What term describes the idea that the strongest and best-adapted individuals are more likely to survive and breed?

• A. Survival of the fittest
• B. Evolution
• C. Adaptation
• D. Artificial selection

Answer: (A)

Differential survival and reproduction based on fitness drives changes in populations; the term that captures this idea is "survival of the fittest." Here, "fittest" means the individuals best suited to their environment, possessing traits that help them live longer, avoid predators, find food, or reproduce more successfully. Those individuals leave more offspring, passing on their advantageous traits, so over generations the population becomes better adapted to its surroundings. This description directly describes the mechanism behind natural selection, the process by which evolution occurs.

Other ideas fit a bit differently: evolution is the broader process of allele frequencies changing over time; adaptation refers to the traits that improve survival or reproduction; artificial selection is when humans deliberately choose which organisms reproduce. The phrase in question specifically highlights the idea of some individuals being more likely to survive and breed due to their traits.