Phylogenetic relationships in the Ranidae. Independent origin of direct development in the genera Philautus and Taylorana.
Phylogenetic relationships within a group of Ranidae were studied, particularly between the genera Philautus and Taylorana, to determine whether their original reproductive mode (direct development) appeared independently. To study these relationships, we used the DNA sequences of the 5' end of the gene coding for mitochondrial ribosome small subunit in 28 species. Parsimony analysis resulted in two equiparsimonious trees, 867 steps long (CI = 0.382; RI = 0.429). Data saturation was studied and we applied weighting (weight of 5 for transversions and 1 for transitions) to enhance the phylogenetic information. The tree we obtained (2,212 steps long, CI = 0.408; RI = 0.482) is best supported and allows us to determine clearly that direct development has appeared independently in Philautus and Taylorana. In addition, it is confirmed that the genus Rana sensu lato is heterogeneous. The genera Occidozyga and Phrynoglossus form a clade basal to all the group but this position is not supported. The inclusion of the Rhacophorinae in the Ranidae is confirmed. Finally, this study confirms that the relationships within the group Tomopterna sensu Boulenger, 1918 should be re-evaluated.