Research Group of Evolutionary Biology (IBED-EB)
Central to evolutionary biology is the evolution of species, i.e. speciation. This phenomenon is responsible for the staggering biodiversity that we observe in the variety of fossil and extant life forms. Crucial processes in speciation are genetic population differentiation and reproductive isolation. The research group studies the evolutionary genetic mechanisms behind these two processes, as well as the resulting phylogeographic patterns. As model groups we use moth species that differ in their host plant use, phytophagous mites, and marine zooplankton. The knowledge generated is applied in nature conservation, sustainable development, and biological control. Pest organisms are among our main subjects.
(1) Evolution of host plant choice in Lepidoptera
Host plant choice plays a key role in speciation. Switches in host plant choice can be linked to speciation events, because host plant specificity may reduce genetic exchange between populations. We address the following questions:
(i) Which genes vary in relation to differential host plant use? Of special interest are genes coding for receptor proteins specifically recognizing plant odours and taste. Read more.
(ii) What is the extent of phenotypic differentiation in the chemosensory system of host races or closely related specialist species, and how do changes in sensory perception contribute to changing ecological relations? Read more.
(iii) Understanding evolutionary patterns of host plant use across the Lepidoptera. Read more.
(2) Evolution of sexual communication in Lepidoptera
Variation in sexual communication can directly lead to reproductive isolation. The main question is when and how mating signals and preferences for these signals coevolve. Moths are ideal organisms to address this question, because moth sexual communication is purely chemical: males are attracted from a distance to a species-specific sex pheromone, produced by conspecific females. Specific questions that we address are:
(i) Which genes underlie variation in sex pheromone production and perception? Read more.
(ii) What environmental factors affect variation in signal and response? Factors under study include parasitoid wasps homing in on pheromonal signals and interference from closely related species. Read more.
(3) Evolutionary genetics of host-bacterial interactions
Interactions between arthropods and internal bacteria are widespread and diverse. These interactions have important effects on host fitness, adaptation, and reproductive isolation as well as on the evolution of host reproductive systems. We investigate the functional and evolutionary consequences of intra- and extracellular microorganisms on the mode of reproduction and speciation of spider mites and moths. Our research focuses on the following questions:
(i) The role of cytoplasmic incompatibility- or parthenogenesis-inducing microorganisms on reproductive isolation, host adaptation, clonal diversity, and speciation. Read more.
(ii) Evolutionary consequences of microbial midgut communities on host adaptation and mate choice. Read more.
(4) Population structure and phylogeography
Current population structure is the result of historical events and processes. Phylogeography in combination with coalescence theory enable us to reconstruct the evolutionary history of populations and species. This provides insights in the factors that are important in species distribution patterns and speciation processes, and how these are affected by ever-increasing human pressures.
We study the following issues:
(i) Phylogeography, genetic population structure, and diversity of marine zooplankton (chaetognaths, pteropods). Read more.
(ii) Genetic population structure and connectivity in endangered reptile species in the Netherlands. Read more.