Unintelligent Design? Cancer, Cataracts, and Irreducible Complexity

Intelligent design, often used as an argument for the existence of God, posits that the natural world shows signs of having been designed by some form of intelligence rather than as the result of an undirected process such as natural selection. Proponents often cite the harmony and complexity of various elements of the human body. Intelligent design itself has received very little scientific support. But such issues have recently come to the fore since astronaut Tim Peake stated, “I’m not religious [but] it doesn’t necessarily mean that I don’t seriously consider that the universe could have been created from intelligent design”. Further to arguing that intelligent design has no evidential basis, many opponents are taking issue with the very idea that the human body and nature in general shows signs of perfection (and therefore of creative intelligence). Clearly, all human systems have flaws that allow them to malfunction. Our cells can develop cancer, our immune system can attack us, our eyes fail us. Evolutionary biologist Matan Shelomi asks, “who designed these faulty things? The answer can’t be a God, because a God so incompetent in designing vision sensors isn’t worth worshiping.”

It must be said that such critics have somewhat misrepresented the argument about the human eye and the main thrust of the intelligent design theory, which is less about perfection and more about complexity and codependence of elements. ‘Irreducible complexity’ describes a system in which all the parts work together to achieve a certain function, and which would not work if any one small part were omitted; advocates for intelligent design propose that many biological mechanisms can be described in this way, and therefore that natural selection could not bring about these mechanisms. Darwin himself conceded, “if it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down”; however, he added, “I can find out no such case.” In fact, in the 20^th century Herman Muller contemplated a sort of irreducible complexity—but rather than seeing it as an obstacle to evolution he described it as the expected result of evolution by natural selection: “being thus finally woven, as it were, into the most intimate fabric of the organism, the once novel character can no longer be withdrawn with impunity, and may have become vitally necessary”. Moreover, the irreducible complexity argument ignores the phenomenon of expiation, whereby an already existing trait may change function during the course of evolution.

Applicants for Biology or Natural Sciences (B) should be familiar with both historical and contemporary research on evolution. Those interested in Theology or Philosophy may wish to look into intelligent design as well as arguments from teleology.