BIOL 59200 Lecture Notes - Lecture 6: Carpenter Ant, Symbiodinium, Volvox
24 Mar 2019
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Cooperation: behavior shown by a cooperator that has been selected to be beneficial to the recipient of the behavior. Recipients can benefit from behaviors that are not selected to provide that benefit (this is not cooperation) Ex. dung beetles benefit from the excretion behavior of many animals but defecation is not selected to provide dung to beetles. Who benefits from cooperation: recipient, actor (but not always!) Net cost/benefit: altruism: actor loses and recipient benefits (-/+, mutualism: actor and recipient both benefit (+/+) Example of within species: volvox cells form multicellular groups with somatic (non- reproducing) cells surrounding larger (but less numerous) reproducing cells. Example of between species: cassiopia jellyfish are infected by an algal symbiont that shares photosynthates with the jellyfish in exchange for nitrogen and inorganic nutrients from jellyfish. Cooperation takes many forms: reproduction: organisms helping other organisms with reproduction increases fitness! Examples: meerkats, scrub jays- dominant pair does most of breeding; subordinates help care for young.
