Multilocus analysis of honeyeaters (Aves: Meliphagidae) highlights spatio-temporal heterogeneity in the influence of biogeographic barriers in the Australian monsoonal zone

Abstract

Multilocus studies in phylogenetics and comparative phylogeography have the power to explore a broader spectrum of evolutionary questions than either discipline has alone. To examine the origins of sympatry in a group of closely related birds of mostly mesic eucalypt woodlands in Australia, we reconstructed the relationships among species of Entomyzon and Melithreptus honeyeaters (Aves: Passeriformes: Meliphagidae) using a mitochondrial marker, ND2, and six non-coding nuclear loci (total 4719 base pairs). By sampling across the geographical range of each species, we studied not only their phylogenetic relationships to each other but also the spatial distribution of their genetic diversity. We tested several biogeographic hypotheses concerning the role of Pleistocene environmental change in Australia. Phylogenetic gene trees support the current understanding of E. cyanotis as the sister to Melithreptus. Non-monophyly of M. lunatus in Australia's southern temperate woodlands highlights the need for a revision of systematics within Melithreptus. Phylogeographic analysis of the three northern species in Australia's monsoon tropics, M. gularis, M. albogularis and E. cyanotis, suggests that the roles of the Carpentarian and Torresian Barriers in shaping geographic structure in each of the species have been more complex and temporally dynamic than earlier morphology-based arguments of vicariance had suggested. We discuss their roles as ecological filters as well as barriers.

Reticulation, divergence, and the phylogeography–phylogenetics continuum

“…Early sequencebased phylogeographic studies in babblers [Pomatostomus (58)] reported deep divergence across the CB relative to divergence within the eastern and western regions of the continent. Subsequent multilocus analyses of several avian systems revealed mostly Pleistocene divergences across the CB for congeners (59)(60)(61), as well as within species (62,63). Some studies examining divergence across the region have discovered clines (64) or complex reticulate patterns in the form of introgression; for example, in butcherbirds (Cracticus), populations east of the KTEB are introgressed with mtDNA from populations of arid-adapted species to the south that expanded during the last glacial maximum, whereas populations west of the KTEB are not introgressed (65).…”

Phylogeography of the antilopine wallaroo (Macropus antilopinus) across tropical northern Australia

“…However, phylogeographic studies of birds have shown contradictory patterns across the Carpentarian barrier: strong differentiation (Lee and Edwards 2008; Toon et al. 2010; Kearns et al. 2011) and the apparent absence of any impact on species differentiation (Kearns et al.…”

“…2010), “Bonaparte Gap or Barrier” (Toon et al. 2010), Daly River Drainage Barrier (Potter et al. 2012), and the Victoria River Drainage Barrier (Joseph and Omland 2009).…”

Eocene fossil is earliest evidence of flower-visiting by birds

“…All nectarivorous Passeriformes belong to the oscine clade, which has no fossil record before the Late Oligocene [9]. Calibrated molecular phylogenies including a comprehensive sampling of Nectariniidae and Meliphagidae do not exist, but analyses of smaller subsets suggest their diversification after the Eocene [22,23]. Fossils of crown group Psittaciformes are unknown before the Early Miocene [24], and molecular divergence estimates indicate that the flower-visiting parrot taxa likewise evolved after the Eocene [25].…”