DNA Barcoding in Avian Species with Special Reference to Taxonomically Wide Biogeographic Studies

Abstract

The establishment of DNA Barcode project in 2003, intending to construct a strong molecular identification tool via standardised genetic sequences, marked a new era of species identification and taxonomy. DNA barcoding so far proved to be simple and one of the excellent tools for identification of not only animals and plants but also the aves. The avian fauna represents an excellent contender for testing DNA barcode validation as aves or birds are amongst the most prominent groups in which a wide variety of morphological, genetic and behavioural studies have been conducted, thereby establishing a prime line of stable taxonomy. The idea of All Bird barcode initiative (ABBI) was conceived in 2005 with the intention to collect genetic data samples for deciphering a DNA barcode for over 10,000 known avian species. Regardless of hundreds of vigilant studies carried out during the past decade, there are still numerous avian species to be discovered and identified. ABBI is new hope for speedy identification of novel avian species and will also help in hundreds of new samples to be identified, thereby opening up new avenues for avian identification and its related scientific research. Adding on, with the advancement of the mt-DNA gene cytochrome c oxidase I (COI) library via DNA barcoding projects of avian species, there will be a better understanding of different avian realms and taxonomic territories. It will also serve as an unbiased taxonomic representation of different avian groups. The advantage is that the DNA barcode sequences deposited in these databases are of high quality and are standardised and therefore have fewer ambiguities, short sequence span, bidirectional sequencing and uniform sequence alignment. It has been observed that the rate of error on BOLD is much lower than on other databases, DNA barcoding in avian species in future will undoubtedly provide more specific species identification, recognition of cryptic species and tracing the line of avian evolution through different eras, deciphering their causes of divergence.