Question

If the narrow sense heritability for a quantitative trait is 0.68, and the population mean for the trait is 10 units, assuming that the selection differential is 1 unit, what would be the new population mean after 6 generations of selection?

a. 4.08 units

b. 6.80 units

c. 14.08 units

d. 16 units

e. 16.08 units

Answer 1

Solution:-

Narrow sense of heritability (h2) = R/S

S=Selection difference = mean of parents - mean of population

R=Selection response = mean of offspring of selected parents - mean of population

Here it is given that h2=0.68 and S =1 unit

Then, R= h2S

= 0.68 X 1 unit.

= 0.68 units

This is after the first generation.

0.68 = mean of offspring of selected parents - mean of population ( mean of population given as 10 units)

mean of Offsprings of selected parents = mean of population + 0.68

mean of Offsprings of selected parents = 10 unit +0.68 unit

= 10.68 units

After 6 generations,

mean of Offsprings of selected parents = 10+ 6x0.68

= 14.08 units.

So, the answer is option (C).