Here's a video where several IDiots take on Francis Collins and his book The Language of God,. Jonathan Wells is prominently featured in this video and much of the attack is concerned with junk DNA. Wells makes his position very clear. He claims that modern scientific evidence has overthrown the "myth" of junk DNA and those of us who still believe in junk DNA are guilty of a "Darwin of the gaps" kind of argument. That's because, according to Welles, we don't have an explanation for junk DNA therefore we attribute it to Darwinian evolution (6.00 minute mark).
There is a lot of positive evidence that much of the DNA in our genome is non-functional. Wells is dead wrong about this. Furthermore, assuming that this junk DNA is non-functional and assuming that species share a common ancestor, we can explain many observations about genomes. IDiots can't do this. They have yet to provide an explanation for shared pseudogenes1 in the chimp and human genomes, for example. And I haven't heard any IDiot explain why the primate genomes are chock full of Alu sequences derived from a particular rearranged 7SL RNA sequence while rodent genomes have SINES from a different rearranged 7SL sequence and lots of others from a tRNA pseudogene [Junk in Your Genome: SINES].
Did Francis Collins use the existence of junk DNA as support for Darwin's theory of evolution? Here's what Wells says in the video (50 second mark).
If fact he relies on so-called junk DNA—sequences of DNA that apparently have no function—as evidence that Darwin's theory explains everything we see in living things.I searched in the The Language of God for proof that Wells is correct. The best example I could find is from pages 129-130 where Collins describes the results from comparing DNA sequences of different organisms. He points out that you can compare coding regions and detect similarities between humans and other mammals and even yeast and bacteria. On the other hand, if you look at non-coding regions the similarities fall off rapidly so that there's almost no similarity between human DNA and non-mammalian genomes (e.g. chicken). This is powerful support for "Darwin's theory of evolution" according to Francis Collins. First, because you can construct phylogenetic trees based on DNA sequences and ...
Second, within the genome, Darwin's theory predicts that mutations that do not affect function (namely, those located in "junk DNA") will accumulate steadily over time. Mutations in the coding regions of genes, however, are expected to be observed less frequently, since most of these will be deleterious, and only a rare such event will provide a selective advantage and be retained during the evolutionary process. That is exactly what is observed.I leave it as an exercise for Sandwalk readers to figure out how to explain this observation if the regions that accumulate fixed mutations aren't really junk but functional DNA. Your explanation should consist of two parts: (1) why the DNA is functional even though the sequence isn't conserved (provide evidence)2, and (2) why coding regions show fewer changes and why comparisons of different species lead to a tree-like organization.
I wasn't able to find where in Origin of Species Darwin discuss this prediction but I'm sure it must be there somewhere. Perhaps some kind reader can supply the page numbers?
1. Every knowledgeable, intelligent biologist knows that pseudogenes exist and they are junk. That's not in dispute. I haven't heard any Intelligent Design Creationists admit that there are thousands of functionless pseudogenes in our genome.
2. I can think of two or three possibilities but no evidence to support them.