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An exact test for neutrality based on the Ewens sampling distribution

Published online by Cambridge University Press:  14 April 2009

Montgomery Slatkin
Affiliation:
Department of Integrative Biology, University of California, Berkeley, California 94720
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Summary

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Using the Ewens sampling distribution of selectively neutral alleles in a finite population, it is possible to develop an exact test of neutrality by finding the probability of each configuration with the same sample size and observed number of allelic classes. The exact test provides the probability of obtaining a configuration with the same or smaller probability as the observed configuration under the null hypothesis. The results from the exact test may be quite different from those from the Ewens—Watterson test based on the homozygosity in the sample. The advantages and disadvantages of using an exact test in this and other population genetic contexts are discussed.

Type
Short Paper
Copyright
Copyright © Cambridge University Press 1994

References

Ewens, W. J., (1972). The sampling theory of selectively neutral alleles. Theoretical Population Biology 3, 87112.CrossRefGoogle ScholarPubMed
Ewens, W. J., (1979). Mathematical Population Genetics. Berlin: Springer-Verlag.Google Scholar
Fuerst, P. A., Chakraborty, R., & Nei, M., (1977). Statistical studies on protein polymorphism in natural populations. I. Distribution of single locus heterozygosity. Genetics 86, 455483.CrossRefGoogle ScholarPubMed
Guo, S. W., & Thompson, E. A., (1992). Performing the exact test of Hardy-Weinberg proportion for multiple alleles. Biometrics 48, 361372.CrossRefGoogle ScholarPubMed
Hartl, D., & Clark, A. G., (1989). Principles of Population Genetics, Second Edition. Sunderland, Mass.: Sinauer Associates.Google Scholar
Keith, T. P., Brooks, L. D., Lewontin, R. C., Martinez-Cruzado, J. C., & Rigby, D. L., (1985). Nearly identical distributions of xanthine dehydrogenase in two populations of Drosophila pseudoobscura. Molecular Biology and Evolution 2, 206216.Google ScholarPubMed
Kimura, M., (1968). Evolutionary rate at the molecular level. Nature 217, 624626.CrossRefGoogle ScholarPubMed
Mehta, C. R., & Patel, N. R., (1983). A network algorithm for performing Fisher's exact test in r × c contingency tables. Journal of the American Statistical Association, Series B 78, 427434.Google Scholar
Raymond, M., & Rousset, F., (1994). GenePOP (ver. 1.1), a population genetics software package for exact tests and oecumenism. Journal of Heredity, in press.Google Scholar
Slatkin, M., (1982). Testing neutrality in a subdivided population. Genetics 100, 533545.CrossRefGoogle Scholar
Slatkin, M., (1994). Linkage disequilibrium in growing and stable populations. Genetics 137, 331336.CrossRefGoogle ScholarPubMed
Watterson, G. A., (1977). Heterosis or neutrality. Genetics 85, 789814.CrossRefGoogle ScholarPubMed
Watterson, G. A., (1978). The homozygosity test of neutrality. Genetics 88, 405417.CrossRefGoogle ScholarPubMed
Weir, B. S., (1990). Genetic Data Analysis. Sunderland, Mass.: Sinauer Assoc.Google Scholar