These antiquated terms – “blue-green algae,” “protozoa,” “higher animals,” “lower plants,” and many others – remain in use despite their penchant to propagate biological malaise and ignorance. The use of these insults to the living benefits those people whose budgets, class notes, and social organization depend on their continuity. I suggest that one reason Wallin’s good ideas [Juan Wallin, who originally proposed in the 1920s that various cell components originate as symbiotic bacteria] were opposed or ignored was that he was thoroughly misunderstood by the many biologists and teachers who reinforce the misconception of fixed classification. Bacteria, seen only as causes of disease, were then and are now nearly alway branded as “enemy agents.” Note how they are “waiting to be conquered” by the “weapons” of modern medicine. It is ridiculous, of course, to describe them primarily in military, adversarial terms: most bacteria are no more harmful than air, nor can they, like air, ever be removed from our bodies and our environment. But many still erroneously believe that any bacteria, if present, should be eradicated. Bacteria now and even more in Wallin’s day must be vanquished. How could they “inhabit” healthy tissue? Wallin’s colleagues confused the map with the territory.
Lynn Margulis, Symbiotic Planet: A New Look at Evolution, 1998, pp. 55.
