Christina Cobbold

From maladaptivity to adaptivity -the evolution of developmental timing

The timing of developmental milestones such as egg hatch or bud break can be important predictors of population success and survival. Many insect species rely directly on temperature as a cue for their developmental timing. With environments constantly under pressure to change, developmental timing has become highly adaptive in order to maintain seasonal synchrony. However, climatic change is threatening this synchrony. Our model couples existing models of developmental timing to a quantitative genetics framework which describes the evolution of developmental parameters. We use this approach to examine the ability of a population of eruptive bark beetle to adapt to an environment that it is highly maladapted to. Through a combination of numerical and analytical approaches we explore the dynamics of the infinite dimensional system of integrodifference equations. The model indicates that developmental timing is surprisingly robust in its ability to maintain synchrony even under climatic change which works constantly to maintain maladaptivity. I will discuss the implications of this for bark beetle outbreaks.