Recently published in Molecular Ecology (PDF available above), this article presents a novel method to describe the host specificity of pathogens by combining host species’ phylogenetic and functional distances into a single informative metric. Our method has a wide array of potential applications, and will be useful to improve our understanding of host-pathogen evolution and the future risks of disease emergence as pathogens shift hosts.
New host specificity metric uncovers hidden aspects of parasite specialisation
Clark, NJ, Clegg, SM. Integrating phylogenetic and ecological distances reveals new insights into parasite host specificity (2017). Molecular Ecology doi: 10.1111/mec.14101
A variety of historical and contemporary mechanisms can lead to phylogenetic dispersion patterns of host use by parasites. Here we illustrate some of these on a hypothetical host phylogeny, where black shading indicates infection by a multi-host parasite.
Parasite host specificity changes (compared to null expectations) as we vary contributions of host phylogenetic and ecological distance to our functional-phylogenetic distance. Most parasites are phylogenetic host specialists, infecting more closely related hosts than expected as phylogenetic weighting increases (alpha values approaching 1).