Humans (Homo sapiens) are primates of the family Hominidae, and the only extant species of the genus Homo. Humans are characterized by having a large brain relative to body size, with a particularly well developed neocortex, prefrontal cortex and temporal lobes, making them capable of abstract reasoning, language, introspection, problem solving and culture through social learning. This mental capability, combined with an adaptation to bipedal locomotion that frees the hands for manipulating objects, has allowed humans to make far greater use of tools than any other species. Humans are the only extant species known to build fires and cook their food, as well as the only known species to clothe themselves and create and use numerous other technologies and arts. The scientific study of humans is the discipline of anthropology.
Humans are uniquely adept at utilizing systems of symbolic communication such as language and art 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 states. Social interactions between humans have established an extremely wide variety of values, social norms, and rituals, which together form the basis of human society. Humans are noted for their desire to understand and influence their environment, seeking to explain and manipulate phenomena through science, philosophy, mythology, and religion.
Homo sapiens originated in Africa, where it reached anatomical modernity about 200,000 years ago and began to exhibit full behavioral modernity around 50,000 years ago. The human lineage diverged from the last common ancestor with its closest living relative, the chimpanzee, some five million years ago, evolving into the Australopithecines and eventually the genus Homo. The first Homo species to move out of Africa was Homo erectus, the African variety of which, together with Homo heidelbergensis, is considered to be the immediate ancestor of modern humans. Homo sapiens proceeded to colonize the continents, arriving in Eurasia 125,000-60,000 years ago, Australia around 40,000 years ago, the Americas around 15,000 years ago, and remote islands such as Hawaii, Easter Island, Madagascar, and New Zealand between the years AD 300 and 1280.
Humans began to practice sedentary agriculture about 12,000 years ago, domesticating plants and animals which allowed for the growth of civilization. Humans subsequently established various forms of government, religion, and culture around the world, unifying people within a region and leading to the development of states and empires. The rapid advancement of scientific and medical understanding in the 19th and 20th centuries led to the development of fuel-driven technologies and improved health, causing the human population to rise exponentially. With individuals widespread in every continent except Antarctica, humans are a cosmopolitan species, and by 2012, their population was estimated to be around 7 billion.