human life
It all started in the mid-1980s when an excited gleam appeared in the eyes of a number of molecular biologists and biochemists.
This was the outward sign of a dream that one day the entire human genome (the 70 to 100 000 genes that add up to a blueprint for a complete human) would be sequenced – laid out in a kind of vast map – then filleted, divvied up and analysed. It was a big ambition and only they fully appreciated its magnitude. To the rest of us, perhaps the project seemed bafflingly expensive (more than $3-billion) and irrelevant to ordinary life.
But now – just half a century after James Watson and Francis Crick discovered the double helix structure of DNA and effectively invented modern genetics – we are approaching a big moment in humanity’s understanding of itself. But while this revolution is about understanding, it is also about a powerful technology that we will use to wrest control from the randomness of nature.
The publicly funded Human Genome Project should produce a rough draft of the great map within a year. Some 20 organisms have been sequenced, the largest of which is a worm called C Elegans, with 19 000 genes, just completed by the Sanger Centre in Cambridge in the United Kingdom.
The average human has about 80 000 genes, which consist of three billion bits of information. The function of most of these genes is unknown and years of research lie ahead to figure out which particular genes are responsible for the traits, talents and flaws of mankind – athleticism, a weak heart, a pug nose.
Beyond this there are goals of almost unimaginable computation – how the genes that come together in one person interact and combine to produce the unique individual. The combination of genes that is formed when two humans mate successfully must have an almost incalculable potential.
If, for example, it had been possible to present scientists with the two relatively ordinary genetic profiles of a couple living in 16th-century Warwickshire, it seems unlikely that they could have predicted that the baby born on April 23 1564, would have the genius of William Shakespeare. Who knows, maybe when the third or fourth generation of DNA computers are in action, such a prediction will be possible.
In the next 25 to 35 years we can expect to see genetic manipulation of human embryos as routine practice. We will be able to eliminate inherited diseases, and solve many problems about aging. Tissue engineers will use genes they have located in the human genome to grow body parts: skin and cartilage have already been made. There will be elaborate gene therapies that will discreetly reprogramme organs without the need for invasive surgery.
In the United States, a scientist has modified the Aids virus to carry instructions to the nucleus of cells; another uses the temporary deployment of an adapted cold virus to create new blood vessels in a damaged heart.
A period of huge discovery is under way and it will alter countless areas of our culture and our history. This came home to me while travelling around labs in America. In Virginia I broke the journey to visit Monticello, the Palladian house built by Thomas Jefferson in the 18th century. You could not imagine a place further from the furious concentration of genetics, and yet the science has thrown light on Jefferson’s character. By testing the descendants of a slave girl named Sally Hemmings, it has been established beyond doubt that Jefferson was the father of her children.
Monticello, once thought of as an Olympus of enlightenment, suddenly seems more like a Middle Eastern seraglio, and Jefferson comes into focus as a hard task-master, an abuser and a control freak.
Knowledge is sometimes unsettling. As the evidence accumulates to show how each of us is the result of traits that were thrown together at the moment of conception, strong determinist arguments will make headway against assumptions of personal responsibility and free will.
Surprisingly, the scientists that I interviewed all argued against the power of their science, insisting that nature and nurture are of roughly equal influence in a human being’s development. Lee Silver says that in the right circumstances aggressive genes are expressed as assertiveness. Likewise, heart disease may be avoided with a good diet and exercise. There are choices, he insists. Still, this won’t prevent the reflex opinion that a person is programmed with certain flaws.
The gleeful abandon with which we have set about creation is truly worrying. Already we are fashioning plants and animals to more convenient sizes, colours, rates of production. Just for the hell of it, someone has produced a green fluorescent mouse by adding to its embryo a gene that makes octopuses glow in the dark. Creation has become a playground.
In the 21st century, earnest scientists will be approaching the next great frontier of knowledge – the mystery of the human mind. We will want to know exactly how the instructions of some of those 80 000 genes form the organ that produces the sensation of consciousness. Prise open this mystery and we will come to know ourselves in ways that we have not before: we will feel awe, no doubt, but also a kind of baffled revulsion as we reduce everything to a set of material explanations.
One is reminded of Hamlet. “What a piece of work is man! How noble in reason! How infinite in faculty! In form, in moving, how express and admirable … And yet to me, what is this quintessence of dust? Man delights not me.”