Genetic drift operates in :-
- Small isolated population
- Large isolated population
- Fast reproductive population
- Slow reproductive population
The Correct Option is A
Solution and Explanation
The random changes in gene frequencies in a population occurring by chance alone rather than by natural selection are called genetic drift or the Sewall Wright effect. The effects of genetic drift are mostly visible in tiny isolated populations, although it occurs in all people.
Important Notes on Genetic Drift
- By genetic drift often the phenotype of this small population becomes different from the parent population.
- According to the Hardy-Weinberg principle, there are many factors that contribute to the Hardy-Weinberg equilibrium. Any change to this results in evolution.
- Gene flow, genetic drift, mutation, genetic recombination, and natural selection can affect this equilibrium.
- Gene frequency changes in the population during migration as new alleles get lost from the older population.
- Gene flow occurs when gene migration happens multiple times. If it occurs by chance, it is called genetic drift.
- The population from which the new one was formed became founders and this is called the founder effect.
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Concepts Used:
Evolution
Evolution is a process that occurs in changes in the genetic content of a population over time. Evolutionary change is generally classified into two: microevolution and macroevolution. The process of changes in allele frequencies in a population over time is a microevolutionary process. Three main mechanisms that cause allele frequency change are natural selection, genetic drift, and gene flow. On the other hand, macroevolution refers to change at or above the level of the species.