Another example of irreducible complexity is a process most of us take for granted when we cut ourselves—blood clotting. Normally, any liquid will immediately leak out of a punctured container and will do so until the container is empty. Yet, when we puncture or cut our skin, the leak is quickly sealed by the formation of a clot. However, as doctors know, “blood clotting is a very complex, intricately woven system consisting of a score of interdependent protein parts.” These activate what is called a clotting cascade. This delicate healing process “depends critically on the timing and speed at which the different reactions occur.” Otherwise, a person could have all of his blood clotting and solidifying, or on the other hand, he could bleed to death. Timing and speed are the vital keys. Biochemical investigation has shown that blood clotting involves many factors, none of which can be missing for the process to succeed. Behe asks: “Once clotting has begun, what stops it from continuing until all the blood . . . has solidified?” He explains that “the formation, limitation, strengthening, and removal of a blood clot” make up an integrated biological system. If any part fails, then the system fails. Russell Doolittle, evolutionist and professor of biochemistry at the University of California, asks: “How in the world did this complex and delicately balanced process evolve? . . . The paradox was, if each protein depended on activation by another, how could the system ever have arisen? Of what use would any part of the scheme be without the whole ensemble?” Using evolutionary arguments, Doolittle tries to explain the origin of the process. However, Professor Behe points out that there would be an “enormous amount of luck needed to get the right gene pieces in the right places.” He shows that Doolittle’s explanation and casual language conceal tremendous difficulties. Thus, one of the major objections to the evolutionary model is the insurmountable hurdle of irreducible complexity. Behe states: “I emphasize that natural selection, the engine of Darwinian evolution, only works if there is something to select—something that is useful right now, not in the future.”
