Atheists are sometimes fond of saying that we should face the natural world with the presumption of atheism. That is, until convincing evidence for the existence of God can be adduced, we should assume that God does not exist. This claim gets it exactly backwards.
If you look at nature with your eyes open, everything has the appearance of having been designed. Flowers, trees, crystals, chambered nautilus shells, the human body. And the complexity of the natural world argues further for a designer or creator. Metamorphosis, the blood-clotting cascade, an entire set of baby teeth being replaced by permanent teeth. It is the most logical to conclude that all these things came about because of the creation or guidance of God. That's what people naturally believe.
To attribute these things to chance, random mutation, natural selection, and so forth, in the absence of God, requires an (unnatural) set of arguments and explanations. Atheism must be trained into people in the process of explaining away the appearance of design. And to be an atheist in the face of the elegance and complexity of the processes in a single cell--the molecular machines, DNA, hormonal controls, the process of cell division--this, it would seem, requires more faith than that possessed by many theists.
If you can argue persuasively for the presumption of atheism, then Neo-Darwinist evolutionary theory can maintain a modicum of plausibility, which, if God is anywhere even remotely present, the theory has lost completely. This explains why science has been redefined from "the search for truth and explanations of nature and its processes" into "the search for natural explanations of nature and its processes."
Losing the argument? Redefine the terms.