Molecular phylogenetic analysis among species of Paridae, Remizidae and Aegithalos based on mtDNA sequences of COI and cyt b

The phylogeny of Paridae and allies has been studied intensively during past decades. However, the phylogenetic relationship among species tends to become increasingly controversial as different genetic markers emerge. In our study, the partial mitochondrial genes cytochrome b (cyt b) and cytochrome c oxidase subunit Ι (COI) were obtained from 15 species that included 10 tits, 4 long-tailed tits and a Chinese penduline tit. Analyses were conducted on the combined cyt b and COI sequences with maximum likelihood and Bayesian algorithms. Based on strong, congruent support among the different temporal partitions and models of sequence evolution, a highly resolved consensus of the relationships among Parids and their allies has been formed. The monophyly of Paridae and Remizidae is strongly supported. However, the monophyly of Paridae and Aegithalos is rejected. This agrees with previous studies using other molecular markers. Our results suggest the promotion of the subgenus Machlolophus from genus Parus to a separate genus. The phylogeny of Aegithalos is robust in the current study. However, by considering differences of both morphological and molecular characters within species, we conclude that more data are needed to define their phylogeny. Based on the patterns of taxonomic diversity and endemism, we suggest the southwestern mountain ranges of China might be the center of origin of the Aegithalos species. Divergence time estimates for the long-tailed tits range from the late Miocene to the Pleistocene (from 5.5 to 0.1 Mya) using a calibration of 2% divergence per million years. In a comparative sense, we found a congruent genetic differentiation among sympatric distribution taxa.