A história evolucionária é repetidamente reescrita à luz de novas descobertas de fósseis?

quinta-feira, setembro 02, 2010

Is evolutionary history repeatedly rewritten in light of new fossil discoveries?

J. E. Tarver*†, P. C. J. Donoghue and M. J. Benton

-Author Affiliations

Department of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ, UK
*Author for correspondence (james.tarver@bristol.ac.uk).

↵† Present address: Department of Biological Sciences, Dartmouth College, North College Street, Hanover, NH 03755, USA.

Abstract

Mass media and popular science journals commonly report that new fossil discoveries have ‘rewritten evolutionary history’. Is this merely journalistic hyperbole or is our sampling of systematic diversity so limited that attempts to derive evolutionary history from these datasets are premature? We use two exemplars—catarrhine primates (Old World monkeys and apes) and non-avian dinosaurs—to investigate how the maturity of datasets can be assessed. Both groups have been intensively studied over the past 200 years and so should represent pinnacles in our knowledge of vertebrate systematic diversity. We test the maturity of these datasets by assessing the completeness of their fossil records, their susceptibility to changes in macroevolutionary hypotheses and the balance of their phylogenies through study time. Catarrhines have shown prolonged stability, with discoveries of new species being evenly distributed across the phylogeny, and thus have had little impact on our understanding of their fossil record, diversification and evolution. The reverse is true for dinosaurs, where the addition of new species has been non-random and, consequentially, their fossil record, tree shape and our understanding of their diversification is rapidly changing. The conclusions derived from these analyses are relevant more generally: the maturity of systematic datasets can and should be assessed before they are exploited to derive grand macroevolutionary hypotheses.

fossil record   macroevolution   primate   dinosaur   systematics   hominids

Footnotes

Received March 26, 2010.
Accepted August 12, 2010.
© 2010 The Royal Society

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