Professor Robert Poulin’s interests center around how and in what ways parasites manipulate the behavior of their hosts. He joins the show to discuss his fascinating research. In this episode, you will learn:
Over the course of millions of years, parasitism has been gradually shaped and enhanced by evolution, resulting in parasites that have the amazing ability to induce behavioral and physical modifications in their hosts in ways that ultimately benefit the parasite. Consider, for instance, the hairworm, which is a parasite that grows inside a terrestrial insect in coil-like fashion until it becomes two to three feet in length, at which point it induces the insect to essentially commit suicide for its survival; the hairworm causes the insect to search for and jump into a body of water, where the hairworm can then emerge from the parasite (killing it in the process), find a mate, and reproduce.
This is just one example of a parasitic relationship that Poulin hopes to better understand. In part, his research involves an examination of gene expression within the genome of the brain cells of infected host insects. Poulin is also interested in other mechanisms by which parasites manipulate hosts, such as those that may involve the microbes that parasites carry with them, or the presence of symbiotic viruses that manipulate host behavior. Among other topics, Poulin discusses how parasites are so effective at evading host immune systems, counter-adaptations to host defenses, examples of how parasites can form part of a larger ecosystem, which tissues are preferential for parasites to reside in and why, and so much more.