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Within the Canidae, the African wild dog ( Lycaon pictus ) is the most specialized with regards to cursorial adaptations (specialized for running), having only four digits on their forefeet. In addition, this species is one of the few canids considered to be an obligate meat-eater, possessing a robust dentition for taking down large prey, and displays one of the most variable coat colorations amongst mammals. Here, we used comparative genomic analysis to investigate the evolutionary history and genetic basis for adaptations associated with cursoriality, hypercanivory, and coat color variation in African wild dogs. Genome-wide scans revealed unique amino acid deletions that suggest a mode of evolutionary digit loss through expanded apoptosis in the developing first digit. African wild dog-specific signals of positive selection also uncovered a putative mechanism of molar cusp modification through changes in genes associated with the sonic hedgehog (SHH) signaling pathway, required for spatial patterning of teeth, and three genes associated with pigmentation. Divergence time analyses suggest the suite of genomic changes we identified evolved ~1.7 Mya, coinciding with the diversification of large-bodied ungulates. Our results show that comparative genomics is a powerful tool for identifying the genetic basis of evolutionary changes in Canidae.

African lovebirds are popular pet parrots commonly hybridized by breeders leading to genetic admixture. Trade escapees and land use change have now led lovebirds to genetically admix in the wild. Sampling origin is therefore of utmost importance when deriving genetic data from lovebird species to reconstruct phylogeny or historical demographic events as the inclusion of taxa of hybrid origin is a source of spurious results. Here we present complete genomes of all nine currently recognized lovebird species. Each species is represented by an archival geo-referenced individual collected within their natural range.

Non‐native species can be introduced to novel environments such as cities via wildlife trade. These populations may have conservation value—particularly if they are of a species threatened in its native range. Genetic tools can help assess the fitness of introduced populations by indicating if they are (1) suffering the consequences typically associated with small, isolated populations derived from few founders (e.g., inbreeding, low genetic diversity) or (2) they demonstrate gene flow indicative of mixed‐origin founders, successful breeding, and/or continual introductions of conspecifics. Such data can inform management interventions in the ex‐situ environment and highlight potential contributions of introduced populations to native‐range conservation. We examined multiple metrics of genetic health of a non‐native population of ca. 200 critically endangered Yellow‐crested Cockatoos (Cacatua sulphurea)—native to the eastern Indonesian archipelago—introduced to Hong Kong (HK) from the 1960s. We sequenced whole genomes and mitochondrial DNA of HK cockatoos and compared them to native‐range C. sulphurea, Sulphur‐crested Cockatoos (C. galerita) from Australia, and representatives from five additional wild parrot populations. Results indicate HK's cockatoos may have as yet evaded the severe negative genetic consequences of small, isolated populations, and currently have Ne and nucleotide diversity comparable to other wild parrot populations. Their genetic characteristics conform to those of young, mixed‐origin, non‐native populations: high individual‐level variance in relatedness and inbreeding/outbreeding, and influences of admixture. Given that C. sulphurea subspecies exhibit very low genetic distances, HK's city cockatoos are worthy of further examination as a potential genetic reservoir and rescue source for C. sulphurea.

Understanding the genetic basis of convergence at broad phylogenetic scales remains a key challenge in biology. Kingfishers (Aves: Alcedinidae) are a cosmopolitan avian radiation with diverse colors, diets, and feeding behaviors—including the archetypal plunge-dive into water. Given the sensory and locomotor challenges associated with air-water transitions, kingfishers offer a powerful opportunity to explore the effects of convergent behaviors on the evolution of genomes and phenotypes, as well as direct comparisons between continental and island lineages. Here, we use whole-genome sequencing of 30 diverse kingfisher species to identify the genomic signatures associated with convergent feeding behaviors. We show that species with smaller ranges (i.e., on islands) have experienced stronger demographic fluctuations than those on continents, and that these differences have influenced the dynamics of molecular evolution. Comparative genomic analyses reveal positive selection and genomic convergence in brain and dietary genes in plunge-divers. These findings enhance our understanding of the connections between genotype and phenotype in a diverse avian radiation. An analysis of 30 diverse kingfisher species identifies genomic signatures associated with their convergent feeding behaviors, including plunge-diving.

The remarkable radiation of South American (SA) canids produced 10 extant species distributed across diverse habitats, including disparate forms such as the short-legged, hypercarnivorous bush dog and the long-legged, largely frugivorous maned wolf. Despite considerable research spanning nearly two centuries, many aspects of their evolutionary history remain unknown. Here, we analyzed 31 whole genomes encompassing all extant SA canid species to assess phylogenetic relationships, interspecific hybridization, historical demography, current genetic diversity, and the molecular bases of adaptations in the bush dog and maned wolf. We found that SA canids originated from a single ancestor that colonized South America 3.9 to 3.5 Mya, followed by diversification east of the Andes and then a single colonization event and radiation of Lycalopex species west of the Andes. We detected extensive historical gene flow between recently diverged lineages and observed distinct patterns of genomic diversity and demographic history in SA canids, likely induced by past climatic cycles compounded by human-induced population declines. Genome-wide scans of selection showed that disparate limb proportions in the bush dog and maned wolf may derive from mutations in genes regulating chondrocyte proliferation and enlargement. Further, frugivory in the maned wolf may have been enabled by variants in genes associated with energy intake from short-chain fatty acids. In contrast, unique genetic variants detected in the bush dog may underlie interdigital webbing and dental adaptations for hypercarnivory. Our analyses shed light on the evolution of a unique carnivoran radiation and how it was shaped by South American topography and climate change.

Abstract Many 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. Four subspecies are currently recognised based on morphology. Australian subspecies and populations are abundant, but several factors threaten those in New Guinea and Melanesia. Genetic data from natural populations are scarce—information that is vital to identifying evolutionarily significant units (ESUs) important for modern conservation planning. We used whole-genome resequencing to investigate patterns of differentiation, evolutionary affinities, and demographic history across C. galerita's distribution range to assess whether currently recognised subspecies represent ESUs. We complement this with an assessment of bioacoustic variation across the species' distribution landscape. Our results point to C. galerita sensu lato (s.l.) comprising two species. We restrict C. galerita sensu stricto (s.s.) to populations in Australia and the Trans-Fly ecodomain of southern New Guinea. The second species, recognised here as Cacatua triton, likely occurs over much of the rest of New Guinea. Restricting further discussion of intraspecific diversity in C. triton, we show that within C. galerita s.s. two ESUs exist, which align to Cacatua galerita galerita in eastern Australia and southern New Guinea and Cacatua galerita fitzroyi in northern and north-western Australia. We suggest that the evolution of these species and ESUs are linked to Middle and Late Pleistocene glacial cycles and their effects on sea level and preferential habitats. We argue that conservation assessments need updating, protection of preferential forest and woodland habitats are important and reintroductions require careful management to avoid possible negative hybridization effects of non-complementary lineages.

Islands are natural laboratories for studying patterns and processes of evolution. Research on island endemic birds has revealed elevated speciation rates and rapid phenotypic evolution in several groups (e.g. white-eyes, Darwin’s finches). However, understanding the evolutionary processes behind these patterns requires an understanding of how genotypes map to novel phenotypes. To date, there are few high-quality reference genomes for species found on islands. Here, we sequence the genome of one of Ernst Mayr’s “great speciators,” the collared kingfisher (Todiramphus chloris collaris). Utilizing high molecular weight DNA and linked-read sequencing technology, we assembled a draft high-quality genome with highly contiguous scaffolds (scaffold N50 = 19 Mb). Based on universal single-copy orthologs, we estimated a gene space completeness of 96.6% for the draft genome assembly. The population demographic history analyses reveal a distinct pattern of contraction and expansion in population size throughout the Pleistocene. Comparative genomic analysis of gene family evolution revealed that species-specific and rapidly expanding gene families in the collared kingfisher (relative to other Coraciiformes) are mainly involved in the ErbB signaling pathway and focal adhesion. Todiramphus kingfishers are a species-rich group that has become a focus of speciation research. This draft genome will be a platform for future taxonomic, phylogeographic, and speciation research in the group. For example, target genes will enable testing of changes in sensory structures associated with changes in vision and taste genes across kingfishers.

We report the first chromosome-length genome assemblies for three species in the mammalian order Pholidota: the white-bellied, Chinese, and Sunda pangolins. Surprisingly, we observe extraordinary karyotypic plasticity within this order and, in female white-bellied pangolins, the largest number of chromosomes reported in a Laurasiatherian mammal: 2n = 114. We perform the first karyotype analysis of an African pangolin and report a Y-autosome fusion in white-bellied pangolins, resulting in 2n = 113 for males. We employ a novel strategy to confirm the fusion and identify the autosome involved by finding the pseudoautosomal region (PAR) in the female genome assembly and analyzing the 3D contact frequency between PAR sequences and the rest of the genome in male and female white-bellied pangolins. Analyses of genetic variability show that white-bellied pangolins have intermediate levels of genome-wide heterozygosity relative to Chinese and Sunda pangolins, consistent with two moderate declines of historical effective population size. Our results reveal a remarkable feature of pangolin genome biology and highlight the need for further studies of these unique and endangered mammals.

The parrots (Psittaciformes, Aves) are a group of colorful, intelligent, long-lived birds with a wide range of body sizes and plumage colors and patterns.  One third of the parrot species is threatened with extinction due to habitat loss and the pet trade, a larger percentage than any other comparable bird order.  We present the complete genome sequences of 22 species of parrots from 14 genera and 3 families: Anodorhynchus hyacinthinus, Ara ararauna, Ara chloropterus, Ara glaucogularis, Ara militaris, Aratinga solstitialis, Aratinga weddellii, Cacatua leadbeateri, Eclectus roratus, Eupsittula pertinax, Guaruba guarouba, Lorius garrulus, Myiopsitta monachus, Nymphicus hollandicus, Pionus senilis, Psittacus erithacus, Psittacus timneh, Psitteuteles goldiei, Pyrrhura frontalis, Pyrrhura griseipectus, Pyrrhura molinae, Pyrrhura perlata.  Genomic data can be used to better understand species identity, hybridization, genetic diversity, and identification of animal products possibly derived from endangered species.

Reference genomes from representative species across families provide the critical infrastructure for research and conservation. The Cetacean Genomes Project (CGP) began in early 2020 to facilitate the generation of near error-free, chromosome-resolved reference genomes for all cetacean species. Towards that goal, and using the methods, goals and genome assembly quality standards of the Vertebrate Genomes Project (VGP), we generated 13 new reference genomes across eight of the 14 cetacean families. Additionally, we summarize the genome assembly characteristics for 18 species, including these newly-generated and five published genome assemblies that meet the completeness and quality standards. We infer ancestral linkage groups (ALG) for cetaceans, showing that the ancestral karyotype of 22 ALGs is largely conserved in extant species, except for Ziphiidae, and for Balaenidae and Kogiidae, which exhibit similar independent fusions. Gene annotation, characterization of historical demography, heterozygosity and runs of homozygosity (ROH) reveal important information for conservation applications. By comparing the new reference genomes to previous draft assemblies, we show that the reference genomes have enhanced characteristics that will support and promote scientific research. Specifically, the genomes improve resolution and characterization of repetitive elements, provide validation (or exclusion) of genes linked to complex traits, and allow more complete characterization of gene regions such as the highly complex Major Histocompatibility Complex (MHC) Class I and II gene clusters that are important for population health.