Evolutionary divergence in brain size between migratory and resident birds

D Sol, N Garcia, A Iwaniuk, K Davis, A Meade, W A Boyle, Tamas Szekely

Research output: Contribution to journalArticle

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Abstract

Despite important recent progress in our understanding of brain evolution, controversy remains regarding the evolutionary forces that have driven its enormous diversification in size. Here, we report that in passerine birds, migratory species tend to have brains that are substantially smaller (relative to body size) than those of resident species, confirming and generalizing previous studies. Phylogenetic reconstructions based on Bayesian Markov chain methods suggest an evolutionary scenario in which some large brained tropical passerines that invaded more seasonal regions evolved migratory behavior and migration itself selected for smaller brain size. Selection for smaller brains in migratory birds may arise from the energetic and developmental costs associated with a highly mobile life cycle, a possibility that is supported by a path analysis. Nevertheless, an important fraction (over 68%) of the correlation between brain mass and migratory distance comes from a direct effect of migration on brain size, perhaps reflecting costs associated with cognitive functions that have become less necessary in migratory species. Overall, our results highlight the importance of retrospective analyses in identifying selective pressures that have shaped brain evolution, and indicate that when it comes to the brain, larger is not always better.
Original languageEnglish
Article numbere9617
Number of pages8
JournalPLoS ONE
Volume5
Issue number3
DOIs
Publication statusPublished - 10 Mar 2010

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divergent evolution
Birds
Brain
brain
birds
Costs and Cost Analysis
Markov Chains
Body Size
migratory behavior
Life Cycle Stages
cognition
Markov processes
Cognition
Costs
Life cycle
life cycle (organisms)
body size
phylogeny

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Sol, D., Garcia, N., Iwaniuk, A., Davis, K., Meade, A., Boyle, W. A., & Szekely, T. (2010). Evolutionary divergence in brain size between migratory and resident birds. PLoS ONE, 5(3), [e9617]. https://doi.org/10.1371/journal.pone.0009617

Evolutionary divergence in brain size between migratory and resident birds. / Sol, D; Garcia, N; Iwaniuk, A; Davis, K; Meade, A; Boyle, W A; Szekely, Tamas.

In: PLoS ONE, Vol. 5, No. 3, e9617, 10.03.2010.

Research output: Contribution to journalArticle

Sol, D, Garcia, N, Iwaniuk, A, Davis, K, Meade, A, Boyle, WA & Szekely, T 2010, 'Evolutionary divergence in brain size between migratory and resident birds', PLoS ONE, vol. 5, no. 3, e9617. https://doi.org/10.1371/journal.pone.0009617
Sol D, Garcia N, Iwaniuk A, Davis K, Meade A, Boyle WA et al. Evolutionary divergence in brain size between migratory and resident birds. PLoS ONE. 2010 Mar 10;5(3). e9617. https://doi.org/10.1371/journal.pone.0009617
Sol, D ; Garcia, N ; Iwaniuk, A ; Davis, K ; Meade, A ; Boyle, W A ; Szekely, Tamas. / Evolutionary divergence in brain size between migratory and resident birds. In: PLoS ONE. 2010 ; Vol. 5, No. 3.
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