What is the significance of Charles Darwin’s theory of natural selection?

Darwin's theory of natural selection is significant because it emphasizes the process by which certain traits become more common in a population over time due to their advantages for survival and reproduction. This natural selection mechanism explains how species evolve and adapt to their environments. Through the survival of individuals who are better suited to their surroundings, populations gradually shift, leading to the development of new species and the adaptability of life forms.

In contrast to the other options, natural selection does not focus on explaining the origin of genetic mutations, which are part of the underlying genetic variation that drives evolution. While classification of organisms is vital for understanding biological diversity, it does not directly relate to the evolutionary processes highlighted by Darwin. Furthermore, Darwin's theory fundamentally challenges the idea that species remain fixed and unchanging, as this static view opposes the dynamic nature of evolution that natural selection entails.