"Species do not live in isolation, but adapt and ultimately, evolve, in relationship with other species as well as with their chemical and physical environment. In the marine environment, this interaction is intimately two-way – the surface biogeochemical environment modulates the makeup of the pelagic ecosystem, yet at the same time, the ecosystem assemblage, by setting the strength of the biological pump and ultimately, in regulating the carbon and nutrient inventory of the ocean and atmospheric pCO2, influences the surface geochemical environment. Feedbacks, both negative and positive, must therefore exist between plankton ecology and global biogeochemical cycles. This has implications for understanding the geological record and particularly the response and recovery of marine ecosystems following major environmental perturbation, but also complicates making projections of future ocean changes.The proposed project – PALEOGENiE – will directly address these challenges via the development of a unique coupled model of past plankton ecology and global biogeochemical cycles. The geological record of planktic ecosystems – nannofossils – will be collated and analyzed across a spectrum of geological events for which evidence of major changes in climate and massive carbon release together with the response of planktic ecosystems are recorded: the Paleocene-Eocene Thermal Maximum, the end Cretaceous, and Ocean Anoxic Event 2. Both model and data will then be brought together in a unique attempt to better understanding the micropaleontological record of how sensitive marine ecosystems are to global change as well as how they recover. If successful, PALEOGENiE may help constrain the potential for adaptation as well as rates of evolutionary change, and ultimately could lead to meaningful insights and guidance for the next generation of Earth system models we need to better constrain the future response of marine ecosystems to continued fossil fuel combustion."