the gene frequency of a population does not accurately represent that of its parental population
“The gene frequency of a population does not accurately represent that of its parental population.”
Answer: This statement touches on a concept in population genetics known as genetic drift and the founder effect, among other factors that can cause gene frequencies to differ between generations.
1. Genetic Drift:
Genetic drift refers to random changes in allele frequencies in a population. This often occurs in small populations where chance events can lead to certain alleles becoming more or less common over time. These random changes might cause the genetic makeup of a population to differ greatly from that of its parent population.
2. Founder Effect:
When a small group from a population establishes a new population elsewhere, the new population might not represent the genetic diversity of the original population. This is known as the founder effect. Since the founders carry only a subset of the original population’s genetic diversity, the gene frequencies in the new population can differ significantly.
3. Bottleneck Effect:
A dramatic reduction in population size due to an environmental event can make the surviving population’s gene frequencies different from the original population. This is known as a genetic bottleneck.
4. Mutations and Natural Selection:
Mutations introduce new genetic variants, which can alter gene frequencies over generations. Natural selection can also shift allele frequencies if certain alleles confer advantages or disadvantages to survival and reproduction.
Illustrative Example:
Imagine a population of rabbits, some with white fur and some with brown fur. If a few brown rabbits from a large, mixed population migrate to a new area and establish a new population, their genetic makeup might initially be more skewed towards brown fur. If this new population eventually grows, it might still have a higher frequency of the brown fur gene compared to the original population, unless significant gene flow or mutations introduce more white fur alleles.
Summary: Gene frequencies in a new population may not match those of the original population due to random events like genetic drift, the founder effect, genetic bottlenecks, mutations, and natural selection. These processes can lead to significant differences in the genetic composition over generations.