Résumé
In complex environments, such as seasonal environments, adaptation relies on several traits interacting with the environment. Using mathematical modeling of batch experimental evolution, we explored the link between selection, traits and season length.In yeast glucose batch cultures, population dynamics can be separated in three seasons: a fermentation season, during which glucose is consumed and ethanol produced; a respiration season, where ethanol is consumed and a last one where resources are exhausted. Using an ordinary differential equations model calibrated on data of a yeast experimental evolution in successive batch cultures (Spor et al, Evolution, 2014), we showed that the seasonality drives the selection. We found that: (a) a long phase increases selection on the growth rate during this phase, (b) traits that drive response to environmental changes are also under selection (c) different types of feedback between environmental changes and selection pressures occur. Indeed, selection affects the composition of the population, which in turn leads to changes in resources (glucose and ethanol) and poison (ethanol) dynamics and consequently modifies season length and thus selective pressures on traits. We will present these different feedbacks and discuss their impact on life-history traits evolution.