Evolution in Australasian Mangrove Forests: Multilocus PhylogeneticAnalysis of the Gerygone Warblers (Aves:Acanthizidae)

摘要

The mangrove forests of Australasia have many endemic bird species but their evolution and radiation in those habitats has been little studied. One genus with several mangrove specialist species is Gerygone (Passeriformes: Acanthizidae). The phylogeny of the Acanthizidae is reasonably well understood but limited taxon sampling for Gerygone has constrained understanding of its evolution and historical biogeography in mangroves. Here we report on a phylogenetic analysis of Gerygone based on comprehensive taxon sampling and a multilocus dataset of thirteen loci spread across the avian genome (eleven nuclear and two mitochondrial loci). Since Gerygone includes three species restricted to Australia's coastal mangrove forests, we particularly sought to understand the biogeography of their evolution in that ecosystem. Analyses of individual loci, as well as of a concatenated dataset drawn from previous molecular studies indicates that the genus as currently defined is not monophyletic, and that the Grey Gerygone (G. cinerea) from New Guinea should be transferred to the genus Acanthiza. The multilocus approach has permitted thenuanced view of the group's evolution into mangrove ecosystems havingoccurred on multiple occasions, in three non-overlapping time frames, mostlikely first by the G. magnirostris lineage, and subsequentlyfollowed by those of G. tenebrosa and G.levigaster.