1. Chapter 7, Models for Human Evolution Key Terms

2. encephalization The proportional size of the brain relative to some other measure, usually some estimate of overall body size. allometry The differential proportion among various anatomical structures. The relative size of the brain changes during the development of an individual.

3. motor cortex That portion of the cortex pertaining to outgoing signals involved in muscle use. anthropocentric Viewing nonhuman phenomena in terms of human experience and capabilities; emphasizing the importance of humans over everything else.

4. conspecifics Members of the same species. territories Portions of an individual’s or group’s home range actively defended against intrusion, particularly by conspecifics.

5. core area The portion of a home range containing the highest concentration and most reliable supplies of food and water. altruism Behaving in a manner that benefits another individual but at some potential risk or cost to oneself.

6. biological continuum Refers to the fact that organisms are related through common ancestry and that behaviors and traits seen in one species are also seen in others to varying degrees.