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What I Said about Chromosomal Fusion and Why I Said It

Science and Human Origins.jpgI'm going to try to help out science writer and Discover magazine blogger Carl Zimmer one more time.

In his latest post he repeats his question: "An article on Evolution News & Views stated that the evidence for the fusion of human chromosome two "appears in a 'degenerate,' 'highly diverged' form that should not be the case if the joining happened in the recent past, circa 6 million years ago, as the Darwinian interpretation holds." Where is the scientific evidence for this?"

He was referring to an article I wrote here about Casey Luskin's chapter "Francis Collins, Junk DNA, and Chromosomal Fusion" in Science and Human Origins. I was and am glad that the topic caught Zimmer's attention. That's why I invited him to debate Casey or one of the other two authors of SHO here at ENV. I invited him to read the book and evaluate the case it makes that Darwinian accounts fail to explain the origin of human beings. I invited him to send me his mailing address so we could mail him a free copy of the book. However he consistently refused or ignored all these pleas for a reasoned discussion.

I repeat my contention that reasoned discussion of a book isn't possible unless you grapple with the argument the book makes, as opposed to obsessively flogging one small point because you figure you may have an advantage there. Zimmer simply will not consider the larger case for skepticism about evolutionary explanations of human origins. He'll only lecture us about human chromosome 2.

It would seem to be reasonable at this point to give up on Carl Zimmer. For readers who want to know what Casey said in his chapter, and what I had in mind when I wrote my own post, here are several paragraphs I highlighted in my copy of SHO:

...[T]he evidence for chromosomal fusion isn't nearly as clear-cut as evolutionists like [Kenneth] Miller claim.

Telomeric DNA at the ends of our chromosomes normally consists of thousands of repeats of the 6-base-pair sequence TTAGGG. But the alleged fusion point in human chromosome 2 contains far less telomeric DNA than it should if two chromosome were fused end-to-end: As evolutionary biologist Daniel Fairbanks admits, the location only has 158 repeats, and only "44 are perfect copies" of the sequence.46

Additionally, a paper in Genome Research found that the alleged telomeric sequences we do have are "degenerated significantly" and "highly diverged from the prototypic telomeric repeats." The paper is surprised at this finding, because the fusion event supposedly happened recently -- much too recent for such dramatic divergence of sequence. Thus the paper asks: "If the fusion occurred within the telomeric repeat arrays less than ∼6 mya [million years ago], why are the arrays at the fusion site so degenerate?"47 The conclusion is this: If two chromosomes were fused end-to-end in humans, then a huge amount of alleged telomeric DNA is missing or garbled.

Finally, the presence of telomeric DNA within a mammalian chromosome isn't highly unusual, and does not necessarily indicate some ancient point of fusion of two chromosomes. Evolutionary biologist Richard Sternberg points out that interstitial telomeric sequences (ITSs) are commonly found throughout mammalian genomes, but the telomeric sequences within human chromosome 2 are cherry-picked by evolutionists and cited as evidence for a fusion event....

In other words, the evidence from human chromosome 2 for human-ape common ancestry is ambivalent at best. When you consider that in the context of all the rest of the evidence bearing on the same question, it becomes clear, as I said in the title of my earlier article, that "A Veil Is Drawn Over Our Origin as Human Beings." The ambiguity is only really impressive when you consider all the evidence, as Gauger, Axe and Luskin do in Science and Human Origins.

There's more -- much more -- to the book's overall argument, but Zimmer won't even consider it so as to argue against it.