Individual variation and evolutionary potential of parasite traits in a songbird-tick system: direct and indirect genetic effects.

The interaction between parasites and hosts is generally considered as one of the main driving forces in evolution. Evolution can occur if individual characteristics ("traits") are at least partly inherited, and are subject to natural selection. Therefore, to study the evolution of parasite traits, it is necessary to follow the success of individual parasites throughout their life-cycle. In many parasite species this is nearly impossible, except in highly artificial laboratory conditions. We will study the variation and heritability of parasite traits in ticks that are specialized on songbirds. We will breed ticks in the lab, and allow individual ticks to feed once per stage (larva, nymph or adult) on great tits taken from a wild population. In this way we will have information on the genetic relatedness of individual ticks as well as individual birds used in the study. This allows us to study to what extent variation in parasite success (feeding success, survival, number of eggs) is due to genetic variation in the parasite, or genetic variation in the host, or a combination of both. We will also study whether ticks that are highly successful on great tits do less well on other birds, and vice versa. Similarly we will study whether great tits vary in their ability to resist, or at least tolerate infestation by ticks, and whether birds that do better against one tick, are also successful against other tick species.

Keywords:EVOLUTIONARY BIOLOGY

Disciplines:Microbiology, Veterinary medicine