Question

3. a. What determines the reproductive fitness of a genotype in a population?

      b. If the absolute fitnesses of genotypes in our rodent population are 3 for TT, 4 for Tt and 6 for tt, determine the relative fitness of each genotype.

      c. Selection will occur on a locus when different genotypes result in different phenotypes that differ in reproductive fitness. What type of selection is occurring at the T locus (i.e. on the T and t alleles) in our population? Based on this information alone, what would you expect will happen to the f(T) and f(t) over time and why?

Answer 1

3. a. Ans: Reproductive fitness determined by environments, its phenotype to attract a mate and reproduce successfully or escapes a predator,

b. Ans: total population of genotypes Tt are 3+4+6=13. Relative fitness calculated as 3/6=0.5, 4/6=0.66, 6/6=1

     

c. Ans: When we look at the relative fitness of genotypes eventhough ‘tt’ genotype having higher relative fitness, but total fitness of ‘TT and Tt = 1.16 higher than ‘tt’. This shows that genotype ‘T’ consider dominant selection is occurring at ‘T’ locus. In each generation ‘T’ locus can be dominant 1.16 times over the locus ‘t’, hence over time relative fitness f(t) decreases.