According to Charles Darwin, what biological mechanism helps members of the same species adapt to different natural conditions?

The correct answer is adaptation. Adaptation is a key concept in evolutionary biology introduced by Charles Darwin, referring to the process through which species become better suited to their environments over generations. This phenomenon can occur through a variety of mechanisms, including natural selection, where traits that enhance survival and reproduction become more common within a population.

When members of the same species face different environmental challenges, those with advantageous traits may thrive and reproduce more successfully in those specific conditions, thereby passing those traits to their offspring. Over time, this leads to a population that is well adapted to varied environments, showcasing the diversity of forms and behaviors that species can take based on ecological demands.

Instinct pertains to innate behaviors that organisms exhibit, typically without prior experience or learning, which do not specifically address how species adapt over time to changes in their environments. Evolution is a broader concept that encompasses the process of change in populations over generations, while survival focuses on the continuation of life, which is part of adaptation but does not directly describe the mechanism that allows for change within a species.