Abstract
Maintenance of substantial genetic variation for learning ability in many animal populations suggests that learning ability has fitness costs, but there is little empirical evidence for them. In this paper, we demonstrate an evolutionary trade-off between learning ability and competitive ability in Drosophila melanogaster. We show that the evolution of an improved learning ability in replicated experimental fly populations has been consistently associated with a decline of larval competitive ability, compared with replicated control populations. The competitive ability was not affected by crossing of the replicate populations within each selection regime, excluding differential inbreeding as a potential confounding factor. Our results provide evidence for a constitutive fitness cost of learning ability, i.e. one that is paid irrespective of whether or not the learning ability is actually used.
Full Text
The Full Text of this article is available as a PDF (84.0 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Dubnau J., Tully T. Gene discovery in Drosophila: new insights for learning and memory. Annu Rev Neurosci. 1998;21:407–444. doi: 10.1146/annurev.neuro.21.1.407. [DOI] [PubMed] [Google Scholar]
- Dukas R. Costs of memory: ideas and predictions. J Theor Biol. 1999 Mar 7;197(1):41–50. doi: 10.1006/jtbi.1998.0856. [DOI] [PubMed] [Google Scholar]
- Fellowes M. D., Kraaijeveld A. R., Godfray H. C. Trade-off associated with selection for increased ability to resist parasitoid attack in Drosophila melanogaster. Proc Biol Sci. 1998 Aug 22;265(1405):1553–1558. doi: 10.1098/rspb.1998.0471. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kraaijeveld A. R., Godfray H. C. Trade-off between parasitoid resistance and larval competitive ability in Drosophila melanogaster. Nature. 1997 Sep 18;389(6648):278–280. doi: 10.1038/38483. [DOI] [PubMed] [Google Scholar]
- Laughlin S. B. Energy as a constraint on the coding and processing of sensory information. Curr Opin Neurobiol. 2001 Aug;11(4):475–480. doi: 10.1016/s0959-4388(00)00237-3. [DOI] [PubMed] [Google Scholar]
- McGuire T. R., Hirsch J. Behavior-genetic analysis of Phormia regina: conditioning, reliable individual differences, and selection. Proc Natl Acad Sci U S A. 1977 Nov;74(11):5193–5197. doi: 10.1073/pnas.74.11.5193. [DOI] [PMC free article] [PubMed] [Google Scholar]
- doi: 10.1098/rspb.1998.0378. [DOI] [PMC free article] [Google Scholar]
- Pravosudov Vladimir V., Clayton Nicola S. A test of the adaptive specialization hypothesis: population differences in caching, memory, and the hippocampus in black-capped chickadees (Poecile atricapilla). Behav Neurosci. 2002 Aug;116(4):515–522. [PubMed] [Google Scholar]
- Santos M., Fowler K., Partridge L. On the use of tester stocks to predict the competitive ability of genotypes. Heredity (Edinb) 1992 Dec;69(Pt 6):489–495. doi: 10.1038/hdy.1992.163. [DOI] [PubMed] [Google Scholar]