🥸intro to psychology review

key term - Genetic Drift

Definition

Genetic drift is a random process that occurs in small populations, where certain alleles may become more or less frequent over generations due to chance events, rather than natural selection. It is a mechanism of evolution that can lead to changes in the genetic composition of a population over time.

5 Must Know Facts For Your Next Test

  1. Genetic drift is more pronounced in small populations, where chance events can have a greater impact on allele frequencies.
  2. Genetic drift can lead to the loss of genetic diversity within a population, as some alleles may be lost entirely due to chance.
  3. The founder effect is a type of genetic drift that occurs when a new population is established by a small number of individuals from a larger population.
  4. The bottleneck effect is a severe reduction in population size, which can lead to a significant loss of genetic diversity and increased genetic drift.
  5. Genetic drift is a random process and is not influenced by natural selection, unlike other evolutionary mechanisms such as adaptation and speciation.

Review Questions

  • Explain how genetic drift differs from natural selection as a mechanism of evolution.
    • Genetic drift is a random process that occurs in small populations, where certain alleles may become more or less frequent over generations due to chance events, rather than being influenced by the adaptive advantages or disadvantages of those alleles. In contrast, natural selection is the process by which certain traits become more or less common in a population based on their relative fitness, or ability to survive and reproduce in a given environment.
  • Describe the relationship between population size and the impact of genetic drift.
    • Genetic drift is more pronounced in small populations, where chance events can have a greater impact on allele frequencies. In larger populations, the effects of genetic drift are less significant, as the influence of random chance is outweighed by the effects of other evolutionary mechanisms, such as natural selection. The smaller the population size, the more susceptible it is to the effects of genetic drift, which can lead to the loss of genetic diversity within the population over time.
  • Analyze how the founder effect and the bottleneck effect can contribute to genetic drift in a population.
    • The founder effect occurs when a new population is established by a small number of individuals from a larger population. This can lead to a change in allele frequencies, as the genetic makeup of the new population may not be representative of the larger source population. The bottleneck effect, on the other hand, is a severe reduction in population size, which can also result in a significant loss of genetic diversity. Both the founder effect and the bottleneck effect can contribute to genetic drift by reducing the effective population size and increasing the impact of chance events on allele frequencies, potentially leading to the loss of genetic diversity within the population.