Chance cannot produce complexity  Evolution depends on chance mutations in genes producing changes that make it more complex and introduce survival benefits. Mutations do not increase the complexity of organisms, but damages them: for example, cancer. Mutants might gain new powers in comic books, but not in real life. [1]  Mutations may have beneficial side-effects, but do not add new information. For example, sickle-cell anemia increases resistance to malaria. [2] However, it does this because the normal functioning of the blood cells is impaired, not by evolving into something more complex, which is necessary for evolution to take place.  Many biological systems are irreducibly complex: you need all the parts to work, or they will not work at all, like a mousetrap. They cannot have arisen by step-by-step changes.  [1] Daniel W. McShea, ‘Complexity and Evolution: What Everyone Knows’, Biology and Philosophy, 6: 303-324, 1991.  Accessed 1/6/2011  [2] Michael Aidoo et al., ‘Protective effects of the sickle cell gene against malaria morbidity and mortality’, Lancet 2002; 359: 1311-12  Accessed 3/6/2011