DNA barcoding aims at providing an efficient method for specieslevel
separation using a partial sequence of the mitochondrial COI gene. The
efficiency of the barcode in separating species is based on the amount of
genetic distance among samples. While in many taxa the species can be
efficiently identified through the barcode, other situations cannot be treated by
this approach. The causes for such discrepancy appear to be mostly related to
the nature of speciation events and to the different roles of the genetic system,
natural selection and evolutionary time. Thus, DNA barcode represent just
one important descriptor in the framework of the multidimensional species
approach.
