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.

    47/344 (page 31)
    Since all children in the former mating and half the children in the latter mating are of type M, the probability and thus theoretical frequency of the mother M- child M combination is V 4 + è ( 2 P 3 ?) = P 3 (P + ^ - P 3 - Similarly, we can calculate ihe frequencies of other mother-child com binations. Hence, we get the following table : Child M MN N M S 0 p ¿ py _ Mother MN p-q pq pq 2 N *> fi - pq q The actual observations are found to be in complete agreement with the expectancies as given by the above table. A table of this kind can be regarded as the correlation table between mother and child. It can be easily verified that the coefficient of correla tion for the above table is \ being independent of gene frequencies. § 5. Medicolegal applications Since the M-N blood types are influenced by one pair of autosomal genes without dominance, therefore if a child possesses M or N, the said factor must be present in one or both parents, otherwise non-paternity would be established. Conversely, if a man is of type M (or N) but his child is of type N (or M), non-paternity is established just the same. Thus, we see that it is impossible for the father to be of the type N when mother- child have one of the following combinations : mother M —child M. mother MN —child M. mother N —child MN. Referring to the previous table of mother-child combinations, we find that the total probability for these three kinds of combinations is p3 4- p2q + pq2 _ p^p2 + pq + q 2 ) = p(l — pq) 33