| Humans |
| Humans, or human beings, are bipedal primates belonging to the mammalian species Homo sapiens (Latin: "wise man" or "knowing man") under the family Hominidae (the great apes).[1][2] 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. Humans originated in Africa, but now inhabit every continent, with a total population of over 6.5 billion as of 2007.
Like most primates, humans are social by nature. However, humans are particularly adept at utilizing systems of communication for self-expression and the exchange of ideas. Humans create complex social structures composed of cooperating and competing groups, ranging in scale from individual families to nations, and social interaction between humans has established a variety of traditions, rituals, ethics, values, social norms, and laws which form the basis of human society. Humans also have a marked appreciation for beauty and aesthetics which, combined with the human desire for self-expression, has led to cultural innovations such as art, literature and music. Humans are also noted for their desire to understand and influence the world around them, seeking to explain and manipulate natural phenomena through religion, science, philosophy and mythology. This natural curiosity has led to the development of advanced tools and skills; humans are the only known species to build fires, cook their food, clothe themselves, and use numerous other technologies. One of the earliest defining human traits, bipedalism�walking on two legs as the primary form of locomotion�evolved more than 4 million years ago. Other important human characteristics�such as a large and complex brain, the ability to make and use tools, and the capacity for language�developed more recently. Many advanced traits�including complex symbolic expression, such as art, and elaborate cultural diversity�emerged mainly during the past 100,000 years. Humans are primates. Physical and genetic similarities show that the modern human species, Homo sapiens, has a very close relationship to another group of primate species, the apes. Humans and the so-called great apes (large apes) of Africa�chimpanzees (including bonobos, or so-called pygmy chimpanzees) and gorillas�share a common ancestor that lived sometime between 8 million and 6 million years ago. The earliest humans evolved in Africa, and much of human evolution occurred on that continent. The fossils of early humans who lived between 6 million and 2 million years ago come entirely from Africa. Most scientists distinguish among 12 to 19 different species of early humans. Scientists do not all agree, however, about how the species are related or which ones simply died out. Many early human species�probably the majority of them�left no descendants. Scientists also debate over how to identify and classify particular species of early humans, and about what factors influenced the evolution and extinction of each species. |
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