Sequence Comparison Of Mitochondrial DNA And Phylogenetic Evolution In Raptors And Nighthawks

The phylogenetic relationship of raptors and nighthawks were estimated by mitochondrial rRNA gene sequences in this study by comparing the partial basepair fragments of 12S rRNA and 16S rRNA genes among 5 species of Falcoiformes, 3 species of Strigiformes and 1 species of Caprimulgiformes sequenced in this experement, together with the homologous segments of mtDNA in other 17 species of birds downloaded from GenBank. Our result firstly reported the complete 12S rRNA genes from Accipiter virgatus,Otus scops and Otus spilocephalus, and reported the partial genes of 12S rRNA and 16S rRNA from Accipiter trivirgatus,Falco tinnunculus,Otus spilocephalus and Caprimulgus indicus, which could provide some new gene data for the research of phylogenetic relationship in raptors and nighthawks.Our analyses showed that results of constructed phylogenetic trees could not be influenced by different parameter models, p-distance and Kimma 2-Parameter distance, but would be changed by different methods for construction of phylogenetic tree. For example, the phylogenetic trees constructed by NJ, ME, or MP methods basing on 12S rRNA complete sequence, indicated Falconidae branched off prior to the other avian, but the UPGMA tree placed Falco peregrine into a single branch and formed sister group with Accipitridae species and Strigiformes specie. The reason of this phenomenon might be that the UPGMA method could not be used for constructing phylogenetic branches with different evolution rate. Our research showed that the genetic variation of raptors and nighthawks was abundant and that the number of transitions and transversions in 12S rRNA and 16S rRNA genes increased gradually with p-distance and appeared not to be saturated, which indicated the phylogenetic relationship made in this study was really reflected.Our study showed that Accipitridae was closer to Strigiformes and Caprimulgiformes than to Falconidae, which was different to the traditional classification system. NJ, ME or MP Phylogenetic trees basing on 12S-b genes,12S rRNA genes and 12S rRNA and 16S rRNA combined sequence supported that Falconidae branched into one clade firstly, then species of Strigiformes branched into one clade, species of Caprimulgiformes into another clade containing, and finally Accipitridae branched off at the tail of phylogenetic tree. Our data also suggeted that genetic distance between Accipitridae and Falconidae was longer than the average. However, our study on the phylogenetic relationship among the Accipitridae ( in Falcoiformes), Ardeidae (Ciconiiformes), Estrildidae and Corvidae (Passeriformes), Caprimulgidae (Caprimulgiformes), and Strigidae and Tytonidae (Strigiformes), the results did not support Sibley's viewpoint which conbined Falcoiformes...