Evolutionary dynamics in changing environments

Evolution can be understood as an optimization mechanism on the fitness function, which is defined as the reproductive success of a species. If the environmental conditions remain constant, the stationary states of the evolutionary dynamics are the phenotypes at the local maxima of the fitness function. However, a more realistic assumption is that the environmental conditions permanently change on several timescales. The temperature, for example, typically changes between day and night, between summer and winter, and due to short-term weather changes and long-term climate changes. Since the fitness of a species depends on the environmental conditions, evolution in fluctuating environments is an optimization on a temporally changing fitness function. In the first half of this thesis, we show that evolutionary games with environmental fluctuations can have a completely different dynamics than evolutionary games with constant averaged environmental conditions. In the second half, we develop a model for the evolution of shared antibiotic resistance in bacteria and a model for the adaptation of nematodes to changing temperatures to explore possibilities to experimentally test the effects of environmental fluctuations on evolution