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.