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Genome divergence is greatly influenced by gene flow during early stages of speciation. As populations differentiate, geographic barriers can constrain gene flow and so affect the dynamics of divergence and speciation. Current geography, specifically disjunction and continuity of ranges, is often used to predict the historical gene flow during the divergence process. We test this prediction in eight meliphagoid bird species complexes codistributed in four regions. These regions are separated by known biogeographical barriers across northern Australia and Papua New Guinea. We find that bird populations currently separated by terrestrial habitat barriers within Australia and marine barriers between Australia and Papua New Guinea have a range of divergence levels and probability of gene flow not associated with current range connectivity. Instead, geographic distance and historical range connectivity better predict divergence and probability of gene flow. In this dynamic environmental context, we also find support for a nonlinear decrease of the probability of gene flow during the divergence process. The probability of gene flow initially decreases gradually after a certain level of divergence is reached. Its decrease then accelerates until the probability is close to zero. This implies that although geographic connectivity may have more of an effect early in speciation, other factors associated with higher divergence may play a more important role in influencing gene flow midway through and later in speciation. Current geographic connectivity may then mislead inferences regarding potential for gene flow during speciation under a complex and dynamic history of geographic and reproductive isolation., (© 2018 John Wiley & Sons Ltd.)

Erythropygia scrub-robins and their allies are distributed throughout Africa, Europe, Southeast Asia, India, Madagascar and the Seychelles. This broad distribution, as well as the distribution of Erythropygia taxa across Africa, presents an interesting opportunity to explore the mechanisms by which this biogeographic distribution was achieved. Multilocus sequence data (3310 base pairs from two mitochondrial and two nuclear genes) were generated for all species of Erythropygia and Cercotrichas scrub-robins, as well as from genera previously shown to render Erythropygia paraphyletic. Using model-based phylogenetic methods and molecular clock dating, we constructed a time-calibrated molecular phylogenetic hypothesis for the lineage. Ancestral area reconstructions were performed on the phylogeny using probabilistic approaches implemented in LaGrange and BioGeoBEARS. Our results confirm that Erythropygia is not monophyletic, and that one of the two Erythropygia clades is more closely related to a clade of Asian and Indian Ocean islands distributed species. Overall, the Erythropygia and allies clade originated in Africa in the late Miocene c. 6.9 Ma. Subsequently, a number of overwater dispersals occurred to include an initial colonization of Southeast Asia, and an ensuing progression of colonizations from Southeast Asia to the Seychelles, from there to Madagascar, and from these Indian Ocean islands back to Southeast Asia. Within the two clades of Erythropygia, ancestral area reconstructions within Africa indicate a Southern Africa origin, with subsequent lineage divergence in each clade indicating northward colonization. Overall, this clade of non-migratory songbirds shows a remarkable number of trans-oceanic colonization events, that were possibly facilitated by wind-driven dispersal; repeated Africa to Asia colonizations, two of which occur in this clade, are exceptionally rare in birds. Also rare is our finding that colonization patterns in Africa indicate a southern to northern progression., (Copyright © 2014 Elsevier Inc. All rights reserved.)

The lories and lorikeets (Aves: Loriinae: Loriini) are a readily recognizable, discrete group of nectarivorous parrots confined to the Indo-Pacific region between Wallace’s Line and the Pitcairn Island group in the central-east Pacific Ocean. We present the first phylogenetic analysis of all currently recognized genera in the group using two mitochondrial and five nuclear loci. Our analyses suggest a New Guinean origin for the group at about 10 million years ago (95% HPD 4.8–14.8) but this origin must be interpreted within the context of that island’s complicated, recent geological history. That is, the origin and early diversification of the group may have taken place as New Guinea’s Central Cordillera arose and the final constituent terranes that form present-day New Guinea were accreted. The latter activity may have promoted dispersal as a key element in the group’s history. We have detected several instances of dispersal out of New Guinea that we argue constitute instances of founder-event speciation. Some phenotypically cohesive genera are affirmed as monophyletic but other genera are clearly in need of taxonomic dismantlement and reclassification. We recognize Parvipsitta Mathews, 1916 for two species usually placed in Glossopsitta and we advocate transfer of Chalcopsitta cardinalis into Pseudeos Peters, 1935. Other non-monophyletic genera such as Charmosyna , Psitteuteles and, probably, Trichoglossus , require improved taxon sampling and further phylogenetic analysis before their systematics can be resolved. Cursory examination of trait mapping across the group suggests that many traits are ancestral and of little use in determining genus-level systematics. [ABSTRACT FROM AUTHOR]