Host use does not clarify the evolutionary history of African ticks (Acari: Ixodoidea)

Abstract

Where host-parasite associations are rigid and unique, the host preference(s) of parasites and the evolutionary relationships between their hosts may offer insights into the parasites’ evolu–tionary history. Where such associations are less rigid, however, the assumption that current host preferences are useful in formulating theories about parasite evolution is more questionable. I examine the validity of this assumption for a subset of African ticks and their hosts using the computer program Treemap to compare published phylogenies for each group. There is a marked lack of congruence between tick and host phylogenies and they offer no support for the hypothesis that cospeciation has been a dominant pattern in tick evolution. While this result does not prove that cospeciation between these taxa has not occurred, it suggests that the current host preferences of ticks are a poor guide to their evolutionary history and should not be used as key components of theories of tick evolution.

Keywords: Ixodidae, host-parasite association, phylogeny, coevolution, cospeciation