The significance of the correlation coefficient when applied to Mendelian distributions / by John Brownlee.

  • Brownlee, John, 1868-1927.
Date:
1910
Catalogue details

Licence: In copyright

Credit: The significance of the correlation coefficient when applied to Mendelian distributions / by John Brownlee. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    If the parents be a, a and b, b | c, c d, d then the offspring having two elements from the same parents are— P. Q. R. a, a C, C a, b d, d b,b c, d which represent different things according as dominance exists or not; for if dominance exist R is included among those having apparently two pairs of dominant zygotes, while if the hybrid is distinct it is grouped with P and Q as containing two units from the same parent. 11. In addition to the methods just given Professor Pearson has also discovered two methods of determining correlation by means of what he calls contingency. It is not necessary to go fully into this part of the question. The manner in which the results given by these methods differ from those just considered is illustrated in the subjoined table. They are not in general suitable for simple Mendelian cases, as they depend for success on the number of divisions being much more numerous than these tables o-ive. Table showing the Correlation Coefficients calculated by different Methods WHERE ONE, TWO, OR THREE DOMINANT ZYGOTES OCCUR IN ONE PARENT AND A like Number of Recessive in the other. Fourfold Table. Product Mean Square Mean Method. Contingency. Contingency. A* B* c.* One zygote ■333 ■32 •37 •5 Two zygotes . •333 •33 •41 •46 •46 Three zygotes •333 •32 •39 •42 •42 •45 * See par. 9. Results of Assortive Mating. 12. With the same notation as just used the most general form of correlation under a Mendelian system for assortive mating between husband and wife, if the standard deviation of each is equal, is the following:— Husbands. Wives. (a, a). (a, b). (b, b). Totals. (a, a) . m 2 r 71 m+n+2r (a, b) . 2 r 4p 2 r 4 (r+p) (b, b) . n 2 r m m + 2 r + n