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Environmental variability can select for optimism or pessimism
Author(s) -
McNamara John M.,
Trimmer Pete C.,
Eriksson Anders,
Marshall James A. R.,
Houston Alasdair I.
Publication year - 2011
Publication title -
ecology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.852
H-Index - 265
eISSN - 1461-0248
pISSN - 1461-023X
DOI - 10.1111/j.1461-0248.2010.01556.x
Subject(s) - pessimism , optimism , biological dispersal , ecology , metapopulation , biology , term (time) , psychology , social psychology , population , demography , philosophy , physics , epistemology , quantum mechanics , sociology
Ecology Letters (2011) 14: 58–62 Abstract We propose operational definitions of reproductive optimism and pessimism; optimism involves behaving in a way that gives too much weight (in terms of producing surviving offspring) to positive events, pessimism gives too much weight to negative events. Natural selection maximizes the long‐term growth of a lineage rather than short‐term measures such as numbers of offspring. Consequently, optimism or pessimism can be favoured by natural selection, even though such biases appear irrational from a short‐term perspective. We investigate the evolution of optimism in a metapopulation. The circumstances of a patch change over time, independently of other patches. With sufficient dispersal between patches, stochasticity affects members of a lineage largely independently and optimism is favoured. With little dispersal, the temporal fluctuations of a patch affect many members similarly; pessimism is then favoured. Our results establish that the spatial and temporal structure of the environment is crucial in determining the direction of evolved biases.