Rapid Evolution of Parasite Resistance in a Warmer Environment: Insights from a Large Scale Field Experiment

Abstract

Global climate change is expected to have major effects on host-parasite dynamics, with potentially enormous consequences for entire ecosystems. To develop an accurate prognostic framework, theoretical models must be supported by empirical research. We investigated potential changes in host-parasite dynamics between a fish parasite, the eyefluke Diplostomum baeri, and an intermediate host, the European perch Perca fluviatilis, in a large-scale semi-enclosed area in the Baltic Sea, the Biotest Lake, which since 1980 receives heated water from a nuclear power plant. Two sample screenings, in two consecutive years, showed that fish from the warmer Biotest Lake were now less parasitized than fish from the Baltic Sea. These results are contrasting previous screenings performed six years after the temperature change, which showed the inverse situation. An experimental infection, by which perch from both populations were exposed to D. baeri from the Baltic Sea, revealed that perch from the Baltic Sea were successfully infected, while Biotest fish were not. These findings suggest that the elevated temperature may have resulted, among other outcomes, in an extremely rapid evolutionary change through which fish from the experimental Biotest Lake have gained resistance to the parasite. Our results confirm the need to account for both rapid evolutionary adaptation and biotic interactions in predictive models, and highlight the importance of empirical research in order to validate future projections.

Environmental stress correlates with increases in both genetic and residual variances: A meta-analysis of animal studies

“…As an adaptive evolutionary response is determined by the strength of selection and amount of genetic variation, high genetic variation will increase the potential speed with which populations adapt to stressful conditions (Fisher 1930). Our finding may therefore contribute to a greater understanding of the evolutionary responses to global change, which is of critical importance now, when animals are responding to stress caused by unprecedented levels and variability in, for example, temperature (Helmuth et al 2002), humidity (Kellermann et al 2009), starvation (Chippindale et al 1996), competition (Rogell et al 2012), or pathogen levels (Mateos-Gonzalez et al 2015). All these stressors were also included among the experimental treatments used by the studies incorporated in the present meta-analysis.…”

A Phylogenomic Framework and Divergence History of Cephalochordata Amphioxus

“…Therefore, a relatively closed habitat may be a key factor for driving the rapid evolution of B. lanceolatum propelled by its weaker ability to buffer against changing ecological factors. Seawater, warmed by a nuclear power plant since 1980 has been reported to cause rapid evolution of parasite resistance in the European perch of the nearly closed Baltic Sea (Mateosgonzalez et al, 2015). Additionally, one of the longer branches in the phylogenetic tree is the branch connecting the amphioxus to the other clades.…”

Long‐term warming affects ecosystem functioning through species turnover and intraspecific trait variation

“…Recently, it has also been shown that the long-term, in situ warming has caused local adaptation as populations of the gastropod grazer Galba truncatula in the heated area have genetically diverged from the nearby populations outside the basin and adapted to the warming in terms of growth rate and survival (Ermold 2016; assessed after 28 years of warming). Moreover, the predatory fish Perca fluviatilis, one of the most common fish species in the heated area, has developed a higher parasite resistance compared to its conspecifics in the nearby archipelago (Mateos-Gonzalez et al 2015; assessed after >30 years of warming). We studied changes in both species assemblage (i.e.…”