Ask Marilyn ® by Marilyn vos Savant is a column in Parade Magazine, published by PARADE, 711 Third Avenue, New York, NY 10017, USA. According to Parade, Marilyn vos Savant is listed in the "Guinness Book of World Records Hall of Fame" for "Highest IQ."
Sheryl Bateman firstname.lastname@example.org wrote to indicate that she did a search for "good virus" and immediately found information about bacteriophages. A bacteriophages is a virus that infects bacteria.
Posted at Jan 03/2008 11:54PM by Jonathan C. Hansen:
I think the answer to this question really depends on the sense in which one interprets the word "good".
Although nobody may be able to identify (to my knowledge) a virus, which in its natural role, somehow improves the adaptability of its host to the environment, such may exist; this would be one sense of the word "good". Even some sort of symbiotic relationship would qualify in this sense.
However, if one interprets the word "good" to mean "useful", many useful applications of viruses can be found. Attenuated viruses are routinely used for immunization against the more virulent strain. Engineered retroviruses are used to introduce segments of foreign DNA into host genomes (gene therapy). Plasmids and (I think) viruses are used in various bioengineering protocols in transfection and similar procedures.
So I can understand Marilyn's answer, but I don't believe it went deep enough, and focused on a narrow interpretation of what makes something "good".
From B. Roth (24 Feb 08): Viruses can transmit genetic material among orgnanisms. In the grand scheme of things, this benefits evolution. It provides species with greater genetic diversity so they are better able to withstand evolutionary pressures. This is undoubtably a good thing, as genetic uniformity is brittle.