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Sibling competition and the evolution of prenatal development rates
John D Lloyd1, Thomas E Martin
1Montana Cooperative Wildlife Research Unit, University of Montana, Missoula, MT 59812, USA. jlloyd@selway.umt.edu
Proceedings. Biological Sciences
|April 26, 2003
Summary
Sibling competition influences bird development rates. Extra-pair paternity negatively correlated with incubation length, suggesting evolutionary pressures on prenatal development, even after controlling for phylogeny.
Area of Science:
- Evolutionary biology
- Comparative genomics
- Animal behavior
Background:
- Sibling competition is a proposed driver of evolutionary variation in developmental rates.
- Understanding these pressures is key to comprehending life-history strategies.
Purpose of the Study:
- To investigate the influence of sibling competition on prenatal development across bird species.
- To analyze the correlations between indices of sibling competition and incubation length.
Main Methods:
- Comparative analysis of 70 bird species.
- Utilized extra-pair paternity, brood parasitism, and hatching asynchrony as indices of sibling competition.
- Controlled for phylogenetic effects in statistical analyses.
Main Results:
- Brood parasitism and hatching asynchrony showed correlations with incubation length, but these disappeared when controlling for phylogeny.
- Extra-pair paternity remained negatively correlated with incubation length after controlling for phylogeny.
- This suggests a potential link between extra-pair paternity and prenatal development, or indirect effects of adult mortality.
Conclusions:
- Mixed support for sibling competition's influence on prenatal development.
- Extra-pair paternity may represent a significant evolutionary pressure on incubation length.
- Life-history strategies involve complex trait linkages previously underestimated.