{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,26]],"date-time":"2026-01-26T02:44:31Z","timestamp":1769395471477,"version":"3.49.0"},"reference-count":16,"publisher":"Hindawi Limited","issue":"2","license":[{"start":{"date-parts":[[2009,4,14]],"date-time":"2009-04-14T00:00:00Z","timestamp":1239667200000},"content-version":"unspecified","delay-in-days":7866,"URL":"https:\/\/www.cambridge.org\/core\/terms"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Genet. Res."],"published-print":{"date-parts":[[1987,10]]},"abstract":"<jats:title>Summary<\/jats:title><jats:p>Kimura used the heterozygosity and the number of low-frequency alleles to estimate that about 14% of mutations are selectively neutral. The method is shown to be subject to biases and to disruption due to bottleneck effects. Let deleterious alleles have selective disadvantage,<jats:italic>s<\/jats:italic>, compared with neutral alleles and let<jats:italic>N<jats:sup>e<\/jats:sup><\/jats:italic>denote the effective diploid population size. The estimator,<jats:inline-graphic xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" mime-subtype=\"gif\" mimetype=\"image\" xlink:type=\"simple\" xlink:href=\"S0016672300023569_inline1\"\/>, of the proportion of neutral alleles is positively biased if (roughly) 4<jats:italic>N<jats:sup>e<\/jats:sup>S<\/jats:italic>&lt; 25 or if 4<jats:italic>N<jats:sup>e<\/jats:sup>s<\/jats:italic>&gt; 200. In the former case, one cannot adequately detect the different influences of deleterious and neutral alleles, whereas in the latter case, deleterious alleles will rarely appear in the sample. These difficulties cause the biases in<jats:inline-graphic xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" mime-subtype=\"gif\" mimetype=\"image\" xlink:type=\"simple\" xlink:href=\"S0016672300023569_inline1\"\/>, and are likely to cause similar biases for any estimation method based solely on allele frequencies. There is substantial sampling variability in<jats:inline-graphic xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" mime-subtype=\"gif\" mimetype=\"image\" xlink:type=\"simple\" xlink:href=\"S0016672300023569_inline1\"\/>in cases of practical interest, when data from 11 loci, or even as many as 31 loci, are pooled. If there has been a recent contraction in population size,<jats:inline-graphic xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" mime-subtype=\"gif\" mimetype=\"image\" xlink:type=\"simple\" xlink:href=\"S0016672300023569_inline1\"\/>will be positively biased, often yielding values greater than 1 or even being infinite. But after a recent expansion in population size, the heterozygosity will not have made as quick an increase and<jats:inline-graphic xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" mime-subtype=\"gif\" mimetype=\"image\" xlink:type=\"simple\" xlink:href=\"S0016672300023569_inline1\"\/>will be negatively biased. Population expansion alone can produce<jats:inline-graphic xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" mime-subtype=\"gif\" mimetype=\"image\" xlink:type=\"simple\" xlink:href=\"S0016672300023569_inline1\"\/>values close to those observed by Kimura, even if all alleles are neutral. In an appendix, a new method for simulating samples of neutral and deleterious genes is described.<\/jats:p>","DOI":"10.1017\/s0016672300023569","type":"journal-article","created":{"date-parts":[[2009,9,17]],"date-time":"2009-09-17T07:36:02Z","timestamp":1253172962000},"page":"155-163","source":"Crossref","is-referenced-by-count":11,"title":["Estimating the proportion of neutral mutants"],"prefix":"10.1155","volume":"50","author":[{"given":"G. 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A. (1984). Estimating the divergence time of two species. Statistics Research Report 94, Monash University."},{"key":"S0016672300023569_ref001","doi-asserted-by":"crossref","first-page":"891","DOI":"10.1093\/genetics\/50.5.891","article-title":"The maintenance of alleles by mutation","volume":"50","author":"Ewens","year":"1964","journal-title":"Genetics"},{"key":"S0016672300023569_ref006","volume-title":"Statistical Computing","author":"Kennedy","year":"1980"},{"key":"S0016672300023569_ref010","doi-asserted-by":"publisher","DOI":"10.1111\/j.1469-1809.1977.tb01918.x"},{"key":"S0016672300023569_ref009","doi-asserted-by":"crossref","unstructured":"Kingman J. F. C. (1980). Mathematics of genetic diversity. 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