Which term best fits the idea of a trait that increases fitness in a local environment?

Which term best fits the idea of a trait that increases fitness in a local environment?

• A. Adaptation
• B. Homozygous
• C. Vestigial
• D. Analogous

Answer: (A)

An adaptation is a heritable trait that helps an organism survive and reproduce in its local environment. When such advantageous traits increase fitness, natural selection favors individuals carrying them, so the trait becomes more common over generations. The idea here is that the benefit is specific to the local conditions—what helps in one environment may not help in another—so a trait that boosts survival or reproductive success in that setting is an adaptation. Other terms don’t fit as well because they describe different ideas: a trait being homozygous is about having two identical alleles, not about increasing fitness in a specific environment; vestigial refers to structures that are reduced or nonfunctional and not necessarily advantageous in the current environment; analogous describes traits that look similar due to convergent evolution, not a trait that inherently increases fitness in the local context.

An adaptation is a heritable trait that helps an organism survive and reproduce in its local environment. When such advantageous traits increase fitness, natural selection favors individuals carrying them, so the trait becomes more common over generations. The idea here is that the benefit is specific to the local conditions—what helps in one environment may not help in another—so a trait that boosts survival or reproductive success in that setting is an adaptation.

Other terms don’t fit as well because they describe different ideas: a trait being homozygous is about having two identical alleles, not about increasing fitness in a specific environment; vestigial refers to structures that are reduced or nonfunctional and not necessarily advantageous in the current environment; analogous describes traits that look similar due to convergent evolution, not a trait that inherently increases fitness in the local context.