What are the four requirements for natural selection to occur?

Natural selection operates based on specific criteria that drive the adaptation and evolution of species. The four key requirements for natural selection to take place include competition among individuals, variation in traits within a population, heritable traits that can be passed down to the next generation, and traits that enhance an individual's survivability or reproductive success.

Competition arises because resources, such as food, mates, and shelter, are limited. This competition leads to the survival of individuals with advantageous traits. Variation in traits means that individuals within a population show differences in characteristics, such as size, coloration, or resistance to diseases. These variations must be heritable, meaning they can be transmitted to offspring. Finally, traits that improve the ability to survive in a specific environment or contribute to higher reproductive success are favored by natural selection, leading to an increase in those traits in subsequent generations.

The other options do not accurately capture the necessary conditions for natural selection. While population size and environmental factors may influence selection dynamics, they are not prerequisites for the process itself. Random mating, mutations, and migrations are factors that can impact genetic diversity but are not requirements for the fundamental mechanism of natural selection.