Department of Biology

Community Evolution: What is it and why is it important?

Dr. Thomas Whitham

January 27, 2021
4-5pm

Hosted By Dr. Jim Coleman

Evolution has been viewed as occurring primarily through selection among individuals (Williams 1966). I present an alternative framework based on multilevel selection for evaluating evolutionary change from individuals to communities, with supporting empirical evidence focused primarily on long-term studies of cottonwoods and pinyon pine. Community evolution is defined as, “the outcome of selection operating at multiple levels that results in the differential extinction and proliferation of communities.” Thus, community evolution can be detected as a change in the average community phenotype in response to a selection event through time. Essential to this evaluation is the role that interspecific indirect genetic effects (IIGEs) play in shaping community structure, in generating variation among community phenotypes, and in creating community heritability. If communities vary in phenotype, and those phenotypes are heritable and subject to selection at multiple levels, then a community view of evolution should be merged with mainstream evolutionary theory. Based on studies in the wild and in common gardens with plants of known genetic makeup (replicate clones of individual genotypes or half-sibs), these key requirements are evaluated and their importance for both basic and applied research explored.