TT Tt tall stems tt short stems Natural selection favors

TT & Tt = tall stems; tt = short stems. Natural selection favors tall over short plants because pollinators are more likely to visit tall plants. Among 5000 plants monitored on transects, the seed set averaged 3.6 for tall & 3.2 for short plants.

1. What is stt?

2. What is mean relative fitness when f(t)=0.8?

3. If f(T) = 0.36, what will be f(T) after one generation?

Solution

2. According to hardy Weinberg principle the sum of the allele frequencies for all the alleles at the locus must be 1, so p + q = 1

Here

Now Relative fitness is calculated by dividing each individuals survival and/or reproductive rate by the highest survival and/or reproductive rate.

The mean relative fitness of a population is calculated as the frequency of each type in the population times its fitness.                                                                                                     

Hence mean relative fitness =[ relative frequency of T allele in current generation * relative fitness of T allele] +[ relative frequency of t allele in current generation * relative fitness of t allele]

                                         = (0.2*1)+(0.8*0.89)

                                          =0.912

3. According to HARDY WEINBERG EQUILIBRIUM allele frequency remains constant generation after generation