Editing Lynn Margulis (section)

===Symbiosis as evolutionary force===
{{main|Symbiosis}}
{{See also|Horizontal gene transfer}}

Margulis opposed competition-oriented views of evolution, stressing the importance of symbiotic or cooperative relationships between species.<ref name="Mann-1991">{{cite journal |last1=Mann |first1=C |title=Lynn Margulis: Science's unruly Earth mother |journal=Science |year=1991 |volume=252 |issue=5004 |pages=378–381 |doi=10.1126/science.252.5004.378 |bibcode=1991Sci...252..378M |pmid=17740930}}</ref>

She later formulated a theory that proposed symbiotic relationships between organisms of different phyla, or kingdoms, as the driving force of [[evolution]], and explained [[genetic variation]] as occurring mainly through transfer of nuclear information between [[bacteria|bacterial cells]] or [[virus]]es and [[eukaryotic cell]]s.<ref name="Mann-1991"/> Her organelle genesis ideas are now widely accepted, but the proposal that symbiotic relationships explain most genetic variation is still something of a fringe idea.<ref name="Mann-1991"/>

Margulis also held a negative view of certain interpretations of [[Neo-Darwinism]] that she felt were excessively focused on competition between organisms, as she believed that history will ultimately judge them as comprising "a minor twentieth-century religious sect within the sprawling religious persuasion of Anglo-Saxon Biology."<ref name="Mann-1991"/>
She wrote that proponents of the standard theory "wallow in their zoological, capitalistic, competitive, cost-benefit interpretation of Darwin – having mistaken him ... Neo-Darwinism, which insists on [the slow accrual of mutations by gene-level natural selection], is in a complete funk."<ref name="Mann-1991"/>