Evolution Icon Evolution
Intelligent Design Icon Intelligent Design

The Demise of Junk DNA and Why It Matters

Jonathan McLatchie


ENV’s Casey Luskin has already drawn our attention to the groundbreaking research published this week by ENCODE. A number of ID critics are asking the question: “Why should a pro-intelligent design news site care about these results?” After all, the discovery that a great proportion of the non-coding regions of the genome are functional does nothing to undermine Darwinism or support ID, does it?

Well, these results are indeed significant, and of great interest to ID theorists and Darwin critics. That is for at least four reasons.

The first reason is that the claim that the majority of our DNA is “junk” has long been used by ID critics as an objection to design: Why would a designer fill our chromosomes with so much redundancy? That would be surprising given the hypothesis of design but would make perfect sense under a Darwinian framework, where such sequences can be understood to be “the remains of nature’s experiments which failed” (Ohno, 1972). So, while these findings do not necessarily support ID or discredit Darwinism, they answer an often-heard criticism of the design hypothesis.

The second reason is that this news demonstrates the greater heuristic value of ID relative to evolutionary naturalism. While the notion that life is the product of an entirely blind and unguided natural process fits well with the observation that a lot of our DNA is without function, the hypothesis of design expects that we will find engineering purposes wherever we look in the cell. While the paradigm of evolutionary naturalism discourages and hinders the search for function, the ID paradigm actively encourages it.

Thirdly, shared “junk DNA” has often been alleged to offer compelling evidence for common descent. But if these non-coding sequences are, in fact, functional, then why can these shared sequences not be explained just as readily by common design?

Finally, the prized 98% sequence-identify figure between humans and chimpanzees relates to the 2% of DNA that codes for the production of proteins. The non-protein-coding regions of DNA are far more species-specific. If these stretches of non-coding DNA really are functional, then what becomes of this sequence-identity figure and its significance with respect to shared ancestry?