Margulis is one of the most brilliant scientists alive. She's a member of the prestigious National Academy of sciences and won Bill Clintons medal of science in 1999. She's also supported the dissident scientists like Duesberg who have doubted HIV's causal role in AIDS. You can see the film hiv fact or fraud to learn about their views, seems crazy until you see it. Keep an open mind I thought it was nuts to.
http://www.archive.org/details/aids_scam

Dr. Barrett, you should also read 2 of the top Cancer researchers book Project Day Lily, Garth and Nancy Nicolson PHD's that found a microbe that Army Scientist Dr. Shyh ching Lo MD PHD published on called mycoplasma incognitus in the blood of Sick GWI vets and CFS patients, unlike HIV this microbe kills every animal inoculated. Lo was an HIV skeptic as well in the early 90's.

"He said the participants were ''very impressed with the quality of science that Dr. Lo's group displayed.''

''The pathology data was solid and convinced us that the agent is in the tissues,'' Dr. Baseman said. The ability of M. incognitus to cause a fatal wasting disease in monkeys and mice persuaded most participants that the microbe ''has the potential to cause disease in humans
New York Times 1990

This is what the nicolsons found in Sick GWI vets, when they found it armed agents from The DOD threatened them to stop their research, this is their true story slightly fictionilized to stay out of court and protect their sources in the Pentagon.
http://www.projectdaylily.com/