Caroline Williams, PhD

The Williams lab studies the evolution of metabolic physiology in ectotherms, using insects as models. We are interested in the mechanisms and consequences of metabolic responses to emerging winter environments. This is important because winter climate change is altering energy balance, phenology, and cold stress in overwintering organisms leading to cascading biological impacts that carry over into the growing season and affect survival and fitness. The ability to adapt or acclimate metabolic systems to compensate for changing winter conditions will strongly determine organismal responses to winter climate change. However, we know little about the mechanisms underlying metabolic plasticity in ectotherms, nor the evolutionary potential of metabolic systems on macro or micro scales. As climate change leads to the emergence of novel climates, we can no longer rely on bioclimatic envelope models to predict organismal responses to climate change; we need a mechanistic and predictive understanding that explicitly includes winter processes. 

We use an integrative “genes to fitness” approach through the lens of intermediary metabolism and metabolic physiology to find the genes that influence overwintering energetics, from the level of naturally segregating variation within populations, through inter-population local adaptation, to interspecific divergence. This provides a novel framework for predicting ecological and evolutionary responses to winter climate change based on a mechanistic understanding of metabolic physiology. Addressing genotype – phenotype interactions through the lens of intermediary metabolism is advancing our understanding of the genetic control of complex, fitness-relevant traits.