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. 1980 Dec;77(12):7501–7505. doi: 10.1073/pnas.77.12.7501

Density-dependent selection in a random environment: An evolutionary process that can maintain stable population dynamics

Michael Turelli 1, Doug Petry 1
PMCID: PMC350533  PMID: 16592939

Abstract

A theoretical analysis of natural selection is presented in which fitnesses depend on population density and randomly varying environmental processes. The theory is based on a general, heuristic analysis of a pair of coupled, nonlinear, stochastic difference equations that describe the joint dynamics of allele frequencies and population size. Four main conclusions emerge from the investigation of a particular class of models: (i) growth rates at low population densities tend to increase; (ii) individual selection, given sufficient genetic flexibility, will mold growth rates at higher densities so that in spite of i, stable deterministic population dynamics are maintained; (iii) “more fit” genotypes cannot be simply characterized—in particular, the mean population size need not be increased; and (iv) genetic polymorphisms can be maintained in both haploid and diploid organisms.

Keywords: ecological genetics, r-selection, chaos, stochastic approximations

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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