In a population, what happens to individuals that are better adapted to the environment in which they live?

• A. They are more likely to die early.
• B. They reproduce less than others.
• C. They pass their genetic variants to the next generation, and those traits increase in frequency over time.
• D. They become more genetically diverse with each generation.

Answer: (C)

Better-adapted individuals have higher fitness, meaning they are more likely to survive and leave offspring in their environment. Because they reproduce more successfully, the genetic variants that help them thrive are passed to the next generation and become more common over time. This cumulative effect is natural selection shaping the population’s genetics based on which traits confer an advantage.

In other words, advantageous traits increase in frequency because those individuals contribute more copies of their genes to future generations. This is why the population gradually becomes better suited to its environment.

The idea that they would die sooner or reproduce less isn’t consistent with higher fitness. And while mutation continues to introduce new genetic variation, adaptation through natural selection often reduces genetic diversity by favoring specific alleles rather than increasing diversity.