Barcode Gap
Definition
A barcode gap is separation between observed within-taxon and between-taxon genetic variation for a specified marker and reference dataset. Its presence and size depend on sampling and the taxa examined rather than providing one universal threshold for species identification.
- Context
- Species identification
For example, apparent separation in a small reference set can disappear when additional close relatives or within-species variants are represented.
The best reference match is not automatically the true species. Where resolution is limited, report the supported family, genus or complex instead of forcing a species name.
Related terms
- Barcode
- A selected genetic region used for taxonomic comparison with appropriate references. A taxonomic result depends on marker performance, reference quality and the...
- Introgression
- Transfer of genetic material across population or species boundaries through hybridisation and subsequent breeding. Mitochondrial markers can therefore be shared despite other...
- Metabarcoding
- Sequencing a mixture of DNA from many organisms simultaneously and using bioinformatics to assign each read to a taxon. For plant eDNA,...
- Voucher
- A documented specimen linked to observations or reference data and available for appropriate checking. Retained, documented material can support identification and later...
Explained in
- Non-Human DNA and Species IdentificationSeparation of observed within- and between-taxon variation for a specified marker and dataset.