I’ve spent quite a bit of time debunking creationist arguments. One thing that I haven’t done is debunk evolutionist arguments. I’ve decided the time for that is now.
Bad Argument One: Conflating Common Ancestry with Genetic Population Changes
I’ve seen youtube videos that run along the following lines: creationist says evolution isn’t a fact. Evolutionist says it is, points to an example of evolution happening (like bacteria adapting to a new environment). The problem is: no creationist doubts that changes can occur in the genetic make-up of a population. They don’t doubt that the process of evolution occurs. Rather, they have trouble with believing that those kinds of processes have given rise to fish, whales, humans, frogs, and so on. This is a clear case of confusion. It is unclear whether or not the evolutionist here is making a bad argument; that would depend on whether she thinks that the evolution of antibiotic resistant bacteria implies anything about the common ancestry of humans and chimps or about the mechanisms that gave rise to life in its modern forms.
Bad Argument Two: Vestigial Organs
It is occasionally asserted that animals have lots of useless organs and appendages which are inexplicable except for evolution. The problem with this argument is that it is very difficult to know whether or not something has no function, and that’s something that has to be demonstrated, not merely assumed. In certain cases it can be demonstrated. In other cases, it can’t be, and so the argument ought to be abandoned in favor of a more defensible form of the argument from vestigial organs. As Dr. Douglas Theobald put it:
“Vestigial characters, if functional, perform relatively simple, minor, or inessential functions using structures that were clearly designed for other complex purposes. Though many vestigial organs have no function, complete non-functionality is not a requirement for vestigiality. For example, wings are very complex anatomical structures specifically adapted for powered flight, yet ostriches have flightless wings. The vestigial wings of ostriches may be used for relatively simple functions, such as balance during running and courtship displays—a situation akin to hammering tacks with a computer keyboard. The specific complexity of the ostrich wing indicates a function which it does not perform, and it performs functions incommensurate with its complexity. Ostrich wings are not vestigial because they are useless structures per se, nor are they vestigial simply because they have different functions compared to wings in other birds. Rather, what defines ostrich wings as vestigial is that they are rudimentary wings which are useless as wings.” (Be sure and check out the link for a ton of cool pictures and interesting examples).
Bad Argument Three: “Disproving Evolution Does Not Prove Creationism”
In this context, “disproof” doesn’t mean an absolute disproof, it just means finding really strong evidence against evolution, or confirming observations that are really unlikely to be made if evolution is true. Creationists who argue this side of the case also presuppose that their “evolution disproofs” are better predicted by creationism than by evolution. According to Bayes’ Theorem, if evidence is really improbable under the theory of evolution but is somewhat more probable under the theory of creationism, then that evidence adds weight to the theory of creationism. This is not to say that such evidence actually exists or that the creationists have their facts straight (they usually don’t). However, if the above conditions are met then the creationists have a logically sound argument.
Bad Argument Four: Creationism is not a Scientific Hypothesis / Is Not Falsifiable.
How does one define a “scientific hypothesis”? My philosophy is that any statement that can be tested, at least theoretically, is scientific. Most versions of creationism are abundantly testable not just in theory but in actuality. In fact, they’ve been tested and proven false dozens of times. Example: the thesis that the earth and universe are less than ten thousand years old entails that we ought not to be able to see stars that are millions of light years away, that we ought not have rocks with radiometric ages of millions of years, and so on. And we have all that. Of course, some creationists will make up un-evidenced excuses for all this stuff, and their critics see this as a reason to think creationism is unfalsifiable. But that doesn’t follow: the fact that you can make up excuses for failed predictions doesn’t make creationism different from any other scientific idea. Since we don’t consider other scientific ideas unfalsifiable simply because falsifications can be explained away, creationism should not be treated any differently. All that said, there are two points here that still stand which aren’t favorable to creationism:
1. The necessity of making up contrived excuses for creationism is a good reason to it is false.
2. The willingness of creationists to engage in this to defend their position shows that they aren’t behaving like good scientists, or even remotely reasonable people.
Ironically, I’ve seen a number of authors make the mistake of declaring that supernatural hypotheses cannot be tested, ignoring the fact that they have been tested repeatedly (psychic abilities have been tested by James Randi). I’ve seen authors claim that no evidence could possibly falsify creationism, and then go on to adduce a long list of evidence that falsifies creationism (example: Douglas Futuyma’s Evolutionary Biology under the section on creationism). Obvious contradictions. Creationism is falsified in light of the fact that it doesn’t predict the evidence we have as well as evolution (transitional fossils, biogeography, and so on).
