Natural Selection vs Genetic Drift

Genetic drift occurs most quickly in -

• small populations.

• populations with large genetic variation.

• populations with small genetic variation.

• large populations.

What is genetic drift?

• A population for which the gene frequencies do not change

• A change in allele frequencies due to selection

• The addition or removal of alleles in a population due to individuals entering or leaving one population for another

• A change in the gene pool due to chance

Natural selection happens when an individual's genes ______________ from the genes of other members of its species.

• Become different

• Stay the same

• Become separated

Tags

8-LS4-4

In the phrase "survival of the fittest," the term "fittest" refers to:

• The best-adapted organisms

• The biggest organisms

• The smartest organisms

• The fastest organisms

Tags

8-LS4-4

When nature "selects" a variation, that means that the trait:

• Gets passed along from generation to generation

• Causes the population to shrink

• Has brought about a new species

• Helps prey escape predators

Tags

8-LS4-4

Which term describes when better adapted organisms survive to pass traits along to offspring?

• Evolution

• Natural Selection

• Extinction

• Artifical Selection

Tags

8-LS4-4

Why are advantageous traits more likely to be passed onto offspring?

• Because they are more likely to survive and reproduce.

• Because they come from dominant alleles.

• Because they come from recessive alleles.

• Because the trait is an acquired phenotype.

Tags

8-LS4-4

Which of the following describes what is meant by Natural Selection?

• An organism will survive no matter what its adaptations may be

• An organism with adaptations that do not allow it to reproduce as effectively as others will survive.

• An organism with adaptations that allow it to obtain resources and reproduce more effectively than others will survive.

• No organisms will survive.

Tags

8-LS4-4

Which of the following best describes genetic drift?

• A change in allele frequencies due to chance

• A change in allele frequencies due to natural selection

• A change in allele frequencies due to mutation

• A change in allele frequencies due to migration

In a small population, which evolutionary mechanism is most likely to cause significant changes in allele frequencies over time?

• Natural selection

• Genetic drift

• Gene flow

• Mutation