title: Rarity in mass extinctions and the future of ecosystems.
abstract: The fossil record provides striking case studies of biodiversity loss and global ecosystem upheaval. Because of this, many studies have sought to assess the magnitude of the current biodiversity crisis relative to past crises-a task greatly complicated by the need to extrapolate extinction rates. Here we challenge this approach by showing that the rarity of previously abundant taxa may be more important than extinction in the cascade of events leading to global changes in the biosphere. Mass rarity may provide the most robust measure of our current biodiversity crisis relative to those past, and new insights into the dynamics of mass extinction.
authors.affiliation: Department of Geology and Geophysics, Yale University, New Haven, Connecticut 06520-8109, USA.
authors.forename: Pincelli M
authors.initials: PM
authors.lastname: Hull
authors.affiliation: Department of Paleobiology, National Museum of Natural History, Washington, DC 20013-7012, USA.|Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, Tennessee 37235-1805, USA.
authors.forename: Simon A F
authors.initials: SA
authors.lastname: Darroch
authors.affiliation: Department of Paleobiology, National Museum of Natural History, Washington, DC 20013-7012, USA.
authors.forename: Douglas H
authors.initials: DH
authors.lastname: Erwin
mesh_terms: D000818:Animals; D044822:Biodiversity; D005075:Biological Evolution; D002965:Classification; D003247:Conservation of Natural Resources; D004463:Ecology / Q000379:methods; D017753:Ecosystem; D053476:Extinction, Biological; D005580:Fossils; D011156:Population Density