Here is an excellent example of how a creationist argument can still help us understand the scientific method! And it starts on a topic we’ve been discussing in my Evolution class this week: Homology! Larry Hufford of Washington State University was preparing a lecture on homology, went googling for any new supporting material, stumbled upon the Conservapedia entry on homology, and ended up discussing their creationist claim in the classroom! And the result is something that should make creationists think twice about continuing to demand that biologists (real scientists) give equal time to creationism in the classroom. Its a risky proposition (for creationists) if a competent biologist takes creationism on in such a thoughtful discussion because it is so easy to show why creationism is not a science! Do you want us to keep doing that over and over again? I suppose there is some educational benefit to that – but I’d rather use our class time to explore the real wealth of insights from evolutionary biology, than keep flogging the intellectually dead horse of creationism (or Conservapedia). It is nice therefore to have Hufford’s article which lays out the argument with regards to one creationist “claim” about the invalidity of homology. It is worth your while to read the whole story, which starts by outlining what the homology argument is and how a scientific explanation of it can be constructed:
Homology is basically a proposal of equivalence. If we say that the arm of a human, the arm of a chimpanzee, and the wing of a bird are homologous, then we are hypothesizing that these corresponding structures are somehow equivalent. The somehow of that equivalence is what a biologist wants to explore and to explain. In a facile manner, I could say that homology of the arm of a human, the arm of a chimpanzee, and the wing of a bird is explained because they are all modifications of a corresponding structure in their most recent common ancestor, which is to say that we have homology because of evolution.
A less facile explanation would require us to explain how common position within bodies and possible similarities in development, including perhaps similar genes being expressed to control development, of humans, chimpanzees, and birds lead to a hypothesis of homology. We might also be expected to explain how intermediate structures in the lineages ‘between’ humans and chimpanzees as well as between them and birds help to demonstrate the transformations that could have occurred since their divergence from a common ancestor. Formulating this set of explanations to propose an hypothesis of homology is sometimes called a ‘homology argument.’
After laying out that excellent explanation, Hufford went looking for examples:
As I wrote my lecture on Monday, I wanted to look for new examples of homology arguments—so I googled ‘homology argument.’ One of the top links that Google returned in the search was for an entry in the Conservapedia, which subtitles itself as “The Trustworthy Encyclopedia.” The link took me to the Conservapedia entry for homology, which it defined as “. . . the theory that macroevolutionary relationships can be demonstrated by the similarity in the anatomy and physiology of different animals.” While I don’t regard that definition as accurate, it’s neither egregious nor exactly untruthful.
It was the section below the Conservapedia’s definition of homology that caught my attention—it was labelled “Invalidity of the Homology Argument.” How could the homology argument be invalid, I wondered? After all, a homology argument is a method of comparing and reasoning rather than an assertion of truth.
The explanation offered by the Conservapedia for the invalidity of the homology argument is straightforward: “Creation scientists claim that similarity can just as readily be explained by a common Designer as common ancestry, and that homology is therefore not evidence that can be used to support the evolutionary view.”
So a “claim” from creationists is sufficient to dismiss out of hand a logically constructed and repeatedly well tested scientific argument? And they claim that scientists are the ones acting in an authoritarian manner when keeping creationism out of the classroom? Interesting. Anyway, the above “claim” then led to a useful class discussion on what separates scientists and creationists:
We discussed in class a critical difference between a scientist and a creationist. Creationists think they have THE answer from the beginning, whereas a scientist has only a question in the beginning. While a creationist may accept absurd dogma and simplistic dismissals of rational ideas, a scientist looks for a way to test ideas. That willingness to test and to infer from the results of those tests the best explanations distinguishes the scientific method from the creationist method. [A great untruth of the Conservapedia’s entry on homology was its claim that there are creation ‘scientists’—creationists offer religious explanations and dismiss the results of repeatable scientific studies rather than using a scientific method.]
Once this very basic difference between the two approaches is recognized, is there really any reason to keep discussing all the other creationist arguments in the classroom?