Dominic Lawson: An old dilemma: who wants to live for ever?

One of the virtues of the internet – for a news organisation, at least – is that it tells the provider which stories have aroused the greatest interest among readers. Over the past few days, users of The Independent's online edition have "hit" one story above all others.

It was not the tale of the solitary Société Générale trader who lost his company $7bn. It was nothing to do with anything involving sport, still less politics. No, the item which has transfixed readers of this newspaper was the report that a Dr Valter Longo had managed to extend the lifespan of a strain of yeast fungus to 10 weeks.

As an excited Dr Longo told The Independent's science correspondent, this was a 10-fold increase in the fungus' normal longevity, "which is, I think, the longest that has been achieved in any organism". Dr Longo's team from the University of Southern California managed this by (among other things) removing two genes, known as RAS2 and SCH9 – which cause ageing in yeast and cancer in humans.

So we're not just talking here about the creation of a uniquely smelly piece of fungus. We're talking about the possibility of humans living for over 1,000 years. That, at least, was Dr Longo's claim: "If ageing is programmed in yeast and the metabolic pathway is very similar, then isn't it possible that humans also die earlier than they have to?"

With this claim, it's no wonder that the Longo yeast fungus has captured mass media attention. Fear of death is the existential angst at the heart of the human condition: the prospect of eternal life is not just the metaphorical holy grail of medicine, it is the apparently unprovable promise on which entire religions have been founded, most notably Christianity.

In other words, it is held almost as an axiom that the avoidance of death is A Good Thing: the Best Thing, even. In fact, a certain amount of reflection should tell us that immortality is not necessarily an unparalleled delight – or even a delight at all. Jonathan Swift made this point brilliantly in Gulliver's Travels.

At one point Gulliver visits Luggnagg, where he is told that, very rarely, a "A Child happened to be born in a Family with a red circular Spot in the Forehead, directly over the left Eyebrow, which was an infallible Mark that it should never dye." These immortals, he is told, are called Struldbruggs.

Gulliver is enraptured: "Happy Nation where every Child hath at least a Chance for being immortal! ... Happiest beyond all comparison are those excellent Struldbruggs, who born exempt from that universal Calamity of human Nature, have their Minds free and disengaged, without the Weight and Depression of Spirits caused by the continual Apprehension of Death."

The Luggnuggians soon correct Gulliver's wide-eyed excitement. He is told how, by the time they are 80, the Struldbruggs had "not only the Follies and Infirmities of other old Men, but many more which arose from the dreadful Prospect of never dying". In their nineties, they "can never amuse themselves with reading, because their Memory will not serve to carry them from the beginning of a Sentence to the end; and by this Defect they are deprived of the only entertainment whereof they might otherwise be capable."

Worse follows: "The Language of this Country being always upon the Flux ... neither are they able after two hundred years to hold any Conversation (farther than a few general words) with their Neighbours the Mortals; and thus they lye under the Disadvantage of living like Foreigners in their own Country."

This is a terrifyingly accurate description of the plight of many extremely old people of in the Britain of 2008. For modern medicine, even without gene therapy, has led to a general life expectancy which would have amazed Swift. Those who are not suffering from any form of dementia are indeed aware of being "foreigners" in their own country. It is not a recipe for happiness, especially as they can never return, like tourists from an unfortunate journey, to the country as they remember it.

Scientists such as Dr Longo will protest, reasonably enough, that this is not at all what their experiments are designed to perpetuate. They are not simply trying to find ways of making us all live much longer. They are actually attempting to reverse the ageing process, so that at the age of 200, for example, we would have the health and aptitude now associated with early middle age.

This holds out the prospect of a much more beneficent outcome than that endured by the Struldbruggs. Yet even this is no Nirvana. More modern writers than Swift have encapsulated the problem: in Karel Capek's The Makropulos Affair, a 337-year old character, Emilia, complains that "No one can love for 300 years ... and then everything tires one. And then you find out that there is nothing at all."

It will be objected to this complaint that there is nothing to stop Emilia, or any other healthy 337 year old, from committing suicide. Yet if suicide is the appropriate answer, then this is not such a happy future world. In fact, suicide would not necessarily be the worst outcome. It is easy to imagine how the demands of the younger generation – the thrusting young things in their 150s – would lead to a policy of involuntary euthanasia.

The alternative would be a country full of frustrated people like Prince Charles, who this week achieved the dubious record of becoming the longest-serving heir to the British throne. Another hundred years of waiting, and the man who would be King would definitively have gone round the bend.

Rights of succession apart, we would enter a world in which there was a combination of extreme longevity and minimal procreativity. This, after all, is what evolutionary science predicts: it has already demonstrated that the shorter the life expectancy of any creature – both human and non-human – the earlier and more frequent is the reproductive process.

It can be argued that an extraordinarily long life combined with minimal reproduction is no worse than the opposite (an alternative fate which we can witness in some unfortunate parts of Africa).

Yet I can't help thinking that scientists above all should recognise the benefits of generational change; the great breakthroughs in mathematics, physics – and medicine – have been the products of relatively youthful minds, unconstrained by the ingrained preconceptions of age and habit. If we grind to a halt as a reproductive species – satisfied with the prospect of permanent tenure for those of us currently on the planet – then the prospect is not so much one of a uniquely evolved, self-modified life form, as of an evolutionary dead-end.

d.lawson@independent.co.uk

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