It seems that the greatest quest of modern man is to understand the nature and origin of life. In this enterprise the supreme place of God as Creator is totally ignored in favour of seeking a wholly naturalistic explanation of life and its beginnings.

Two landmark steps have characterised man’s search. The first was the discovery in 1953 of the double helical structure of DNA (deoxyribonucleic acid) by Watson and Crick, based upon the largely unrecognised study of DNA crystals by Rosalind Franklin. The second, almost exactly fifty years later, was the completion by several teams of the description of the human genome, the entire sequence of base units that make up human DNA.

Scientists have trumpeted great possibilities as the result of these discoveries: that many cancers and genetic diseases will become curable, and that the secrets of life itself will be uncovered. So far, no fewer than nine Nobel prizes have been awarded for DNA research. But in truth, while some practical benefits will undoubtedly accrue, each new discovery seems only to open the door to ever greater complexity and consequent incontrovertible evidence of intelligent, purposeful design by the great Creator.

The structure of DNA

To mark the fiftieth anniversary of the discovery of the double helix, a series of articles was commissioned by New Scientist describing the present understanding of the structure and activity of DNA.¹ It seems that the double helix configuration is now recognised to be only a part of the story. Within the nuclei of cells, DNA is wound and folded in an amazingly intricate manner, and mixed with more than twice as much other protein material. This was once thought to be merely rather dull scaffolding, albeit with the daunting task of folding the two metres or so length of DNA inside the tiny five-micrometer-diameter² cell nucleus. However, that view is changing rapidly.

The building blocks of the scaffold, called nucleosomes, are formed from eight special proteins called histones, which are rolled into tightly packed balls with loose ends sticking out (see Figure 1 below). Successive sections of the DNA double helix are wound around each ball, not quite two turns, and then trail off to the next one, forming a chain like a string of hairy beads. This chain is then tightly coiled up to form chromatin fibre which, in turn, is folded up into the chromosomes. Each human cell contains a complement of forty-six chromosomes.

It used to be thought that the chromosomes were simply jumbled in the cell nucleus like pieces of string in a bag, but recent work has shown that they have highly complex and ordered locations within the cell nucleus. There seems to be a general rule that ‘busy’ genes, that is, ones that are frequently switched on to synthesise proteins, are sited at the outer edges, which may be because there they have better access to the special chemicals known as enzymes that activate their operation. But this research is at an early stage, and very little is known about how changes in location can apparently awaken dormant genes and inactivate others. The whole structure of DNA and its packaging within the cell nucleus displays the greatest possible ingenuity, and that alone declares the intelligence which designed it.

Fig. 1. The amazing way DNA is packaged into the nuclei of cells:
1. Balls of histone proteins form the core of nucleosomes—DNA is wrapped around the nucleosomes
2. The nucleosomes are packed into chromatin fibre
3. Chromatin fibre is packed into chromosomes, within the nucleus of each cell.

DNA Repair

Soon after the discovery of the chemical structure of DNA it was predicted that it would be a conductor of electricity, and this has been confirmed using purified DNA in the test tube. At first this seemed to be of only academic interest, but it is now suspected by many workers in the field that this ability of DNA has a vital role in the detection and repair of damage. DNA is a surprisingly unstable molecule and is under constant attack in the cell, primarily from the effects of oxidation by highly active chemical groups called free radicals. It has recently been shown that affected sites can migrate electrically along the DNA chain, and it seems possible that in this way the damage is conducted away from vital genes to special inactive areas to await the attention of repair enzymes. Much of this damage comes from environmental sources such as ultraviolet light and toxic chemicals, especially those in cigarette smoke, and can lead to many diseases, including cancers and genetic disorders. There is also growing evidence that accumulated damage to DNA is primarily responsible for the universal phenomenon of ageing. As a result, cells expend a great deal of energy in searching for and rectifying damage. The cell has four main mechanisms for repairing DNA, both before and after cell division, and as many as 130 genes are thought to be involved. Repair enzymes constantly patrol the DNA chains looking for distortions of the double helix and repairing them.

There is a deep irony here. All organisms share the same repair mechanisms, and so these are considered by evolutionists to have evolved very early in the history of life. But another name for DNA damage is mutation, the accidental chance process by which new advantageous characteristics are supposed to appear in organisms and be preserved by natural selection. Evolution is thus dependent upon DNA damage. So the repair mechanisms must have evolved to prevent evolution!

But scientists cling to their faith. One researcher recognises that if the repair system were absolutely perfect evolution would be stopped in its tracks: “Without mutation, there can be no evolution”. So although DNA damage is so dangerous to the cell and consequently to life, and although elaborate mechanisms work constantly to repair it, evolutionists have to believe that enough ‘good’ mutations survive the repair process to allow evolution to proceed.

Mind-boggling complexity

Scientists are adept at conveying the impression that their theories are virtually complete and that all the facts are now explained. So with the sequencing of the human genome the impression can be given that the secrets of life have now been unravelled. All that it has done, however, is to reveal even deeper layers of complexity.

Every one of the cells in our body contains the same genetic blueprint in the form of its DNA, yet cells are specialised, or differentiated, into hundreds of different types: bone, muscle, liver, retina, and so on. Thus each type of cell must be reading the DNA code in a different way, and that implies the existence of another set of instructions even more complex than DNA’s string of genetic ‘letters’. Researchers now believe that this code is encrypted in the histone balls (or nucleosomes) described above, around which the DNA is packaged in the cell nucleus.

The ‘loose ends’ that stick out from the histone balls around which the DNA is wound (Figure 1 above) have been found to contain various chemical groups which affect whether nearby genes are active or inactive. Recently, researchers have proposed that these chemical groups on the histone tails are working as a code to control the activity of single genes or of whole groups of genes together. The overall effect is described as mind-bogglingly complicated; the number of combinations on a single nucleosome may run into thousands, and the code can constantly change as enzymes add or remove tail groups. Already medical researchers are exploring ways of modifying these groups to treat specific diseases.

The Creator's Genius

To imagine that all of these deeper and deeper levels of complexity are the result of purely chance processes is absurd in the extreme. The very fact that cells have complex mechanisms with sets of instructions that can be referred to as ‘codes’ implies that they have an intelligent origin. These codes are in fact the equivalent of computer software, the sets of instructions that allow computers to carry out complex tasks. As everyone knows, producing such software is a highly skilled, costly and lengthy process, and no one would imagine that it could possibly write itself! Yet this is precisely what the naturalistic explanation of the origin of life demands — that all of these immensely complex codes controlling the multitudinous operations of the living cell have written themselves, by accident!

How much more satisfying to recognise the remarkable discoveries of the past fifty years as revealing the beauty and wonder of the work of an Almighty Hand, and, as even greater marvels come to light through the continuing investigations of science, to ascribe to their Designer the praise which is His due: “Let all the earth fear the LORD: let all the inhabitants of the world stand in awe of Him. For He spake, and it was done; He commanded, and it stood fast” (Ps. 33:8,9).

Footnotes

1 “DNA—50 years of the double helix”, New Scientist, 15 Mar. 2003.

2 A micrometer is one millionth of a meter.

With thanks to The Testimony magazine, http://www.testimony-magazine.org (first published October 2004).

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Leamington Christadelphians, 2006