A new type of DNA sequencing technology has been developed and used to identify and characterize key regions of the genome called “enhancer” sequences. These are novel DNA features that were once thought to be a part of the so-called “junk DNA” regions of the genome. These key elements are now proven to be part of the indispensable and irreducibly complex design inherent to proper gene function for all types and categories of genes.
Jeff Tomkins’ New Technology Reveals More Genome Complexity is one of those articles that hits you with the nonsense almost from the beginning. Deconstructing that opening paragraph we find that the first sentence is perfectly accurate. There do exist in the genome regions, called enhancers, which promote the expression of the gene(s) they are associated with. Enhancers have been known for some time – they were even taught in my biology class last year, so they must be ancient – but a new paper in Science talks about a new method for identifying these regions. To quote the abstract:
Genomic enhancers are important regulators of gene expression, but their identification is a challenge, and methods depend on indirect measures of activity. We developed a method termed STARR-seq to directly and quantitatively assess enhancer activity for millions of candidates from arbitrary sources of DNA, which enables screens across entire genomes. When applied to the Drosophila genome, STARR-seq identifies thousands of cell-type–specific enhancers across a broad continuum of strengths, links differential gene expression to differences in enhancer activity, and creates a genome-wide quantitative enhancer map. This map reveals the highly complex regulation of transcription, with several independent enhancers for both developmental regulators and ubiquitously expressed genes. STARR-seq can be used to identify and quantify enhancer activity in other eukaryotes, including humans.
Moving on to the second sentence the mention of ‘junk DNA’ should already have set off alarm bells. Alas, this aspect seems to have originated at least in the press release if not the original paper (which is behind paywall). It is of course perpetuating the myth that the junk DNA idea owes its origins to ignorance about the role of non-coding DNA, which is simply not true. I wouldn’t be surprised to learn that we have known about enhancers longer than the junk DNA idea has been around (they did make it into the curriculum, remember), but it wouldn’t matter if we haven’t.
It is sufficient to say of the third sentence that it is just ‘typical Tomkins’ and leave it at that. I have long grown tired of pointing out that ‘irreducible complexity’ is a claim that requires evidence – one might say extraordinary evidence – which we never seem to see. Complexity is not in itself something that could pose a problem for evolution (or other natural processes), but irreducible complexity is supposed to be strictly defined so as to only include features and structures that could not be incrementally created. However I think Tomkins recognises how hand-waving it is to point to mere complexity as something that evolution could not produce, and so adds the ‘irreducible’ part to try to make his argument more convincing.
Indeed, calling the genome irreducibly complex is particularly silly. An irreducibly complex system would not have any redundancy, because one part of a redundant system can be removed, ‘reducing’ the system while leaving its function intact. The press release for this paper, for example, even mentions redundancy as a potential explanation for why there seem to be multiple enhancers per gene. In addition, as we saw back in September, it seems to be possible to remove large sections (in the order of millions of consecutive bases) of DNA without proportionate repercussions. If the genome were truly irreducibly complex – rather than just plain old complex – we shouldn’t see such things.
Thankfully, the next couple of paragraphs are just a description of the process and don’t merit line-by-line examination. Skipping ahead, therefore:
This new technology and the increased picture of complexity described by it add even more weight to the fact that the genome is completely functional and irreducibly complex. This is a fact recently highlighted by 30 simultaneously published research papers in the 2012 ENCODE (encyclopedia of DNA elements) project reports.
Ah, ENCODE. It was inevitable, really.
In the lead ENCODE research paper, published in the journal Nature, the authors wrote, “These data enabled us to assign biochemical functions for 80% of the genome, in particular outside of the well-studied protein-coding regions.” For a recent review of the ENCODE discoveries and their significance to the creation-evolution debate, see the recent review of ENCODE in Acts & Facts.
So ends the important part of this article.
I didn’t go over the Acts & Facts ‘review’ because it was largely a reprint of an earlier posting, which we did look at. To be brief, even if junk DNA really doesn’t exist the evidence in the ENCODE study does not actually show that – the term “biochemical function” is quite misleading. If you have the time I recommend listening to this podcast on the issue, or start here if you prefer text.
Stripped of the irreducible complexity and junk DNA aspects, Tomkins really doesn’t have anything. Yes, we now have a tool that could potentially tell us a lot about our genome. But so far, at least, we have learnt nothing that should excite a creationist.