Wordly Huffman wrote:
> Have things gotten to the point where biologists can change a
> bacterium or virus so that it will become active only if certain
> characteristics exist in the host? So that, for example, if somebody
> wanted to diminish the number of blue-eyed people, he could alter some
> deadly disease so that it did its work only in blue-eyed people?
There are deadly diseases which are specific to one's genetic
heritage. For example, having just one copy of the sickle-cell
anemia gene increases your resistance to malaria. It's believed
that's why this otherwise deleterious gene was able to propagate.
(Two copies of this gene makes you vulnerable to sickle-cell.)
I suppose an airborne agent which preferentially attacked people
who either had this gene or did not have this gene would be
within the realm of reasonable science fiction. Coming up with
an agent to attack blue-eyed people would be much more
difficult, unless you could find some fundamental difference
between them and everybody else. In the case of sickle-cell
anemia, that difference is one amino acid in the hemoglobin
molecule.
