An introduction to population genetics / by Ching Chun Li.

  • Li, Jingchun.
Date:
1948
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: An introduction to population genetics / by Ching Chun Li. Source: Wellcome Collection.

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    if the three genotypes are in Hardy's proportion. This offers a test as to whether our hypothesis is correct. If the observed sura of the square-roots of the proportions of the two homozygous classes is nearly unity, it confirms both that the character under consideration is due to one pair of Mendelian factors and the correctness of Hardy's law. In our example, Sum = 1.0028. There remains the statistical problem to determine th<?significance of the observed discrepancy from unity {i.e. 0.0028). Wiener (1932) gives the the sample. In our case, We see that the discrepancy from unity is not significant and therefore we conclude that the observed data is in accordance with our theory. This method seems to work well in this case. But we note that, in the first place, taking the square roots of the homozygous proportions is a less efficient estimate of the true values of gene frequencies in the popu lation from which the sample has been drawn. Secondly, this practice of finding gene frequencies would be entirely erroneous if the mating is not at random, while the method described in the previous section always gives the correct value as far as the gene frequencies are concerned. Nicoletti (quoted by Ride, 1935) tested three hundred persons in Sicily for their blood types and found the following results : p = v / D = ■/' .3324 = .5765 q - |/ Jti = V .1817 = .4263 §3, Blood type M MN N Total 150 90 60 300 Observed .50 .30 .20 1.00 .4225 .4550 .1225 1.00 Expected 126.75 136.50 36.75 300