This one requires a little algebra You monitor changes in ge

This one requires a little algebra. You monitor changes in genetic diversity over several decades in a population of walruses, and estimate, based on the genetic dynamics of the population, that the effective population size (N_e) = 100. That is, the population is experiencing as much genetic drift as would an ideal population of size N = 100. You census the population and find that there are 300 males and 300 females. You observe that 200 of these females are producing offspring, therefore N_f is 200. Using this information, and using the formula for N_e based on breeding sex ratio, how many males are responsible for siring the offspring?

Solution

Census population N = 300 males + 300 females = 600

In an ideal population , the effective population is equal to census population.So, effective population size Ne = N=600

Effective population size (Ne) = 4Nm*Nf / Nm +Nf......equation( 1)

where Nm = number of males breeding and Kf = number of females breeding.

Substituting the values in equation (1) we get

600 = 4 * Nm * 200 / Nm + 200

600Nm+ 120000 = 800Nm

200Nm = 120000

Nm = 400.

So number of males required for siring the offsprings are (400 ans.)