Fwd: SCOUTED: Kitty CAT scan: More vets use high tech

[Robert D. Zimmerman]

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Date: Tue, 31 Dec 2002 13:08:23 EST
Subject: Fwd: SCOUTED: Kitty CAT scan: More vets use high tech
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In a message dated 12/30/2002 8:39:33 PM Eastern Standard Time, [EMAIL PROTECTED] writes:

They can't put the genie back in the battle, they'll simply drive the
scientists to countries which DON'T ban them, many of which WILL
misuse cloning.

The thing that does not come up in the cloning debate is intrinsic limitation of this technique. There are huge number of errors in DNA replication. Given the size of the mammalian genome these mistakes are inevitable and likely to be fatal sooner or later. I have seen cloning compared to IVF in terms of the relative success rate. The arguement goes that IVF failed many times initially because of technical difficulties but technologic advances eliminated most of these problems. This is true and it likely that cloning techniques will improve but what cannot improved is the intrinsic copying error rate. Think about it for a minute. Why does life use sex at all. From the gene's point of view cloning is always more efficient. You get 100% chance of getting into the next generation. So why sex? Two reasons. 1) It allows the organism to shuffle some of its membrane proteins. This provides resistance from parasites. Cells have chemical locks and the parasite has the key. With sex there is a reshuffling of genes and the locks change. The host and parasite dance through various combinations, the host changing the parasite changing and the host changing back etc. The second reason (the one that is germaine to cloning) involves error correction. Cloning leads to inevitable build up of errors (like the game of telephone where messages are repeated by individuals and after several repeats the errors overwhelm the message). Sex leads to genetic reshuffling and in this process some organisms end up with lots of errors and others end up with just a few. These organisms survive. The potential complexity of living creatures is governed by their genes. The more genes you have the more complex you can be. But gene number is limited by errors or more accurately error correcting mechanism. DNA replaced RNA because the double strand model was less error prone and errors could be detected and eliminated. In more complex creatures other techniques were needed and sex is by far the most important of these! for org anisms of our genetic complexity. Even with standard sexual reproduction there are a huge number of errors. The majority of human embryos are spontaneously aborted because either because these errors are fatal or they are detectex and the embryo is destroyed. Even if the clone survives to be born it will have more errors than a "wild" type individual and will likely die young from a variety of causes.
Sources:
"The Red Queen" by Matt Ridley (author of Genome)
"The Cooperative Gene" by Mark Ridley (no relation) author of one the major texts on evolution.

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From: "Andrew Crystall"
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Date: Tue, 31 Dec 2002 00:41:36 -0000
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Subject: Re: SCOUTED: Kitty CAT scan: More vets use high tech
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On 30 Dec 2002 at 16:34, Deborah Harrell wrote:

> clones are currently prone). My views on human
> reproductive cloning are the same (although the
> ability to clone/create *organs* such as livers,
> kidneys, hearts and skin would be terrific).

Unfortunately there seems to be no taste for not throwing the baby out
with the bathwater among goverments these days.

They can't put the genie back in the battle, they'll simply drive the
scientists to countries which DON'T ban them, many of which WILL
misuse cloning.

*shrugs*

This was one part of why I'm not a genetics student anymore.

Andy
Dawn Falcon

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