Breeched Wales Bloviating in the Hot Sun

Location: Long Island, New York, United States

Monday, December 27, 2004

How is evolutionary theory falsifiable?

I saw the question "I've been asking people all day how Darwinism is falsifiable and no one seems to have an answer." posted on another blog so I decided to answer it. here is my response:

Most people don't take their schooling seriously so they never get to the point where they would be able to both correct you and answer your question.

Evolution is a fact that has been established by geologists, palentologists, and the like.

The Theory of Natural Selection was at one time a hypothesis that was produced to explain how (the fact of) evolution occured. There are other hypotheses create to explain evolution such as lamarkianism, mutationism and saltationism that have been falsified.

In science a hypothesis is an educated guess at how something works that is falsifiable. Hypotheses that are mature in the sense that all attempts to falsify them have failed are called theories.

Darwin's theory of natural selection is falsifiable at many levels. It made predictions about the nature by which genetics should work in order for natural selection to operate. No one knew genetics at the time but Darwins theory required genetics to operate a certain way for natural selection to be the proper explanation of the fact of evolution.

As an example, natural selection requires that heritability not act like the mixing of paints, instead it requires particulate heritability. Further it requires some source of changes to the heritable material.

Darwin's theory would have been falsified for instance if it was found that Lamarcks theories were instead correct. If for instance we were able to stretch the necks of horses over a period of several generations and then the offspring were born naturally with longer necks then natural selection would not be able to explain that.

Deduction from Darwin's theories makes other predictions. For instance, since man is an animal like any other one would expect that he had evolved by natural selection also. So it would be expected that there should be intermediate forms between man and his ancestors in the fossil record. At the time of Darwin no such fossils had been found or were even thought to be looked for. Natural selection predicted that if we look for them we would probably find them. Well guess what, that prediction worked out on the side of natural selection.

Biologists also can make empircal predictions of what would be more advantagous characteristics under certain circumstances. They can then test populations under such circumstances to see if natural selection acts to change the frequency of genes in the predicted direction.

Natural selection deductively predicts that the evolution that is observed in the fossil record should have a certain structure. It should have a certain nesting characteristic that looks like a bush going back in time. This also has proven to be true. If you found a human fossil that was two billion years old that would pretty much put a nail in the coffin of the theory of natural selection.

One can deduce from natural selection that the current species on the planet should be able to also be organized into classifications that nest in a certain way, and their genetics must match. If we found that human DNA matched a fishes DNA more than a chimps then that would not be explanable under Darwin's theory.

There are many other areas in which Darwin's theory will deduce facts that can be tested to disprove the theory. The theory has passed all tests thrown at it so far. Not only is it falsifiable but it is as well tested as the best scientific theories of any discipline.