Free Faith Versus Fact : Why Science and Religion Are Incompatible (9780698195516) by Jerry A. Coyne Page A

atoms and one oxygen atom, that the speed of light in a vacuum is unchanging (and close to 186,000 miles per second), and that the closest living relatives of humans are the two species of chimpanzees. After all, you bet your life on science every time you take medicines like antibiotics, insulin, and anticholesterol drugs. If we consider “proof” in the vernacular to mean “evidence so strong that you’d bet your house on it,” then, yes, science is sometimes in the business of proof.
    So what are the components of the toolkit of science? Like many of us, I was taught in high school that there is indeed a “scientific method,” one consisting of “hypothesis, test, and confirmation.” You made a hypothesis(for instance, that DNA is the genetic material) and then tested it with laboratory experiments (the classic one, done in 1944, involved inserting the DNA of a disease-causing bacteria into a benign one and seeing if the transformed bacteria could both cause disease and pass this pathogenicity on to its descendants). If your predictions worked, you had supported your hypothesis. With strong and repeated support, the hypothesis was finally considered “true.”
    But scientists and philosophers now agree that there is no single scientific method. Often you must gather facts before you can even
form
a hypothesis. One example is Darwin’s observation, made on his
Beagle
voyage, that oceanic islands—usually volcanic islands that rose above the sea bereft of life—have lots of birds, insects, and plants that are
endemic,
native only to those islands. The diverse species of finches of the Galápagos and the fruit flies of Hawaii are examples. Further, oceanic islands like Hawaii and the Galápagos either have very few species of native reptiles, amphibians, and mammals or lack them completely, yet such creatures are widely distributed on continents and “continental islands” like Great Britain that were once connected to major landmasses. It is these facts that helped Darwin concoct the theory of evolution, for those observations can’t be explained by creationism (a creator could have put animals wherever he wanted). Rather, they lead us to conclude that endemic birds, insects, and plants on oceanic islands descended, via evolution, from ancestors that had the ability to migrate to those places. Insects, plant seeds, and birds can colonize distant islands by flying, floating, or being borne by the wind, while this is not possible for mammals, reptiles, and amphibians. Collecting that data and then recognizing a pattern in it was what helped produce the theory of evolution.
    And sometimes the “tests” of hypotheses don’t involve experiments, but rather observations—often of things that occurred long ago. It’s hard to do experiments about cosmology, but we’re completely confident in the existence of the Big Bang because we observe things predicted by it, like the expanding universe and the background radiation that is the echo of that event. Historical reconstruction is a perfectly valid way of doing science, so long as we can use observations to test our ideas (this, by the way, makes archaeology and history disciplines that are, in principle, scientific). Creationists often criticize evolution because it can’t be seen in “real time”(although it has been), apparently ignorant of the massive
historical
evidence, including the fossil record, the useless remnants of ancient DNA in our genome, and the biogeographic pattern I described above. If we accept as true only the things we see happen with our own eyes in our own lifetime, we’d have to regard all of human history as dubious.
    While scientific theories can make predictions, they can also be tested by what I call “retrodictions”: facts that were previously known but unexplained, and that suddenly make sense when a new theory appears. Einstein’s