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The body of humans is described in the human anatomy group of articles. Humans have a wide range of variability in physical and other characteristics.
The evolution of Homo sapiens is characterized by a number of important trends:
expansion of the brain cavity and brain itself, which is typically about 1,400 cm3 in volume, well over twice that of a chimpanzee or gorilla. Some physical anthropologists argue that a reorganization of the structure of the brain is more important than cranial expansion itself.
canine tooth reduction.
bipedal locomotion
descent of the larynx (which makes possible the production of the complex sound known as vocal language).
How these trends are related, in what ways they have been adaptive, and what their role is in the evolution of complex social organization and culture, are matters of ongoing debate among physical anthropologists.
Although body size is highly heritable, it is also significantly influenced by environmental and cultural factors such as diet. The mean height of an American adult female is 162 centimetres and the mean weight is 62 kg. Males are typically heavier - 175 cm and 78 kilogram. Humans vary substantially around these means, and the means themselves have varied depending on locality and historical factors.
Human children, typically weighing 3-4 kilograms and 50-60 centimetres in height, are born after a nine-month gestation period. Helpless at birth, they continue to grow for some years, typically reaching sexual maturity at around 12-15 years of age. Boys continue growing for some time after this, often only reaching their maximum height around the age of 18. The average human lifespan is approaching 80 years in wealthy nations, with the assistance of science and technology.
See also human physical appearance.
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