Journal article
The Effects of Density Dependence and Immigration on Local Adaptation and Niche Evolution in a Black-Hole Sink Environment
Theoretical population biology, Vol.55(3), pp.283-296
06/1999
Handle:
https://hdl.handle.net/2376/105887
PMID: 10366553
Abstract
We examine the effects of density dependence and immigration on local adaptation in a “black-hole sink” habitat, i.e., a habitat in which isolated populations of a species would tend to extinction but where a population is demographically maintained by recurrent one-way migration from a separate source habitat in which the species persists. Using a diploid, one-locus model of a discrete-generation sink population maintained by immigration from a fixed source population, we show that a locally favored allele will spread when rare in the sink if the absolute fitness (or, in some cases, the geometric-mean absolute fitness) of heterozygotes with the favored allele is above one in the sink habitat. With density dependence, the criterion for spread can depend on the rate of immigration, because immigration affects local densities and, hence, absolute fitness. Given the successful establishment of a locally favored allele, it will be maintained by a migration-selection balance and the resulting polymorphic population will be sustained deterministically with either stable or unstable dynamics. The densities of stable polymorphic populations tend to exceed densities that would be maintained in the absence of the favored allele. With strong density regulation, spread of the favored allele may destabilize population dynamics. Our analyses show that polymorphic populations which form subsequent to the establishment of favorable alleles have the capacity to persist deterministically without immigration. Finally, we examined the probabilistic rate at which new favored alleles arise and become established in a sink population. Our results suggest that favored alleles are established most readily at intermediate levels of immigration.
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Details
- Title
- The Effects of Density Dependence and Immigration on Local Adaptation and Niche Evolution in a Black-Hole Sink Environment
- Creators
- Richard Gomulkiewicz - Department of Genetics & Cell Biology and Department of Pure & Applied Mathematics, P.O. Box 644234, Washington State University, Pullman, Washington, 99164-4234, f1E-mail: gomulki@wsu.eduf1Robert D Holt - Department of Systematics & Ecology and Natural History Museum, Dyche Hall, University of Kansas, Lawrence, Kansas, 66045, f2E-mail: predator@kuhub.cc.ukans.eduf2Michael Barfield - Division of Biological Sciences, Haworth Hall, University of Kansas, Lawrence, Kansas, 66045, f3E-mail: m-barfield@ukans.eduf3
- Publication Details
- Theoretical population biology, Vol.55(3), pp.283-296
- Academic Unit
- Biological Sciences, School of
- Publisher
- Elsevier Inc
- Identifiers
- 99900546777001842
- Language
- English
- Resource Type
- Journal article