The theory of natural selection emphasizes which of the following?

The theory of natural selection, formulated by Charles Darwin, primarily emphasizes how natural selection acts on variations within a population. This process determines which individuals are more likely to survive and reproduce based on certain advantageous traits. These traits enhance the organisms' ability to adapt to their environment, thereby increasing their chances of survival and passing those favorable traits to the next generation.

Natural selection operates on existing variations in a population, which arise through random mutations and other genetic mechanisms, but it is not the mutations themselves that drive evolution; rather, it is the selection of those variations that promote survival and reproductive success. This process leads to the gradual adaptation of species over time. Thus, the focus on how natural selection acts specifically on favorable variations aligns perfectly with the core principles of evolutionary biology.

Other choices, such as survival of the strongest, random mutations, and inheritance of acquired traits, do not accurately capture the essence of natural selection as proposed by Darwin, which is based on the interaction between environmental challenges and the inherited, variable traits within a population.