How does variation help a population adapt?

How does variation help a population adapt?

• A. Variation makes all individuals more alike.
• B. Variation is caused only by aging.
• C. Variation means individuals in a population are genetically identical.
• D. Variation provides different traits; natural selection favors traits that help organisms survive in their environment.

Answer: (D)

Variation among individuals provides the raw material for adaptation. When individuals in a population have different traits, they respond to environmental challenges in different ways. Some of those traits help with surviving and reproducing, so the individuals with them leave more offspring. Over many generations, those helpful traits become more common, helping the whole population better fit its environment. For example, if a group of beetles includes many colors and predators hunt the lighter ones, the darker beetles may survive longer and reproduce more, shifting the population toward darker coloration over time. Without variation, everyone would respond the same way, and there’d be nothing for natural selection to act on, making it harder for the population to adapt to changing conditions.

Variation among individuals provides the raw material for adaptation. When individuals in a population have different traits, they respond to environmental challenges in different ways. Some of those traits help with surviving and reproducing, so the individuals with them leave more offspring. Over many generations, those helpful traits become more common, helping the whole population better fit its environment. For example, if a group of beetles includes many colors and predators hunt the lighter ones, the darker beetles may survive longer and reproduce more, shifting the population toward darker coloration over time. Without variation, everyone would respond the same way, and there’d be nothing for natural selection to act on, making it harder for the population to adapt to changing conditions.