Too radical, too early. On the streets of San Francisco and New York, it may have been the Summer of Love, with young men and women engulfing each other with ardor, but in scientific halls, Margulis’s engulfment theory was met with a barrage of skepticism. For her, the summer of endosymbiotic love turned into a long winter of ridicule and rejection—until decades later, when scientists began to note not just the structural similarities between mitochondria and bacteria but also their molecular and genetic commonalities.
