More nails in the coffin of ‘junk DNA’
Published: 13 September 2011 (GMT+10)
(Page numbers relate to Jonathan Wells’ book, The Myth of junk DNA.1)
There is an ever growing list of arguments that supposedly supported evolutionary beliefs but which have now been debunked. Chief among these are the claims of ‘vestigial organs’, which were said to be useless leftovers from our evolutionary past. Doctors were so convinced of this argument that they routinely removed ‘vestigial tonsils’, ‘vestigial tail bones’ and other ‘vestigial organs’, and treated the ‘vestigial thymus’ with radiotherapy. We can thank God that we now have a better understanding of what these organs actually do, and doctors treat them with greater care.
The reasoning behind the belief in ‘vestigial organs’ was remarkable: ‘we don’t know what they do so we have concluded they don’t do anything.’ Given the dozens of wrongly labeled ‘useless organs’, one would think that evolutionists would have learnt their lesson and would be slow to deem anything in our bodies redundant and without function. Not so! For many years, evolutionists have been arguing that much of our DNA is ‘junk’, left over from millions of years of evolution.
When a baby grows from a fertilized egg, its development is very carefully controlled. The right things have to grow at the right time and in the right way. All this happens as it should because it is directed by a software program residing in our DNA. Similarly, the exceedingly complex activities going on in the cells of our bodies are guided by this software. Many people of my generation learnt to write simple programs at school using languages like BASIC, which use the letters from our English alphabet (A to Z). The program in DNA is similar, but uses just four different letters, rather than twenty-six. However, although it uses fewer letters, it is far, far more complex than any programs written by humans.
Why do some people believe in ‘junk DNA’?
As scientists began to read our DNA, they found it very puzzling. The information in genes (the DNA instructions for producing proteins), for example, isn’t written in one continuous sentence or paragraph, but is split up and interspersed with seemingly meaningless letters. Some sequences that looked like genes, but apparently did not produce any proteins, were thought to be genes that had lost their function and were given the name ‘pseudogenes’. This lead one prominent anti-creationist to describe our DNA as ‘graveyards of dead genes’ (p. 26). Many seemingly pointless sequences of letters are repeated and repeated. To some scientists, there were other sequences that appeared to be the useless calling cards of viruses, which evolutionists claimed had infected our ancestors millions of years ago. All this caused the vociferous protagonist of evolution Kenneth Miller to ridicule the idea that DNA provided evidence for intelligent design, describing our DNA as a ‘hodgepodge of borrowed, copied, mutated and discarded sequences and commands that has been cobbled together by millions of years of trial and error’ (p. 22).
Evolutionists also push the idea of ‘junk DNA’ because it solves some serious mathematical problems for them. According to the theory of evolution, humans and chimps diverged from a common evolutionary ancestor around five million years ago. Unless most of our DNA is ‘junk’ it is very difficult to see how mutations over the last five million years could have given rise to the many millions of differences now known to exist between human and chimp DNA. Natural selection couldn’t do it, because it doesn’t act fast enough, even given lots of assumptions in favour of evolution.2,3
As geneticists have continued their research, more and more facts have come to light that challenge the view that all this DNA is ‘junk’—and quite a number of evolutionists are beginning to admit this.4 For example, machines inside our cells ‘read’ most of this DNA (i.e., they produce RNA copies of the information). If it were truly junk, why would the cell bother with it? Such an activity would be wasteful of energy and resources, and would have been eliminated by natural selection long ago. This is because all DNA is subject to mutation, and natural selection would only preserve the integrity of DNA which controls necessary or useful functions (p. 29).
Furthermore, many ‘junk DNA’ sequences have been found to be the same in very different creatures. For example, some sequences are the same in both humans and mice. Evolutionists would say that humans and mice have these similar sequences because they inherited them from a common ancestor. However, if they were really junk it is most unlikely that they would have retained their similarity over millions of years of independent evolution. This is because, again, natural selection would not act on junk so as to preserve it from degradation by mutation (pp. 36, 37). Moreover, more and more scientific papers have now documented observed functions of the so-called ‘junk DNA’.
Some examples of what ‘junk DNA’ actually does
Critical to the correct growth of embryo to baby and the subsequent correct working of the body is the timing of protein production: the right genes must be switched on at the right times so as to produce the right amount of the right proteins when they are needed. Increasingly, it is being discovered that the DNA controlling the use of genes lies in areas formerly deemed ‘junk’ (pp. 37, 38).5
It is now known that one gene often produces many different proteins, and the ‘junk DNA’ interspersed within the gene contains information needed to facilitate this (p. 41). Moreover, ‘junk DNA’ can modify the way chromosomes (packages of DNA) are organized, thus changing the way the DNA functions (p. 44). Some genes, formerly deemed to be functionless and therefore labeled ‘pseudogenes’, have now been found to function, and actually produce proteins. Other ‘pseudogenes’ are now known to switch off genes when they are not needed, or to increase their use, when more proteins are required (pp. 91, 92).
‘Junk DNA’ thought to be the left-overs of viral infections has also be found to be active in, for example, the control of genes involved in blood cell production and producing proteins which enable the placenta to fuse to the uterus in pregnant mammals (p. 93).
Sometimes a stretch of DNA can perform a role simply because of its physical presence. In other words, the DNA sequence doesn’t have to contain information to perform its function. Recently, I used some pages of a magazine as temporary packing material when a making a piece of furniture. Clearly, there was no need for the magazine to contain anything meaningful. Biologists have found evidence that the length of a section of ‘junk DNA’ can control when and how a gene is used, and that this is independent of the exact sequence of the letters (p. 45). ‘Junk’ DNA is also known to provide material that acts in a mechanical way, as ‘scaffolding’ (p. 73), and can even function as a lens in the eyes of nocturnal mammals, improving their night vision (pp. 78, 79, 94, 95).
Of course, there is plenty of DNA for which we do not know the function; but those who have demonstrated the foresight and tenacity to look for functions appear to find them in abundance. It may well be that, due to harmful mutations (the consequence of sin and our living in a fallen world), some DNA is genuinely junk—but there is growing evidence that this is a very small part, indicating that yet another argument for evolution is finding its way into the waste bin.
Our DNA was written by a master programmer
Bill Gates, one of the founders of Microsoft, declared, ‘DNA is like a computer program but far, far more advanced than any software ever created.’6 Indeed, rather than being the hodgepodge that Kenneth Miller claims it to be, DNA appears to be the most complex, ingenious and awe-inspiring information system that mankind will ever behold.
- Wells, J., The myth of junk DNA, Discovery Institute Press, Seattle, 2011. Return to text.
- Carter, R.W., The slow, painful death of junk DNA. Return to text.
- See also, Carter, R.W., The chimpanzee Y chromosome is radically different from human. Return to text.
- According to Dr. John Greally of the Albert Einstein College of Medicine, New York, ‘It would now take a very brave person to call non-coding DNA junk.’ Andy Coghlan, ‘Junk’ DNA Makes Compulsive Reading, New Scientist 13 June 2007. Return to text.
- See also Batten, D., No joy for junkies, J. Creation, 19(1):3, April 2005. Return to text.
- Gates, B., The Road Ahead, Penguin Group, New York, p. 188, 1995. Return to text.