September 26, 2012 @ 4:45 pm
Dr. White is a careful and conservative scientist. One fascinating aspect of this topic I couldn't draw her into speculating about was the link between bacterial and cultural evolution, in other words, whether people invented the cultural practice of circumcision (the removal of the foreskin) at least partly to deal with infections. The medical literature argued back and forth about the effectiveness of circumcision for years until three randomized clinical trials in Africa agreed that the surgery cut HIV infection rates by about 60%. A clinical trial, involving thousands of subjects, is our gold standard for evidence. When we can't agree based on the best, most trusted procedures we know of, what chance did the ancients have? What would the ancients have used to make that decision? Was it even conscious? Did they think "wrath of God" when they saw penile ulcers? Were there penis ulcer outbreaks in Babylon?
Apparently, as Dr. White said, the oxygen may be the most important factor. Not just killing H. ducreyi, but a whole host of anaerobic bacteria species that create an "inflammation environment" that would make HIV infection easier.
My quick Googling for "influenza etymology" turned up argument even there, about the word's history.
The problem with cultural evolution, again, is that we're hung up on knowing what the unit of information is. What exactly is passed down? With words it's easy to imagine. They seem like discrete units. Or songs, or stories. But what about surgeries? Are they discrete units? Personally I think DS Wilson and the multilevel selection people are right. There are multiple possible units of information, of different sizes, and they all cooperate with or compete against one another. That's not a very satisfying answer until we know what all of the rules are, but it's an incremental answer, one that (I think) allows for more slow steady progress, rather than waiting around for some genius to hand us the one magical answer.