D.M. Ekkers, MSc
Understanding how the developmental and physiological complexity of the genotype-phenotype map determines what phenotypes can be realized during adaptation is a major challenge. In my project I study the interplay of selection and constraints in the evolution of diversity under varying selection. Evolutionary diversification is a critical component of speciation, adaptive radiation and other processes generating biodiversity. Phenotypic diversification is predicted to depend crucially on the presence of constraints that are strong enough to favor specialization and prevent the evolution of a generalist. As the actual mechanisms that impose these constraints have not been included in the theoretical models, it remains questionable under what conditions evolutionary diversification occurs. Furthermore, natural populations can diversify in several different ways, involving either the maintenance of genetic variation or phenotypic diversification mechanisms such as plasticity and stochastic phenotype switching. I am adopting an experimental evolution approach to study how molecular level developmental constraints and varying environmental conditions affect adaptive diversification through the formation of polymorphisms. The model bacterium Lactococcus latis will be grown in chemostats under different regimes of environmental variation. Evolved strains derived from this experiment are checked for phenotypic diversification. This approach strives to marry knowledge and findings on the molecular genetic level (network interactions, network topology and mutagenic mechanisms) with specific environmental variation in space and time by examining the phenotypic diversity (transcriptional, growth, frequency distribution and metabolic profiles) of the evolved populations. The experiment will provide insight into the interaction between selective forces generated in a heterogeneous environment and the molecular level constraints caused by molecular interactions and gene regulation in the context of metabolism. The results will clarify what types of phenotypic diversification (genetic, plastic or stochastic) and population dynamics are expected under which conditions.
|Last modified:||22 October 2018 07.36 a.m.|