What is natural selection?

What is natural selection?

• A. It is caused by human intervention
• B. It prevents any genetic change
• C. It occurs only in laboratory settings
• D. Animals with higher fitness are more likely to reproduce

Answer: (D)

Natural selection is the process by which heritable variation leads to differential reproductive success in a given environment. Individuals with traits that increase their survival or mating success leave more offspring, so the alleles for those advantageous traits become more common in the population over generations. This gradual shift in trait frequencies drives adaptation to the environment. For example, predators may more readily catch individuals with certain appearances, or bacteria with resistance genes survive antibiotic exposure and pass those genes on. This mechanism operates in natural settings without human intervention and does not prevent genetic changes; rather, it sorts and amplifies those changes that improve fitness. The core idea is that those with higher fitness are more likely to reproduce, shaping the population over time.

Natural selection is the process by which heritable variation leads to differential reproductive success in a given environment. Individuals with traits that increase their survival or mating success leave more offspring, so the alleles for those advantageous traits become more common in the population over generations. This gradual shift in trait frequencies drives adaptation to the environment. For example, predators may more readily catch individuals with certain appearances, or bacteria with resistance genes survive antibiotic exposure and pass those genes on. This mechanism operates in natural settings without human intervention and does not prevent genetic changes; rather, it sorts and amplifies those changes that improve fitness. The core idea is that those with higher fitness are more likely to reproduce, shaping the population over time.