The significant variation in host specificity exhibited by parasites has been separately linked to evolutionary history and ecological factors in specific host-parasite associations. Yet, whether there are any general patterns in the factors that shape host specificity across parasites more broadly is unknown. Here we constructed a molecular phylogeny for 249 helminth species infecting free-range mammals and find that the influence of ecological factors and evolutionary history varies across different measures of host specificity.
Results/Conclusions
The mean pairwise phylogenetic distance of hosts a helminth can infect is strongly influenced by evolutionary history, whereas the recorded number of hosts a helminth infects is not. Our results shed new light on the evolution of host specificity in parasites, suggesting that evolutionary history may shape the potential of a parasite to jump between hosts, whereas the number of hosts may reflect ecological opportunity. Additionally, we discuss how parasite phylogenies can provide an alternative perspective on zoonosis by identifying which hosts are infected by a broad phylogenetic range of parasites.
