Question

this causes the allele frequency of a population to be altered when individuals move into (or out of) a population
frequency
evolution
gene flow
geographic separation
natural selection
genetic drift
variation

Explanation:

To solve this, we analyze each option:

• "frequency" refers to how often an allele occurs, not the process of altering it via movement.
• "evolution" is a broad change in species over time, not specific to movement - related allele frequency change.
• "gene flow" is defined as the transfer of genetic material (alleles) when individuals move into or out of a population, which matches the description.
• "geographic separation" is about physical separation of populations, not movement in/out affecting alleles.
• "natural selection" is about differential survival/reproduction based on traits, not movement.
• "genetic drift" is random change in allele frequencies (e.g., bottleneck, founder effect), not due to movement.
• "variation" is differences in traits, not the process of allele frequency change via movement.

Answer:

C. gene flow