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Re: Glickman and Biotech
In Article <VA.0000004f.0473dba2@wrcs.u-net.com>, William R Hite
<wrhite@cix.compulink.co.uk> wrote:
>In article <E11IC5.KrA@plamondon.COM> on Mon, 18 Nov 1996 00:21:41 GMT
>robert@plamondon.COM (Robert Plamondon) wrote:
>> You mean, like in THE FLY? You get a creature that's half scientist,
>> half insect? Genetic engineering is FAR more mundane than that.
>
>No, No and No. a) I mean like RR Soy b) RR Soy is part soy, part
>bacterium, c) and the pigs with human genes to act as sources for
>transplants?
A multicellular species can't realistically be defined on the basis of a
single gene. Remember also that we have many, many genes in common with
bacteria, for example most of those involved in basic metabolism
(glycolysis, etc.). Humans are even "part bacterium" in a very real sense
(mitochondrial genome).
>With respect to the food that I eat you must agree that I do have an interest
>in both the definition of "runs ok" and the results?
You certainly DO have an interest! Everyone does.
>I also have a legitimate interest in the World's gene pool and want to feel
>confident that it will not become corrupted.
If you don't know a lot about the subject and don't trust the scientists,
how do you propose to know what constitutes "corruption" of the gene pool?
I'm often surprised that those who would take a 'holistic' or ecological
approach to the production of their food often seem ignorant of the fact
that humans have evolved, like all other organisms on earth. Most of our DNA
coding sequences are shared with other forms of life, including plants,
animals, and bacteria. We share common structural elements (C,H,O,N,etc.),
macromolecules like proteins and DNA, and even specific gene sequences. That
'the whole world is interconnected' thing is more than skin deep!
>If any of the molecular biologists or genetic engineers here on the
>list can tell us the present state of science's understanding of the
>complete range of interactions between one gene and the whole organism
>expressed by the DNA that would be instructive - wouldn't it?
Of course asking people to 'fully explain nature' is just being silly.
Nobody knows everything there is to know.
>Just as one example of the almost complete ignorance of science's
>understanding of genetic expression there is the problem of why some
>genes express in some cells and not others. For instance the same DNA
>that you have in your liver cells only expresses some genes whereas in
>the kidney it expresses others. Similarly, over time the same DNA
>expresses in different ways. This is the problem of differentiation and
>as I understand it nobody really knows the answers.
The tissue-specific nature of gene expression is one area where knowledge
has actually advanced fairly quickly over the last decade or so, but of
course there will always be more unanswered questions. In some such cases
there are multiple copies of the same gene under the control of different
tissue-specific promoter and enhancer elements. In other cases, specific
gene sequences are permanently excised from certain cell types during
development. Another mechanism is deactivation of specific genes through
permanent rearrangements or methylation events. This is just the 'tip of the
iceberg'. Sure, we have much to learn, but some of these mechanisms are well
understood.
>Do you really believe that same ignorance is capable of predicting the full
>range of effects of transgenic creations?
Of course not, but who has claimed to be "capable of predicting the full
range of effects of transgenic creations"? It is not possible to rule out
every possibility, but it is possible to make a reasonable assessment of the
risks involved. Based on current knowledge, most of the scenarios commonly
envisioned (imagined?) so far are unlikely to occur. Exactly what potential
"effects of transgenic creations" concern you? What basis is there for concern?
Tracy
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