The challenges to inferring the regulators of biodiversity in deep time

Attempts to infer the ecological drivers of macroevolution have long drawn inspiration from work on extant systems, but long-term evolutionary and geological changes complicate the simple extrapolation of such theory into a deep-time setting. Recent efforts to incorporate a more informed ecology into macroevolution have moved beyond the descriptive to attempts that seek to isolate the generating mechanisms of dynamic signatures to produce testable hypotheses of how species and larger groups usurp or co-exist alongside one another over vast spans of time. The papers of this Theme Issue exemplify this progress, providing a series of case studies of how novel modelling approaches are helping infer the regulators of biodiversity in deep time. In this Introduction, we aim to discuss the challenges associated with this area. We break our Introduction into four main areas. First, we discuss how our choices of biological units for study have implications for the conclusions subsequently drawn. Second, we emphasize the need to embrace the interdependence of biotic and abiotic change, because no living organism ignores its environment. Third, in the light of parts 1 and 2, we discuss the set of dynamic signatures that we might expect to observe in the fossil record. Finally, we ask whether these signatures are the most ecologically informative foci for research efforts aimed at inferring the regulators of biodiversity in deep time. The papers in this Theme Issue contribute in each of these areas.