This is testing to see if the structure requires all of its parts to function. When researchers find “irreducible complexity” in biology, it points to the theory of intelligent design (Intelligent Design). This test was first presented by Michael Behe in his book Darwin’s Black Box: The Biochemical Challenge to Evolution (Irreducible Complexity). He proves this through the use of three major examples: the bacterial flagellum, blood clotting, and the immune system (Irreducible