Estimating the distribution of fitness effects from DNA sequence data: Implications for the molecular clock
- Centre for the Study of Evolution and School of Biological Sciences, University of Sussex, Brighton BN1 9QG, United Kingdom
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Edited by Tomoko Ohta, National Institute of Genetics, Mishima, Japan, and approved July 11, 2003 (received for review May 22, 2003)
Abstract
We present a method for estimating the distribution of fitness effects of new amino acid mutations when those mutations can be assumed to be slightly advantageous, slightly deleterious, or strongly deleterious. We apply the method to mitochondrial data from several different species. In the majority of the data sets, the shape of the distribution is approximately exponential. Our results provide an estimate of the distribution of fitness effects of weakly selected mutations and provide a possible explanation for why the molecular clock is fairly constant across taxa and time.
Footnotes
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↵ * To whom correspondence should be addressed. E-mail: a.c.eyre-walker{at}sussex.ac.uk.
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This paper was submitted directly (Track II) to the PNAS office.
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Abbreviation: MK, McDonald-Kreitman.
- Copyright © 2003, The National Academy of Sciences
