Democrats: Evolve!

Like me, perhaps you have been wondering what to do now that the election is over, and how to make it come out differently next time. Here's a place to start: Get involved in stopping the disaster under way as three more states are moving to remove or qualify the teaching of evolution in high schools.

Not sure where to begin, because, after all, evolutionary theory is just a theory, like they say? Here's a primer to help you out.

First, the theory of evolution by natural selection is widely regarded as the most well-confirmed theory we have. Second, the opposing "theory" of intelligent design is not a scientific theory at all. How can you tell? Well, this is difficult and controversial terrain, but here is a start: scientific theories must be falsifiable, they must make predictions that could turn out to be false and thereby disconfirm the theory. Evolutionary theory does this. Intelligent Design and Creationism do not, they are compatible with all possible data so they are unfalsifiable. Proponents of those "theories" emphasize the fact that evolutionary theory is not verifiable, that we cannot know for certain that it is true, and this that it is (in their words) "just" a theory. But no scientific theory is verifiable in that sense--they are all open to disconfirmation by newly discovered evidence. This is what distinguished scientific theories from science fiction stories.

OK, but isn't there genuine disagreement among scientists about evolutionary theory? No, not over the basic validity of the theory of evolution by natural selection. The critics make it look this way because they confuse several different notions. Roughly:

Evolution: the theory of biological change over time.

Evolution by natural selection: the idea that the primary mechanism for evolution is natural selection.

Darwinism: in popular culture, belief in evolution by natural selection; in technical terms, the belief that natural selection acts gradually over time.

Adaptationism: in its most extreme form, the belief that natural selection is the only mechanism of evolution.

So... for example, when the late Stephen J. Gould is cited as critiquing adaptationism, he is not saying that there is no evolution by natural selection; he is critiquing the idea that natural selection is the only mechanism of evolution. (Darwin did not believe that it is, and neither did Gould.) And when Gould is cited as critiquing Darwinism, he is critiquing the idea that evolutionary change occurs gradually and continually—for Gould's own theory is that evolution occurs in spurts, what he called the punctuated equilibrium theory. The punctuated equilibrium theory is a theory about how evolution occurs, not an alternative to evolutionary theory. The debates among biologists concern the mechanisms and characteristics of evolutionary change, and the relative contributions of forces other than natural selection (for example, random drift and mutation) in accounting for evolution. There is no mainstream debate over whether natural selection is an important mechanism for evolutionary change.

Now you have the basic tools. Go forth and make sure our schools keep teaching science. Evolve!