I confess I don’t fully understand what sequencing the human genome means for us. Somewhere between the Secret Of Life and a tall story, it appears. molecular biology, which for 20 years has been on the A level syllabus, wasn’t discovered when I was in the sixth form. It was so simple then: there was Mendel and there were Crick and Watson, and they more or less explained everything.
Now we have mitochondrial DNA, not then known to school text books. We have junk DNA, more respectfully known as non-coding DNA, and now it is widely thought to have functions we don’t yet understand. Since it comprises 98% of our genome, that’s a huge potential influence. Then there is epigenetics, which explains – in part – why identical twins reared together don’t always have the same illnesses, careers and taste in boyfriends. Add the enormous effect of environment and lifestyle, and for most of us most of the time what determines our lives has more to do with our phenotype and our environment than our genotype.
Members of the public are already having key genetic markers in their genome sequenced. Advertisements invite them to investigate their ancestry. Y chromosomes being very stable, men, for as little as $199 for 20 markers, can identify hitherto unknown relatives around the world, sharing information through a database. Or they may discover that someone they thought a blood relative isn’t, so this interesting hobby is not without a potential to harm. You can have a test to find out if you have genes from exotic races, but until more genomes have been sequenced you won’t know whether you are glamorously unusual in having, say, Neanderthal genes, or whether everyone else round the dinner party table has them too.