Question

In what sense is natural selection more “predictable” than genetic drift?

Short answer

Natural selection allows change in allele frequencies in a random way, which increases the reproductivity of the population. However, genetic drift occurs by chance, and it can decrease or increase the allele frequency. Thus, natural selection is more predictable than genetic drift.

Step-by-step solution

Natural selection

Natural selection is the evolutionary force that acts on the population to increase its survival in the environment. It allows adaptation in organisms, which increases the population. Natural selection only occurs when the population possesses an inheritable variation.

Genetic drift

The change in allele frequency causes genetic drift in the population. Migration, mutation, or random mating bring changes in allele frequencies and cause genetic drift. A small population caused by genetic drift is more likely to go extinct. Founder effect and bottleneck effect are two forms of genetic drift.

The reasons that make genetic drift unpredictable

Allele frequencies are constantly changing in a population for better adaptation.Genetic drift is an evolutionary process that causes speciation and genetic variation in species.

However, genetic drift does not increase the degree of adaptation in an individual or population. It alters the allele frequency in such a way that it may be harmful or beneficial to the population.

It is not necessary that a change in allele frequency in a population will lead to genetic drift. However, the inheritable changes in allele frequencies always go through natural selection. Therefore, natural selection is more predictable.