Question

Develop a hypothesis for how the size of a population (and therefore the effects of genetic drift) might affect the course of natural selection.

Answer 1

let us consider the population of small size. as we know the evolution is based on two consequences which are genetic variability which is due to mutations and secondly the change in frequency or alleles over the period of time.

take an example, let the frequency of allel A in population changes from 40% to 30%, it shows the population has evolved but not the individuals as the natural selection is applied on individual organism, the changes in frequency of population changes as whole.

the fate of mutations occuring affects the fitness so it is determined by natural selection asnew alleles which confers the higher standards of survivality tends to become a population of that area, this may be regarded as positive or directional selection and those that tends to disappear from the population causes negative or purifying selection.