Hostname: page-component-7b7567c8c-fvjsw Total loading time: 0 Render date: 2026-11-15T16:43:55.127Z Has data issue: false hasContentIssue false

A test for evolutionary equilibria: Phanerozoic brachiopods and Cenozoic mammals

Published online by Cambridge University Press:  08 April 2016

Graham A. Mark
Affiliation:
Department of Ecology and Evolution, State University of New York at Stony Brook, Stony Brook, New York 11794
Karl W. Flessa
Affiliation:
Department of Earth and Space Sciences, State University of New York at Stony Brook, Stony Brook, New York 11794

Abstract

The fossil record of Phanerozoic brachiopod genera and Late Cenozoic New World mammal genera is examined for evidence of evolutionary equilibria. One necessary (but insufficient) condition is met: within temporal intervals, numbers of originations correlate with numbers of extinctions. Eliminating temporally short-ranging brachiopods, however, reduces the correlation so that it explains only 16% of the variation. More decisive tests of the equilibrium hypothesis appear impossible with available data. Difficulties of temporal and geographic scale, taxonomic level, and ecological consistency must be resolved before equilibrium models can be applied in paleontology for other than inspiration.

Information

Type
Research Article
Copyright
Copyright © The Paleontological Society 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable