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| This is a comprehensive bibliography (under construction) of primary and secondary sources on the neutral theory of molecular evolution. It currently covers the period 1973-2001. |
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Author :
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Colgan, D. J.
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Year :
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1997
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Title :
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Estimating selective coefficients of allelic substitutions from patterns of interspecific allozymic mobility difference
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Journal :
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Heredity
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Volume :
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78
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Pages :
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655-664
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Date :
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Jun
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Short Title :
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Estimating selective coefficients of allelic substitutions from patterns of interspecific allozymic
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Alternate Journal :
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Heredity
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Custom 2 :
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ISI:A1997XE87300011
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Abstract :
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The neutral hypothesis of molecular evolution predicts that there should be a 1:1 ratio between allozymes in a species which are faster or slower than allozymes at the corresponding loci in a second species. Methods are presented in this paper for estimating selective differentials from observed values of r, the deviation from a fraction of 1/2 in the proportion of substitutions conferring a mobility change in a specified direction. Although the methods were developed for allozymes, they are readily applied to cases where two taxa may differ in other properties, such as DNA sequence. r is related to the selection coefficient s under a 'genic selection' model. If a change in one direction is favoured in one species and a change in the other direction is equally favoured in the second species, both s and N are assumed constant and only one substitution has occurred at each locus, then the estimate of s is approximately (ln(1/2+r)-ln(1/2-r))/4N. If selective coefficients follow an unspecified distribution f(s) and N is assumed constant, then the average value of s lies between r/2N(1/2 + r) and r/2N(1/2 - r). Specifying the distribution of s to enable point estimation of E(s) is mathematically difficult for the usual probability density functions. A new family of distributions is suggested to overcome these difficulties. The analysis is extended to cover estimation of r where more than one substitution has occurred. The range of the various estimates of s provided by these methods from electrophoretic data is usually below 1/N and mostly substantially so.
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Notes :
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Times Cited: 0
6
XE873
HEREDITY
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| | -- contributed by John Beatty, March 29, 2002 |
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