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[A review on mitochondrial DNA of avian].

Mitochondrial DNA as a genetic marker has been successfully applied to the study of molecular evolution of birds. The apparently maternal inheritance of mitochondrial DNA and its fast evolution in primary sequence has made it attractive in population and evolutionary genetics. Mitochondrial DNA of birds displays two characteristics not seen in other vertebrates mtDNA, that is, a novel gene order and the absence of an equivalent to the light-strand replication origin. The research on polymorphism of mtDNA can resolve phylogenies of birds both at lower and higher taxonomic levels. Here we review progress on avian molecular evolution in recent years,and make preliminary studies of the development in this field.