Population Sampling
Definition
Collecting DNA profiles from multiple individuals of the same species at the scene and in the surrounding area to estimate how common a particular genotype is. Without population data, a match has no statistical context.
- Purpose
- Estimate how common a genotype is
- Scope
- Multiple individuals of the same species, scene and surrounding area
- Without it
- A match has no statistical context
Common questions
Why sample many individuals instead of just the evidentiary one?+
A single sample only tells you the genotype exists; sampling the broader population establishes how rare or common that genotype actually is, which is what gives a match its evidentiary weight.
What kind of case relies on this approach?+
Wildlife and plant forensic cases, such as the Palo Verde seed case, where matching a seed genotype to a specific plant depends on knowing how many other plants in the area could share that genotype.
Related terms
- Daubert Standard
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- Frye Standard
- The US legal test for admissibility of scientific evidence, originating from Frye v. United States (1923), which required that a technique be...
- Individualisation
- The ability to distinguish one individual organism from all others of the same species. In plant forensics, individualisation requires profiling a locus...
- Parkinsonia Florida
- The Blue Palo Verde, a thorny desert tree of the Sonoran Desert in the southwestern United States and northwestern Mexico. The species...
- RAPD (Randomly Amplified Polymorphic DNA)
- A PCR technique using short arbitrary primers (8-10 bases) that bind at multiple sites across a genome, generating a fingerprint pattern of...