Editing Lynn Margulis (section)

===Gaia hypothesis===
{{Further|Gaia hypothesis}}
Margulis initially sought out the advice of [[James Lovelock]] for her own research: she explained that, "In the early seventies, I was trying to align bacteria by their metabolic pathways. I noticed that all kinds of bacteria produced gases. Oxygen, hydrogen sulfide, carbon dioxide, nitrogen, ammonia—more than thirty different gases are given off by the bacteria whose evolutionary history I was keen to reconstruct. Why did every scientist I asked believe that atmospheric oxygen was a biological product but the other atmospheric gases—nitrogen, methane, sulfur, and so on—were not? 'Go talk to Lovelock,' at least four different scientists suggested. Lovelock believed that the gases in the atmosphere were biological."<ref name=BrockmanInterview/>

Margulis met with Lovelock, who explained his Gaia hypothesis to her, and very soon they began an intense collaborative effort on the concept.<ref name=BrockmanInterview/> One of the earliest significant publications on Gaia was a 1974 paper co-authored by Lovelock and Margulis, which succinctly defined the hypothesis as follows: "The notion of the biosphere as an active adaptive control system able to maintain the Earth in homeostasis we are calling the 'Gaia hypothesis.'"<ref>{{Cite journal |last1=Lovelock |first1=J.E. |last2=Margulis |first2=L. |date=1974 |title=Atmospheric homeostasis by and for the biosphere: the gaia hypothesis |journal=Tellus A |volume=26 |issue=1–2 |pages=2–10 |doi=10.3402/tellusa.v26i1-2.9731 |doi-access=free |s2cid=129803613 |language=en |bibcode=1974Tell...26....2L }}</ref>

Like other early presentations of Lovelock's idea, the Lovelock-Margulis 1974 paper seemed to give living organisms complete agency in creating planetary self-regulation, whereas later, as the idea matured, this planetary-scale self-regulation was recognized as an [[Emergence|emergent]] property of the [[Earth system science|Earth system]], life and its physical environment taken together.<ref>{{cite book|last1=Lovelock|first1=James|title=The Ages of Gaia: A Biography of Our Living Earth|date=1988|publisher=W.W.Norton & Co|location=New York}}</ref> When climatologist Stephen Schneider convened the 1989 American Geophysical Union Chapman Conference around the issue of Gaia, the idea of "strong Gaia" and "weak Gaia" was introduced by James Kirchner, after which Margulis was sometimes associated with the idea of "weak Gaia", incorrectly (her essay "''Gaia is a Tough Bitch''" dates from 1995 – and it stated her own distinction from Lovelock as she saw it, which was primarily that she did not like the metaphor of Earth as a single organism, because, she said, "No organism eats its own waste").<ref name=BrockmanInterview/> In her 1998 book ''Symbiotic Planet'', Margulis explored the relationship between Gaia and her work on symbiosis.<ref>{{cite book |last1=Margulis |first1=Lynn |title=Symbiotic Planet |date=1998 |publisher=Basic Books |location=New York, NY}}</ref>