It is always an interesting, if not trying experience conversing with hard-core science-denialists. It's one thing to be skeptical of scientific claims. It's quite another to be actively opposed to and biased against all the claims and evidence of an entire field of scientific investigation. A skeptic naturally wants to see the evidence. He wants to have sufficient reason to believe some claim, regardless of where that claim comes from. A science denier is motivated to disbelieve all claims and all evidence, specifically because they come from a particular field of science to which he is ideologically opposed.
This ideological opposition is usually either religious or political in nature. Politically motivated science denial is manifested, for example, in those who oppose the scientific consensus on anthropogenic global warming. They dedicate tremendous resources to producing pseudo-scientific arguments, data, and propaganda in support of their ideological position. This is typically driven by deep-pocketed research groups and think-tanks financed by individuals and corporations with a vested interest in continuing their industrial practices that contribute significantly to the problem. They produce the bulk of source information in the guise of scientific research that is then consumed and regarded as "truth" by a community of dedicated, politically motivated, and deeply biased ideologues. These ideologues function as evangelists for the pseudo-science. The pseudo-science itself is so avidly followed by the evangelists that it practically achieves the status of a religion. They refuse to listen to any facts or evidence that would dispute it.
Similarly, with regard to evolution science, it is religious motivation that produces hyper-skepticism of the scientific consensus, and a pseudo-scientific approach to countering it. You might think it would be difficult to be hyper-skeptical in the face of a well-established theory that is so abundantly supported by evidence as evolution theory, but ideological motivation is capable of producing extreme bias. Their bias allows them to ignore or dismiss evidence that would be persuasive to any reasonable person who lacks this ideological motivation.
This is what I observed in my recent foray into a blog known as CADRE, which has multiple contributors. I noticed a post there by Don McIntosh titled Darwinism, Naturalism and Falsification that had some interesting things to say about evolution theory, including this:
Darwinists happily explain examples of seemingly useless non-adaptive characteristics like junk DNA as evidence of unguided randomness; but they also explain stunning examples of functional complexity (like the mammalian eye or echolocation in bats) as evidence of boundless adaptability. Similarly every biological eventuality is explainable in terms of "descent with modification," where extremely wide levels of taxa-spanning variation and diversity are evidence of modification, but shared characteristics like homologous structures and identifiable body plans are evidence of (common) descent.That's a pretty strong claim, and it's patently untrue. It seems that the assertion stems from philosopher of science Karl Popper, who examined evolution theory and initially concluded that the inability to observe long-term macro-evolutionary changes makes the theory unfalsifiable. But what these creationists don't tell you is that Popper examined it more thoroughly and subsequently changed his position, concluding that evolution theory meets the criterion of falsifiability after all, as discussed in this article. Instead, they try to build a case that evolution theory incorporates any discrepant findings into the theory, and that these discrepant findings occur frequently. This makes the theory so malleable that it has essentially no scientific value. Let's get this straight. Evolution theory is definitely falsifiable, as any evolutionary biologist will attest. Here's what Jerry Coyne has to say about it. Furthermore, the supposed wealth of discrepant findings that the creationists claim, such as out-of-place fossils, doesn't exist.
In short, there's no conceivable biological feature that Darwinism cannot explain in principle. But if there's nothing that it cannot adequately explain in principle, there's also no way in principle to falsify it.
But just as with the climate science deniers, it is the strategy of the creationists and ID "scientists" to build a pseudo-science, characterized by unsubstantiated theories and contrived or cherry-picked evidence, that completely ignores the vast body of factual information that doesn't fit. They adhere to this pseudo-science religiously. At the same time, to give it some appearance of legitimacy, they attack genuine science and try to make it sound fraudulent and devoid of supporting evidence. They make false assertions like "There is zero empirical evidence of macro-evolution." If you show them an excellent summary of evidence for macro-evolution, it is dismissed as "links to inferential opinion".
Don McIntosh caps off his case for unfalsifiability by ridiculing a statement made by PZ Myers that he believes there can be no evidence for God:
To recap: All possible evidence confirms Darwinism by default, while no possible evidence is sufficient to confirm that God exists. It looks as if Myers has created for himself the best of all possible atheistic worlds.While I don't believe that Myers is correct, it is much more ridiculous for McIntosh to claim that all possible evidence confirms evolution. At least Myers can honestly say that no empirical evidence for God exists. McIntosh's claim is an outright lie. But like his other religion, he believes it with every fiber of his being.