Comparative genomics in ecological physiology: toward a more nuanced understanding of acclimation and adaptation.

Organisms that live in variable environments must adjust their physiology to compensate for environmental change. Modern functional genomics technologies offer global top-down discovery-based tools for identifying and exploring the mechanistic basis by which organisms respond physiologically to a detected change in the environment. Given that populations and species from different niches may exhibit different acclimation abilities, comparative genomic approaches may offer more nuanced understanding of acclimation responses, and provide insight into the mechanistic and genomic basis of variable acclimation. The physiological genomics literature is large and growing, as is the comparative evolutionary genomics literature. Yet, expansion of physiological genomics experiments to exploit taxonomic variation remains relatively undeveloped. Here, recent advances in the emerging field of comparative physiological genomics are considered, including examples of plants, bees and fish, and opportunities for further development are outlined particularly in the context of climate change research. Elements of robust experimental design are discussed with emphasis on the phylogenetic comparative approach. Understanding how acclimation ability is partitioned among populations and species in nature, and knowledge of the relevant genes and mechanisms, will be important for characterizing and predicting the ecological and evolutionary consequences of human-accelerated environmental change.