Humans, or human beings, are bipedal primates belonging to the mammalian species Homo sapiens (Latin: "wise human" or "knowing human") in the family Hominidae (the great apes). Compared to other living organisms on Earth, humans have a highly developed brain capable of abstract reasoning, language, and introspection. This mental capability, combined with an erect body carriage that frees their upper limbs for manipulating objects, has allowed humans to make far greater use of tools than any other species. DNA evidence indicates that modern humans originated in Africa about 200,000 years ago,[LINK: http://www.mnh.si.edu/anthro/humanorigins/ha/sap.htm] The Smithsonian Institution, Human Origins Program and they now inhabit every continent, with a total population of over 6.6 billion as of 2007. History Origin