Editing Lynn Margulis (section)

===Endosymbiosis theory===
{{Main|Symbiogenesis}}
[[File:Glaucocystis sp.jpg|thumb|The [[chloroplast]]s of [[glaucophyte]]s like this ''[[Glaucocystis]]'' have a [[peptidoglycan]] layer, evidence of their [[endosymbiotic theory|endosymbiotic]] origin from [[cyanobacteria]].<ref>{{cite journal |journal=[[American Journal of Botany]] |year=2004 |volume=91 |issue=10 |pages=1481–1493 |title=Diversity and evolutionary history of plastids and their hosts |first=Patrick J. |last=Keeling |doi=10.3732/ajb.91.10.1481 |pmid=21652304|doi-access=free }}</ref>]]

In 1966, as a young faculty member at [[Boston University]], Margulis wrote a theoretical paper titled "On the Origin of Mitosing Cells".<ref>{{cite journal |last1=Sagan |first1=Lynn |title=On the origin of mitosing cells |journal=Journal of Theoretical Biology |year=1967 |volume=14 |issue=3 |pages=225–274 |doi=10.1016/0022-5193(67)90079-3 |pmid=11541392|bibcode=1967JThBi..14..225S }}</ref> The paper, however, was "rejected by about fifteen scientific journals," she recalled.<ref name=BrockmanInterview>Margulis, Lynn, [http://www.edge.org/documents/ThirdCulture/n-Ch.7.html Gaia Is a Tough Bitch] {{Webarchive|url=https://web.archive.org/web/20171122013320/https://www.edge.org/documents/ThirdCulture/n-Ch.7.html |date=November 22, 2017 }}. Chapter&nbsp;7 in The Third Culture: Beyond the Scientific Revolution by John Brockman (Simon & Schuster, 1995)</ref> It was finally accepted by ''[[Journal of Theoretical Biology]]'' and is considered today a landmark in modern [[endosymbiotic theory]]. Weathering constant criticism of her ideas for decades, Margulis was famous for her tenacity in pushing her theory forward, despite the opposition she faced at the time.<ref name="Lake-2011"/> The descent of mitochondria from bacteria and of chloroplasts from cyanobacteria was experimentally demonstrated in 1978 by [[Murder of Robert Schwartz#Background|Robert Schwartz]] and [[Margaret Dayhoff]].<ref>{{cite journal |last1=Schwartz |first1=R. |last2=Dayhoff |first2=M. |title=Origins of prokaryotes, eukaryotes, mitochondria, and chloroplasts |journal=Science |year=1978 |volume=199 |issue=4327 |pages=395–403 |doi=10.1126/science.202030 |pmid=202030 |bibcode=1978Sci...199..395S}}</ref> This formed the first experimental evidence for the symbiogenesis theory.<ref name="Lake-2011"/> The endosymbiosis theory of organogenesis became widely accepted in the early 1980s, after the genetic material of [[mitochondria]] and [[chloroplast]]s had been found to be significantly different from that of the symbiont's [[nuclear DNA]].<ref>{{cite encyclopedia |first=Nicholas W. |last=Gillham |title=Chloroplasts and Mitochondria |encyclopedia=Encyclopedia of Genetics |editor-first=Eric C.R. |editor-last=Reeve |url=https://books.google.com/books?id=PuCYAgAAQBAJ&pg=PA721 |date=January 14, 2014 |publisher=Routledge |isbn=978-1-134-26350-9 |pages=721–735}}</ref>

In 1995, English evolutionary biologist [[Richard Dawkins]] had this to say about Lynn Margulis and her work:
<blockquote>I greatly admire Lynn Margulis's sheer courage and stamina in sticking by the endosymbiosis theory, and carrying it through from being an unorthodoxy to an orthodoxy. I'm referring to the theory that the eukaryotic cell is a symbiotic union of primitive prokaryotic cells. This is one of the great achievements of twentieth-century evolutionary biology, and I greatly admire her for it.<ref name=BrockmanInterview/></blockquote>