Charles Darwin proposed the scientific theory of evolution through natural selection, which fundamentally changed the understanding of biological life. In his groundbreaking work, "On the Origin of Species," published in 1859, Darwin outlined how species evolve over time through the process of natural selection, where those individuals best adapted to their environments are more likely to survive and reproduce. This concept challenged contemporary views on creation and offered a scientific explanation for the diversity of life on Earth. Darwin's theory laid the foundation for modern evolutionary biology and has had profound implications in various fields, including genetics, ecology, and anthropology.