The Survival Of The Most Fitting

The genetic voice usually gives the initial impetus in forming sexual relationships. It is part of the instinctual knowledge we are born with in order to survive. Babies know how to suck the breast, cry for help and scream when they are soiled. They naturally stimulate their parents' loving and caring instincts, even when the parents are stumbling around the house like zombies from lack of sleep. Babies know how to smile when only a few weeks old to trigger love in a mother fatigued by constant caring. This parental loving and caring is also part of our instinct to a greater or lesser degree. I remember looking into the eyes of my newly born daughter and seeing into the centre of the world, deep and still. It was like seeing into human nature before society had changed it. I was enchanted. It was like looking into a very clear pool, yet not seeing the bottom. Our instincts go high as well as deep.

Most of the time these genetic instincts are unconscious. They are effortless. Sometimes it takes effort to deny them. Yet they come with being born.

Our genetic knowledge has evolved with us. Genes are the tools of evolution. They are the units of inheritance, millions and millions on every chromosome, 46 chromosomes in every cell in our body. They are the hard-wired, bred in the bone instructions passed from one generation to the next, telling them what sort of offspring to produce. They influence everything - size, colouring, strength, resistance to disease, reproductive capabilities and intellect.

The passing on of genes was understood long before the word itself had been invented. Friends and relatives have argued for generations about the physical characteristics inherited by babies. They have looked at a scrunched up bawling bundle of humanity and noticed similarities between its bud of a nose and that of its 90-year-old great-grandmother.

I was on holiday with my family in Boulder, Colorado, many years ago. Our daughter Lara was about two-and-a-half years old. We were walking downtown where there were many pavement artists and Lara wanted to have her portrait drawn. She picked an artist who did caricatures. He drew her eating a hamburger. It only took a few minutes. He stepped back and showed me the picture. Lara was delighted. I looked at the picture. There, staring out from the paper, was my mother-in-law! The resemblance was uncanny. All the artist had done was accentuate a feature here, bring out a certain look and the family resemblance was striking. I still have the portrait.

Genetic messages that work positively and are compatible with the environment survive, or, more accurately, they increase the chance of survival for the person who has them. Those that do not work decrease the chance of survival of those who carry them; they slowly diminish from one generation to the next until they are gone.

As environments change, so different genes acquire survival value. Darwin called this process 'survival of the fittest', although it may be more easily understood as the survival of the 'most fitting' - those who are most suited to the environment they inhabit. Being the biggest, fastest or strongest does not always make you the fittest, as the dinosaurs found out. Nor are genes simple carriers, one per feature. They work together, just as evolution is more like co-evolution of species balancing and needing each other to survive in the dance of life.