Finding the right mating partner is crucial for all sexually reproducing species, including humans. Variation in sexual attraction between populations is hypothesized to be important in the speciation process. To determine the role of sexual attraction in speciation, genes responsible for within-species variation will need to be identified, and the level of phenotypic plasticity needs to be assessed. Moths are ideal animals to identify these factors: i) Females attract males through a well-defined species-specific sex pheromone, which is produced in a special pheromone gland. ii) We found significant geographic variation in the pheromone blend of the noctuid moth Heliothis subflexa (Hs), especially in one group of compounds with a dual function: the acetates not only enhance attraction of conspecific males but also inhibit attraction of heterospecific Heliothis virescens (Hv) males. iii) Through QTL analysis we found one major QTL, explaining 40% of the geographic variance in the acetates, and we constructed a cDNA library from the pheromone gland to generate candidate genes involved in the pheromone biosynthetic pathway. This sets the ideal stage to identify the responsible gene(s) for the acetate variation. iv) Recently, we found that Hs females change their signal when emerged in the odor of heterospecific Hv. Such phenotypic plasticity has not been explored in moth sexual communication before. Therefore, we also propose to determine the level of phenotypic plasticity in Hs sexual communication. Identifying genes (G) and the level of environmental variation (E) will give the unique opportunity to disentangle evolutionary forces shaping sexual attraction.

The force of sexual selection is easy to envision when the signalling sex produces elaborate traits, more of which is sexier: Fisherian runaway selection. However, when closely related species have very similar mating signals, these signals are important for species recognition to minimize the risk of interspecific attraction. In this case, mating signals seem to be under stabilizing selection, and sexual selection is not likely to be a driving force in the speciation process. The underlying assumption is that one sex is the signaller and the other sex the responder. The forces of sexual selection can be very different when both sexes are signallers and responders. Such sexual communication occurs in one of the most diverse group of animals: moths. In moths, the species-specific female sex pheromones to which males are attracted from a distance have been studied in detail, because these pheromones can be used for pest management. However, at close-range, males produce and emit males produce a biosynthetically related but different pheromone from elaborate glands (hairpencils) that is likely important for close-range female choice and/or male competition. We aim to determine the role of close-range courtship in generating variation in the sexual communication channel to assess the strength of mutual mate choice in a species where we have found a within-population polymorphism in the female sex pheromone, which is not expected under stabilizing selection. Understanding the forces of sexual selection in the speciation process is imperative for understanding biodiversity patterns in general and for pest development in particular.

The timing of light exposure, physical activity, and food intake are important cues for synchronising the biological clock. Disruption of the biological clock is a clear threat to both public health and vulnerable ecosystems. Especially in a highly industrialised country such as The Netherlands there is a mismatch between biological clocks and social demands. However, these cues have drastically – and abruptly - changed in our modern society due to the widespread use of artificial light and the round-the-clock demand for goods and services. Fundamental research has shown that precisely these conditions cause desynchrony among clock cells.

This project addresses questions across three scientific fields—predicting evolution, finding lifes building blocks in space, and improving science communication. The first effort studies C. elegans worms to predict how organisms evolve in response to climate change, identifying 681,232 DNA differences across populations to forecast evolutionary outcomes for food security. The second project investigated amino acids in space using SURFRESIDE3, finding they remain on dust grains at temperatures below 300 K, providing data for space missions. The third project analyzed 630 articles on astrobiology communication, finding that speculation requires contextualization and advocating for epistemological modesty—communicating what we dont know.