11.1 Genetic Variations Within Populations

Explain the concept of genetic drift as illustrated in the diagram with the boars.

• Genetic drift is a mechanism of evolution that refers to random changes in the frequency of alleles in a population.

• Genetic drift is the process by which organisms better adapted to their environment tend to survive and produce more offspring.

• Genetic drift is the transfer of genetic variation from one population to another.

• Genetic drift is the change in the heritable characteristics of biological populations over successive generations.

Define Allele frequency:

• Allele frequency: how common an allele is within a population Ex. % of A (dominant allele) or % of a (recessive allele).

• Allele frequency: the number of alleles in a single organism.

• Allele frequency: the genetic makeup of an individual.

• Allele frequency: the total number of alleles in a population.

What is behavioral isolation?

• Little or no attraction.

• High genetic similarity.

• Geographical separation.

• Temporal differences.

What is mass extinction?

• Mass extinction occurs very quickly, affects many species, and can reach globally.

• Mass extinction is a slow process affecting only a few species.

• Mass extinction is a local event affecting a single ecosystem.

• Mass extinction is a natural process that happens every year.

Explain the point of the Hardy-Weinberg principle in demonstrating that evolution is happening because not all 5 conditions could be met in a population at the same time.

• The principle shows that evolution is inevitable because the conditions are never met.

• It demonstrates that populations are always in equilibrium.

• It proves that genetic drift does not affect evolution.

• It indicates that natural selection is the only factor in evolution.

What is extinction?

• Elimination of a species from Earth.

• A process of creating new species.

• A temporary disappearance of a species.

• A method of conserving species.

Genetic drift is a change in the gene pool due to chance.

• True

• False

What is background extinction?

• Background extinction occurs continuously at a slow rate and affects 1 or 2 species in a small area.

• Background extinction is a rapid event affecting many species globally.

• Background extinction is the result of human activities leading to habitat loss.

• Background extinction is a temporary increase in species population.

What is microevolution?

• A change in a population’s gene pool over a succession of generations; evolutionary changes over a brief period of time

• A change in a population’s gene pool over millions of years

• A change in a population’s physical characteristics over a brief period of time

• A change in a population’s behavior over a succession of generations

What evolutionary concept is demonstrated by the ladybugs moving to an island in the diagram?

• Founder effect

• Bottleneck effect

• Natural selection

• Genetic drift