CicilaProblem

So I finally figured out the Cicila coefficient of inbreeding vs probability of inheriting the recessive allele problem. I'm posting a sheet I made that shows how you get both answers by hand. The top half is for coefficient of inbreeding where you are looking at the probability of the great grandchild inheriting any of the 4 different alleles that are possible at a given locus. 4 alleles are possible because the great grandfather can have 2 different alleles at the locus and the great grandmother can have 2 different alleles at the same locus. We have only been learning basic 2 allele inhertance but in actuality there are numerous different alleles that can occupy a given locus in throughout the population.

The bottom half shows you get the probability that the great grandchild can become (inherit) homozygous mutant alleles at a locus that either of his great grandparents were heterozygous for.

In the Coefficient scenario there are potentially 4 alleles that can come down and become homozygous in the great grandchild and in the other problem there are only 2 alleles that can come down and be homozygous in the great grandchild. Only 2 alleles because either the great grandfather OR the great grandmother have 1 mutant allele at that locus. So for the coefficient of inbreeding question you get 4 times 1/64 (which is the probability of one allele coming down) giving you the probability that the great grandchild receives homozygous alleles at a given locus that originate from one allele in either great grandparent. and in the other question you get 2 times 1/64 because there are only 2 alleles that can come down. If you need more help on this and you see me around come up to me and I can explain it to you in even simpler terms.

The file I made showing the math for both problems is attached below.