Fitness Outcome, Not Closeness Alone, Classifies a Symbiosis
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Classifying a symbiotic relationship, per Bio 3595, requires checking each species' fitness outcome — closeness alone does not indicate mutualism, commensalism, or parasitism.
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A cleaner fish and the fish it grooms both gain, so it classifies as mutualism despite one depending on visiting the other.
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"Any close relationship is parasitic," per Bio 3599, ignores that many intimate pairings are mutualistic.