From wiki
"DNA barcoding is a taxonomic method that uses a short genetic marker in an
organism's mitochondrial DNA to identify it as belonging to a particular
species. It is based on a relatively simple concept: most eukaryote cells
contain mitochondria and mitochondrial DNA (mtDNA) has a relatively fast
mutation rate, which results in significant variance in mtDNA sequences
between species and, in principle, a comparatively small variance within
species. However, because all mtDNA genes are maternally inherited (except
in a few bivalves[citation needed]), any occurrences of hybridization[1],
male-killing microoroganisms[2], cytoplasmic incompatibility-inducing
symbionts (e.g., Wolbachia)[2], horizontal gene transfer (such as via
cellular symbionts[3]), or other "reticulate" evolutionary phenomena in a
lineage can lead to misleading results (i.e., it is possible for two
different species to share mtDNA[4], or for one species to have more than
one mtDNA sequence exhibited among different individuals)[5][6]. A 648-bp
region of the cytochrome c oxidase subunit I gene (COI) was initially
proposed as a potential 'barcode'."
I can see how picking the number of individuals would be incredibly useful.
Cheers
Graham Turner
|