So if syphilis causes AIDS, and not HIV, where is the evidence? As microbiologist and epidemiolist Tara Smith points out in her excellent blog, Margulis offers none. Instead, she says to the credulous and uncritical interviewer:
The idea that penicillin kills the cause of the disease is nuts. If you treat the painless chancre in the first few days of infection, you may stop the bacterium before the symbiosis develops, but if you really get syphilis, all you can do is live with the spirochete. The spirochete lives permanently as a symbiont in the patient. The infection cannot be killed because it becomes part of the patient’s genome and protein synthesis biochemistry. After syphilis establishes this symbiotic relationship with a person, it becomes dependent on human cells and is undetectable by any testing.
Great. Just what we need: an untestable hypothesis promoted by assertion and reputation, not something concrete that scientists could test (although most specialists in microbiology would say the evidence is clear that the HIV retrovirus, and not the spirochaete bacterium Treponema pallidum, is the true cause of AIDS).