Only 30,000 genes! - Dr Nancy Darrall considers the implications

How did you react to the news? Did it feel rather like being told that you had only got 30% in an examination, or only a third of the salary you had expected?

Worse than only having 30,000 genes is the comparison with a small garden weed with 26,000 and a fruit fly with 14,000 genes. Professor Bowbrow was not to be upset.

'Knowing that a fruit fly only has slightly fewer genes than me doesn't make me feel degraded - they are pretty complex things; they have four wings and can fly - I can't do that'. Others feel that the news will 'be a source of humility and a blow to the idea of human uniqueness' (S. Paabo, Max Plank Institute, Germany). Underlying these responses is the unspoken assumption that we are only as valuable as our genes. DNA and genes have been elevated in the public perspective to a supernatural position. They are 'the recipe for making a human being', they 'contain and create information in coded language' to 'make us' what we are.

Parts list

Genes are like the parts list for an aeroplane. Nearly all genes contain the code to make part or all of a protein and these are the building blocks of our body, making muscles, skin, brain tissue, etc. Our genes are the instructions to make around 250,000 parts or proteins, a similar number of parts to a modern jet aeroplane. These comparisons were made in The Daily Telegraph on February 12, but no one asked whether the manufacturer was Boeing or Airbus. No one pointed out the obvious implication. An aeroplane needs a design team working over many years. The human body is no less complex, the Designer should receive the accolades that the teams working on the Human Genome Project have been given and more. After all, they are only 'thinking God's thought after Him'.

So are we only as much as our genes, about twice as valuable as a fruit fly? John Peet (In the Beginning, God Created, Grace Publications, 1994) helpfully discusses the distinction between man and the other created life. Animals were each the first of their kind and reproduced 'after their kind'. Man, in contrast, was made 'in our image', 'after God's likeness'. These descriptions of man refer to those things that make him human and of such value in the sight of God. Would we expect to find evidence of these characteristics in human genes? Certainly, some would need coding, for example the muscle and brain development to allow complex sequencing of movement for speech, the use of complex tools and the capability of complex reasoning. The creativity, moral and spiritual dimensions, may not be linked to any particular gene.

We are told that the Human Genome Project provides 'confirmation, at the level of molecules, of Darwin's theory of evolution'. One third of all sequences in yeast, fruit fly, worm and human have strong similarity. Our genes contain 'our history', from primeval slime to man. 'Evolution is a constant reworking or random recombination of DNA parts.' How is it possible to say all this?

The Genome Project is an enormous achievement, akin to taking many copies of a book with unnumbered pages and putting each one through a different shredder page by page. Then one copy is pieced back together, helped by comparison of the different bits from the other shredders. Part of the genome is very very similar to bacterial DNA and so scientists have come to the conclusion that this section came from bacteria in the recent past.

Interpretation

The interpretation of the information depends entirely on the starting point of the writer. The evolutionist will look at the similarities and differences and understand that the differences in DNA code are the new genes that were added as one form of life evolved from another. Computer programmes are used to work out the most likely pattern of change from one living thing to the next, based on the assumed pathway of evolution.

Believe in a Designer and you will see that the 'parts list' in some forms of life are used elsewhere as appropriate, from bacteria to humans. The proteins in the bodies of animals and humans are very similar. Why change a good design when the same function is needed in different forms of life?

Neither point of view is unequivocally proved by the mere listing of the DNA code. Other evidence is more useful in the debate. The parts or proteins do not function independently, but interact directly with four to five others, so a change to one part will affect a number of others. Sometimes several genes contribute sections to a single protein molecule and sometimes some genes can produce a number of different proteins.

Irreducible complexity

Further, genes interact with various regulators, to fine tune the chemistry of bodily functions. Genes have been described 'not as beads on a chain but as a complex three-dimensional organelle, a unified entity of interdependent components' (cited in the Journal of the Biblical Creation Society, Origins, no. 29). The Human Genome Project is providing us with ever more examples of the irreducible complexity of living things. At a higher level, the body functions (breathing, feeding, growing, breeding, etc.) are a complex web of chemical reactions needed for the creature to live successfully. Such complexity cannot evolve piecemeal, it must all be put in place from the beginning to function; it is irreducibly complex. Michael Behe, in Darwin's Black Box, helpfully discusses these issues of irreducible complexity. Stuart Burgess, in Hallmarks of Design, Day One Publications, also has an excellent chapter on irreducible complexity for the non-technical reader and he points us on to consider our Creator God.

'Junk' DNA?

Most of our DNA, the papers say, is junk, another proof of past evolution. Some of this junk is claimed to be the raw material for future evolution as duplication frees up some DNA to code for new proteins. This is equivalent to saying that if you copy Twelfth Night and mistakes are found in the copy then this is the raw material for another play. A creator is needed just as much to design a new bit of chemistry for a different living thing as an author is needed to write a play. Other junk DNA is considered to be 'leftovers' of previous evolution. There is a clear parallel here with the so-called vestigial organs of the human body. Once there were thought to be over 100 'leftovers' of evolution, now there are just a very few for which no clear function is known. Surely it is more a case of our ignorance of the human body than evidence for evolution.

As more is being learnt about this 'junk' DNA the name is being changed to 'non-coding' DNA. Rather than being useless 'leftovers', roles are rapidly emerging. Some are structural and some control gene expression - switch on or off, enhancement, modulation and inhibition. Some sections are duplicates, complete or incomplete, some are 'back-up copies', some sections appear to move around and some are known to cause disease. We are indeed looking here at the history of man, a genome designed to be 'very good', but affected by the Fall.

Implications for medicine

There are vast implications in the Human Genome Project for medicine. Understanding the chemistry behind various diseases by knowing about the genes will allow new types of treatment to be developed that should be more effective. On the other hand, screening for diseases will become more commonplace with implications that Christians need to consider carefully.

Pre-natal screening for an increasing number of conditions will add pressure on parents for abortion of 'defective embryos'. It will also increase the demand for in vitro fertilisation as gene identification will lead to the possibility of 'designer babies'. It is currently illegal in the UK to alter the genetic make-up of sperm and eggs, but will society decide one day that it is permissible to correct such defects? Here again we will see our value being counted merely in terms of our genes with no regard for the image of God in all human life.

Screening for potential diseases could become a valid part of employment selection to ensure an efficient work force with less long-term sickness. Insurance companies may demand information before issuing policies, much as premiums can depend on our postcode today. Should we take steps now to prevent such marginalisation of a section of our society?

Challenges

Two positive outcomes hoped for by the press are greater racial tolerance and greater compassion for hereditary disabilities as we all carry virtually the same genes with just a small number of differences. Again, value judgements based purely on our genes.

Now we have the outline of the human genome, how do we respond? We have a draft of the parts list to make a human body, but we yet know very little about how they are all put together and interact. There are challenges to be taken up in the social and political arenas to ensure dignity and respect for human life. This is the time to reaffirm that we are 'fearfully and wonderfully made', but, like an aeroplane, we are vastly more than the parts list. There is nothing random or haphazard, there is design and purpose and, supremely, the image of God in each one of us.

Dr. Nancy Darrall worked for many years as a research biologist for CEGB and is a member of Radcliffe Road Baptist Church, Bury.