Abstract
This paper presents the first theoretical study of spatial genetic structure within nonuniformly distributed continuous plant populations. A novel individual-based model of isolation by distance was constructed to simulate genetic evolution within such populations. We found larger values of spatial genetic autocorrelations in highly clumped populations than in uniformly distributed populations. Most of this difference was caused by differences in mean dispersal distances, but aggregation probably also produced a slight increase in spatial genetic structure. Using an appropriate level of approximation of the continuous distribution of individuals in space, we assessed the potential effects of density, seed and pollen dispersal, generation overlapping, and overdominance selection at an independent locus, on fine-scale genetic structure, by varying them separately in a few particular cases with extreme clumping. When selfing was allowed, all these input variables influenced both aggregation and spatial genetic structure. Most variations in spatial genetic structure were closely linked to variations in clumping and/or local density. When selfing was not allowed, spatial genetic structure was lower in most cases.
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Selected References
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- Barbujani G. Autocorrelation of gene frequencies under isolation by distance. Genetics. 1987 Dec;117(4):777–782. doi: 10.1093/genetics/117.4.777. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Epperson B. K., Li T. Measurement of genetic structure within populations using Moran's spatial autocorrelation statistics. Proc Natl Acad Sci U S A. 1996 Sep 17;93(19):10528–10532. doi: 10.1073/pnas.93.19.10528. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Epperson B. K. Spatial autocorrelation of genotypes under directional selection. Genetics. 1990 Mar;124(3):757–771. doi: 10.1093/genetics/124.3.757. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Epperson B. K. Spatial distributions of genotypes under isolation by distance. Genetics. 1995 Aug;140(4):1431–1440. doi: 10.1093/genetics/140.4.1431. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hubbell S. P. Tree dispersion, abundance, and diversity in a tropical dry forest. Science. 1979 Mar 30;203(4387):1299–1309. doi: 10.1126/science.203.4387.1299. [DOI] [PubMed] [Google Scholar]
- Sokal R. R., Jacquez G. M., Wooten M. C. Spatial autocorrelation analysis of migration and selection. Genetics. 1989 Apr;121(4):845–855. doi: 10.1093/genetics/121.4.845. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sokal R. R., Wartenberg D. E. A Test of Spatial Autocorrelation Analysis Using an Isolation-by-Distance Model. Genetics. 1983 Sep;105(1):219–237. doi: 10.1093/genetics/105.1.219. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Turner M. E., Stephens J. C., Anderson W. W. Homozygosity and patch structure in plant populations as a result of nearest-neighbor pollination. Proc Natl Acad Sci U S A. 1982 Jan;79(1):203–207. doi: 10.1073/pnas.79.1.203. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wright S. Isolation by Distance. Genetics. 1943 Mar;28(2):114–138. doi: 10.1093/genetics/28.2.114. [DOI] [PMC free article] [PubMed] [Google Scholar]