"The Shifting Balance of Diversity Among Major Marine Animal Groups" by J. Alroy, Science 329 (2010)

Science (3 September 2010), Vol. 329, No. 5996, 1191-1194; DOI: 10.1126/science.1189910

The Shifting Balance of Diversity Among Major Marine Animal Groups

J. Alroy^*

 

Abstract

The fossil record demonstrates that each major taxonomic group has a consistent net rate of diversification and a limit to its species richness. It has been thought that long-term changes in the dominance of major taxonomic groups can be predicted from these characteristics. However, new analyses show that diversity limits may rise or fall in response to adaptive radiations or extinctions. These changes are idiosyncratic and occur at different times in each taxa. For example, the end-Permian mass extinction permanently reduced the diversity of important, previously dominant groups such as brachiopods and crinoids. The current global crisis may therefore permanently alter the biosphere’s taxonomic composition by changing the rules of evolution.

 

Paleobiology Database, University of California, 735 State Street, Santa Barbara, CA 93101, USA.  

^* Present address: Department of Biological Sciences, Faculty of Science, Macquarie University, NSW 2109, Australia.

Link:  http://www.sciencemag.org/cgi/content/abstract/329/5996/1191