Nudity is a state of being in which a human is not wearing clothing or specifically is not covering the genitals. Nakedness , or the loss of body fur, was one of the physical characteristics that marked the evolution of anatomically modern humans from their hominini ancestors. For many thousands of years, humans wore no clothing, which continues to be the norm in some isolated indigenous societies in tropical climates. It is generally accepted that the widespread adoption of clothing occurred as people migrated to other climates which required protection from the elements. In addition, as societies developed from being hunter-gatherers to being agrarian, clothing became part of cultural evolution as individuals and groups became differentiated by status and class. In early civilizations such as Egypt, slaves, children, and others with lower status often continued to be naked.