Related Experiment Videos
The effective size of a subdivided population
1Department of Zoology, University of British Columbia, Vancouver, Canada. whitlock@zoology.ube.ca
Genetics
|May 1, 1997
Summary
This study explores the long-term effective size (Ne) in subdivided populations, considering complex factors like varying fitness and migration. Population subdivision generally reduces effective population size compared to a single, panmictic population.
Area of Science:
- Population Genetics
- Evolutionary Biology
- Ecology
Background:
- Understanding effective population size (Ne) is crucial for evolutionary and conservation genetics.
- Previous models often simplified metapopulation dynamics, neglecting factors like differential deme fitness and intergenerational correlations.
Purpose of the Study:
- To derive a general formula for the long-term effective size (Ne) of a subdivided population.
- To unify various long-term Ne measures and apply them to complex metapopulation models.
Main Methods:
- Derivation of a general formula for Ne incorporating deme fitness, migration, extinction, and colonization.
- Application of the formula to catastrophic extinction and explicit metapopulation dynamics models.
- Analysis of demographic equilibrium conditions and Wright's FST.
Main Results:
- Demonstrated the equivalence of various long-term Ne measures.
- Provided a formula for metapopulation Ne: Ne = 1/(1 + var(upsilon)((1 - FST)/Nin)).
- Showed that population subdivision typically decreases Ne compared to a panmictic population.
Conclusions:
- The derived formula offers a unified approach to calculating Ne in complex metapopulations.
- Subdivision's impact on Ne is generally negative, contrary to some island model expectations.
- This framework is applicable to diverse ecological scenarios, including extinction and chaotic dynamics.