present a broad perspective on the potential importance of evolution for ecological dynamics. However, the core question of the symposium will be left open, to be addressed by the other speakers. The symposium will then proceed through levels of organization, from populations, to communities, to ecosystems. It will conclude with a meta-analysis study that examines evolutionary effect sizes across levels of organization. Population talks will examine evolutionary effects in several classic systems. These include the effects of a single gene on butterfly metapopulation dynamics and the effects of evolutionary vs. environmental drivers on large mammal population dynamics. Community talks will address evolutionary effects that are mediated by trophic interactions, focusing on pelagic freshwater food webs. Talks about community effects include two experimental studies examining the effects of either predator or prey evolution on community structure and dynamics. Ecosystem talks will address the emergent effects of recently evolved genetic and phenotypic divergence in dominant species on whole ecosystem responses, including rates of nutrient cycling, primary production, and decomposition. Study systems addressing ecosystem effects include both plant and animal systems. The final talk will bridge levels of organization. This talk will focus on a meta-analysis of plant genetic effects from individuals, to communities, to ecosystems. Our hope is that by bringing together researchers examining evolutionary effects at multiple levels of organization and in a diversity of study systems, we will help stimulate work that moves the field of eco-evolutionary dynamics beyond the current era of independent case studies and into an era of synthetic growth.