Charlesworth's paradox
Charlesworth's Paradox is a paradox related to kin selection, Hamilton's Rule and the evolution of altruism. The paradox was proposed by Brian Charlesworth[1] and is sometimes used as a teaching example to discuss kin selection.[2][3][4]
The paradox
[edit]Hamilton's rule states that altruistic genes or strategies (in a prisoner's dilemma for example) should increase in frequency if
Where
- is the genetic relatedness of individuals concerned.
- is the benefit gained by the recipient of altruism.
- is the cost to the individual performing the act.
Charlesworth imagines a species of bird in which young can stay behind to help their parents care for the next season's young, rather than founding their own nests.
A situation arises where an individual can sacrifice its own reproductive success to save the lives of its four younger siblings. This will result in and (the 4 young survive and the older sibling dies). For siblings . Since this behaviour should evolve by Hamilton's rule. However it cannot be viable, because any individual exhibiting this behaviour sacrifices itself and does not reproduce.
Resolution
[edit]McElreath and Boyd[3] suggest that Hamilton's rule only applies in cases of weak selection, which is an underlying assumption in deriving it. Other authors[5] resolve the paradox for strong selection through a modified version of inclusive fitness.
References
[edit]- ^ Charlseworth, Brian (1978). "Some Models of the Evolution of Altruistic Behaviour between Siblings". Journal of Theoretical Biology. 72: 297–319.
- ^ Dawkins, R. (1979). "Twelve misunderstandings of kin selection". Zeitschrift für Tierpsychologie. 51 (2): 184–200.
- ^ a b McElreath, R; Boyd, R (2008). Mathematical models of social evolution: A guide for the perplexed. University of Chicago Press. ISBN 9780226558288.
- ^ Ehud Lamm (2011). "A Gentle Introduction to The Price Equation" (PDF).
- ^ Garcia‐Costoya, Guillermo; Fromhage, Lutz (2021). "Realistic genetic architecture enables organismal adaptation as predicted under the folk definition of inclusive fitness". Journal of Evolutionary Biology. 34 (7): 1087–1094. doi:10.1111/jeb.13795.
