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altruistic behaviour

biology
Also known as: altruism, epimeletic behaviour

Quick Summary

Altruistic behavior in biology refers to actions that benefit others at a cost to oneself. This seemingly counterintuitive behavior can evolve through kin selection, a form of natural selection that considers the genetic fitness of relatives. The concept of inclusive fitness explains this: an individual's genetic success includes not only its own reproduction but also the reproduction of its relatives.

Hamilton's rule quantifies this, stating that altruism evolves when the benefit to the recipient (B), weighted by the genetic relatedness (r) between the altruist and recipient, exceeds the cost to the altruist (C). Essentially, genes promoting altruism can spread if they help copies of themselves in relatives reproduce more successfully than the altruist could on its own. Examples include parental care and alarm calls in social animals.12

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2 Britannica Sources
  1. kin selection
  2. Hamilton’s rule

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