SFB-TRR 212

The role of niche construction and evolutionary capacitance for evolvability in the Red Flour Beetle, Tribolium castaneum

Niche construction is a process by which organisms modify their environment. Evolutionary capacitance is the storage and release of genetic variation, which may help to sustain fitness under stressful environmental conditions. Niche construction and evolutionary capacitance have in common that they modify the genotype - phenotype - environment relationship and are thus challenging any simple or static view of the ecological niche. Importantly, both processes are assumed to enhance evolvability, however, a clear test of this assumption is as yet lacking. In the Red Flour Beetle Tribolium castaneum, niche construction and evolutionary capacitance are closely connected to the threat of pathogen infection; beetles secrete quinones to manipulate flour microbiota (i.e., 'keeping their environment clean'), thereby constructing their niche. Moreover, in the presence of wounded conspecifics in a group of beetles (i.e., under infection risk), naive individuals reduce the expression of a genetic capacitor, the molecular chaperone heat shock protein HSP90. The resulting release of cryptic genetic variation would have the potential to enhance adaptability. This creates a unique possibility to explore the effect of individuals with immunological experience on niche construction and evolutionary capacitance of the group, as well as the role of these processes for evolutionary adaptation. Therefore, the central question of this proposal is: what is the role of individual niche construction and evolutionary capacitance, alone and in concert, for evolvability?