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Article
A Simple and General Explanation for the Evolution of Altruism
Proceedings of the Royal Society B (2009)
  • Jeffrey Alan Fletcher, Portland State University
  • Michael Doebeli, Portland State University
Abstract

We present a simple framework that highlights the most fundamental requirement for the evolution of altruism: assortment between individuals carrying the cooperative genotype and the helping behaviours of others with which these individuals interact. We partition the fitness effects on individuals into those due to self and those due to the ‘interaction environment’, and show that it is the latter that is most fundamental to understanding the evolution of altruism. We illustrate that while kinship or genetic similarity among those interacting may generate a favourable structure of interaction environments, it is not a fundamental requirement for the evolution of altruism, and even suicidal aid can theoretically evolve without help ever being exchanged among genetically similar individuals. Using our simple framework, we also clarify a common confusion made in the literature between alternative fitness accounting methods (which may equally apply to the same biological circumstances) and unique causal mechanisms for creating the assortment necessary for altruism to be favoured by natural selection.

Keywords
  • Altruism--Statistics,
  • Kin selection (Evolution)
Publication Date
January, 2009
Publisher Statement
Copyright 2009 Royal Society Publishing
Citation Information
Jeffrey Alan Fletcher and Michael Doebeli. "A Simple and General Explanation for the Evolution of Altruism" Proceedings of the Royal Society B Vol. 276 Iss. 1654 (2009)
Available at: http://works.bepress.com/jeff_fletcher/8/