Increasing the genetic diversity within a population of a focal species tends to alter the performance of that population. Populations with greater diversity may perform better because diversity reduces niche overlap among conspecifics, reducing competition for limiting resources and increasing the effective carrying capacity. In this regard, ecologists have tended to think about genetic diversity and niches in a Hutchinsonian sense, genetic diversity affects the overlap in niche requirements of individuals within that population. Less understood however, is the way genetic diversity affects niches in an Eltonian sense, in other words, how genetic diversity affects the overlap in niche impacts of individuals on the environment and other species. In this talk, I present results from work in my group on genetic diversity effects in sessile marine invertebrates and bacteria and explore genetic diversity effects from both a Hutchinsonian and Eltonian niche perspective.
Results/Conclusions
As for other taxa, we find strong effects of genetic diversity on the performance of populations and find that even minor genetic differences can reduce Hutchinsonian niche overlap among individuals. When we explore the effects of genetic diversity on interspecific interactions, we find complex effects. In some instances, genetic diversity affects the broader community in ways that enhance the benefits of genetic diversity for the focal population while in others, the effects of genetic diversity on the community counteract the benefits of genetic diversity for the focal population. I will argue that we need to consider the effects of genetic diversity from both a niche requirement and niche impact perspective if we are to understand the ecological role of genetic diversity in natural communities.