The Hardy-Weinberg principle comes from considering what happens when Mendelian genes act in a population.
The model predicts that there will be no change in allele frequencies when
Migration into the population occurs at a steady rate.
The population suffers a bottleneck.
A rare new mutation is associated with a sharp increase in fitness.
No evolutionary process is at work.
The Hardy-Weinberg principle, derived from considering the effects of Mendelian genes in a population, predicts that there will be no change in allele frequencies when no evolutionary processes are at work. This assumption is based on the following conditions:
No mutations: The absence of new mutations ensures that there are no new alleles introduced into the population.
No migration: There is no migration into or out of the population, which would bring in or remove alleles.
Random mating: Individuals in the population mate randomly, without any preference for specific genotypes or alleles.
Large population size: The population size is large enough to prevent genetic drift, which is the random change in allele frequencies due to chance events in small populations.
No natural selection: There is no differential survival or reproductive advantage associated with specific genotypes. All genotypes have equal fitness and contribute equally to the next generation.
Under these assumptions, the Hardy-Weinberg principle predicts that the allele frequencies in a population will remain constant from generation to generation. This stable equilibrium is expressed by the Hardy-Weinberg equation, which relates the frequencies of alleles and genotypes in a population. Any deviation from the Hardy-Weinberg equilibrium indicates the presence of evolutionary processes such as mutation, migration, genetic drift, or natural selection.
Hence, the correct answer is option 4.