Question

what is the relationship between the probabilty of fixation and the initial proportion of an allele in natural seection

Answer 1

In evolution, fixation refers to the process by which the frequency of an allele becomes 1 (or 100%) in a population. This means, only the fixed allele can be found at this locus in all the individuals of a particular population.

Allele frequency refers to the proportion of any allele at a locus in a given population. More the initial frequency of an allele, more is its probability of getting fixed by natural selection. This is simply because alleles which are already at higher frequency in the population , in general , should have higher fitness value than the other allele at that locus in the population. Conversely, allele which has a lower initial frequency has less chances of getting fixed.

• The probability of fixation is directly proportional to the frequency of an allele.

For example, if frequency of an allele is 0.05, then its probability of getting fixed is alsp 0.05 or 5%.

If frequency of an allele is 0.68, then probability of its fixation will also be 0.68 or 68%.

Hence, probability of fixation is directly proportional to the initial frequency of an allele in natural selection.