What term describes reduced genetic variation when a new population is started by individuals?

What term describes reduced genetic variation when a new population is started by individuals?

• A. Founder effect
• B. Genetic drift
• C. Bottleneck effect
• D. Mutation

Answer: (A)

When a new population is started by only a few individuals, the genetic variation in that group is limited to the genes those founders carry. This is the founder effect. Because the founding group is small, random sampling of alleles can miss much of the diversity present in the original population. As a result, allele frequencies in the new population can differ markedly from the source population, and rare alleles may be lost while common ones become disproportionately represented. Over generations, this drift in a small population can lead to noticeable differences in traits and can increase the chance of certain genetic diseases if the founders carried particular alleles. It is a specific case of genetic drift—the random fluctuation of allele frequencies in small populations. A bottleneck effect involves a population-wide collapse due to a catastrophe and does not inherently describe starting a new population, while mutation introduces new variation rather than reducing it.

When a new population is started by only a few individuals, the genetic variation in that group is limited to the genes those founders carry. This is the founder effect. Because the founding group is small, random sampling of alleles can miss much of the diversity present in the original population. As a result, allele frequencies in the new population can differ markedly from the source population, and rare alleles may be lost while common ones become disproportionately represented. Over generations, this drift in a small population can lead to noticeable differences in traits and can increase the chance of certain genetic diseases if the founders carried particular alleles. It is a specific case of genetic drift—the random fluctuation of allele frequencies in small populations. A bottleneck effect involves a population-wide collapse due to a catastrophe and does not inherently describe starting a new population, while mutation introduces new variation rather than reducing it.