Evolution in heterogeneous environments: Effects of migration on habitat specialization
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Richard Levins introduced fitness sets as a tool for investigating evolution within heterogeneous environments. Evolutionary game theory permits a synthesis and generalization of this approach by considering the evolutionary response of organisms to any scale of habitat heterogeneity. As scales of heterogeneity increase from fine to coarse, the evolutionary stable strategy (ESS) switches from a single generalist species to several species that become increasingly specialized on distinct habitats. Depending upon the organisms' ecology, the switch from one to two species may occur at high migration rates (relatively fine-grained environment), or may only occur at very low migration rates (coarse-grained environment). At the ESS, the evolutionary context of a species is the entire landscape, while its ecological context may be a single habitat.
Evolution towards the ESS can be represented with adaptive landscapes. In the absence of frequency-dependence, shifting from a single strategy ESS to a two strategy ESS poses the problem of evolving across valleys in the adaptive surface to occupy new peaks (hence, Sewell Wright's shifting balance theory). Frequency-dependent processes facilitate evolution across valleys. If a system with a two strategy ESS is constrained to possess a single strategy, the population may actually evolve a strategy that minimizes fitness. Because the population now rests at the bottom of a valley, evolution by natural selection can drive populations to occupy both peaks.
Keywordshabitat selection migration ESS fitness set frequency-dependent selection evolution of specialization landscape ecology adaptive surface
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- Abrams, P. A. (1987) Alternate models of character displacement. I. Displacement when there is competition for nutritionally essential resources.Evolution 41, 651–61.Google Scholar
- Abrams, P. A. (1990) Mixed responses to resource densities and their implications for character displacement.Evol. Ecol. 4, 93–102.Google Scholar
- Brown, J. S. (1990) Habitat selection as an evolutionary game.Evolution 44, 732–46.Google Scholar
- Brown, J. S. and Vincent, T. L. (1987) Coevolution as an evolutionary game.Evolution 41, 66–79.Google Scholar
- Holt, R. D. and Gaines, M. S. (1992) Analysis of adaptation in heterogeneous landscapes: implications for the evolution of fundamental niches.Evol. Ecol. 6, 433–47.Google Scholar
- Levins, R. (1968)Evolution in Changing Environments. Princeton University Press, Princeton, New Jersey.Google Scholar
- Matsuda, H. and Namba, T. (1989) Co-evolutionarily stable community structure in a patchy environment.J. Theor. Biol. 136, 229–43.Google Scholar
- Morris, D. W. (1992) Scales and costs of habitat selection in heterogeneous landscapes.Evol. Ecol. 6, 412–32.Google Scholar
- Pease, C. M., Lande, R. and Bull, J. J. (1989) A model of population growth, dispersal, and evolution in a changing environment.Ecology 70, 1657–64.Google Scholar
- Rice, W. R. and Salt, G. W. (1990) The evolution of reproductive isolation as a correlated character under sympatric conditions: experimental evidence.Evolution 44, 1140–52.Google Scholar
- Rosenzweig, M. L. (1978) Competitive speciation.Biol. J. Linn. Soc. 10, 275–89.Google Scholar
- Rosenzweig, M. L. (1981) A theory of habitat selection.Ecology 62, 327–35.Google Scholar
- Slatkin, M. (1980) Ecological character displacement.Ecology 61, 163–77.Google Scholar
- Taper, M. L. and Case, T. J. (1985) Quantitative genetic models for the coevolution of character displacement.Ecology 66, 355–71.Google Scholar
- Taper, M. L. and Case, T. J. (1992) Models of character displacement and the theoretical robustness of taxon cycles.Evolution 46, 317–33.Google Scholar
- Tilman, D. (1982)Resource Competition and Community Structure. Princeton University Press, Princeton, NJ, USA.Google Scholar
- Wright, W. (1977)Evolution and Genetics of Populations. Vol. 3, Experimental Results and Evolutionary Deductions. University of Chicago Press, Chicago, IL, USA.Google Scholar