Darwinism Darwinism, a scientific theory that supported the belief of evolution, was manipulated and applied to different areas of life, and thus it became the shaping force in European thought in the last half of the nineteenth century. Darwin, through observation of organisms, determined that a system of natural selection controlled the evolution of species. He found that the organisms that were most fit and assimilated to the environment would survive. They would also reproduce so that over time they would eventually dominate in numbers over the organisms with weaker characteristics. This new theory was ra