What foundational concept is Charles Darwin known for?

Charles Darwin is renowned for the Theory of Evolution, which he articulated primarily through the mechanism of natural selection. This foundational concept explains how species evolve over time through the process of heritable traits becoming more or less common in a population as a result of the advantages or disadvantages they confer on individuals in their environment. Darwin's work, particularly in his book "On the Origin of Species," demonstrated that all species share a common ancestry and that the diversity of life is a result of gradual changes driven by environmental pressures, reproduction, and variation among individuals. This theory transformed the biological sciences and continues to underpin the field of genetics and our understanding of the natural world.