Form and Function

Because my husband and I are apparently old and boring liberals, or something of the sort, we listen to a lot of public radio podcasts and a couple weeks ago we caught a really interesting segment from Canadian public radio on the history of the HIV virus. The researcher, Dr. Michael Worobey, had come across two tissue samples from the Congo, circa 1960, with different strains of HIV. Based on the the amount of difference between the two strains and the known rate of mutation in the HIV virus, he was able to estimate that the two strains had differentiated from a single strain beginning around the year 1900. 1900! About 70 to 80 years before any knowledge of the virus really hit the worldwide scene.

Dr. Worobey believes that that virus was present (but still lethal) in widely dispersed populations in Africa for many decades before being recognized as a unique condition because those who succumb to the HIV virus die of opportunistic infections, primarily tuberculosis in many non-industrialized countries, and therefore deaths from HIV were not unlike the many other TB-related deaths. He also believes that the virus would not have grown to epidemic proportions had Africa's population remained dispersed in small tribes, but that the growth of city populations in the 1900s allowed HIV to spread very quickly, becoming the worldwide epidemic it is today.

The .mp3 of the interview with Dr. Worobey can be downloaded here.