Processes of current and past global change have been successfully identified and modeled by treating the earth as a physical or chemical system. Quantitative characterization of global change in the biota lags far behind. Units of measurement include biomass, productivity, abundance, diversity and species longevity. The response time to forcings of the physical and chemical systems range from seasons to a few thousand years. Response times of quantifiable aspects of the biosphere, however, may range from the ecological time-scale of days up to the evolutionary time-scale of millions of years. The models used by ecologists and evolutionists focus both on characterizing the type and extent of abiotic and biotic processes acting on living and on evolving populations of organisms. The spacial and temporal scales to be considered in studies of ecological and evolutionary controls, however, are vastly different. Investigations of the seasonal dynamics of coccolithophores document their strong correlation with changes of the physical-chemical environment (bottom-up control). A few detailed stratigraphic studies indicate that physical forcing also operated on evolutionary time-scales. Although commonly observed in living communities and laboratory experiments, the quantification of the influence of biotic forcing (top-down) by organism-organism interactions (grazing, predation, competition, infection) in ecology and particularly in paleontology, remains elusive. Difficulties in reconciling plankton diversity and longevity with commonly accepted ecological and evolutionary theory underscores the need for better understanding basic behaviors of the biosphere.
Thierstein, H. R., Cortés, M. Y., & Haidar, A. T. (2004). Plankton community behavior on ecological and evolutionary time-scales: when models confront evidence. In Coccolithophores (pp. 455–479). Springer Berlin Heidelberg. https://doi.org/10.1007/978-3-662-06278-4_17