"Edward L. Ferman - Best From F&SF, 23rd Edition" - читать интересную книгу автора (Ferman Edward L)

therefore, of the person from whom the somatic cell was taken? If so, the new organism would be a
clone of the person who donated the somatic cell.
The technique has been tried on different animals. You begin with an unfertilized egg cell and treat it
in such a way as to remove its nucleus, either by delicately cutting it out or by using some chemical
process. In the place of the removed egg cell nucleus, you insert the nucleus of a somatic cell of the same
(or, possibly, an allied) species, and then let nature take its course.
This has been successfully tried with animals as complex as a tadpole.
It stops being easy after the frog, though. Frog eggs are naked and can be manipulated easily. They
develop in water and can just lie there after the micro-operation.
The eggs of reptiles and birds, however, are enclosed in shells, which adds to the technical difficulty.
The eggs of mammals are very small, very delicate, very easily damaged. Furthermore, even if a
mammalian egg has had its nucleus replaced, it would then have to be implanted into the womb of a
female and allowed to come to term there.
The practical problems of mammalian cloning are such that there is no chance of its happening for
some time yet. Yet biologists are anxious to perform the feat and are trying hard. Eventually, they will no
doubt succeed. What purpose will it serve?
If clones can be produced wholesale, a biologist can have a whole group of animals with identical
genetic equipment; a set of ten thousand identical-twin mice, let us say. There are many animal
experiments that can be conducted with the hope of more useful results if the question of genetic variation
could be eliminated.
By the addition of other genetic-engineering techniques, it might be possible to produce a whole
series of animals with identical genetic equipment, except that in each case, one gene is removed or
alteredтАФa different gene in each individual perhaps. The science of genetics would then advance in
seven-league strides.
There would be practical uses, too. A prize bull or a champion egg-laying hen could be cloned, and
the genetic characteristics that make the record-breaking aspects of the animal possible would be
preserved without the chance of diminution by the interplay of genes obtained from a second parent.
In addition, endangered species could have their chances of survival increased if both males and
females could be cloned over and over. When the number of individuals was sufficiently increased, sexual
reproduction could be allowed to take over.
We might even dream of finding a frozen mammoth with some cell nuclei not entirely dead. We might
then clone one by way of an elephant's womb. If we could find a male and a female mammothтАФ
To be sure, if cloning is overdone, the evolutionary advantage of sexual reproduction is to some
extent neutralized, and we might end up with a species in which genetic variability is too narrow for
long-term survival.
It is important to remember that the most important genetic possession of any species is not this gene
or that, but the whole mixed bag. The greater the variety of genes available to a species, the more secure
it is against the vicissitudes of fortune. The existence of congenital disorders and gene deficiencies is the
price paid for the advantage of variety and versatility.
And what about cloned human beings, which is, after all, the subject matter of "RandallтАЩs Song"?
These may never be as important as you think. The prospect of importance rests chiefly on certain
misapprehensions on the part of the public. Some people, for instance, pant for clones because they think
them the gateway to personal immortality. That is quite wrong.
Your clone is not you. Your clone is your twin brother (or sister) and is no more you than your
ordinary identical twin would be. Your clone does not have your consciousness, and if you die, you are
dead. You do not live on in your clone. Once that is understood, I suspect that much of the interest in
clones will disappear.
Some people fear clones, on the other hand, because they imagine that morons will be cloned in
order to make it possible to build up a great army of cannon fodder that despots will use for world
conquest.