|
|
|
Evolution of Sexual Reproduction
What is sex good for, if only half of a parent’s genes are transmitted to its offspring? How can a sexual population compete with an asexual population that, all else equal, produces twice as many individuals? Do coevolutionary interactions between hosts and their parasites account for the widespread occurrence of sexual versus asexual reproduction (Red Queen hypothesis)? These and other questions are being examined using the freshwater snail Melanoides tuberculata and its trematodes.
|
Multiple Infections and the Evolution of Virulence
Host-parasite interactions rarely involve a one-to-one partnership in nature. Instead, in many natural populations, hosts are commonly found to be multiply-infected by a variety of parasite strains or species. Theory suggests that under conditions of frequent multiple infections, lineages of virulent parasites will be more competitive than those exploiting their host more prudently, leading to an overall increase in virulence. We use different parasite strains and parasite species with diverse host exploitation strategies and transmission modes to test some of these theoretical predictions.
|
Environmental, Epigenetic and Maternal Effects on Host Immunity
The biotic and abiotic environmental conditions under which an organism lives may affect its own or its offspring’s susceptibility to infection by pathogens. But what kind of stress conditions actually affect host immunity? How long do they last or need to last in order to provide a benefit to the host?
|
Hybrids and Parasitism
The observation of hybridization events in molluscs raises questions about the establishment and maintenance of hybrid zones, and the effects of biotic and abiotic factors on hybrids. Species belonging to the freshwater gastropod genus Melanopsis frequently hybridize, and surprisingly they have been doing so for more than a million years. This long-term persistence is itself enigmatic, because hybrids have often been labeled evolutionary dead ends due to their lower fertility and viability. We try to understand why and how Melanopsis hybrids persist against the odds.
|
Rock Pool Metapopulation Dynamics
The rock pools on the Skerry islands of the Baltic Sea harbor freshwater communities often dominated by planktonic crustaceans of the genus Daphnia. In collaboration with Basel University, Helsinki University and CNRS Montpellier, we study the ecology and evolution of these Daphnia and their parasites. This project addresses aspects of local adaptation, metapopulation and metacommunity dynamics, inbreeding, parasitism, and genetic population structure. Methods include field surveys, experimental evolution and next generation sequencing.
www.helsinki.fi/en/research-stations/tvarminne-zoological-station/research/current-research-projects#section-30172 |