Supporting Predators: Changes in the Global Ecosystem Inferred from Changes in Predator Diversity

Abstract

This paper presents new estimates of the genus diversity of predators in each major taxon containing predators, as well as an estimate of the total genus diversity of predators through the Phanerozoic. Predators have never been numerically abundant compared to prey. However, the diversity of predators and the proportion of total faunal diversity composed of predators have both increased over time, implying that ecosystems have increased their ability to support either more predators or more specialization among predators. Also, turnover in diversity dominance among predator groups, with more energetic predator taxa replacing or being added to a fauna of less energetic groups, implies that the energy available in marine food webs has increased. The apparent increase in diversity and biomass of primary producers plus patterns of diversity change in prey taxa supports these inferences based on patterns of change in predators alone.