SICB 2015: Lizards in a Warming World: Ectotherm Plasticity in Changing Thermal Environments

While it wasn’t technically a talk about anoles, we’re sure AA readers will want to know the latest work from Alex Gunderson (pictured below), currently a postdoc with Jonathon Stillman at UC Berkeley and SFSU. Yesterday at SICB, Alex described his work on thermal plasticity in five major ectotherm clades (insects, crustaceans, fish, amphibians, and reptiles). Using acclimatization response ratios (ARR) for hundreds of species from these groups, Alex tested the hypothesis that animals in more variable thermal environments would exhibit greater flexibility in thermal acclimation. While he did not find support for that relationship, he did find that habitat type has a strong association with plasticity, as freshwater and marine species have more thermal flexibility than terrestrial species (like our favorite anoles). Next, he extracted the standard deviation of weekly temperatures from the NOAA database, and found that terrestrial animals had more plastic responses to cold tolerance (critical thermal minimum or ‘CTmin’), but not heat tolerance (critical thermal maximum or ‘CTmax’). Additionally, he found and there was no relationship between standard deviation of weekly temperatures and tolerance traits in aquatic species. Thus, terrestrial species had greater plasticity to lower temperatures than higher temperatures. Overall, he found that many types of ectotherms have relatively low capacity for acclimation. This result suggests that plasticity in acclimatization responses will not allow animals to compensate for rising temperatures across the planet, and behavioral responses will instead become more critical.