E-mail: sslowins AT indiana DOT edu
While it is well known that hosts can reduce the impact of vector-borne diseases by employing constitutive and inducible immune defenses, far less is known about the adaptations hosts employ to reduce their exposure to vectors. Recent research suggests the possibility that birds are able to produce volatile chemicals in the preen gland that repel disease vectors. Preen oil volatiles may be costly to produce and the production of vector-repellant volatile compounds may trade off with other preen oil functions like intra-specific communication, or defense against ectoparasites. Given these potential costs and trade-offs, selection may favor production of vector-repellent compounds only in the presence of disease vectors. My research will test the hypothesis that volatile compounds in avian preen oil protect birds against disease vectors. I will further assess whether the volatile compounds in the preen oil of dark-eyed juncos vary in composition across populations depending on the vector community, and whether defensive volatile compounds can be induced by exposure to vectors.
I am also interested in how host-parasite coevolutionary interactions affect the evolution of reproductive systems in host populations. The Red Queen Hypothesis suggests that coevolutionary interactions between hosts and parasites can generate negative frequency-dependent selection that favors rapid changes in host genotype frequencies. This fluctuating selective pressure can favor bi-parental reproduction. Caenorhabditis elegans populations are composed of hermaphrodites and males, and hermaphrodites can reproduce either by self-fertilizing their own eggs or by outcrossing with males. I will use behavioral assays to test whether the propensity of C. elegans hermaphrodites to mate evolves in response to coevolutionary pressure from the virulent parasite Serratia marcescens, and whether such changes are driven by evolution in the production of mate attraction pheromones in C. elegans hermaphrodites.