Population genetics—first cousins: This is a continuation. Double first cousins are first cousins in two ways—that is, each of the parents of one is a sibling of a parent of the other. First cousins...

Population genetics—first cousins: This is a continuation. Double first cousins are first cousins in two ways—that is, each of the parents of one is a sibling of a parent of the other. First cousins in general have six different grandparents, whereas double first cousins have only four different grandparents. For matings between double first cousins, the proportions of the genotypes of the children can be accounted for in terms of those of parents, grandparents, and great-grandparents:

a. Find all solutions to the cubic equation above and identify which is λ1.

b. How many solutions did you expect to the cubic equation?

c. After 5 generations what proportion of the population will be homozygous?

d. After 20 generations what proportion of the population will be homozygous?