Report

Evolutionary and Preservational Constraints on Origins of Biologic Groups: Divergence Times of Eutherian Mammals

+ See all authors and affiliations

Science  26 Feb 1999:
Vol. 283, Issue 5406, pp. 1310-1314
DOI: 10.1126/science.283.5406.1310

You are currently viewing the abstract.

View Full Text

Abstract

Some molecular clock estimates of divergence times of taxonomic groups undergoing evolutionary radiation are much older than the groups' first observed fossil record. Mathematical models of branching evolution are used to estimate the maximal rate of fossil preservation consistent with a postulated missing history, given the sum of species durations implied by early origins under a range of species origination and extinction rates. The plausibility of postulated divergence times depends on origination, extinction, and preservation rates estimated from the fossil record. For eutherian mammals, this approach suggests that it is unlikely that many modern orders arose much earlier than their oldest fossil records.

  • * To whom correspondence should be addressed. E-mail: mfoote{at}midway.uchicago.edu

View Full Text