I don't agree with this last statement. The genetic engineers are
_manipulating_ a natural process to reach their goals. If this process
were not natural, there would be not even a modicum of credibility in the
anti-GE claims that these genes will escape and move into numerous
other species. (Of course, that argument is self-defeating, since, if this
natural gene movement were so easy and ubiquitous, the genes in
question would already be everywhere).
In engineering a bacterium to produce some desired chemical
product, say, insulin, the natural ability of bacteria to take up genetic
material from their evironment may be used. The engineer isolates
the desired genetic sequence and sticks it onto a bacterial plasmid.
Intact bacteria in solution will then take in these plasmids and,
sometimes, incorporate the desired characteristic. Alternatively, a
bacteriophage may be used as a vector -- the phage injects the
genes into the bacteria -- if the reproductive mechanism of the phage
has first been crippled, the bacteria survive with the new genetic
material functioning to produce the desired metabolic by-product.
Of course, the _natural_ movement of genetic material by viruses is not
directed at a human goal. In the process of infecting a cell, certain types
of viruses (the retroviruses) end up transferring extra DNA that codes
for who-knows-what. The genetic engineers use this ability of
these viruses to carry specific, desired characteristics into the target
The process in the lab is not precisely controlled. Not every target
bacterial, plant, or mammalian cell ends up expressing the new traits.
That is why it has been common practice to link the traits to antibiotic
genes (originally from existing bacteria). This provides the
technicians to cull the ones without the trait and culture the others.
As far as I know, the lab scientists are not designing new genes;
human knowledge is not yet anywhere near advanced enough to do this
with foreknowledge of what it is that is being designed. The genes
that are being moved already exist in nature; the GE technicians are
just manipulating bacterial and viral characteristics to put these genes
where their expression can be more useful (obviously, to the owners of
the technology or holders of the patents).
You may not like the idea of gene movement without sex (or some form
of untampered microbiological conjugation); you may be fearful of the
ultimate consequences of doing this; you may (well!) doubt the good
intentions of the corporate developers of this technology; but, to claim
this process doesn't even mimic nature demonstrates an incomplete
understanding both of nature and of genetic engineering.
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