Conversations about Phanerozoic global diversity

The emergence of Phanerozoic global diversity as a central theme of investi gation has resulted from a confluence of factors, including the assembly by several researchers of global taxonomic databases; the advent of computers , which permitted construction and analysis of global Phanerozoic diversity trajectories; and the recognition that Phanerozoic diversity trends are im portant bellwethers of the evolutionary processes that cause biotic transit ions. Despite the enormous progress in the measurement and interpretation o f Phanerozoic diversity over the past quarter century, much of which has be en reported in Paleobiology, these studies have collectively generated at l east as many new questions as they have answered-arguably the mark of an ar ea of inquiry that continues to be vital. In this essay, I discuss several outstanding issues in the investigation of Phanerozoic diversity, ranging f rom the viability of literature-derived databases for investigating global diversity trends, to the biological significance of the myriad biotic trans itions that have taken place throughout the Phanerozoic.