Phylogeny of major lineages of suboscines (Passeriformes) analysed by nuclear DNA sequence data

Phylogenetic relationships among major groups of passeriform birds were stu died by analyses of nucleotide sequence data from two nuclear genes, c-myc and RAG-1. The results corroborated both the monophyly of the order Passeri formes, and the major dichotomy into oscine and suboscine passerines previo usly suggested based on syringeal morphology and DNA-DNA hybridizations. Th e representatives of the Old World suboscines (families Eurylaimidae, Phile pittidae and Pittidae) formed a monophyletic clade. The New World suboscine s clustered into two clades. The first contained Conopophaga (Conopophagida e), Furnarius (Furnariidae), Lepidocolaptes (Dendrocolaptidae), Thamnophilu s (Formicariidae), and Rhinocrypta (Rhinocryptidae). Previously, the monoph yly of this group has been inferred from their possession of a unique, "tra cheophone" syrinx, and from DNA-DNA hybridisation data. The second clade of New World suboscines includes Gubernetes and Muscivora (Tyrannidae), Phyto toma (Phytotomidae), Tityra (Cotingidae) and Pipra (Pipridae). This group o f families have been considered monophyletic based on morphology (although ambiguously) and DNA-DNA hybridisation. The sister group relationship of Ti tyra and Phytotoma supports the previously supposed cotingid affinity of Ph ytotoma. Nuclear DNA data also unambiguously group the lyrebirds Menura wit h the oscines. The presented results from the analysis of nuclear DNA agree well with morp hology and DNA-DNA hybridisation data. The precise age of the divergences s tudied herein are unknown but based on interpretations of the fossil record of passerine birds many of them might date back to the early Tertiary. The agreement between data from the nuclear DNA and other sources, along with the fact that neither of the studied genes showed sign of saturation, indic ate the great potential of these two nuclear genes to resolve very old dive rgences in birds.