Creation magazine has shown how DNA is the ultimate information storage molecule in the universe.1 We also showed how cutting-edge discoveries refute the idea of ‘junk’ DNA, which doesn’t code for proteins, showing that this has an amazing array of functions that we are only just beginning to learn about. Dr John Mattick, a leading researcher into DNA function, proposes that ‘junk’ DNA acts like an advanced computer operating system.1 More recently, he lamented how the idea that non-protein–coding DNA was just junk had greatly harmed science:
‘The failure to recognize the full implications of [non-protein–coding DNA] may well go down as one of the biggest mistakes in the history of molecular biology.’2
Another intriguing property is how DNA in cells conducts electricity.1,3 DNA is easily damaged. Some chemicals, including free radicals, attack DNA by stealing an electron from (i.e. oxidizing) one of the bases—the chemical ‘letters’ of the DNA code. The resulting electron ‘hole’ can hop along the DNA, behaving like a positive electric current.
We already reported that some of the ‘junk’ DNA comprises pairings between the ‘letters’ A and T (the bases adenine and thymine), and this blocks this damaging electrical current. These pairings act as insulators or ‘electronic hinges in a circuit’ to protect essential genes from electrical damage from free radicals attacking a distant part of the DNA.1
More recently, Jacqueline Barton of the California Institute of Technology has shown that DNA also uses its electrical properties for protection. At the edge of some genes, there is a string of G ‘letters’ (the base guanine). They readily absorb the electron hole, so the electron hole moves along until it reaches this string of Gs. This deflects the damage from the parts of the DNA that code for proteins.4
This is very much like the principle behind galvanized iron. Here, a coating of a more reactive and less important metal, zinc, sacrificially takes all the oxidation, thus protecting the iron from rusting.
DNA errors are scanned electrically
Such ingenious repair machinery must have been present in all life right from the beginning.
Our cells have elaborate machinery to repair DNA. But with 3 billion ‘letters’ worth of information in every cell, there is a lot to scan for errors.
However, unbroken DNA conducts electricity, while an error blocks the current. Now Dr Barton has found that some repair enzymes exploit this. One pair of enzymes lock onto different parts of a DNA strand. One of them sends an electron down the strand. If the DNA is unbroken, the electron reaches the other enzyme, and causes it to detach. I.e. this process scans the region of DNA between them, and if it’s clean, there is no need for repairs.
But if there is a break, the electron doesn’t reach the second enzyme. This enzyme then moves along the strand until it reaches the error, and fixes it. This mechanism of repair seems to be present in all living things, from bacteria to man.5
Such ingenious repair machinery must have been present in all life right from the beginning, otherwise life could not have survived breaks in its DNA. As scientists discover more of the intricate design of life, we can see more how we are ‘fearfully and wonderfully made’ (Psalm 139:14).
Pseudogene not so pseudo
One of the main categories of ‘junk’ DNA is ‘pseudogenes’. Evolutionists claim that they are corrupted and disabled copies of genes. But with all the new discoveries of uses for the ‘junk’, it is becoming increasingly rash to claim that any DNA is ‘useless’.1
Geneticists at Saitama Medical School in Japan have now shown that a pseudogene has a function. They genetically engineered mice to carry a fruit fly gene. The mice were mostly OK, but some died in infancy when the fly gene was inserted into a pseudogene, called Makorin1-p1.2
This shows that the pseudogene has a vital function (otherwise disabling it wouldn’t have mattered), so is not junk at all. The pseudogene has such a similar sequence to the gene, not because it is corrupted from it, but because it was designed that way. The sequences must be highly similar because the pseudogene codes for RNA that allows the ‘real’ gene to operate.3
This is a good lesson—just because we don’t know a function, it is rash to claim that there is no function.
References and notes
References and notes
- Sarfati, J., DNA: marvellous messages or mostly mess? Creation 25(2):26–31, 2003. Return to text.
- Mattick, J., cited in: Gibbs, W.W., The unseen genome: gems among the junk, Scientific American 289(5):26–33, November 2003. Return to text.
- However, more up-to-date information shows that long-distance conduction is probably due to the surrounding water molecules rather than the DNA itself—Biever, C., Electrifying claims dashed, New Scientist 177(2388):17, 29 March 2003. Return to text.
- Lawton, G., Live wire, New Scientist 177(2386):38–39, 15 March 2003. Return to text.
- Ananthaswamy, A., Enzymes scan DNA using electric pulse, New Scientist 180(2417):10, 18 October 2003. Return to text.