What term describes the process by which organisms that are better suited to their environment survive and reproduce more successfully?

• A. Adaptation
• B. Natural selection
• C. Reproduction
• D. Speciation

Answer: (B)

Natural selection is the mechanism by which inherited traits that help an organism survive and reproduce in its environment become more common in a population over generations. When the environment favors certain traits, individuals with those traits tend to live longer, reach reproductive age, and leave more offspring. Over time, the frequency of these advantageous traits increases in the population, leading to a population that is better suited to its surroundings.

An example helps make this clear: if a drought makes water scarce and animals with more efficient water conservation survive and reproduce more, their efficient traits become more common in the next generation.

Understanding the other terms helps see why natural selection is the right description here. An adaptation is a trait that helps survival, but it’s the trait itself, not the process. Reproduction is merely the act of making offspring and doesn’t by itself explain why certain traits become more common. Speciation is the formation of new species, which can be a long-term outcome of natural selection but is not the process that makes certain traits more common in a single population.