Project: Beyond maternal effects: Transgenerational plasticity in thermal performance

Description from NSF award abstract:
Many marine species are currently undergoing significant range shifts and exceedingly rapid changes in phenotype driven, potentially, by warming, ocean acidification, and human-induced evolution. Dramatic shifts in body size and maturation have been observed in many marine fishes worldwide. There is considerable debate over whether these changes are the result of rapid evolution or physiological responses to changes in environmental variables. Attempts to address these issues typically assume that thermal physiology is fixed or slow to evolve. Transgenerational plasticity (TGP) occurs when the environment experienced by the parents directly translates, without any changes in DNA sequences, into significant changes in offspring. TGP in thermal performance provides a mechanism for a rapid response to climate change that has, to date, been demonstrated only in terrestrial plants. This project will provide the first test of thermal TGP in marine systems and will explore its implications for forecasting responses to human-induced evolution and climate change. First, the PIs will test for thermal TGP in four taxonomically distinct fishes. Then, using sheepshead minnows as a model, they will study the dependence of transgenerational responses on the predictability of the thermal environment and test whether disparate thermal environments select for different levels of TGP. With these data they will develop the first stochastic population model including TGP and use it to understand life history evolution and predict responses to climate change.

The existence of thermal TGP poses a serious challenge to the idea that changes in thermal physiology are slow to evolve and can safely be ignored in modeling population responses to climate change or harvest selection. By extension, virtually all field estimates of heritability and physiological measurements will need to be reconsidered in light of thermal TGP, as will conclusions regarding rapid evolution in shifting environments. The research team has made significant contributions to theoretical and empirical work on the evolutionary, behavioral, and physiological ecology of growth in many different species and environments. Together, the team has substantial prior experience in all aspects of the proposed research and has worked together successfully for many years.