Genetic Equilibrium and Natural Selection

The video tutorial discusses evolution as a genetic change, focusing on how natural selection affects allele frequencies in populations. It explains the types of natural selection: directional, stabilizing, and disruptive. The concept of genetic drift and the founder effect are introduced as random events affecting allele frequencies. The Hardy-Weinberg principle is explained, outlining conditions for genetic equilibrium where evolution does not occur.

What is the primary mechanism by which evolution occurs in populations?

• Migration

• Mutation

• Natural selection

• Genetic drift

In a population, what happens to alleles that provide a survival advantage?

• They remain constant

• They decrease in frequency

• They increase in frequency

• They disappear

Which type of natural selection favors individuals at one extreme of a trait distribution?

• Balancing selection

• Disruptive selection

• Stabilizing selection

• Directional selection

What is the result of stabilizing selection on a population?

• Increased variation

• Decreased variation

• Creation of new species

• Shift in trait distribution

What occurs during disruptive selection?

• A new phenotype emerges

• The middle phenotype is favored

• All phenotypes are equally favored

• Extreme phenotypes are favored

What is genetic drift?

• A change in allele frequency due to migration

• A change in allele frequency due to mutation

• A random change in allele frequency

• A change in allele frequency due to natural selection

What is the founder effect?

• A population experiencing a bottleneck

• A mutation spreading through a population

• A small group starting a new population

• A large population colonizing a new area

According to the Hardy-Weinberg principle, what condition is NOT required for genetic equilibrium?

• No mutations

• Large population size

• No natural selection

• Non-random mating

What does the Hardy-Weinberg principle state about allele frequencies?

• They change rapidly over time

• They remain constant unless influenced by specific factors

• They are determined by genetic drift

• They are always in flux

Which of the following is NOT a factor that can disrupt genetic equilibrium?

• Natural selection

• Random mating

• Mutations

• Migration