Phylogenetic Analysis of Selected Avian Species Based on Mitochondrial Gene Sequences Using Neighbor-Joining and Kimura 2-Parameter Model

الملخص

Mitochondrial DNA markers have been extensively used to study avian phylogenetics and to identify species, but their relative effectiveness across major orders has not been systematically evaluated. This paper examined 16 COI and 13 cytochrome b sequences that were retrieved in GenBank and they represented species of Galliformes, Anseriformes, and Columbiformes.. Phylogenetic reconstruction was performed using MEGA11 with node robustness established through 1,000 bootstrap replicas. Multiple sequence alignment, Kimura 2-parameter (K2P) distance estimation, and Neighbor-Joining phylogenetic reconstruction were done using MEGA11. Analysis of genetic distance and nucleotide composition was also done. Results showed a highly conserved intraspecific variation (0.000 -0.007) versus a good deal of interspecific and inter-order divergence (0.12 -0.35), establishing an obvious hierarchical pattern of divergent change. These two markers resolved three major order-level lineages with high bootstrap support (≥90%) and consistently recovered three major order-level lineages, indicating high topological congruence. Although shallow nodes demonstrated strong support, deeper basal relationships demonstrated weak confidence, potentially due to rapid evolutionary radiation or short length of sequences. The compositionally stable content of GC across taxa (mean: 47.248.6%). Together, these results support the use of COI and cytochrome b as highly reliable markers when it comes to the discrimination of avian species and phylogenetic inferences at shallow evolutionary depths. The given genetic distance thresholds provide practical standards of future DNA barcoding and taxonomic studies of birds.