 There is another problem with the simulation-duplication distinction, arising from the process of evolution. Searle wishes to see original intentionality and genuine understanding as properties only of certain biological systems, presumably the product of evolution. Computers merely simulate these properties. At the same time, in the Chinese Room scenario, Searle maintains that a system can exhibit behavior just as complex as human behavior, simulating any degree of intelligence and language comprehension that one can imagine, and simulating any ability to deal with the world, yet not understand a thing. He also says that such behaviorally complex systems might be implemented with very ordinary materials, for example with tubes of water and valves.