What is meant by "adaptation" in biological terms?

In biological terms, "adaptation" refers to a heritable trait that enhances an organism's ability to survive and reproduce in its environment. This concept is fundamental to the theory of evolution, which posits that species evolve over time through processes such as natural selection. Traits that improve survival chances are more likely to be passed on to subsequent generations.

Adaptations can manifest in various forms, including physical characteristics (like the thick fur of arctic foxes for insulation), behavioral traits (like migration patterns), and physiological changes (like developing resistance to toxins). These traits arise from genetic variations that provide some individuals with advantages over others in their particular environments, allowing them to thrive and reproduce more effectively.

Understanding adaptation underscores the importance of heritability; without the genetic basis for traits, there wouldn't be a mechanism for adaptations to persist in a population over time. This is why options describing temporary changes, learned behaviors, or non-heritable characteristics do not fit the definition of adaptation in the biological sense. Adaptations are inherently tied to the genetic makeup of organisms, influencing their evolutionary trajectory.