Host-Parasite Coevolution
Coevolutionary interactions between hosts and parasites are recognised
as main potential forces influencing the life-history of both antagonists. A
central prediction of coevolutionary theory is the
reciprocal increase in parasite virulence and host defence,
acting antagonistically to shape virulence evolution. Virulence is defined as
the fitness reduction of the host caused by a parasite (including here
viruses, bacteria and macroparasites).
Abiotic environmental conditions such as temperature
affect both parasites and hosts and are known to variably influence virulence
on the short-term. However, how coevolutionary
dynamics shape virulence evolution on the long-term under changing
temperatures is unresolved.
Within this project we have made use of an experimental coevolution
approach to study how increasing temperatures influence virulence evolution
on the long-term. To answer this question, we used the ciliate Paramecium tetraurelia infected with Caedibacter
taeniospiralis bacteria. Particularly, we analysed how temperature influences the reciprocal
evolutionary increase in parasite virulence and host defence
predicted by coevolutionary theory. The main goal
of this project was to experimentally test for temperature dependent coevolutionary dynamics shaping virulence evolution to
better understand how host-parasite interactions change in a highly variable
world.
This project was associated to the Priority Programme "Host-Parasite Coevolution - Rapid Reciprocal
Adaptation and its Genetic Basis" of the German Research Foundation (Deutsche
Forschungsgemeinschaft, DFG) and part of the PhD thesis of Eike Dusi (Institute of Hydrobiology, TU Dresden), performed in close cooperation
with Oliver Kaltz (Institut
des Sciences de l'Evolution, CNRS, Université Montpellier 2, France).