“Evolution is a theory. It is a theory in the same sense as the atomic theory of matter or the germ theory of disease. This is what scientists mean by theories: In the scientific hierarchy, theories are higher than fact, because theories explain facts. Facts are simply individual, isolated, verifiable observations or experimental results.
“For example, is it fact that the sun is shining in the sky where I am right now? Yes. Is it a fact that in an hour the sun will have apparently moved its position? Yeah. That’s a fact as well. Is it a fact that the moon will rise a little bit later today after the sun sets? Yeah. So you have all these facts. How can we put all these facts together? The Copernican theory of the solar system, the heliocentric theory of the solar system, is a theory that makes sense of all these facts.
“Evolution is a theory that makes sense of millions of facts of natural history — the age of the earth, the succession of fossils in the fossil record, the genetic capabilities of organisms — and as such it ties things together in an extraordinary way that has been equaled by few theories in biology.
“Should evolution be critically examined? Yes. Everything in science should be critically examined. If the disclaimer were to urge that all scientific theories should be critically examined with an eye toward the evidence and contrary points of views and so forth, it would have my complete agreement.