|Marine biodiversity dynamics over deep time|
|Marshall, C.R. (2010). Marine biodiversity dynamics over deep time. Science (Wash.) 329(5996): 1156-1157|
|In: Science (Washington). American Association for the Advancement of Science: Washington DC. ISSN 0036-8075, more|
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The fossil record provides our only direct window into how Earth's biodiversity has changed over the past 530 million years. Efforts to dissect diversity dynamics, however, have been impeded by gaps in the fossil record and uneven sampling by paleontologists. As a result, two of the most fundamental questions in paleobiology remain contentious. How, in detail, has diversity changed over geologic time? And what is the nature of the rules that governed these diversity changes? More specifically, was the diversification of most groups of organisms unconstrained, or was it subject to some sort of limit? On page 1191 of this issue, Alroy (1) presents a new analysis of the marine fossil record that goes to the heart of these questions. The results are unlikely to be universally accepted, but they help to pinpoint the critical issues.