Marjolein is an evolutionary ecologist, with broad interests in host-microbe interactions, life history evolution and population ecology. Her research integrates theory with empirical research. Marjolein completed my PhD at Radboud University Nijmegen in 2019, on the importance of genetic variation and plasticity in, amongst others, water fleas. For her post-doctoral research at Princeton University, she became interested in the microbiome, and in particular in the role of the microbiome in host evolution and adaptation. In 2022, Marjolein joined the department of Evolutionary and Population Biology as an assistant professor. She has various opportunities for student projects, so don't hesitate to contact her if you are interested.

Microbes living in and on hosts, termed the microbiome, are critical for healthy hosts. The relationships between hosts and their microbiomes are among the most intimate interactions found on the planet, and their coevolutionary trajectories are both fascinating and puzzling. For instance, is the microbiome under host or under microbe control? Can the microbiome rescue populations that are otherwise maladapted? When do good microbes become bad? Can we select for beneficial microbes, for instance to increase crop yield or for conservation?

Specific research topics include:

Microbiome extensions of host evolutionary potential. Marjolein studies how and when microbiomes can benefit their host, and how this is shaped by patterns of microbial transmission, contrasting selection pressures, interactions between hosts and microbes, and within-host microbial interactions. To do so, she develops methods to incorporate the microbiome into traditional evolutionary theory.

The microbiome in mediating disease dynamics. The impact of pathogens on natural populations is expected to intensify under global change. As the microbiome has the potential to mediate host responses to such pathogen infections, it is important to understand the causal links between the microbiome, pathogens and host performance. How do population adapt to climate change, and can we harness the microbiome to alleviate future epidemics? Marjolein plans to unravel this in water fleas, a keystone species in freshwater systems and a bio-indicator for ecosystem health, combining novel experiments with modelling.

Automated image analysis. Marjolein's work advances novel technologies and methods. She previously developed software to obtain automated population counts using computer vision, available as an R-package trackdem (see CRAN and Github).