Avian diversification has been influenced by global climate change, plate tectonic movements, and mass extinction events. However, the impact of these factors on the diversification of the hyperdiverse perching birds (passerines) is unclear because family level relationships are unresolved and the timing of splitting events among lineages is uncertain. We analyzed DNA data from 4,060 nuclear loci and 137 passerine families using concatenation and coalescent approaches to infer a comprehensive phylogenetic hypothesis that clarifies relationships among all passerine families. Then, we calibrated this phylogeny using 13 fossils to examine the effects of different events in Earth history on the timing and rate of passerine diversification. Our analyses reconcile passerine diversification with the fossil and geological records; suggest that passerines originated on the Australian landmass ∼47 Ma; and show that subsequent dispersal and diversification of passerines was affected by a number of climatological and geological events, such as Oligocene glaciation and inundation of the New Zealand landmass. Although passerine diversification rates fluctuated throughout the Cenozoic, we find no link between the rate of passerine diversification and Cenozoic global temperature, and our analyses show that the increases in passerine diversification rate we observe are disconnected from the colonization of new continents. Taken together, these results suggest more complex mechanisms than temperature change or ecological opportunity have controlled macroscale patterns of passerine speciation.
Songbirds (oscine passerines) are the most species-rich and cosmopolitan bird group, comprising almost half of global avian diversity. Songbirds originated in Australia, but the evolutionary trajectory from a single species in an isolated continent to worldwide proliferation is poorly understood. Here, we combine the first comprehensive genome-scale DNA sequence data set for songbirds, fossil-based time calibrations, and geologically informed biogeographic reconstructions to provide a well-supported evolutionary hypothesis for the group. We show that songbird diversification began in the Oligocene, but accelerated in the early Miocene, at approximately half the age of most previous estimates. This burst of diversification occurred coincident with extensive island formation in Wallacea, which provided the first dispersal corridor out of Australia, and resulted in independent waves of songbird expansion through Asia to the rest of the globe. Our results reconcile songbird evolution with Earth history and link a major radiation of terrestrial biodiversity to early diversification within an isolated Australian continent.
The avian family Timaliidae is a species rich and morphologically diverse component of African and Asian tropical forests. The morphological diversity within the family has attracted interest from ecologists and evolutionary biologists, but systematists have long suspected that this diversity might also mislead taxonomy, and recent molecular phylogenetic work has supported this hypothesis. We produced and analyzed a data set of 6 genes and almost 300 individuals to assess the evolutionary history of the family. Although phylogenetic analysis required extensive adjustment of program settings, we ultimately produced a well-resolved phylogeny for the family. The resulting phylogeny provided strong support for major subclades within the family but extensive paraphyly of genera. Only 3 genera represented by more than 3 species were monophyletic. Biogeographic reconstruction indicated a mainland Asian origin for the family and most major clades. Colonization of Africa, Sundaland, and the Philippines occurred relatively late in the family's history and was mostly unidirectional. Several putative babbler genera, such as Robsonius, Malia, Leonardina, and Micromacronus are only distantly related to the Timaliidae.
Todiramphus chloris is the most widely distributed of the Pacific's ‘great speciators’. Its 50 subspecies constitute a species complex that is distributed over 16 000 km from the Red Sea to Polynesia. We present, to our knowledge, the first comprehensive molecular phylogeny of this enigmatic radiation of kingfishers. Ten Pacific Todiramphus species are embedded within the T. chloris complex, rendering it paraphyletic. Among these is a radiation of five species from the remote islands of Eastern Polynesian, as well as the widespread migratory taxon, Todiramphus sanctus. Our results offer strong support that Pacific Todiramphus, including T. chloris, underwent an extensive range expansion and diversification less than 1 Ma. Multiple instances of secondary sympatry have accumulated in this group, despite its recent origin, including on Australia and oceanic islands in Palau, Vanuatu and the Solomon Islands. Significant ecomorphological and behavioural differences exist between secondarily sympatric lineages, which suggest that pre-mating isolating mechanisms were achieved rapidly during diversification. We found evidence for complex biogeographic patterns, including a novel phylogeographic break in the eastern Solomon Islands that separates a Northern Melanesian clade from Polynesian taxa. In light of our results, we discuss systematic relationships of Todiramphus and propose an updated taxonomy. This paper contributes to our understanding of avian diversification and assembly on islands, and to the systematics of a classically polytypic species complex.
Dry forest bird communities in South America are often fragmented by intervening mountains and rainforests, generating high local endemism. The historical assembly of dry forest communities likely results from dynamic processes linked to numerous population histories among codistributed species. Nevertheless, species may diversify in the same way through time if landscape and environmental features, or species ecologies, similarly structure populations. Here we tested whether six co-distributed taxon pairs that occur in the dry forests of the Tumbes and Marañón Valley of northwestern South America show concordant patterns and modes of diversification. We employed a genome reduction technique, double-digest restriction site-associated DNA sequencing, and obtained 4407-7186 genomewide SNPs. We estimated demographic history in each taxon pair and inferred that all pairs had the same best-fit demographic model: isolation with asymmetric gene flow from the Tumbes into the Marañón Valley, suggesting a common diversification mode. Overall, we also observed congruence in effective population size (N ) patterns where ancestral N were 2.9-11.0× larger than present-day Marañón Valley populations and 0.3-2.0× larger than Tumbesian populations. Present-day Marañón Valley N was smaller than Tumbes. In contrast, we found simultaneous population isolation due to a single event to be unlikely as taxon pairs diverged over an extended period of time (0.1-2.9 Ma) with multiple nonoverlapping divergence periods. Our results show that even when populations of codistributed species asynchronously diverge, the mode of their differentiation can remain conserved over millions of years. Divergence by allopatric isolation due to barrier formation does not explain the mode of differentiation between these two bird assemblages; rather, migration of individuals occurred before and after geographic isolation.
Aim Kingfishers are the most species‐rich family in the avian order, Coraciiformes. Their modern distribution is largely pantropical; however, global species diversity is unevenly distributed. For example, 19 of the 114 kingfisher species occur in New Guinea, whereas only six species occur in the entire New World. This disparity in diversity suggests regions with high species richness could represent the ancestral range of the family. Furthermore, some clades of kingfishers (Ceyx, Todiramphus) are thought to be the product of rapid insular radiations. Here, we investigated the biogeographical history and speciation dynamics of the Alcedinidae using a fully sampled molecular phylogeny. Location Global. Taxon Kingfishers (Aves: Coraciiformes: Alcedinidae). Methods We inferred a time‐calibrated, species‐level phylogeny of kingfishers from DNA sequences. Our data set comprised up to five Sanger‐sequenced gene regions for all species (one mitochondrial, one nuclear exon and three nuclear introns), plus genus‐level sampling of thousands of ultraconserved elements. We estimated ancestral ranges of kingfishers and explored macroevolutionary rate shifts and diversification rates across the phylogeny. Results We recovered a well‐supported phylogeny of kingfishers that includes 34 species whose phylogenetic relationships were not previously known. The pygmy‐kingfishers (subfamily Alcedininae) sit on a long branch, sister to all other kingfishers: subfamilies Cerylinae and Halcyoninae. Crown‐group kingfishers originated in the Indomalayan region approximately 27 Ma with subsequent colonizations into Africa (six times), the New World (twice) and Australasia (representing several major radiations). Main conclusions Oceanic islands of Wallacea, the Philippines and Oceania promoted multiple, independent radiations in three species‐rich genera: Ceyx, Actenoides and Todiramphus. In particular, Todiramphus showed patterns consistent with explosive and recent diversification relative to the background speciation rate of non‐Todiramphus kingfishers, which we attribute to recent colonization of the vast archipelagos of Wallacea and the Pacific.
We reconstructed the phylogeographic relationships of the Variable Dwarf-Kingfisher (Ceyx lepidus) using DNA sequence data. Maximum likelihood and Bayesian analysis methods were used to reconstruct trees from a multilocus data set of all named subspecies of the Ceyx lepidus species complex. The concatenated data-set length was , base pairs and included two mitochondrial genes and two noncoding nuclear introns. Support for the monophyly of C. lepidus was equivocal. We instead found support for a clade including all C. lepidus subspecies plus two endemic Philippine taxa: C. argentatus and C. cyanopectus. Relationships among subspecific taxa were not well resolved, and many nodes were collapsed into polytomies suggesting a rapid and widespread colonization. In situ diversification likely played a role in generating current diversity within four archipelagos: the Philippines, Malukus, Bismarcks, and Solomons. Some biogeographic patterns recovered for the Solomon Islands taxa match those seen in other bird species, such as the close relationship of taxa on Bougainville, Choiseul, and Isabel. By contrast, the sister relationship between populations on Guadalcanal and the New Georgia Group is novel. We discuss species limits and make taxonomic recommendations to treat all subspecies of C. lepidus as species.
With more than 70 described subspecies distributed from Java to Fiji, the Golden Whistler species complex (Aves: Pachycephala pectoralis/melanura) is the world's most geographically variable bird species. We sequenced ten genes totalling 5743 bp from 202 individuals and 32 nominal subspecies, mostly from the Australasian and Polynesian lineages. We used concatenated maximum likelihood and Bayesian inference, as well as coalescent species tree analysis, to reconstruct a phylogeny. The resulting phylogeny is the most densely sampled and robust estimate of this group's evolutionary history to date and many novel relationships are revealed. The ingroup comprised three well‐supported clades. An Australasian clade inclusive of Vanuatu was sister to a clade including the Bismarck Archipelago, the Solomon Islands, and the Polynesian taxa minus Vanuatu, and sister to these two clades was Pachycephala citreogaster collaris of the Louisiade Archipelago. Some species‐level taxa endemic to the Pacific were found to be embedded in the ingroup (e.g. Pachycephala feminina, Pachycephala flavifrons, and Pachycephala jacquinoti), whereas others were found to be outside of the species complex (e.g. Pachycephala implicata). Generally, most nodes in the tree had strong support with the exception of several Polynesian lineages whose relationships remain equivocal. Relationships within each clade are discussed in detail, and current taxonomic treatments are critiqued in light of our results. © 2013 The Linnean Society of London
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.