Speaker
Description
Both biotic (e.g. pollinators, herbivores) and abiotic ecological factors (e.g. soil, temperature) cause selection and thus impact adaptive evolution in plants. Nevertheless, we know little about the impact of individual factors and their interactions, as well as the speed of evolutionary adaptation, because of the paucity of controlled experimental studies addressing these questions in plants and insects. Since several years my group has been using experimental evolution in semi-natural conditions in the greenhouse, to study real-time plant evolution driven by different ecological factors. In my talk I will give an overview of some of the evolutionary effects that we have demonstrated, with particular focus on floral attractiveness- and defense traits. We have found that efficient generalist bee pollinators like bumblebees select for taller plants and more attractive flowers, including higher scent emission and UV reflection. Low efficient pollinators on the other hand select for more selfing. Bumblebees also select against defense compounds, whereas herbivores select for more defense, leading to a reduction in the attractiveness of flowers. For the abiotic factors, soil enables or disables evolutionary responses to selection, through the availability of nutrients. Increased temperature leads to reduction in floral volatiles, and more but smaller flowers. Biotic and abiotic factors also show strong interactive effects, for example, bumblebee pollination leads to phenotypic divergence in response to soil type, and elevated temperature leads to more UV-reflection with bumblebee pollination. Overall, experimental evolution shows how plants can rapidly adapt to environmental factors, explaining the geographic variability in pant traits in nature. Our experiments also show how environmental change may impact evolutionary trajectories of plants in the future.
