Biology / Unit 14 Bio 3601 short lesson, about 20 seconds
Fitness Outcome, Not Closeness Alone, Classifies a Symbiosis
Captions available
The idea
Classifying a symbiotic relationship, per Bio 3595, requires checking each species' fitness outcome — closeness alone does not indicate mutualism, commensalism, or parasitism.
In practice
A cleaner fish and the fish it grooms both gain, so it classifies as mutualism despite one depending on visiting the other.
Where people slip
"Any close relationship is parasitic," per Bio 3599, ignores that many intimate pairings are mutualistic.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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