On 23/03/2011 16:51, Peter Scott wrote:

Mealy-mouthed! Hmmph. Not what I'm usually accused of.

Never before have we mixed genes from totally different organisms,
animals and plants for example, or viruses. Selective breeding in the
past has been on the basis of accelerated evolution of the genes of one
organism by breeding from those with desired qualities.

It is the DNA that determines the nature of the organism, so mixing
alien genes has the potential for highly dangerous variation. After all,
small changes in a virus changes its virulence. Adding alien genes is a
trial and error process. No-one could have had any idea what might
result. Yes, the experiments are done in a sealed environment with the
destruction of anything shown to be hazardous, but no-one knew what
would happen when apparently benign new gene forms inter-acted with
those in nature.

What consequences? New virulent diseases as a result of the mixing of
the viruses used. Cancers produced by toxic effects of digestion of
alien materials. Animal species being wiped out by variants of their
genes used in other GM organisms. The point is that these were unknown
unknowns. I am sure I could think of more, but you get the point. As I
said this was one of the most profound experiments ever done, and we are
lucky.

Umm.. mixing their DNA in with the host is exactly what retroviruses
(best known being HIV/AIDS) and there is a growing theory that eukaryote
organisms evolved from assemblies of prokaryotes working in symbiosis.
The separate inheritance of the partial DNA of mitochondria is why you
can track the maternal line - and it is only partial DNA.

Take this with caution, I am many years out of the field.

Andy

p.s. "Silent Spring" first published 1962 it says in my copy.