How could blood clotting have evolved? Blood clotting automatically swings into action when we get a cut. The formation of a blood clot is a complex, multi-step process that utilizes numerous proteins, many with no other function besides clotting. Each protein depends on an enzyme to activate it.
So which evolved first-the protein or enzyme? Not the protein; for it cannot function without the enzyme to switch it on. But why would nature evolve the activating enzyme first? Without the protein, it serves no purpose. Furthermore, if blood clotting had evolved step-by-step over eons, creatures would have bled to death before it was ever perfected. The system is irreducibly complex and could not have evolved.
("The Case Against Darwin" by James Perloff, WorldNetDaily, February 20, 2001)