Steve B wrote:
I find it difficult to accept the basic anti-GE premise that the way
genes happened to have been sorted among organisms by everything from
chance bolts of lightning over the primordial organic soup to
accidental, or human-generated (but "natural") cross-fertilisations
represents "the best of all possible worlds", and that "GE" poses a
significant risk of stuffing this up, within a few years, simply
because it's "unnatural".

This pov appears to presuppose what I call "a supernatural filing
clerk" with "good" intentions (essentially a theist view), or an
extrordinary efficiency on the part of Darwinian "natural selection."

Let's see what we can learn from a little math exercise.
If something has only a 1% selection pressure, so in each generation
the portion of the population with a given trait is 99% of the portion
of the previous generation, and they start out being 99% of the population,
then in 1,000 generations, the 99% has been reduced to 0.004%.
So if we have genes a, b, c, d such that the combination a & b or c & d
fail to work together with only a 1% selective effect on population,
then in 1,000 generations you have a population for which
over 99.99% have neither a & b nor c & d - in other words, you have a
population with a very high degree of correlation among these genes.
1,000 generations is a fleeting blip in evolutionary history.
In a million generations the percentage is so infinitesimal that my
calculator can't calculate it, the negative exponent is so large.
Remember Nature has been doing this for a billion years.

Thus almost all of the genes in any natural genome or gene pool have been
related to each other and working together (or coevolving if you can't
stand a human perspective Jim) for a very very very long time, and modern
science is only beginning to get a clue of the web of interrelationships
among them. Genomes and population gene pools are ecosystems. The
tinkertoy mentality of genetic engineers that presumes you can randomly
interchange genes from different places is out of touch with reality.

Perfectly natural species taken out of context and inserted into other
ecosystems have upset the balance of the ecosystem to become invasive
exotics causing major damage, including snuffing out natives and pushing
them to the brink of extinction. In the US there has been substantial
damage from Kudzu, Dutch Elm disease, Gypsy Moths, and Zebra Mussels;
Chestnut blight was catastrophic. The Glassy-winged Sharpshooter is
considered a serious threat to California agriculture. The Irish potato
blight killed a million people.

A little-known fact is that these invaders typically start out as seemingly
innocuous and often take decades to be recognized as a serious problem.
Mimosa pigra (catclaw mimosa) was a minor weed in Australia for about a
century before excluding other plants on a large scale.

The Royal Horticultural Society awarded a gold medal for importation of
Japanese Knotweed to Britain in the Victorian era, which was subsequently
revoked when they realized what a big mistake it was. Now huge sums are
being spent in an unsuccessful effort to control it.

A study at Cornell University concluded that "nonindigenous species in
the United States cause major environmental damage and losses totaling
approximately $137 billion a year" (BioScience January 2000).
Thus the cost to date of species taken out of context is already
over a trillion dollars and no one knows how many more trillions
will be incurred before things settle into some equilibrium.

Species of Mass Destruction are the number one cause of biodiversity loss
in the Great Lakes and are expected to be the leading cause of extinctions
in North American freshwater ecosystems this century.
Insects and diseases from Europe and Asia have caused damage in 70% of
the 165 million acres of forest in the American Northeast and Midwest.
Leafy Spurge has reduced the value of some ranch land by 90%.

It stands to reason that the consequences of genes taken out of context
may well have similar characteristics and similar orders of magnitude
to species taken out of context, in which case we're liable to find
ourselves decades from now with the Mooshes of the world just beginning
to wake up as the evidence of harm becomes so obvious and pervasive
it's impossible to ignore even with blinders on, at which point it will be
decades too late to prevent incurring costs of trillions of dollars of
damages over the ensuing decades or centuries or millenia or ...
It has already been documented that a gene inserted by genetic engineering
is 20 times more invasive than the same gene acquired by mutation
with the natural genetic regulatory system intact.

As Brian has posted, natural organisms have over millions of years
evolved DNA repair mechanisms without which the error rates would be
catastrophically high.
Genetic engineering defeats natural repair mechanisms while
introducing genetic instabilities. Given that gene pools are already
stressed by man-made chemical and radiological mutagens, it may not take a
very large increase in disruption from genetic engineering to push some
beyond their repair capacity even if it doesn't by itself cause
self-destruction (see http://www.i-sis.org.uk/meltdown.php).
Most things in the world of life are nonlinear.
The fact that you can increase something by x% without significant problems
does not mean you can increase by an additional x% without serious problems.
For a counter-intuitive example of a way GE can lead to extinction see
http://www.organicconsumers.org/ge/frankenfish.cfm

Of course Nature will recover in some fashion eventually, but the costs
could be not only economic but also the extinction of many species and
sickness and death of many people before recovery is accomplished.

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