CAJ | 학술논문

Background: Historically the babblers have been assigned to the family Timaliidae but several recent studies have attempted to rest the taxonomy of this diverse passerine assemblage on a more ifrm evolutionary footing. The result has been a major rearrangement of the group. A well?supported and comprehensive phylogeny for this widespread avian group is an important part of testing evolutionary and biogeographic hypotheses, especially in Asia where the babblers are a key component of many forest ecosystems. However, the genusLiocichla is poorly represented in these prior studies of babbler systematics. Methods: We used a multilocus molecular genetic approach to generate a phylogenetic hypothesis for all ifve cur?rently recognized species in the avian genusLiocichla. Multilocus DNA sequence data was used to construct individ?ual gene trees using maximum likelihood and species trees were estimated from gene trees using Bayesian analyses. Divergence dates were obtained using a molecular clock approach. Results: Molecular data estimate a probable window of time for the origin for theLiocichla from the mid to late Miocene, between 5.55 and 12.87 Ma. Despite plumage similarities between the insular Taiwan endemic,L. steerii, and the continentalL. bugunorum andL. omeiensis, molecular data suggest thatL. steerii is the sister taxon to all continen?talLiocichla. The continentalLiocichla are comprised of two lineages; a lineage containingL. omeiensis andL. buguno-rum and a lineage comprised ofL. phoenicea andL. ripponi. The comparatively early divergence ofL. steerii within the Liocichla may be illusory due to extinct and therefore unsampled lineages.L. ripponi andL. phoenicea are parapatric with a Pleistocene split (0.07–1.88 Ma) occurring between an Eastern HimalayanL. phoenicea and a Northern Indo?china distributedL. ripponi.L. bugunorum andL. omeiensis underwent a similar split between the Eastern Himalaya (L. bugunorum) and Central China (L. omeiensis) divided by the Hengduan Mountains. Conclusions: This study supports an origin of theLiocichla occurring sometime prior to the Miocene–Pliocene boundary, a period of signiifcant climatic upheaval in Asia. The biogeographical patterns within theLiocichla mirror those of other birds in the region and allude to common geological and climatic drivers of avian diversiifcation in Asia.