Have you ever imagined a world where you can look into your child’s eyes and know his/her genetic destiny? Or imagine a world where every facet of your child’s medical history, its strengths, and its vulnerabilities could be uncovered by tapping into a computer. Think about a situation where you can predict the exact number of years you will live or another in which an exact replica of a major organ in your body (maybe your heart or kidneys) can be transplanted if yours fail. No problem of rejection or transplant reactions. Welcome to the world of human genetics.Today, we know more about how to build a human being than ever before. Since the human genome has been sequenced in June 2000, knowledge about this aspect of what makes us humans keeps increasing daily. The funniest thing about this science is that it revolves just around four alphabets of the gene – A, C, G, and T representing Adenine, Cytosine, Guanine and Thymine respectively. We are all made up of cells, the basic structural and functional unit of every human being. Deep inside the nucleus of each cell are some tiny fine strands (too small to be seen with the naked eye) interwoven together. These strands are the chromosomes, containing thousands of genes in all. The genes are also made up of the DNA, which carries the information which makes us what we are. Your genetic make-up determines whether you’ll have blue eyes or brown eyes, black hair or red hair, whether you’ll be tall or short.
Evolutionists have postulated that millions of years ago, that the earliest form of life was a single cell. During this period, the single cell multiplied by cloning, creating multiple identical copies of itself over and over again. There was neither diversity nor variation. It was just the same type of cell with the same genetic make-up. After some time, some sexual forms of life started evolving from some of these earlier cells deep in the ocean. It was these sexual forms of life that gave rise to the unique diversity we find today. Now, during fertilisation, a segment of DNA from each parent combines to form a zygote (offspring) which has the full complement of DNA. The offspring takes a little bit of each parent; takes the mother’s blonde hair colour and the father’s blue eye colour. Just a bit here and a bit there. This is what makes us unique and different from every other individual.
It has been established that the genetic information in our DNA is what determines our physical characteristics. How can we then use this information to predict what is going to happen to us in the future. The branch of genetics which deals with this is just in its early stages – the science of prediction. A recent research was conducted on some army recruits at the Army Training Headquarters, Bassingbourn, United Kingdom. About 100 recruits were used for the study. The recruits made almost perfect guinea pigs for the experiment because the effect of the environment on each of them was almost the same. They were all exposed to the same environmental factors – same food, same source of water, same amount of exercise, same number of sleeping hours, same training, etc. After several weeks of conducting the study, it was discovered that the ACE gene, located on chromosome 17 has two forms which determined athletic abilities. One version of the gene seems to be particularly associated with endurance capability and fatigue resistance of muscle while the other version seems to be particularly associated with strength capacity. Which one would you rather have, the strength form or the endurance form? The body muscles depend on oxygen for their metabolic activities. With the endurance form of the gene, the muscles are able to use less oxygen to produce the same energy than the strength form. This means that the muscles can survive longer periods of oxygen deprivation. This fact is more relevant in people having heart attacks. Whether such individuals would survive the attack would depend on which form of the ACE gene they carry. In the long run, our survival depends on this gene.
In another study, the thrill-seeking gene, D4DR, on chromosome 17, was found to differentiate adventurous people from non-adventurous people. With this gene, you can predict whether an individual would become hooked on drugs or go into extreme sports later in the future. The D4DR gene determines the release and effect of dopamine, a neurotransmitter in the deeper confines of the brain. When there is an increase in the release of dopamine, we feel excitement. Some people’s bodies are resistant to the actions of dopamine. This is what drives them to extremes in order to derive the same excitement that others derive with simple actions. This is also what makes someone to jump from a plane several miles up in the air (in the name of parachuting) or another to get addicted to hallucinogens, just to create an upsurge in dopamine release.
Can our genetic information predict who would become a criminal in the future? And on the basis of this information be able to nip these criminal intents in the bud. A landmark legal case took place some years ago. A man was driving home after work late one night. Suddenly, he felt the urge to stop in front of a shop. He walked up to the store clerk, demanded for all the proceeds of the day. After he had got this, he shot the clerk in the head. The clerk died. The defendant’s lawyer argued the case in a way that had never been done. He pleaded the court to allow the defendant’s genetic information be brought to the court and used as an evidence. He argued that the defendant had in his gene information that made him a criminal. He believed that deep down in his gene was a factor which made him commit the crime. The judge denied the admissibility of the evidence. At the end of the day, the defendant was sentenced to the death row. This case nevertheless brought about a lot of questions regarding the issue of criminality and genetics.
Studies like that of the ACE gene above have shown how much information can be gleaned from our DNA. But would you rather know that you would die a little bit younger because you possess the strength version of the gene? Or would you want to know as a 10,000km marathon athlete that you have the strength version, when your opponent has the endurance form?
The knowledge we have about genetics is much. Today, we know much more than we do years ago. And one thing is certain, in the years to come, we will be able to predict even more about our lives, because this world of prediction has already begun.
