Macroevolutionary forces, such as rare catastrophes, have repeatedly disrupted and reset the evolutionary trajectories of Earth's major organismal groups. The Cretaceous-Paleogene (K/Pg) extinction event, approximately 66 Ma, resulted in the demise of ∼75% of all species at the time, yet despite its magnitude, many major organismal lineages successfully passed through this mass extinction. The evolutionary origins of modern birds (crown-group Aves) remain a subject of substantial debate, as they are often thought to have undergone their primary diversification following the K/Pg boundary.
View Article and Find Full Text PDFBats are known reservoirs for many viruses of zoonotic potential and can tolerate or clear infections efficiently. They are important hosts for multiple coronaviruses and harbour ancestral lineages of coronaviruses known to cause diseases in both humans and animals. In this study, we describe a high-quality hybrid genome assembly of the Blyth's horseshoe bat Rhinolophus lepidus.
View Article and Find Full Text PDFAccurate identification of evolutionarily significant units of rare and threatened organisms provides a foundation for effective management and conservation. Up to seven subspecies of the critically endangered Yellow-crested Cockatoo (Cacatua sulphurea) have been described, four of which were commonly recognised pre-2014. In the absence of genotypic data, C.
View Article and Find Full Text PDFMany highly recognizable species lack genetic data important for conservation due to neglect over their hyperabundance. This likely applies to the Sulfur-crested Cockatoo (Cacatua galerita), one of the world's most iconic parrots. The species is native to Australia, New Guinea, and some surrounding Melanesian islands of the latter.
View Article and Find Full Text PDFSurveillance programs focused on bird ticks are often challenging owing to the difficulty in capturing and screening birds as well as the fact that ticks on avian hosts frequently occur at a low prevalence. Nonetheless, elucidating the diversity and host preferences of avian ticks is critical for understanding public health risks posed by both migratory and resident birds. The first nation-wide surveillance program of avian ticks was initiated to examine bird-tick interactions in Singapore, a key juncture along the East Asian-Australasian flyway.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
September 2024
Proc Natl Acad Sci U S A
May 2024
The origin of the German cockroach, , is enigmatic, in part because it is ubiquitous worldwide in human-built structures but absent from any natural habitats. The first historical records of this species are from ca. 250 years ago (ya) from central Europe (hence its name).
View Article and Find Full Text PDFMol Phylogenet Evol
August 2024
Rivers constitute an important biogeographic divide in vast areas of tropical rainforest, such as the Amazon and Congo Basins. Southeast Asia's rainforests are currently fragmented across islands divided by sea, which has long obscured their extensive history of terrestrial connectivity as part of a vast (but now submerged) subcontinent - Sundaland - during most of the Quaternary. The role of paleo-rivers in determining population structure in Sundaic rainforests at a time when these forests were connected remains little understood.
View Article and Find Full Text PDFBird collisions with buildings are responsible for a large number of bird deaths in cities around the world, yet they remain poorly studied outside North America. We conducted one of the first citywide fine-scale and landscape-scale analyses of bird-building collisions in Asia and used maximum entropy modeling (as commonly applied to species distribution modeling) in a novel way to assess the drivers of bird-building collisions in the tropical city-state of Singapore. We combined 7 years of community science observations with publicly available building and remote sensing data.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2024
The phylogeny and divergence timing of the Neoavian radiation remain controversial despite recent progress. We analyzed the genomes of 124 species across all Neoavian orders, using data from 25,460 loci spanning four DNA classes, including 5,756 coding sequences, 12,449 conserved nonexonic elements, 4,871 introns, and 2,384 intergenic segments. We conducted a comprehensive sensitivity analysis to account for the heterogeneity across different DNA classes, leading to an optimal tree of Neoaves with high resolution.
View Article and Find Full Text PDFAnimals (Basel)
January 2024
Wildlife crossings are implemented in many countries to facilitate the dispersal of animals among habitats fragmented by roads. However, the efficacy of different types of habitat corridors remains poorly understood. We used a comprehensive sampling regime in two lowland dipterocarp forest areas in peninsular Malaysia to sample pairs of small mammal individuals in three treatment types: (1) viaduct sites, at which sampling locations were separated by a highway but connected by a vegetated viaduct; (2) non-viaduct sites, at which sampling locations were separated by a highway and not connected by a viaduct; and (3) control sites, at which there was no highway fragmenting the forest.
View Article and Find Full Text PDFMountains are the world's most important centers of biodiversity. The Sino-Himalayan Mountains are global biodiversity hotspot due to their extremely high species richness and endemicity. Ample research investigated the impact of the Qinghai-Tibet Plateau uplift and Quaternary glaciations in driving species diversification in plants and animals across the Sino-Himalayan Mountains.
View Article and Find Full Text PDFDifferent genomic regions may reflect conflicting phylogenetic topologies primarily due to incomplete lineage sorting and/or gene flow. Genomic data are necessary to reconstruct the true species tree and explore potential causes of phylogenetic conflict. Here, we investigate the phylogenetic relationships of 4 Emberiza species (Aves: Emberizidae) and discuss the potential causes of the observed mitochondrial non-monophyly of Emberiza godlewskii (Godlewski's bunting) using phylogenomic analyses based on whole genome resequencing data from 41 birds.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2023
There is an urgent need for reliable data on the impacts of deforestation on tropical biodiversity. The city-state of Singapore has one of the most detailed biodiversity records in the tropics, dating back to the turn of the 19th century. In 1819, Singapore was almost entirely covered in primary forest, but this has since been largely cleared.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
October 2023
Echolocation, the detection of objects by means of sound waves, has evolved independently in diverse animals. Echolocators include not only mammals such as toothed whales and yangochiropteran and rhinolophoid bats but also fruit bats, as well as two bird lineages, oilbirds and swiftlets. In whales and yangochiropteran and rhinolophoid bats, positive selection and molecular convergence has been documented in key hearing-related genes, such as (), but few studies have examined these loci in other echolocators.
View Article and Find Full Text PDFis a successful disease vector due to its ability to survive in a wide range of habitats. Despite its ubiquity and impact on public health, little is known about its differential gene flow capabilities across different city habitats. We obtained a comprehensive dataset of >27,000 genome-wide DNA markers across 105 wild-caught individuals from Singapore, a dengue-endemic tropical city with heterogeneous landscapes from densely populated urban areas to forests.
View Article and Find Full Text PDFModern advances in DNA sequencing hold the promise of facilitating descriptions of new organisms at ever finer precision but have come with challenges as the major Codes of bionomenclature contain poorly defined requirements for species and subspecies diagnoses (henceforth, species diagnoses), which is particularly problematic for DNA-based taxonomy. We, the commissioners of the International Commission on Zoological Nomenclature, advocate a tightening of the definition of "species diagnosis" in future editions of Codes of bionomenclature, for example, through the introduction of requirements for specific information on the character states of differentiating traits in comparison with similar species. Such new provisions would enhance taxonomic standards and ensure that all diagnoses, including DNA-based ones, contain adequate taxonomic context.
View Article and Find Full Text PDFUnderstanding the relative contributions of historical and anthropogenic factors to declines in genetic diversity is important for informing conservation action. Using genome-wide DNA of fresh and historic specimens, including that of two species widely thought to be extinct, we investigated fluctuations in genetic diversity and present the first complete phylogenomic tree for all nine species of the threatened shorebird genus , known as whimbrels and curlews. Most species faced sharp declines in effective population size, a proxy for genetic diversity, soon after the Last Glacial Maximum (around 20,000 years ago).
View Article and Find Full Text PDFResearch on island species-area relationships (ISAR) has expanded to incorporate functional (IFDAR) and phylogenetic (IPDAR) diversity. However, relative to the ISAR, we know little about IFDARs and IPDARs, and lack synthetic global analyses of variation in form of these three categories of island diversity-area relationship (IDAR). Here, we undertake the first comparative evaluation of IDARs at the global scale using 51 avian archipelagic data sets representing true and habitat islands.
View Article and Find Full Text PDFResource partitioning may facilitate the coexistence of sympatric species with similar ecological requirements. Here, we study a colony of unusual echolocating birds called swiftlets, which nest underground on an island off the coast of Singapore. The colony comprises two congeneric swiftlet species, black-nest swiftlets () and edible-nest swiftlets (), nesting at high densities and in close proximity.
View Article and Find Full Text PDFHuman activities have precipitated a rise in the levels of introgressive gene flow among animals. The investigation of conspecific populations at different time points may shed light on the magnitude of human-mediated introgression. We used the red junglefowl Gallus gallus, the wild ancestral form of the chicken, as our study system.
View Article and Find Full Text PDFThe seasonal migration of birds is a fascinating natural wonder. Avian migratory behaviour changes are common and are probably a polygenic process as avian migration is governed by multiple correlated components with a variable genetic basis. However, the genetic and phenotypic changes involving migration changes are poorly studied.
View Article and Find Full Text PDFQuantifying the magnitude of the global extinction crisis is important but remains challenging, as many extinction events pass unnoticed owing to our limited taxonomic knowledge of the world's organisms. The increasing rarity of many taxa renders comprehensive sampling difficult, further compounding the problem. Vertebrate lineages such as birds, which are thought to be taxonomically well understood, are therefore used as indicator groups for mapping and quantifying global extinction.
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