Evol Ecol Res 11: 1251-1258 (2009)     Full PDF if your library subscribes.

Competition enhances spatial genetic differentiation

Esa Ranta¹†, Lars A. Bach², Veijo Kaitala¹, Mats Björklund³ and Per Lundberg²

¹Department of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland, ²Department of Theoretical Ecology, Lund University, Lund, Sweden and ³Animal Ecology/Department of Ecology and Evolution, Uppsala University, Uppsala, Sweden

Correspondence: L.A. Bach, Department of Theoretical Ecology, Ecology Building, Lund University, Sölvegatan 37, SE-22362 Lund, Sweden.
e-mail: lars.bach@teorekol.lu.se

ABSTRACT

Questions: How does the number of species in a community affect the level of genetic diversity of its constituent species? What is the relation between competitive interactions and the spatial distribution of genetic variation? When spatially structured, how is the genetic differentiation among subpopulations affected by competition and size of the community?

Model features and key assumptions: A model combining one-locus two-allele genetics with density-dependent regulation in population renewal (Ricker function) and demographic stochasticity is extended to incorporate S-species Lotka-Volterra competition. The system is embedded into a spatial context where 1000 populations are connected with stepping-stone dispersal. Beginning from random genotype composition, the system is simulated and the resulting community composition and genetic diversity across space are recorded.

Conclusions: Genetic differentiation in the ensemble increases with the number of competing species in the community (0.30 ± 0.13, normalized coefficient with 95% confidence limit) and with the intensity of pair-wise competition (0.20 ± 0.05) but most strongly with their interaction (0.62 ± 0.22). Although the system-wide differentiation increases, one finds that the process leads to local paucity of genotypes and hence a negative correlation between species diversity and local genetic diversity.

Keywords: community genetics, competition, F_ST, Lotka-Volterra, spatial structure, species diversity, stepping-stone.

DOWNLOAD A FREE, FULL PDF COPY
IF you are connected using the IP of a subscribing institution (library, laboratory, etc.)
or through its VPN.

 

        © 2009 Lars A. Bach. All EER articles are copyrighted by their authors. All authors endorse, permit and license Evolutionary Ecology Ltd. to grant its subscribing institutions/libraries the copying privileges specified below without additional consideration or payment to them or to Evolutionary Ecology, Ltd. These endorsements, in writing, are on file in the office of Evolutionary Ecology, Ltd. Consult authors for permission to use any portion of their work in derivative works, compilations or to distribute their work in any commercial manner.

       Subscribing institutions/libraries may grant individuals the privilege of making a single copy of an EER article for non-commercial educational or non-commercial research purposes. Subscribing institutions/libraries may also use articles for non-commercial educational purposes by making any number of copies for course packs or course reserve collections. Subscribing institutions/libraries may also loan single copies of articles to non-commercial libraries for educational purposes.

       All copies of abstracts and articles must preserve their copyright notice without modification.