h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Yes, that's just standard biological warfare; ebola was successfully weaponised by the US and the USSR (and perhaps others).
Thw whole point of developing a genetically targetable BW is in order to remove the lack of control inherent in such weapons as they
now exist. Furthermore, I would contest the fact that it is not possible to distinguish between genetic populations. It may be difficult
but I am pretty sure it is not impossible. It may be some time off, but it will happen and when it does it will not be pleasant. Both Israel and the apartheid regime in South Africa are/did try to develop such weapons (though in fairness to your point the Israelis are having
difficulties in distinguishing between Arabs and Jews as they share a similar genetic history- i.e. semitic)

Any genetic weapon that isn't precisely targeted is likely to wipe out all life on Earth - we all evolved from the same original lifeform (except for those guys that live in deep sea volcanic vents.
We would have to catch an alien first, study his/her/its dna (which would be completely different, and may not resemble our dna at all), and then we can wipe out all life on his planet. So the real problem is from apocalyptic death cults and xenophobic madmen.

Where did this alien thing come from?

The only way someone could a genetic weapon without wiping out their side as well would be to use it against an alien species, with whom we share absolutely no dna.

Let me get this straight;you are not prepared to accept the feasibility of a genetically targetable bio-weapon but you are
comfortable with the hypothetical/actual existence of an alien species for which no tangible evidence/data exists. Interesting reasoning.

I was hypothesising, pointing out that a genetic weapon is competely impractical (and downright dangerous) when used on one's own species and any other life-forms originating on one's planet. A hypothetical genocidal war on an alien species is the only practical use of such weapons.
A weapon capable of analysing its victims entire dna coding, sorting through the many millions bytes of information stored there, and able to search for a certain, precise combination of genes and attack persons with these codes before the enemy can act on it and release its own weapons of mass destruction staggers the imagination (is that the right phrase?) but the possibility of certain chemicals eventually forming over billions of years of combinations and eventually producing a life form is not that hard to believe. I'd be more suprised if there wasn't any life outside this world.

OK point taken, my apologies for sounding a little abrasive. One thing though; the genetic weapons that have been hypothesised would not need to analyse an entire dna structure.. Rather they are likely to be targeting specific genes (in much the same as beneficial gene research is aiming to target and cure gene abnormalities). The FBI has been doing research into dna forensic evidence and has discovered specific genes which can identify a persons colour and so on. If one can identify a specific gene such as this then it is not a major step towards utlilising this infomation in a malignant way. This is the flip side to the bio-tech revolution and the race to find the 'magic bullet' drug. I am convinced that a specifically targetable weapon is a possibility. It will only take a combination of the scientific knowledge and capability and the will to use it.

I agree that the key could be a single gene, which in turn might be connected to race...but having found that gene, the biological weapon could only turn it off. Could this be fatal?

If some KKK wacko let loose a genetic weapon that merely switched off th gene for black skin, we could end up with the entire continent of Africa populated by Michael Jacksons, which, for the rest of the world, would indeed be fatal. Switching off a gene for something like building lungs, hearts, skin is of course fatal. The body, lacking the "blueprints" for lung maintenance would be unable to build replacement lung tissue when old cells die off. This could take ages. The effect of genetic weapons would be unnoticable at first, and only later would the target discover that they had been attacked, when it is too late to do anything about it.

Hmm - most racists don't have the brains to successfully manipulate shoestrings let alone DNA, but that aside:
The genes that make us do so by turning on and off whilst we are being made...thus when the body development is at the "skin" stage if one gene switches in then your skin will be a certain colour. Removing the gene after it has been triggered will not alter the skin colour. All of this happens at the pre-foetal stage.
But then, I'm no biologist so I'm off to do some research

AND NOBODY GOT HURT !!!!!!!!!!!!!!!!

I think there are about 20 million Russians ... opps sorry.... WERE about 20 million Russians, killed during the cold war that would argue that point.