Biodiversity Change: Past, Present, and Future

The traditional use of indicator species is to monitor for changes in the environment, rather than in biodiversity, so a combined temporal trend for such species may suggest much more rapid biodiversity change. Despite the difficulties, there is unambiguous evidence that biodiversity has changed over time both naturally and as driven by human-caused pressures. This chapter briefly sketches some of this evidence, followed by a summary of how biodiversity is thought likely to change in the near future. Perhaps the best-known examples of biodiversity change in geological history are mass extinctions, such as the end-Permian and end-Cretaceous events, which wiped out trilobites and non-avian dinosaurs, respectively. Most analyses of global biodiversity trends through deep time have been forced to study shallow-sea shelly invertebrates as a proxy, because most other species were unlikely to leave fossils. The Industrial Revolution facilitated and drove sophisticated and intensive management of ecosystems to meet the needs of the growing population.