What are the criteria for natural selection?

Natural selection operates based on specific criteria that are essential for the process to occur effectively. The correct answer highlights three key elements: variation, heritability, and fitness.

Variation refers to the differences observed among individuals within a population. This diversity is crucial because, without variation, there would be no traits for natural selection to act upon, meaning that all individuals would be equally suited or unsuited for their environment.

Heritability is the ability of traits to be passed down from one generation to the next. For natural selection to influence a population over time, the advantageous traits must be inheritable. If beneficial traits cannot be transmitted to offspring, they cannot become more common in future generations.

Fitness relates to how well an organism can survive and reproduce in its environment. This concept encompasses not only physical characteristics but also behaviors and reproductive strategies. Traits that enhance fitness—like better camouflage, faster running speed, or more efficient foraging—tend to become more prevalent in the population because individuals with these traits are more likely to survive and reproduce.

Together, these three components explain how natural selection functions as a mechanism of evolution, allowing populations to adapt over time in response to changing environmental pressures. Understanding this framework is essential for grasping the principles of evolution.