Which term refers to a process that leads to differential survival within a population?

• A. Competition
• B. Fossil
• C. Adaptation
• D. Natural selection

Answer: (D)

Natural selection is the process that leads to differential survival within a population. In every generation, individuals vary in heritable traits. When the environment imposes challenges—like limited resources, predators, or climate—those with traits that give them a survival or reproductive advantage are more likely to survive and produce offspring. Because these successful individuals leave more copies of their genes, the traits that help survival become more common over generations, changing the population’s genetic makeup.

An easy way to see this is through a classic example like the peppered moth. In polluted environments, darker-colored moths survived better and left more offspring than lighter-colored ones, so the population shifted toward the darker form. This shift happens because of natural selection acting on heritable variation.

Other terms don’t describe the mechanism itself. Competition describes the struggle for resources, which can influence survival but is not the process that creates differential survival through heritable traits. A fossil is simply preserved remains from the past, not a process. Adaptation refers to the trait or the outcome of natural selection, not the mechanism that causes differential survival.