Skin, Vrindavan

Vitiligo ( /ˌvɪtɨˈlaɪɡoʊ/) is a condition that causes depigmentation of sections of skin. It occurs when melanocytes, the cells responsible for skin pigmentation, die or are unable to function. The cause of vitiligo is unknown, but research suggests that it may arise from autoimmune, genetic, oxidative stress, neural, or viral causes. The incidence worldwide is less than 1%. The most common form is non-segmental vitiligo, which tends to appear in symmetric patches, sometimes over large areas of the body.

Humans (known taxonomically as Homo sapiens, Latin for "wise man" or "knowing man") are the only living species in the Homo genus. Anatomically modern humans originated in Africa about 200,000 years ago, reaching full behavioral modernity around 50,000 years ago.

Humans have a highly developed brain and are capable of abstract reasoning, language, introspection, and problem solving. This mental capability, combined with an erect body carriage that frees the hands for manipulating objects, has allowed humans to make far greater use of tools than any other living species on Earth. Other higher-level thought processes of humans, such as self-awareness, rationality, and sapience, are considered to be defining features of what constitutes a "person".^{[citation needed]}

Humans are uniquely adept at utilizing systems of communication for self-expression, the exchange of ideas, and organization. Humans create complex social structures composed of many cooperating and competing groups, from families and kinship networks, to nations. Social interactions between humans have established an extremely wide variety of values, social norms, and rituals, which together form the basis of human society. With individuals widespread in every continent except Antarctica, humans are a cosmopolitan species. As of November 2011^[update], the human population was estimated by the United Nations Population Division to be about 7 billion, and by the United States Census Bureau to be about 6.97 billion.

Documentary photography usually refers to a popular form of photography used to chronicle significant and historical events. It is typically covered in professional photojournalism, or real life reportage, but it may also be an amateur, artistic, or academic pursuit. The photographer attempts to produce truthful, objective, and usually candid photography of a particular subject, most often pictures of people.