Interactive effects of environmental change and host-parasite co-evolution on the ecological speciation of sticklebacks
Final Report Abstract
Parasites are a ubiquitous selection pressure in nature. They can drive rapid evolution and divergence of host populations, with the potential to culminate in speciation events. At the same time, they can maintain polymorphism within populations. Besides these direct effects on their host, parasites can affect whole ecosystems, making them a strong link between ecological and evolutionary dynamics. These diverse parasite effects are further altered by environmental conditions which can modify the outcome of host-parasite interactions severely. Modifications of parasite-mediated selection pressures can ultimately change evolutionary trajectories and affect the progression towards speciation of host populations. Along this project we characterized ways in which environmental change may affect parasite mediated aspects of host speciation, using the three-spined stickleback Gasterosteus aculeatus and its parasites as a model system. Using field studies we revealed that eutrophication is associated with different phenotypes and gene expression profiles of the fish. However, under natural condition it is impossible to disentangle the cause and consequences of those traits. Therefore we conducted a series of mesocom experiments and found that both parasites and eutrophication alter feeding ecology and have consequences on the resistance and tolerance capacity of the fish. Furthermore, we demonstrated that those effects that are strong that fish modify the environment they live in, creating new selection pressure for their offspring. With this work, we reveal that the sole presence of parasites is sufficient for eco-evolutionary feedbacks to emerge. Focusing on sexual selection, we found that mating with infected males has costs but also benefits if the parasites experienced by the offspring are the same as the ones experienced by their parents. From the an evolutionary perspective, the combine work on natural and sexual selection reveal that parasites contribute to adaptive divergence of the three-spined stickleback but eutrophication slows down this process.
Publications
- (2017) A field reciprocal transplant experiment reveals asymmetric costs of migration between lake and river ecotypes of three-spined sticklebacks (Gasterosteus aculeatus). Journal of evolutionary biology 30 (5) 938–950
Kaufmann, J.; Lenz, T. L.; Kalbe, M.; Milinski, M.; Eizaguirre, C.
(See online at https://doi.org/10.1111/jeb.13057) - (2017) Experimental evidence that parasites drive eco-evolutionary feedbacks. Proceedings of the National Academy of Sciences of the United States of America 114 (14) 3678–3683
Brunner, Franziska S.; Anaya-Rojas, Jaime M.; Matthews, Blake; Eizaguirre, Christophe
(See online at https://doi.org/10.1073/pnas.1619147114) - (2017) Mate choice in sticklebacks reveals that immunogenes can drive ecological speciation. Behavioral ecology : official journal of the International Society for Behavioral Ecology 28 (4) 953–961
Andreou, Demetra; Eizaguirre, Christophe; Boehm, Thomas; Milinski, Manfred
(See online at https://doi.org/10.1093/beheco/arx074) - 2012. Divergent selection on locally adapted major histocompatibility complex immune genes experimentally proven in the field. Ecology Letters, 15, 723-731
Eizaguirre, C., Lenz, T. L., Kalbe, M. & Milinski, M.
- 2015. The contribution of post-copulatory mechanisms to incipient ecological speciation in sticklebacks. Biology Letters, 11
Kaufmann, J., Eizaguirre, C., Milinski, M. & Lenz, T. L.
(See online at https://doi.org/10.1098/rsbl.2014.0933) - 2016. Can environmental change affect host/parasite-mediated speciation? Zoology, 119, 384-394
Brunner, F. S. & Eizaguirre, C.
(See online at https://doi.org/10.1016/j.zool.2016.04.001) - The association of feeding behaviour with the resistance and tolerance to parasites in recently diverged sticklebacks. Journal of Evolutionary Biology, 29 (11), 2157–2167
Anaya-Rojas, J. M., Brunner, F. S., Sommer, N., Seehausen, O., Eizaguirre, C. & Matthews, B.
(See online at https://doi.org/10.1111/jeb.12934)
