| Understanding the mechanisms and rates of climatic adaptation by marine organisms is a major challenge that requires a cross-disciplinary approach between the fields of biology and geology. There is growing concern that climate change will disrupt marine productivity and calcification by rising ocean temperatures and lowering of ocean pH ('ocean acidification'). However, future predictions are complicated by the fact that physiological responses to environmental change vary both between and within species of extant marine organisms. Using coccolithophores (a prominent group of calcifying algae) as an example, this project aims to unravel why different species respond differently to environmental change, and determine what climatic parameters drive phenotypic plasticity or genetic variation within marine phytoplankton. These questions will be addressed within an interdisciplinary framework of fossil time series data, controlled culture experiments and evolutionary modeling. Fossil time series of coccolith size and shape variability are taken as a measure for species-specific climatic adaptation. This data set has an excellent biogeographic and temporal coverage (~63 million years). Phylogenetic comparative methods will serve as a guide for development of process-based evolutionary models for the analysis of such time series. Combined with detailed knowledge of the physiology and ecology of living descendant species, this research will navigate through the complexities of climatic-biotic interactions across temporal and spatial scales. Bridging the fields of geology and biology, this innovative approach has the potential to revolutionize our understanding of biotic responses to climatic change. Specifically, improved insights into the heterogeneity of adaptive strategies within marine functional plankton groups will aid in the assessment of future climate change impact and mitigation. |
