From: Eugene Leitl (Eugene.Leitl@lrz.uni-muenchen.de)
Date: Sat Mar 29 1997 - 03:20:08 MST
---------- Forwarded message ----------
Date: 24 Mar 1997 18:24:59 GMT
From: William Tivol <tivol@news.wadsworth.org>
To: "bionet.neuroscience mail newsgroup" <bionet-news@dl.ac.uk>
Subject: Re: Clinton vs human cloning : just a reflexion
Timothy Sutter (tpgsutter@geocities.com.x) wrote:
: William Tivol wrote:
: Yeah right, but so-called "identical" twins are not
: really as identical as a clone would be. No?
No. As previously posted by another, the mitochondrial DNA would
be different in a clone, but not in a monozygotic twin.
: > No. Cloning would diminish the gene pool by lowering diversity.
: Yeah, but you wouldn't have to worry about "lethal" genes.
Not is *this* generation.
: But what difference, you clone ten thousand "<insert name here>"
: and these clones each have two chidren with ten thousand regular people.
: You have not really lowered the gene pool any more than if this person
: had had ten thousand children.
Ah, like Wilt Chamberlain ;-).
: Like if they made a run on the sperm bank
: for the genes of a given person.
It would, however, lower the diversity of the gene pool more than
if ten thousand "regular people" had two children each with ten thousand
other "regular people". If we knew enough about what genes were beneficial
and which were detrimental, it might make sense to practise eugenics, and
cloning could play a part in that. Even so, it is not necessary to clone
adults. Separating embryos at the four or eight cell stage will work much
better.
Since something like 90% of the DNA is of unknown function (some
of it used to be called "junk DNA"), it would be very dangerous for us to
act as if we knew what matings were best for the long-term survival and/or
improvement of the human species. Many alleles which seem less fit for
this environment may confer advantages to their owners in an altered en-
vironment. I think that such genes as those which can increase melanin
production and make heat transfer to the environment more efficient could
prove essential as the ozone layer becomes thinner and the earth gets war-
mer. These potential changes are only two which happen to come to mind;
there are surely others which we know nothing about as yet.
: > I don't think that enough is yet known to improve the odds over
: > the old-fashioned way of making brainy and/or fit offspring by people
: > with those characteristics mating with others having like attributes.
: But yes, I suppose the old fashioned way has it's benefit
:
It's cost-effective and lots more enjoyable. Besides, having both
parents available to provide either a "brainy" or "brawny" environment in
which to raise the child would confer additional benefits to those provided
by genetics.
: Accept in a rare case where say, a really nice person with Tay-Sachs
: disease,
: wanted to have chidren but couldn't find a suitable partner.
: Or Tay-Sachs trait rather.
: Would be a way for them to pass on something to a next generation.
: Or just plain sterile people.
Either germline therapy to modify the Tay-Sachs gene or selection
of gametes to choose only those not carrying the Tay-Sachs trait would be
a better method than cloning. N.b., every adult with Tay-Sachs trait must
have at least one normal gene, or (s)he would never have reached adulthood,
so ~50% of the gametes could be used for in vitro fertilization. Once the
gene has been sequenced, a four- or eight-cell embryo could be analysed for
presence of the normal gene, then implanted if the Tay-Sachs trait was ab-
sent.
If we sterilized everyone with "bad" genes, we'd lose Stephen Hawk-
ing, and a lot of other "really nice" people. Furthermore, such action
would be morally reprehensible. I am completely against doing something
which is both evil and stupid.
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