Induced defences alter the strength and direction of natural selection on reproductive traits in common milkweed

Taking a bite crosses the line with sex…in plants. Former MSc student Ken Thompson and NSERC USRA student Katie Cory (Johnson Lab) recently published “Induced defences alter the strength and direction of natural selection on reproductive traits in common milkweed” in the Journal of Evolutionary Biology. Ken and Katie conducted their field studies here on the UTM campus, where they investigated how insect damage, and the hormonal up-regulation of a plant’s chemical defences alters natural selection on plant reproductive traits in common milkweeds. Although the ecology and evolution of plant defences are generally thought to be independent of plant reproduction, their experiment shows that the up-regulation of plant defences leads to natural selection for plants to have a larger number of small flower clusters, whereas control plants experienced selection in the opposite direction - fewer large flower clusters. Their work is an example of how the evolution of a plant’s defences and reproduction are intimately intertwined. As a bonus, Ken and Katie’s paper got the cover of the journal – congratulations and great work!