Studies of eco-evolutionary dynamics have integrated evolution with ecological processes at multiple scales (populations, communities, and ecosystems) and with multiple interspecific interactions (antagonistic, mutualistic, and competitive). However, evolution has often been conceptualized as a single process: short-term adaptive genetic change driven by natural selection. Here we argue that other diverse evolutionary processes should also be considered, to explore the full spectrum of feedbacks between ecological and evolutionary processes. Relevant but underappreciated processes include (1) drift and mutation, (2) disruptive selection causing lineage diversification or speciation reversal, (3) evolution driven by relative fitness differences that may decrease population growth, and (4) topics including multilevel selection, sexual selection and conflict, hard and soft selection, and genetic/genomic architectures/signatures. Because natural selection is not the sole mechanism of rapid evolution, it will be important to integrate a variety of concepts in evolutionary biology and ecology to better understand and predict eco-evolutionary dynamics in nature.

The biomass ratio of herbivores to producers reflects the structure of a community. Four primary factors have been proposed to affect this ratio, including production rate, defense traits, and nutrient contents of producers as well as predation by carnivores. However, the relative importance of these factors across natural communities is elusive, in part because of the lack of a framework for quantitatively comparing their effect sizes. Here, we develop a framework based on Lotka-Volterra equations for examining the relative importance among these factors in determining the biomass ratio. We further utilize it to analyze plankton communities in experimental ponds with different carnivore (fish) abundance and light input. We found that all four factors contributed significantly to the biomass ratio, but carnivore abundance had the largest effect size, followed by the stoichiometric nutrient content. The present framework is useful for quantifying relative roles of these factors shaping terrestrial and aquatic communities.