The famous scientist who developed the theory of evolution by natural selection is Charles Darwin. He published his groundbreaking work, "On the Origin of Species," in 1859, which presented evidence for evolution and proposed that species evolve over time through a process of natural selection. This theory suggested that individuals with traits better suited to their environment are more likely to survive and reproduce, passing those advantageous traits to their offspring. Darwin's work revolutionized the understanding of biology and laid the foundation for modern evolutionary theory, influencing both science and society.