Question

1) (a) A single gene in horses determines coat (hide) color. Palomino (‘dove’) horses are heterozygous (Aa), while homozygous recessive (aa) are cremello, and homozygous dominant (AA) are chestnut. A horse rancher buys 80 palomino horses and 20 cremello horses and lets them breed free. (a) (10 pts) What are frequencies of alleles and genotypes in THIS (parent) generation? Are all genotypes represented? Show your calculations.

Is the population at this moment (i.e. in THIS generation) in Hardy-Weinberg balance or not? Explain.

(b) (8 pts) What would be frequencies of alleles and genotypes in NEXT (children) generation if one assumes Hardy-Weinberg balance? (no selection, new mutation, migration, etc.) Show your calculations.

(c) (7 pts) Now assume (for the purpose of the problem) that Hardy-Weinberg balance is violated by selection against cremello horses (which leave less offspring). Relative fitness of both chestnut and palomino is WAA = WAa = 1.0, but relative fitness of cremello, Waa = 0.8 (which means that selection coefficient s= - 0.2). What are frequencies of alleles and genotypes in NEXT generation?

Answer 1

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