DNA barcoding uses a single mitochondrial gene, COI, to identify species and discover new ones. It aims to create a comprehensive database for species identification. While it has potential, it is controversial due to its reliance on a single gene, which may not always reflect species boundaries. Critics argue that DNA barcoding can lead to overestimation of species divergence and may overlook new or rapidly diverged species. The study by Hebert et al. (2004) tested the resolution of COI barcoding in North American birds, finding that COI sequences between closely related species were significantly more divergent than within species. However, this study did not compare sister species, which are the most closely related, and thus may not fully assess the accuracy of DNA barcoding. The analysis also found that intraspecific variation in COI was not always correlated with geographic distance, suggesting that high levels of intraspecific divergence are uncommon. However, this assumption may not hold for all bird species. The study also highlights the importance of considering other factors, such as morphology and ecology, in species identification. DNA barcoding is not a substitute for traditional taxonomy and should be used in conjunction with other methods. The utility of DNA barcoding in tropical regions, where it could have maximum value, remains uncertain. Overall, DNA barcoding has potential but requires further refinement and integration with existing taxonomic practices to be effective.DNA barcoding uses a single mitochondrial gene, COI, to identify species and discover new ones. It aims to create a comprehensive database for species identification. While it has potential, it is controversial due to its reliance on a single gene, which may not always reflect species boundaries. Critics argue that DNA barcoding can lead to overestimation of species divergence and may overlook new or rapidly diverged species. The study by Hebert et al. (2004) tested the resolution of COI barcoding in North American birds, finding that COI sequences between closely related species were significantly more divergent than within species. However, this study did not compare sister species, which are the most closely related, and thus may not fully assess the accuracy of DNA barcoding. The analysis also found that intraspecific variation in COI was not always correlated with geographic distance, suggesting that high levels of intraspecific divergence are uncommon. However, this assumption may not hold for all bird species. The study also highlights the importance of considering other factors, such as morphology and ecology, in species identification. DNA barcoding is not a substitute for traditional taxonomy and should be used in conjunction with other methods. The utility of DNA barcoding in tropical regions, where it could have maximum value, remains uncertain. Overall, DNA barcoding has potential but requires further refinement and integration with existing taxonomic practices to be effective.