Creationists often charge that evolutionary theory is unfalsifiable; that there is no way to potentially disprove it, if it were in fact incorrect. This is in essence an “I know you are but what am I” response to their critics who have rightfully pointed out that “God did it” as an explanation is not testable against the evidence from the natural world and therefore not a valid scientific explanation for anything.
This is because hypotheses, in order to qualify as scientific, must be testable against observable evidence in the natural world. In other words, in addition to there being potential observations that might support a given hypothesis, there should likewise be some potential observations that would tend to disprove a hypothesis.
Since God can do anything in any way, for any reason, there are no potential observations of the natural world that could disprove God’s involvement, which means the “God did it” hypothesis is unscientific in character.
In any event, is it true, as creationists charge, that there are no potential observations that would tend to disprove evolutionary theory?
The short answer is no, it is not true. However, for something more in depth you should head over to Why Evolution Is True where biologist Jerry Coyne provides several scenarios that would be highly problematic for current evolutionary theory.
In my general talk on the evidence for evolution, I give a list of seven observations that, if repeated and confirmed, would disprove parts of the theory of evolution described above. This shows that it is a scientific theory in the Popperian sense of being falsifiable. Here are some of those conceivable observations:
- Fossils in the wrong place (e.g., mammals in the Devonian). If the fossil record were all out of order like this (a single anomalous fossil might not overturn everything, of course, since it could be in the wrong place for other reasons), we’d have to seriously question the occurrence of evolution.
I recommend you hop over and check out the rest.
The last thing I want to say about this particular creationist claim, is that in addition to it being false, it is also stands in rather blatant contradiction to what creationists do on a regular basis, which is to argue that this or that bit of evidence somehow counts against evolutionary theory.
The mind boggles.
[And now John Wilkins, or some other philosopher of science, will yell at me about Popperian Falsificationism being passé with regards to the demarcation problem. Just to head that off somewhat I am not advocating naive falsificationism.]