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08 Aug 2003 12:04
Here is the nightmare scenario in which reproductive cloning is justified, inevitable and necessary for the survival of the community. You are crowded together by an implacable authority that dictates that there will be neither time nor opportunity for sex.
Rank offenders are ruthlessly weeded out.
This is itself a hideous option, because it means that, sooner or later—death arrives with its scythe arbitrarily and unpredictably, taking out the underfed, the parched, the chemically or biologically polluted—only one of you will be left. The entire community will consist of tens of thousands of clones of one survivor. Genetic variety will have been expunged. Sex, should it ever become possible, could only take place joylessly, between consenting clones.
The scene is, of course, any well-kept suburban lawn. Many plants reproduce both sexually and asexually: elms sucker, potatoes sprout from their own tubers, fruit trees propagate from grafts. Mammals - barristers as well as bats, accountants as well as aardvarks—share a lot of their DNA with lettuces, leeks and lobelias, so it should be no surprise to discover that they too can be persuaded to clone, with immense difficulty. Humans use cloning technology in the garden because it is a great way of keeping the grass trim and the hedges thick. They should not use it in fertility clinics because it is a terrible way to produce babies.
The latest mammalian baby clone is a pretty Halflinger foal called Prometea, born to an Italian research institution on May 28. It took more than 800 embryos and nine would-be surrogate mother mares to arrive at just one foal, which may or may not lead a normal life: it will take a couple of decades to discover the answer to that.
In theory it would be even more difficult to produce a healthy child by cloning. As the pioneers of the technique have pointed out from the start, the old-fashioned way to replicate humanity is the surest, the least cruel and the least wicked. Cloning is a new technique, performed first in 1996. Sexual congress, on the other hand, has been around for maybe 500-million years. There has been plenty of time to get it right.
Why clone at all? Dolly the sheep—the world’s most famous clone, although not the first—was produced in 1996 by a technique called nuclear transfer. A team at Roslin in Scotland took a cell from the udder of a dead ewe and popped it into a sheep’s egg from which the mother’s DNA had been scraped out. So the egg contained the DNA of one individual, not the shared DNA of two, and that single suite of adult mammary gland DNA grew into a whole, bleating sheep.
But the point of the experiment was not to make a clone. Dolly was living proof of a biological marvel. Within the DNA of one specialised cell—a fragment of skin, a sliver of liver, a splinter of bone—lay the recipe, the information, the reconstruction manual for the whole animal. Dolly’s mother started as a single fertilised egg, which doubled, and doubled again, and each of those doubling cells contained within them the whole chain of command that took a single cell from one to 10-trillion cells, of more than 200 different kinds, and the very last one alive—perhaps plucked from tissue after death—contained the wherewithal to turn the clock back and do it all over again.
Having done it, why do it again? One experiment won’t answer all the questions, or perhaps any. To answer the questions—about embryo development, cancer, genes and the environment—researchers have to clone and clone again, not just other sheep, but other mammals. And then there are pressures from beyond science. Could cloning science deliver transgenic animals that reliably produce human or other valuable proteins, over and over again? Could it bring back a beloved pet? Could it recover threatened species from extinction? Could it resurrect the dinosaurs or the woolly mammoth? Could it bring back Hitler, or a child that died?
The answer to the last question is simply no: a clone is genetically identical but that does not mean that the clone would be even very like the genetic parent. A clone would be the product of a different womb, born into a different environment, brought up among different influences. It would be a different person. That much, researchers are sure of: they have seen it in cloned animals. Furthermore, on the evidence of cloned mammals from Dolly to Prometea, it would take around 1 000 donated eggs and perhaps 30 or more volunteer surrogate mothers to produce one live child, and there would have been some pretty distressing miscarriages along the way. That one is simple: it cannot decently be done. And if it could, there are still better ways to produce a child.
But cloning technology really could answer basic questions that would pay off in a better understanding of biology. So it’s worth a shot. Could cloning technology produce herds of identical animals that would produce predictable quantities of fibroblastin, or alpha-1 antitrypsin or spider’s silk every day? Why not? Because they are unnatural? We use herds of artificially inseminated non-identical animals to produce Roquefort cheese, live yoghurt, sour cream and unsalted butter every day and none of those products is all that natural either.
So the question becomes not should you, but can you? Is it worth it? It might really be a good idea to clone a few giant pandas if it were to make the difference between survival and extinction. On the other hand it would be a terrible idea to clone a woolly mammoth after 10 000 years of oblivion, because the world that was its home has also vanished forever. That favourite pet, too, has gone forever: the labrador you loved so much will never come to love you back from that laboratory dish.
But Prometea, tantalisingly, could be, literally, the first of a new race. The world’s thoroughbred racehorses are not exactly genetically identical, but they are very inbred. Like grass lawns, racehorses are already unnatural. So would a cloned racehorse be such a bad idea? If racehorses exist entirely for the delight of spectators and gamblers, why not enhance the spectacle and the odds, and multiply the thrills, by matching a born-again Phar Lap against a replicant Shergar, or a newly minted Mill Reef against a freshly baked Seabiscuit? Supposing it could be done at all? I only ask: I certainly wouldn’t place bets myself. - Guardian Unlimited Â
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