For several years now evolutionists have presented the human chromosome number two as an excellent example of how science supports and confirms evolution and this week science writer Carl Zimmer continued the celebration in his Discover magazine blog. What Zimmer and the evolutionists fail to comprehend, however, is that their argument from the human chromosome number two is an excellent example of the religion and rationalism at the heart of evolutionary thought.
You can read the details of how evolutionists have presented the human chromosome number two evidence here. Simply put, the idea is that after the human and chimpanzee lineages split from their common ancestor about six million years ago, the human lineage experienced a chromosome fusion event where two chromosomes fused together to become one, thus reducing the count from 24 to 23. Since our chromosomes come in pairs, the total number reduced from 48 to 46.
That story is reasonable enough, but in the hands of evolutionists it quickly becomes a sordid tale of lies and misdemeanors. There’s something here for everyone as evolutionists cycle through several of their typical fallacies and hypocrisies including shifting the burden of proof, naïve falsificationism, affirming the consequent, theological naturalism, abuse of science and circular reasoning.
Shifting the burden of proof
Ever since Darwin called for skeptics to prove his speculative ideas wrong this strategy of shifting the burden of proof has been a favorite of evolutionists. Darwin wrote:
If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down. But I can find out no such case.
But this was hardly a concession. Darwin may sound generous here, allowing that his theory would “absolutely break down,” but his requirement for such a failure is no less than impossible. For no one can show that an organ “could not possibly” have been formed in such a way. So in short order Darwin reduced what seemed to be a dilemma for his theory into a logical truism. Evolution was protected from criticism and all that was needed to explain complexity was a clever thought experiment. Darwin so lowered the requirements that anyone with a pen and a vivid imagination can now claim to have solved the problem of complexity.
Zimmer used this same strategy this week when he demanded that skeptics of the chromosome two argument show why the evolutionary fusion hypothesis is not possible:
Why is it so hard to answer one question? What is the evidence claimed by members of the Discovery Institute that human chromosome could [not] have evolved through fusion six million years ago? Why do I have to engage in a drawn-out debate about an entire book to get an answer to this one question? [Note: Zimmer’s point is nonsensical because he accidentally omitted the word “not”]
Of course no such claim was made. It is the evolutionists strategy to shift the burden of proof so that evolution enjoys the position of being true by default. Everything evolved from nothing unless you can prove otherwise to the evolutionist’s satisfaction.
Evolutionists argue that the chromosome two fusion event is important because evolution successfully passes a test of falsification. Zimmer approvingly cites a Ken Miller talk (click above) where Miller makes this argument and concludes:
But there’s something that’s really interesting, and has the potential, if it were true, to contradict evolutionary common ancestry. [0.47]
Evolution has survived so many false expectations with creative conjecture that claims that “this time it’s different” have long since lost credibility. When predictions turn out to be false we are told they were soft and not binding. Evolutionists reassure us that it is all a part of science following the data as the theory is contorted yet again. But when predictions turn out to be true we are told they were hard and binding. An evolutionist once told me that evolution certainly would be falsified by the finding of functionally unconstrained yet conserved DNA sequences. That was before the finding of functionally unconstrained yet conserved DNA sequences.
Beyond this problem of after-the-fact evaluation of predictions, there is the problem that even the success of a hard prediction, by itself, carries only limited information. For instance, science is full of theories that are considered to be false yet enjoy any number of confirmed predictions.
Affirming the consequent
Another problem with successful predictions is that evolutionists view them as not only providing a hard falsification test, but as also providing a sort of confirmation of evolution. At its worst this amounts to the logical fallacy of affirming the consequent. At its best it is a failure to reckon with the meaning of a successful prediction. For instance, Miller triumphantly concludes:
It confirms the prediction of evolution. [3:46]
So what? Science is, again, full of theories considered to be false which make all kinds of successful predictions. This example is particularly awkward since the chromosomal fusion event would have occurred exclusive of any evolutionary speciation event. In other words, perhaps evolution needs it, but it doesn’t need evolution.
Theological arguments for evolution’s strictly naturalistic account are crucial. They are evolution’s raison d'être and no less so in this chromosome two argument. As pointed out above, as a falsification test and as a successful prediction, the case of the chromosome two fusion is, from a scientific perspective, of limited importance. The key, as always, is the religious interpretation.
Evolutionists believe that this chromosomal arrangement would never have been designed or created. The key word here is “believe.” It is a religious argument and it is here that evolution has all its strength. Again, Miller makes it clear:
How would intelligent design explain this? Only one way. By shrugging and saying “That’s the way the designer made it.” No reason, no rhyme. Presumably there’s a designer who designed human chromosome number two to make it look “as if” it was formed by the fusion from a primate ancestor. I’m a Roman Catholic, I’m a theist in the broadest sense I would say I believe in a designer, but you know what, I don’t believe in a deceptive one. I don’t believe in one who would do this to try to fool us. And therefore I think this is authentic and it tells us something about our ancestry. [3:48]
There you have it. If one doesn’t believe the chromosomal arrangement is possible under design or creation then, yes, evolution is left as the “None of the above” answer. It must be true, one way or another. As usual evolutionists are quite clear about the metaphysics that motivates and underwrites their theory. This is the power of evolutionary thought.
Abuse of science
The idea that the universe came from nothing and that the biological world arose spontaneously is, of course, not scientifically motivated and not scientifically expected. It is another case of religion driving bad science. The chromosome two case is not nearly the abuse of science that much of evolutionary theory is, but it does have its problems. The site of the fusion event on human chromosome number two does not provide an obvious picture of a past fusion event. There certainly are suggestions of such an event, but it is far from obvious as evolutionists claim.
Furthermore such an event, if it could survive, would have to take over the pre human population. In other words, the existing 48 chromosome population would have to die off. This is certainly not impossible, but there is no obvious reason why that would occur.
There are problems with the evidence. Perhaps the fusion event occurred, but the evidence carries nowhere near the certainty that evolutionists insist it does. It is not so much that the evidence is conclusive against the event but that it is not conclusive for the event as evolutionists claim. Their interpretation is driven by their theory, and this leads us to the final fallacy.
If you believe evolution is true to begin with, then you would conclude that the human chromosome number two is the result of a fusion of two ancestral chromosomes. There would be no question about it for several reasons. It would reconcile the different chromosome counts in humans and chimpanzees. And there are a great many similarities between the human chromosome number two and the two corresponding chimp chromosomes.
But if evolution is not taken as an a priori, then these evidences are far less compelling. From this theory-neutral perspective, what is important is not reconciling chromosome counts or chimp-human chromosome similarities (after all, those are found throughout the respective genomes). What is important is the more direct evidence of a fusion event, such as in the region where the two chromosomes would fuse, and other tell-tale signs in the chromosome two.
Here the evidence is mixed. Certainly it is far less compelling than evolutionists ever tell their audiences. This need not be controversial. But it is.
Why? Because evolutionists are essentially incapable of such a dispassionate analysis where presuppositions and evidences are clearly laid out. Their analysis is deeply influenced by their dogmatic assertion that evolution is a fact. For evolutionists it is a metaphysical certainty and they simply are unable to evaluate the evidence from a theory-neutral perspective.
All of this results in a stubborn type of circular reasoning where evolution is presupposed, evidence is interpreted accordingly, and the results then service evolutionary apologetics as though they were obtained from objective science.
In this case, from the evolutionary perspective the chromosomal fusion event is beyond any reasonable doubt. And that event is then used as powerful evidence for evolution. It is all circular.
This is a subtle yet influential motif in evolutionary thought that often underlies discussions and debates while escaping detection.
The human chromosome number two is a concise illustration of evolutionary thought. There is, of course, much more to evolutionary thought than can be packed into this tight vignette, but it does capture the subtleties and intricacies that inevitably weave their way through any defense of evolution.