Margulis gets into Gaia Theory 4:00 minutes into this video. Below are a few quotes to emphasize.
“The Gaia concept is that the surface of the earth is regulated and modulated physiologically. That is, the temperature of the earth, the acidity, and the concentration of the gases like oxygen and methane are not here by chance alone! They are a product of the interactions of the organisms. So…we as people, in general, have considered…passive life is adapting to an the environment that’s changing. [That] is the wrong way of looking at it. The way you wanna look at it is: life is actively changing the environment, and then it is responding to that [change], but after responding it’s changing it more. So, it’s not a monologue it’s a dialogue”
“I am convinced that the cell is a microbial community, it is not bacteria grown large. It is the integration of formally…separate entities, whose living co-descendants we can still understand.”