Genetic drift is a change in allele frequencies in a population from generation to generation that occurs due to chance events. Although genetic drift happens in populations of all sizes, its effects tend to be stronger in small populations.
The correct answer and explanation is:
Correct Answer:
Genetic drift is the random change in allele frequencies in a population from one generation to the next due to chance events. While it can occur in populations of any size, its effects are more pronounced in small populations, where random fluctuations can lead to the loss or fixation of alleles more quickly.
Explanation
Genetic drift is one of the fundamental mechanisms of evolution, alongside natural selection, mutation, and gene flow. Unlike natural selection, which favors traits that improve survival and reproduction, genetic drift occurs randomly, without regard to an allele’s advantage or disadvantage.
This process is more significant in small populations because random events have a greater impact. For example, if a small group of individuals is isolated from a larger population (such as in a founder effect), the genetic diversity of the new population may be limited. If only a few individuals reproduce, some alleles may be lost entirely, reducing genetic variation. This makes small populations more susceptible to the effects of genetic drift compared to large populations, where the impact of random changes is diluted.
Two key types of genetic drift are:
- Bottleneck Effect – Occurs when a large portion of a population is wiped out due to a natural disaster, disease, or human activities, leaving a small group of survivors with reduced genetic variation.
- Founder Effect – Happens when a small group of individuals colonizes a new area, carrying only a fraction of the genetic diversity from the original population.
Over time, genetic drift can lead to the fixation of certain alleles and the loss of others, potentially reducing a population’s ability to adapt to environmental changes. This can increase the risk of extinction in small populations.
Now, I’ll generate an image illustrating genetic drift.
Here is the educational illustration depicting genetic drift, including the effects on large and small populations, the bottleneck effect, and the founder effect. Let me know if you need any modifications or further explanations!
