What key concept did Charles Darwin's theory of evolution introduce?

Charles Darwin's theory of evolution is fundamentally grounded in the concept of natural selection as the primary mechanism for evolutionary change. This idea proposes that individuals with traits better suited to their environment are more likely to survive and reproduce, passing those advantageous traits to future generations. This process leads to gradual changes in species over time, allowing them to adapt to their surroundings.

Natural selection is observed in various examples across species, illustrating how environmental pressures can lead to variations that improve survival rates. This concept shifted the understanding of biological development from a static view of life to a dynamic process driven by interactions with the environment.

While mutation does play a role in introducing genetic variation that natural selection acts upon, it is not the core concept of Darwin's theory. The phrase "survival of the fittest," although commonly associated with Darwin's ideas, oversimplifies this concept and removes the critical role of natural selection. Vestigial organs provide an interesting insight into evolutionary history but do not constitute a driving mechanism of evolution themselves. In summary, the key contribution of Darwin's theory lies in establishing natural selection as a crucial process that drives evolutionary change.