Questions: Endangered populations typically have a small number of individuals and little genetic variation. Which statements accurately describe the relationship between evolution and genetic variation in an endangered population? Select all that apply. - Genetic drift can lead to allele fixation, and thus reduce genetic variation in populations. - Gene flow between populations tends to increase when genetic variation is low. - Natural selection can decrease genetic variation by favoring alleles that provide the highest fitness. - Mutation rates typically increase when genetic variation is low.

The answer includes the following statements:

1. Genetic drift can lead to allele fixation, and thus reduce genetic variation in populations.
2. Natural selection can decrease genetic variation by favoring alleles that provide the highest fitness.

Explanation for each option:

1. Genetic drift can lead to allele fixation, and thus reduce genetic variation in populations.

   • This statement is correct. Genetic drift, which is the random fluctuation of allele frequencies in a population, can lead to the fixation of certain alleles (where an allele's frequency becomes 100%) and the loss of others. This process is more pronounced in small populations, such as those of endangered species, leading to a reduction in genetic variation.

2. Gene flow between populations tends to increase when genetic variation is low.

   • This statement is incorrect. Gene flow, or the transfer of alleles from one population to another, generally increases genetic variation within a population. However, gene flow itself is not necessarily more likely to occur when genetic variation is low; it depends on factors such as the movement of individuals between populations and the presence of barriers to gene flow.

3. Natural selection can decrease genetic variation by favoring alleles that provide the highest fitness.

   • This statement is correct. Natural selection can reduce genetic variation by favoring alleles that confer a survival or reproductive advantage, leading to an increase in the frequency of those alleles and a decrease in the frequency of less advantageous alleles.

4. Mutation rates typically increase when genetic variation is low.

   • This statement is incorrect. Mutation rates are generally constant and are not influenced by the level of genetic variation in a population. While mutations can introduce new genetic variation, the rate at which they occur is not typically affected by the existing genetic variation.

Summary: The correct statements are:

1. Genetic drift can lead to allele fixation, and thus reduce genetic variation in populations.
2. Natural selection can decrease genetic variation by favoring alleles that provide the highest fitness.