Which process increases the frequency of advantageous heritable traits in a population?

Which process increases the frequency of advantageous heritable traits in a population?

• A. Mutation
• B. Genetic Drift
• C. Gene Flow
• D. Natural Selection

Answer: (D)

The idea being tested is how advantageous heritable traits become more common in a population through differential survival and reproduction. Natural selection occurs when individuals with traits that improve their chances of surviving and reproducing pass those traits on to more offspring. Over many generations, that increased reproductive success raises the frequency of the beneficial alleles in the population, leading to an overall adaptation to the environment. Mutation can introduce new variation, but it doesn’t inherently increase the frequency of advantageous traits—it’s random and may be neutral, harmful, or beneficial. Genetic drift causes random shifts in allele frequencies that aren’t tied to fitness, so advantageous traits aren’t guaranteed to rise in frequency under drift. Gene flow moves alleles between populations, changing frequencies, but not because those alleles are more advantageous. Natural selection, by contrast, specifically amplifies traits that enhance fitness, making them more common over time.

The idea being tested is how advantageous heritable traits become more common in a population through differential survival and reproduction. Natural selection occurs when individuals with traits that improve their chances of surviving and reproducing pass those traits on to more offspring. Over many generations, that increased reproductive success raises the frequency of the beneficial alleles in the population, leading to an overall adaptation to the environment.

Mutation can introduce new variation, but it doesn’t inherently increase the frequency of advantageous traits—it’s random and may be neutral, harmful, or beneficial. Genetic drift causes random shifts in allele frequencies that aren’t tied to fitness, so advantageous traits aren’t guaranteed to rise in frequency under drift. Gene flow moves alleles between populations, changing frequencies, but not because those alleles are more advantageous. Natural selection, by contrast, specifically amplifies traits that enhance fitness, making them more common over time.