Complex Adaptive Systems
Complex adaptive systems are comprised of individual components, each with their own function: neurons conveying action potential for movement, antibodies binding foreign antigen for immune defense, companies selling products or services for profit. But when these components come together in a complex adaptive system, new properties emerge that may not have been predicted from the base function of the individual.
Source: J.H. Holland, Hidden Order: How Adaptation Builds Complexity, New York, NY: Addison Wesley, 1995.