In the abstract, it might be tempting to imagine that irreducible complexity simply requires multiple simultaneous mutations - that evolution might be far chancier than we thought, but still possible. Such an appeal to brute luck can never be refuted... Luck is metaphysical speculation; scientific explanations invoke causes.
Random mutations much more easily debilitate genes than improve them, and that this is true even of the helpful mutations. Let me emphasize, our experience with malaria’s effects on humans (arguably our most highly studied genetic system) shows that most helpful mutations degrade genes. What’s more, as a group the mutations are incoherent, meaning that they are not adding up to some new system. They are just small changes - mostly degradative - in pre-existing, unrelated genes. The take-home lesson is that this is certainly not the kind of process we would expect to build the astonishingly elegant machinery of the cell. If random mutation plus selective pressure substantially trashes the human genome, why should we think that it would be a constructive force in the long term? There is no reason to think so.
The conclusion of intelligent design flows naturally from the data itself—not from sacred books or sectarian beliefs. Inferring that biochemical systems were designed by an intelligent agent is a humdrum process that requires no new principles of logic or science. It comes simply from the hard work that biochemistry has done over the past forty years, combined with consideration of the way in which we reach conclusions of design every day.
Is the conclusion that the universe was designed - and that the design extends deeply into life - science, philosophy, religion, or what? In a sense it hardly matters. By far the most important question is not what category we place it in, but whether a conclusion is true. A true philosophical or religious conclusion is no less true than a true scientific one. Although universities might divide their faculty and courses into academic categories, reality is not obliged to respect such boundaries.
The most essential prediction of Darwinism is that, given an astronomical number of chances, unintelligent processes can make seemingly-designed systems, ones of the complexity of those found in the cell. ID specifically denies this, predicting that in the absence of intelligent input no such systems would develop. So Darwinism and ID make clear, opposite predictions of what we should find when we examine genetic results from a stupendous number of organisms that are under relentless pressure from natural selection. The recent genetic results are a stringent test. The results: 1) Darwinism’s prediction is falsified; 2) Design’s prediction is confirmed.