Question

List the five conditions that must be true for a population to be in Hardy-Weinberg equilibrium. Why is it useful to know the conditions that pre- vent evolution? For each condition, specify wheth- er violation of that assumption results in changes in genotype frequencies, allele frequencies, or both.

Answer 1

The Hardy-Weinberg equilibrium requires five conditions—no mutation, no migration, a very large population size, random mating, and no natural selection. This equilibrium serves as a model to measure and understand evolutionary changes in real populations, indicating that any deviations from these conditions result in evolution.

Step-by-step explanation:

Conditions for Hardy-Weinberg Equilibrium

To describe the genetic makeup of a population remaining constant over time, the Hardy-Weinberg equilibrium states that five specific conditions must be met. These conditions are essential for the equilibrium to be maintained and serve as a baseline for understanding evolutionary forces that act upon the population.

1. No mutation occurring in the population, meaning the genetic code remains unchanged.
2. No migration or gene flow that alters the population's genetic structure.
3. A very large population size to diminish the effects of genetic drift.
4. Random mating amongst the population members without any preference.
5. No natural selection, where no alleles are favored over others.

Knowing these conditions is useful because it allows scientists to identify when and how evolution occurs. For instance, when mutation happens, it can change not only genotype frequencies but also allele frequencies. Similarly, migration can introduce new alleles to the population, affecting allele frequencies. In cases of non-random mating or natural selection, both genotype and allele frequencies can be altered.

If any one of these conditions is not met, the principle indicates that the population is evolving. This is why the concept is so important for biologists: It provides a mathematical model to determine whether and how real populations deviate from this evolutionary stasis.