Population Structure
Definition
The non-random distribution of genetic variation across subpopulations caused by limited gene flow between them. Different elephant herds separated by geography or habitat accumulate distinct allele frequencies over generations, creating a geographic genetic signal.
- Cause
- Limited gene flow between subpopulations
- Effect
- Distinct allele frequencies by subpopulation
- Example
- Elephant herds separated by geography
Common questions
How is population structure used forensically?+
Because geographically separated groups accumulate distinct allele frequency patterns, a sample's genetic profile can be compared against known regional patterns to estimate where an animal or plant likely originated.
Does population structure fade over time if groups reconnect?+
It can, since renewed gene flow between previously isolated groups gradually blends their allele frequencies, which is why the geographic signal is strongest where separation has been long-standing.
Related terms
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- Isoscape
- A map of isotope ratio variation across a geographic area, derived from systematic sampling of soil, water, plant, or mineral material; used...
- SNP (Single Nucleotide Polymorphism)
- A position in the genome where the nucleotide base differs between individuals. Genome-wide SNP panels are more powerful than STR panels for...
- Strontium-87/86 Ratio
- The ratio of two strontium isotopes in a sample, which mirrors the ratio in local bedrock and water. Because strontium substitutes for...
- STRUCTURE / ADMIXTURE
- Software tools that infer population structure by estimating each individual's fractional ancestry (membership coefficient) across K genetic clusters. Used to assign unknown...