I'm an evolutionary biologist interested in understanding the causes, mechanisms, and emerging patterns in the evolution of discrete phenotypic polymorphisms in insects. Phenotypic polymorphisms are a remarkable, yet common form of diversity, wherein extensive phenotypic differentiation is maintained within single species, and often encoded by a single genetic locus. Phenotypic polymorphisms are therefore well-suited systems to investigate fundamental problems in evolutionary biology, such as the genotype-to-phenotype map, the evolution of genetic correlations and co-adapted phenotypes, the origin of novel traits, and the long-term dynamics of genetic diversity. I combine phylogenetic and molecular tools with field-based research and lab-based experiments, to capitalize on the rich research potential of polymorphic insects.
Graduate Student Search
I am interested in advising graduate students who are enthusiastic about working with damselflies, have research experience, and aim to integrate evolution, development, phylogenetics, and genomics, or subset of these fields in their future research. For 2025, I'm looking to recruit a graduate student who will focus primarily on studying the developmental mechanisms of male mimicry in pond damselflies. In addition to this collaborative project, the student will be encouraged to develop their own research projects (with my support and guidance).
If you are a prospective student for 2025, please contact me well in advance of the December 1st, 2024 deadline (preferably in August-September) and include a brief summary of your interests, research experience, and your CV. For more information, visit the Graduate Field of Entomology website.
Recent Research
My research focuses on inter-sexual mimicry polymorphisms in pond damselflies (family Coenagrionidae). Inter-sexual mimicry occurs when individuals of one sex gain a fitness advantage from their resemblance to the opposite sex. Females of many pond damselfly species occur in two or more discrete and heritable color morphs, one of which is typically similar to males, and in at least some cases, a male mimic. Male mimicry in these damselflies provides a frequency-dependent fitness advantage by reducing excessive male-mating attempts, and thus alleviating the fitness costs of sexual conflict. My recent research bridges three main questions using this damselfly system: first, why do female-limited polymorphisms evolve in some lineages but not others? Second, when inter-sexual mimicry does evolve, what is its molecular basis? Third, even if the polymorphism evolves and is maintained by sexual conflict alone, are there any ecological differences between female morphs?
Selected Publications:
- Willink, B., Ware, J., & Svensson, E. I. (2024). Tropical origin, global diversification and dispersal in the pond damselflies (Coenagrionoidea) revealed by a new molecular phylogeny. Systematic Biology, 73(2), 290-307.
- Willink, B., Tunström, K., Nilén, S., Chikhi, R., Lemane, T., Takahashi, M., Takahashi, Y., Svensson, E. I., & Wheat, C. W. (2024). The genomics and evolution of inter‐sexual mimicry and female‐limited polymorphisms in damselflies. Nature Ecology & Evolution, 8, 83-97.
- Vicente‐Santos, A., Willink, B., Nowak, K., Civitello, D., & Gillespie, T. (2023). Host‐pathogen interactions under pressure: A systematic review and meta‐analysis of stress‐mediated effects on disease dynamics. Ecology Letters, 26, 2003-2020.
- Blow, R., Willink, B., & Svensson, E. I. (2021). A molecular phylogeny of forktail damselflies (genus Ischnura) reveals a dynamic macroevolutionary history of female colour polymorphisms. Molecular Phylogenetics and Evolution, 160, 107134.
- Willink, B., Duryea, M. C., Wheat, C., & Svensson, E. I. (2020). Changes in gene expression during female reproductive development in a color polymorphic insect. Evolution, 74(6), 1063-1081.
- Svensson, E. I., Willink, B., Duryea, M. C., & Lancaster, L. T. (2020). Temperature drives pre‐reproductive selection and shapes the biogeography of a female polymorphism. Ecology Letters, 23(1), 149-159.
- Willink, B., Duryea, M. C., & Svensson, E. I. (2019). Macroevolutionary origin and adaptive function of a polymorphic female signal involved in sexual conflict. The American Naturalist, 194(5), 707-724.
- Willink, B., & Svensson, E. I. (2017). Intra‐ and intersexual differences in parasite resistance and female fitness tolerance in a polymorphic insect. Proceedings of the Royal Society B: Biological Sciences, 284(1847), 20162407.
