Bt corn flap

[Neil Jones]

In article <38e070f8.1315712 at news.qmw.ac.uk>
           r.knell at qmw.ac.uk "Rob Knell" writes:

> 
> 3) Why is it that when sprayed around the environment from a
> helicopter BT is an environmentally friendly organic natural control
> agent, but when the exact same molecule is produced by genetic
> engineering it suddenly transforms into an evil monster that will not
> only kill all the pretty butterflies but will also make your 14 year
> old daughter pregnant, will wipe your hard drive and is responsible
> for Saddam Hussein still being in power in Iraq :-)

The so called Toxin expressed in the BT corn is NOT identical to that
produced in organic control agents. Bacillus thurigiensis is a specialised
bacerial predator of invertebrates. It exists is a variety of strains which
differ from each other. These natural predators are one of the factors which
influence the population dynamics of many species. For example Bacillus
species are a major natural cause of mortality in the endangered Jamaican
Swallowtail Papilio homerus.

Engineered corn contains PART of a gene from ONE strain of Bacillus
thurigiensis. This is an important factor to take into consideration.

The variability of wild Bacillus thurigiensis is an important tool in its
armoury. The "toxin" (actually a tool for enabling it to gain access to
the insect's body) exists in nature in such a range of forms that it is
difficult for insects to develop immunity.
However the ecological consequences of flooding an ecosystem with high
levels of one specific form of the toxin are difficult to predict.
One logical conclusion is that resistance will rapidly spread in the
populations of many species. It is also likely that this will facilitate
the developement of resistance to other wild strains. This could easily
occur once the majority of the population of a species carries a gene
that that works against one strain. Natural selection works just
like this.
The consequences are that we actually decrease the ability of Natural
predators to control pests. That is not a smart thing to do.

What also worries me is that the industry has chosen repeatedly to
describe Bacillus thurigiensis as a "soil bacterium" this is
not truthful at all. I tend to distrust people who are not truthful.

-- 
Neil Jones- Neil at nwjones.demon.co.uk http://www.nwjones.demon.co.uk/
"At some point I had to stand up and be counted. Who speaks for the
butterflies?" Andrew Lees - The quotation on his memorial at Crymlyn Bog
National Nature Reserve