Postdoctoral Fellow

When are coevolving species locally adapted to each other? a meta-analysis.

PI(s): Jason Hoeksema
Start Date: 1-Jul-2006
End Date: 31-Jul-2007
Keywords: local adaptation, coevolution, meta-analysis, natural selection

When do species adapt to each other?

Species interact with each other regularly—competing for resources, protecting each other or providing beneficial services, and eating or parasitizing each other. Often, these interactions are strong enough that one species causes the other to undergo evolutionary changes, and vice versa, resulting in “coevolution.” When coevolving host and parasite species occur together in a diversity of environments across broad geographic areas, host populations frequently differ from each other in a variety of traits. In response, some parasites are able to adapt to their local host populations, allowing them to better colonize or attack their hosts. In other cases, however, the opposite is observed—parasites seem poorly adapted, even mal-adapted, to their local hosts. Researchers Jason Hoeksema and Samantha Forde attempted to uncover the reasons for these variable outcomes of coevolution by analyzing published data from studies of local adaptation in a diverse cross-section of 29 different host-parasite interactions, including worms parasitizing snails, bacteria attacking plants, and ticks inhabiting birds.

They found that when parasites could disperse more readily than their hosts among the different geographic areas where they co-exist, presumably resulting in greater parasite gene flow among those areas, parasites were much more likely to exhibit local adaptation to their hosts. This result suggests that adaptation by parasites to hosts in particular populations is often constrained by the availability of parasite genetic variation, which may be bolstered by frequent gene flow from other populations. More broadly, Hoeksema & Forde’s results (published in the journal The American Naturalist in 2008) help to explain why coevolution results in such variable outcomes among different species interactions. “This kind of synthetic approach, in which data are drawn from numerous published studies, “ says Hoeksema, “allows us to answer questions in evolutionary biology that simply can’t be addressed with an individual empirical or theoretical study.”

Related products

Software and DatasetsPublicationsProposals and Grants
  • Hoeksema J.D., S. Brewer, D. Reed, C. Jackson, M. Holland, C. Ochs, G. Stratton, S. Threlkeld. 2007. University of Mississippi. Graduate Training in Multi-Scale Approaches to Forest Restoration and Management Science. USDA. 2008-2012. $168,000.