Hardy-Weinberg Equilibrium Conditions to Know for AP Biology

Hardy-Weinberg Equilibrium outlines conditions that keep allele frequencies stable in a population. Understanding these conditions helps explain genetic diversity, evolution, and how populations adapt over time, which is key in AP Biology studies.

1. Large population size

   • Reduces the impact of random events on allele frequencies, minimizing fluctuations.
   • Helps maintain genetic diversity, which is crucial for adaptability and survival.
   • Lowers the likelihood of extinction due to environmental changes or disease.

2. Random mating

   • Ensures that all individuals have an equal chance of mating, preventing bias in allele distribution.
   • Promotes genetic variation by mixing alleles from different individuals.
   • Avoids inbreeding, which can lead to a decrease in fitness and increase in genetic disorders.

3. No natural selection

   • Assumes that all individuals have equal reproductive success, regardless of their traits.
   • Prevents certain alleles from becoming more common due to advantageous traits.
   • Maintains the status quo of allele frequencies over generations, allowing for a stable genetic makeup.

4. No migration (gene flow)

   • Prevents the introduction or removal of alleles from the population, keeping allele frequencies stable.
   • Reduces the risk of genetic homogenization between populations, preserving local adaptations.
   • Ensures that the population evolves independently, maintaining its unique genetic identity.

5. No mutations

   • Keeps the genetic makeup of the population constant, as mutations introduce new alleles.
   • Prevents changes in allele frequencies that could disrupt the equilibrium.
   • Allows for a predictable genetic structure, essential for studying population genetics.

6. No genetic drift

   • Ensures that allele frequencies remain stable over time, as genetic drift can cause random changes.
   • Is more significant in small populations, where chance events can drastically alter allele frequencies.
   • Maintains the Hardy-Weinberg equilibrium by preventing random fluctuations that could lead to evolution.