Naturalism was a literary movement that existed from 1865 to 1900 and employed precise realism to argue that social factors, heredity, and the environment all had an inextricable influence on human character. Charles Darwin's evolution hypothesis impacted naturalistic authors. It suggested that humanity's common ancestry with animals and the fact that we share many traits with other living things imply that there is a physical basis for what we call "character." Therefore, writers who wanted to explain behavior had to look beyond personal choice to biology or society. Naturalists rejected authorial control over characters and stressed the role of environmental forces in shaping individuals. They believed that since humans are part of a biological world, their actions have consequences which affect their lives and those around them. The focus of naturalists was on how people are affected by their context - not only what they do but also why they do it and where they get their ideas from. Often these writers were scientists who used their knowledge to explain human behavior. For example, Edward Burnett Tylor developed a theory of cultural evolution based on his studies of primitive peoples. He argued that societies evolve through changes in religion, language, art, and technology just as organisms change through evolution by natural selection. Naturalists often used real events as sources of information for their novels. For example, George Eliot based her 1857 work Adam Bede on her own experience as a farmer's daughter raised up in rural England.