Monday, February 14, 2005

10: New, more lethal HIV strain in NYC

A new, multi-drug reisistant HIV strain progresses very rapidly to AIDS. As evolutionary theory (and specifically Paul Ewald) predicts, the more communicable a parasite is among hosts, the more rapidly fatal it can afford to be. If a pathogen has many opportunities to spread to new hosts, the benefit of reproducing rapidly will outweigh the cost of debilitating and killing one's (current!) host by overwhelming the host's system with so many parasites. Indeed, this is exactly what happened in New York, where a very promiscuous man who refused to use protection gave his HIV parasites many opportunites to spread to new hosts--and thus encouraged their evolution to a more virulent form. (Sidebar: While many of our creationist friends opine that evolutionists only hold to this theory because of our alleged disdain for traditional morality, this tale of pathogen evolution has a very traditional moral. Celibacy until marriage and monogamy thereafter would destroy STDs utterly; even if humans only held to such traditional moral codes most of the time, HIV and other STDs would evolve toward decreased virulence.)

The original report on this case by the New York City Health Department can be found here.