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1.
PLoS One ; 15(10): e0238729, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33048933

RESUMO

The Amazonian and Atlantic Forest share several organisms that are currently isolated but were continuously distributed during the Quaternary period. As both biomes are under different climatic regimes, paleoclimatic events may have modulated species' niches due to a lack of gene flow and imposing divergent selection pressure. Here, we assessed patterns of ecological niche overlap in 37 species of birds with disjunct ranges between the Amazonian and Brazilian Atlantic Forests. We performed niche overlap analysis and ecological niche modeling using four machine-learning algorithms to evaluate whether species' ecological niches evolved or remained conserved after the past South American biogeographic events. We found a low niche overlap among the same species populations in the two biomes. However, niche similarity tests showed that, for half of the species, the overlap was higher than the ones generated by our null models. These results lead us to conclude that niche conservatism was not enough to avoid ecological differentiation among species even though detected in many species. In sum, our results support the role of climatic changes in late-Pleistocene-that isolated Amazon and the Atlantic Forest-as a driving force of ecological differences among the same species populations and potential mechanism of current diversification in both regions.


Assuntos
Evolução Biológica , Aves/classificação , Aves/genética , Ecossistema , Floresta Úmida , Animais , Biodiversidade , Brasil , Mudança Climática/história , Fluxo Gênico , Especiação Genética , História Antiga , Filogeografia , Dinâmica Populacional/história
2.
BMC Evol Biol ; 20(1): 113, 2020 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-32883209

RESUMO

BACKGROUND: The study of speciation has expanded with the increasing availability and affordability of high-resolution genomic data. How the genome evolves throughout the process of divergence and which regions of the genome are responsible for causing and maintaining that divergence have been central questions in recent work. Here, we use three pairs of species from the recently diverged bee hummingbird clade to investigate differences in the genome at different stages of speciation, using divergence times as a proxy for the speciation continuum. RESULTS: Population measures of relative differentiation between hybridizing species reveal that different chromosome types diverge at different stages of speciation. Using FST as our relative measure of differentiation we found that the sex chromosome shows signs of divergence early in speciation. Next, small autosomes (microchromosomes) accumulate highly diverged genomic regions, while the large autosomes (macrochromosomes) accumulate genomic regions of divergence at a later stage of speciation. CONCLUSIONS: Our finding that genomic windows of elevated FST accumulate on small autosomes earlier in speciation than on larger autosomes is counter to the prediction that FST increases with size of chromosome (i.e. with decreased recombination rate), and is not represented when weighted average FST per chromosome is compared with chromosome size. The results of this study suggest that multiple chromosome characteristics such as recombination rate and gene density combine to influence the genomic locations of signatures of divergence.


Assuntos
Evolução Biológica , Aves/classificação , Especiação Genética , Animais , Cromossomos/genética , Genoma , Genômica , Hibridização Genética , Cromossomos Sexuais/genética
3.
PLoS Biol ; 18(8): e3000801, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32810126

RESUMO

The evolutionary radiation of birds has produced incredible morphological variation, including a huge range of skull form and function. Investigating how this variation arose with respect to non-avian dinosaurs is key to understanding how birds achieved their remarkable success after the Cretaceous-Paleogene extinction event. Using a high-dimensional geometric morphometric approach, we quantified the shape of the skull in unprecedented detail across 354 extant and 37 extinct avian and non-avian dinosaurs. Comparative analyses reveal fundamental differences in how skull shape evolved in birds and non-avian dinosaurs. We find that the overall skull shape evolved faster in non-avian dinosaurs than in birds across all regions of the cranium. In birds, the anterior rostrum is the most rapidly evolving skull region, whereas more posterior regions-such as the parietal, squamosal, and quadrate-exhibited high rates in non-avian dinosaurs. These fast-evolving elements in dinosaurs are strongly associated with feeding biomechanics, forming the jaw joint and supporting the jaw adductor muscles. Rapid pulses of skull evolution coincide with changes to food acquisition strategies and diets, as well as the proliferation of bony skull ornaments. In contrast to the appendicular skeleton, which has been shown to evolve more rapidly in birds, avian cranial morphology is characterised by a striking deceleration in morphological evolution relative to non-avian dinosaurs. These results may be due to the reorganisation of skull structure in birds-including loss of a separate postorbital bone in adults and the emergence of new trade-offs with development and neurosensory demands. Taken together, the remarkable cranial shape diversity in birds was not a product of accelerated evolution from their non-avian relatives, despite their frequent portrayal as an icon of adaptive radiations.


Assuntos
Evolução Biológica , Aves/anatomia & histologia , Dinossauros/anatomia & histologia , Crânio/anatomia & histologia , Animais , Fenômenos Biomecânicos , Aves/classificação , Aves/fisiologia , Dinossauros/classificação , Dinossauros/fisiologia , Extinção Biológica , Comportamento Alimentar/fisiologia , Fósseis/anatomia & histologia , Filogenia , Crânio/fisiologia
4.
Nat Commun ; 11(1): 4185, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32826898

RESUMO

Adaptive responses to ecological uncertainty may affect the dynamics of interspecific interactions and shape the course of evolution within symbioses. Obligate avian brood parasites provide a particularly tractable system for understanding how uncertainty, driven by environmental variability and symbiont phenology, influences the evolution of species interactions. Here, we use phylogenetically-informed analyses and a comprehensive dataset on the behaviour and geographic distribution of obligate avian brood parasites and their hosts to demonstrate that increasing uncertainty in thermoregulation and parental investment of parasitic young are positively associated with host richness and diversity. Our findings are consistent with the theoretical expectation that ecological risks and environmental unpredictability should favour the evolution of bet-hedging. Additionally, these highly consistent patterns highlight the important role that ecological uncertainty is likely to play in shaping the evolution of specialisation and generalism in complex interspecific relationships.


Assuntos
Aves/fisiologia , Interações Hospedeiro-Parasita/fisiologia , Parasitos/fisiologia , Incerteza , Animais , Biodiversidade , Coevolução Biológica , Aves/classificação , Clima , Comportamento de Nidação , Parasitos/classificação , Filogenia , Fatores de Risco , Especificidade da Espécie
5.
PLoS One ; 15(8): e0238034, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32857780

RESUMO

Wind energy offers substantial environmental benefits, but wind facilities can negatively impact wildlife, including birds and bats. Researchers and managers have made major efforts to chronicle bird and bat mortality associated with wind facilities, but few studies have examined the patterns and underlying mechanisms of spatial patterns of fatalities at wind facilities. Understanding the horizontal fall distance between a carcass and the nearest turbine pole is important in designing effective search protocols and estimating total mortality. We explored patterns in taxonomic composition and fall distance of bird and bat carcasses at wind facilities in the Northeastern United States using publicly available data and data submitted to the US Fish and Wildlife Service under scientific collecting and special purpose utility permits for collection and study of migratory birds. Forty-four wind facilities reported 2,039 bird fatalities spanning 128 species and 22 facilities reported 418 bat fatalities spanning five species. Relative to long-distance migratory birds, short-distance migrants were found farther from turbines. Body mass of birds and bats positively influenced fall distance. Turbine size positively influenced fall distance of birds and bats when analyzed collectively and of birds when analyzed separately from bats. This suggests that as turbines increase in size, a greater search radius will be necessary to detect carcasses. Bird and bat fall distance distributions were notably multimodal, but only birds exhibited a high peak near turbine bases, a novel finding we attribute to collisions with turbine poles in addition to blades. This phenomenon varied across bird species, with potential implications for the accuracy of mortality estimates. Although pole collisions for birds is intuitive, this phenomenon has not been formally recognized. This finding may warrant an updated view of turbines as a collision threat to birds because they are a tall structure, and not strictly as a function of their motion.


Assuntos
Aves/fisiologia , Quirópteros/fisiologia , Energia Renovável , Migração Animal , Animais , Aves/classificação , Quirópteros/classificação , Conservação dos Recursos Naturais , Mortalidade , Vento
6.
Proc Natl Acad Sci U S A ; 117(31): 18557-18565, 2020 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-32690693

RESUMO

Breeding timed to match optimal resource abundance is vital for the successful reproduction of species, and breeding is therefore sensitive to environmental cues. As the timing of breeding shifts with a changing climate, this may not only affect the onset of breeding but also its termination, and thus the length of the breeding period. We use an extensive dataset of over 820K nesting records of 73 bird species across the boreal region in Finland to probe for changes in the beginning, end, and duration of the breeding period over four decades (1975 to 2017). We uncover a general advance of breeding with a strong phylogenetic signal but no systematic variation over space. Additionally, 31% of species contracted their breeding period in at least one bioclimatic zone, as the end of the breeding period advanced more than the beginning. We did not detect a statistical difference in phenological responses of species with combinations of different migratory strategy or number of broods. Nonetheless, we find systematic differences in species responses, as the contraction in the breeding period was found almost exclusively in resident and short-distance migrating species, which generally breed early in the season. Overall, changes in the timing and duration of reproduction may potentially lead to more broods co-occurring in the early breeding season-a critical time for species' reproductive success. Our findings highlight the importance of quantifying phenological change across species and over the entire season to reveal shifts in the community-level distribution of bird reproduction.


Assuntos
Migração Animal/fisiologia , Aves/fisiologia , Reprodução/fisiologia , Animais , Aves/classificação , Mudança Climática , Finlândia , Filogenia , Estações do Ano
7.
Parasitol Res ; 119(10): 3377-3390, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32638100

RESUMO

The hypersaline lagoons located in evaporation basins or salars (salt flats) in the Atacama Desert are extreme environments harbouring a specialised biota able to survive harsh conditions for life. The knowledge of the parasitic biodiversity of these extreme habitats is still scarce despite their functional importance in regulating relevant non-economic services like habitats of waterbirds. The present study is the first report on the cestode infection of Artemia franciscana Kellogg in Salar de Atacama lagoons in northern Chile. A total of 23 parasite larvae were isolated and identified as belonging to five cestode taxa of the order Cyclophyllidea: two species of the family Hymenolepididae, i.e. Flamingolepis sp. 1 and Flamingolepis sp. 2 (adults parasitic in flamingos); two species of Dilepididae, i.e. Fuhrmannolepis averini (adults parasitic in phalaropes) and Eurycestus avoceti (adult parasitic in charadriforms birds); and one species of Progynotaeniidae, i.e. Gynandrotaenia (?) stammeri (adult parasitic in flamingos). The cysticercoids of each species are described and figured. The study represents the first geographical record of the genera Eurycestus, Gynandrotaenia and Fuhrmannolepis in South America and the first report of Gynandrotaenia and Flamingolepis in A. franciscana in its native range. This survey also contributes to the knowledge of cestodes of Phoenicopteriformes and Charadriiformes and their life cycles in the Neotropical Region. A review of cestodes recorded in brine shrimps of the genus Artemia in the world is provided. Further studies on cestode fauna of aquatic birds and their intermediate hosts in hypersaline habitats of the Neotropical Region are needed to understand their functional role in such extreme and unique ecosystems.


Assuntos
Artemia/parasitologia , Aves/parasitologia , Cestoides/crescimento & desenvolvimento , Infecções por Cestoides/veterinária , Ambientes Extremos , Animais , Aves/classificação , Cestoides/classificação , Cestoides/isolamento & purificação , Infecções por Cestoides/parasitologia , Chile , Ecossistema , Larva/classificação , Larva/crescimento & desenvolvimento , Estágios do Ciclo de Vida
8.
Parasitol Res ; 119(7): 2337-2342, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32500371

RESUMO

Philornis flies Meinert (Diptera: Muscidae) have been documented parasitizing over 250 bird species, some of which are endemic species threatened with extinction. Philornis parasitism is hypothesized to affect nestlings disproportionately more than adult birds because limited mobility and exposed skin of nestlings increase their vulnerability to parasitism. We used a comprehensive literature review and our recent fieldwork in the Dominican Republic, Puerto Rico, and Grenada to challenge the idea that parasitism by subcutaneous Philornis species is a phenomenon primarily found in nestlings, a fact that has not been quantified to date. Of the 265 reviewed publications, 125 (49%) reported incidences of parasitism by subcutaneous Philornis, but only 12 included the sampling of adult breeding birds. Nine of these publications (75%) reported Philornis parasitism in adults of ten bird species. During fieldwork in the Dominican Republic, Puerto Rico, and Grenada, we documented 14 instances of parasitism of adult birds of seven avian species. From literature review and fieldwork, adults of at least fifteen bird species across 12 families and four orders of birds were parasitized by at least five Philornis species. In both the published literature and fieldwork, incidences of parasitism of adult birds occurred predominantly in females and was frequently associated with incubation. Although our findings indicate that Philornis parasitism of adult birds is more common than widely presumed, parasite prevalence is still greater in nestlings. In the future, we recommend surveys of adult birds to better understand host-Philornis relationships across life stages. This information may be essential for the development of effective control measures of Philornis to ensure the long-term protection of bird species of conservation concern.


Assuntos
Aves/parasitologia , Muscidae/fisiologia , Animais , Aves/classificação , Feminino , Incidência , Larva/classificação , Larva/fisiologia , Masculino , Muscidae/classificação , Comportamento de Nidação , Prevalência , Índias Ocidentais/epidemiologia
9.
Nat Commun ; 11(1): 2686, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32483158

RESUMO

Despite growing concern over consequences of global changes, we still know little about potential interactive effects of anthropogenic perturbations and diversity loss on the stability of local communities, especially for taxa other than plants. Here we analyse the relationships among landscape composition, biodiversity and community stability looking at time series of three types of communities, i.e., bats, birds and butterflies, monitored over the years by citizen science programs in France. We show that urban and intensive agricultural landscapes as well as diversity loss destabilize these communities but in different ways: while diversity loss translates into greater population synchrony, urban and intensive agricultural landscapes mainly decrease mean population stability. In addition to highlight the stabilizing effects of diversity on ecologically important but overlooked taxa, our results further reveal new pathways linking anthropogenic activities to diversity and stability.


Assuntos
Agricultura/métodos , Urbanização , Animais , Biodiversidade , Aves/classificação , Borboletas/classificação , Quirópteros/classificação , Conservação dos Recursos Naturais/estatística & dados numéricos , Ecossistema , França , Filogenia , Dinâmica Populacional , Análise de Componente Principal
10.
Proc Natl Acad Sci U S A ; 117(25): 14299-14305, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-32513701

RESUMO

The Lower Cretaceous Huajiying Formation of the Sichakou Basin in northern Hebei Province, northern China contains key vertebrate taxa of the early Jehol Biota, e.g., Protopteryx fengningensis, Archaeornithura meemannae, Peipiaosteus fengningensis, and Eoconfuciusornis zhengi This formation arguably documents the second-oldest bird-bearing horizon, producing the oldest fossil records of the two major Mesozoic avian groups Enantiornithes and Ornithuromorpha. Hence, precisely determining the depositional ages of the Huajiying Formation would advance our understanding of the evolutionary history of the Jehol Biota. Here we present secondary ion mass spectrometry (SIMS) U-Pb zircon analysis results of eight interbedded tuff/tuffaceous sandstone samples from the Huajiying Formation. Our findings, combined with previous radiometric dates, suggest that the oldest enantiornithine and ornithuromorph birds in the Jehol Biota are ∼129-131 Ma, and that the Jehol Biota most likely first appeared at ∼135 Ma. This expands the biota's temporal distribution from late Valanginian to middle Aptian with a time span of about 15 My.


Assuntos
Biota , Aves/classificação , Chumbo/química , Silicatos/química , Zircônio/química , Animais , Evolução Biológica , China , Fósseis , Geologia , Filogenia , Espectrometria de Massa de Íon Secundário
11.
Cytogenet Genome Res ; 160(4): 199-205, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32369809

RESUMO

Bird chromosomes, which have been investigated scientifically for more than a century, present a number of unique features. In general, bird karyotypes have a high diploid number (2n) of typically around 80 chromosomes that are divided into macro- and microchromosomes. In recent decades, FISH studies using whole chromosome painting probes have shown that the macrochromosomes evolved through both inter- and intrachromosomal rearrangements. However, chromosome painting data are available for only a few bird species, which hinders a more systematic approach to the understanding of the evolutionary history of the enigmatic bird karyotype. Thus, we decided to create an innovative database through compilation of the cytogenetic data available for birds, including chromosome numbers and the results of chromosome painting with chicken (Gallus gallus) probes. The data were obtained through an extensive literature review, which focused on cytogenetic studies published up to 2019. In the first version of the "Bird Chromosome Database (BCD)" (https://sites.unipampa.edu.br/birdchromosomedatabase) we have compiled data on the chromosome numbers of 1,067 bird species and chromosome painting data on 96 species. We found considerable variation in the diploid numbers, which ranged from 40 to 142, although most (around 50%) of the species studied up to now have between 78 and 82 chromosomes. Despite its importance for cytogenetic research, chromosome painting has been applied to less than 1% of all bird species. The BCD will enable researchers to identify the main knowledge gaps in bird cytogenetics, including the most under-sampled groups, and make inferences on chromosomal homologies in phylogenetic studies.


Assuntos
Aves/genética , Cromossomos/genética , Citogenética , Bases de Dados Genéticas , Animais , Aves/classificação , Galinhas/genética , Coloração Cromossômica , Diploide , Feminino , Cariotipagem , Masculino , Filogenia , Especificidade da Espécie
12.
PLoS One ; 15(5): e0232509, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32469879

RESUMO

The Cuckoos have a long history of difficult classification. The species of this order have been the subject of several studies based on osteology, behavior, ecology, morphology and molecular data. Despite this, the relationship between Cuculiformes and species of other orders remains controversial. In this work, two species of Cuculidae, Guira guira (Gmelin, 1788) and Piaya cayana (Linnaeus, 1766), were analyzed by means of comparative chromosome painting in order to study the chromosome evolution of this group and to undertake the first chromosome mapping of these species. Our results demonstrate high chromosomal diversity, with 2n = 76 in G. guira, with fission and fusion events involving ancestral syntenies, while P. cayana presented only fissions, which were responsible for the high diploid number of 2n = 90. Interestingly, there were no chromosomal rearrangements in common between these species. Our results, based on Giemsa staining, were compared with previous data for other cuckoos and also with taxa proposed as sister-groups of Cuculiformes (Otidiformes, Musophagiformes and Opisthocomiformes). Cytogenetic comparisons demonstrated that cuckoo species can be divided into at least three major groups. In addition, we found no evidence to place Cuculiformes close to the groups proposed previously as sister-groups.


Assuntos
Aves/classificação , Aves/genética , Cromossomos/genética , Animais , Evolução Biológica , Mapeamento Cromossômico , Coloração Cromossômica , Evolução Molecular , Feminino , Hibridização in Situ Fluorescente , Cariótipo , Masculino , Filogenia , Especificidade da Espécie , Sintenia
13.
Stud Hist Philos Biol Biomed Sci ; 82: 101289, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32386965

RESUMO

In 1948, American ornithologist Rodolphe Meyer de Schauensee began publishing what would be the most complete list of birds from Colombia that had ever been printed up to that time. His work was called The Birds of the Republic of Colombia (TBRC), and at the invitation of Armando Dugand, the director of the Instituto de Ciencias Naturales at the Universidad Nacional de Colombia and of the Caldasia journal, this work was exclusively published in the journal in five installments spanning four years. This paper analyzes the publishing aspects that particularly influenced the process of carrying out this work, with the objective of showing that scientific practices and publishing practices are not two absolutely separate domains. The circuit of communication present in TBRC's development is analyzed, specifically the efforts of the editor, printer and author to bring this work to fruition. This analysis demonstrates the following: (i) how the scientific interests of Meyer and the Instituto de Ciencias Naturales converge, (ii) the contradictions between scientific interests that promoted the publication of TBRC and the publishing rationale of a journal and (iii) how unforeseen publishing issues of the time, such as the increase in printing costs due to inflation, influenced the final structure of the work.


Assuntos
Aves/classificação , História Natural , Publicações Periódicas como Assunto , Editoração/história , Animais , Colômbia , História do Século XX , Humanos , Editoração/economia , Editoração/normas , Estados Unidos
14.
Am Nat ; 195(5): 802-817, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32364787

RESUMO

Variation in species richness across environmental gradients results from a combination of historical nonequilibrium processes (time, speciation, extinction) and present-day differences in environmental carrying capacities (i.e., ecological limits affected by species interactions and the abundance and diversity of resources). In a study of bird richness along the subtropical east Himalayan elevational gradient, we test the prediction that species richness patterns are consistent with ecological limits using data on morphology, phylogeny, elevational distribution, and arthropod resources. Species richness peaks at midelevations. Occupied morphological volume is roughly constant from low elevations to midelevations, implying that more species are packed into the same space at midelevations compared with low elevations. However, variance in beak length and differences in beak length between close relatives decline with elevation, which is a consequence of the addition of many small insectivores at midelevations. These patterns are predicted from resource distributions: arthropod size diversity declines from low elevations to midelevations, largely because many more small insects are present at midelevations. Weak correlations of species mean morphological traits with elevation also match predictions based on resources and habitats. Elevational transects in the tropical Andes, New Guinea, and Tanzania similarly show declines in mean arthropod size and mean beak length and, in these cases, likely contribute to declining numbers of insectivorous bird species richness along these gradients. The results imply that conditions for ecological limits are met, although historical nonequilibrium processes are likely to also contribute to the pattern of species richness.


Assuntos
Altitude , Aves/fisiologia , Ecossistema , Animais , Butão , Biodiversidade , Aves/classificação , Índia
15.
PLoS One ; 15(4): e0230150, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32298293

RESUMO

Subspecies are often less well-defined than species but have become one of the basic units for legal protection. Evidence for the erection or synonymy of subspecies therefore needs to be founded on the best science available. Here we show that there is clear genetic disjunction in the Sarus Crane Antigone antigone, where previously the variation had appeared to be clinal. Based on a total sample of 76 individuals, analysis of 10 microsatellite loci from 67 samples and 49 sequences from the mitochondrial control region, this research establishes that the Australian Sarus Crane A. a. gillae differs significantly from both A. a. antigone (South Asia) and A. a. sharpii (Myanmar and Indochina). A single sample from the extinct Philippine subspecies A. a luzonica clustered with A. a. gillae, hinting at the potential for a more recent separation between them than from A. a. antigone and A. a. sharpii, even though A. a. sharpii is closer geographically. The results demonstrate that failure to detect subspecies through initial genetic profiling does not mean discontinuities are absent and has significance for other cases where subspecies are dismissed based on partial genetic evidence. It could also be potentially important for sourcing birds for reintroduction to the Philippines.


Assuntos
Aves , Loci Gênicos , Repetições de Microssatélites , Filogenia , Animais , Austrália , Aves/classificação , Aves/genética , Feminino , Masculino
16.
Proc Natl Acad Sci U S A ; 117(17): 9423-9430, 2020 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-32284401

RESUMO

The notion that certain animal groups disproportionately maintain and transmit viruses to humans due to broad-scale differences in ecology, life history, and physiology currently influences global health surveillance and research in disease ecology, virology, and immunology. To directly test whether such "special reservoirs" of zoonoses exist, we used literature searches to construct the largest existing dataset of virus-reservoir relationships, consisting of the avian and mammalian reservoir hosts of 415 RNA and DNA viruses along with their histories of human infection. Reservoir host effects on the propensity of viruses to have been reported as infecting humans were rare and when present were restricted to one or two viral families. The data instead support a largely host-neutral explanation for the distribution of human-infecting viruses across the animal orders studied. After controlling for higher baseline viral richness in mammals versus birds, the observed number of zoonoses per animal order increased as a function of their species richness. Animal orders of established importance as zoonotic reservoirs including bats and rodents were unexceptional, maintaining numbers of zoonoses that closely matched expectations for mammalian groups of their size. Our findings show that variation in the frequency of zoonoses among animal orders can be explained without invoking special ecological or immunological relationships between hosts and viruses, pointing to a need to reconsider current approaches aimed at finding and predicting novel zoonoses.


Assuntos
Aves/virologia , Doenças Transmissíveis Emergentes/veterinária , Reservatórios de Doenças/veterinária , Mamíferos/virologia , Viroses/veterinária , Zoonoses/virologia , Animais , Aves/classificação , Doenças Transmissíveis Emergentes/virologia , Humanos , Mamíferos/classificação , Fatores de Risco , Especificidade da Espécie , Viroses/virologia
17.
Nature ; 579(7799): 397-401, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32188952

RESUMO

Our understanding of the earliest stages of crown bird evolution is hindered by an exceedingly sparse avian fossil record from the Mesozoic era. The most ancient phylogenetic divergences among crown birds are known to have occurred in the Cretaceous period1-3, but stem-lineage representatives of the deepest subclades of crown birds-Palaeognathae (ostriches and kin), Galloanserae (landfowl and waterfowl) and Neoaves (all other extant birds)-are unknown from the Mesozoic era. As a result, key questions related to the ecology4,5, biogeography3,6,7 and divergence times1,8-10 of ancestral crown birds remain unanswered. Here we report a new Mesozoic fossil that occupies a position close to the last common ancestor of Galloanserae and fills a key phylogenetic gap in the early evolutionary history of crown birds10,11. Asteriornis maastrichtensis, gen. et sp. nov., from the Maastrichtian age of Belgium (66.8-66.7 million years ago), is represented by a nearly complete, three-dimensionally preserved skull and associated postcranial elements. The fossil represents one of the only well-supported crown birds from the Mesozoic era12, and is the first Mesozoic crown bird with well-represented cranial remains. Asteriornis maastrichtensis exhibits a previously undocumented combination of galliform (landfowl)-like and anseriform (waterfowl)-like features, and its presence alongside a previously reported Ichthyornis-like taxon from the same locality13 provides direct evidence of the co-occurrence of crown birds and avialan stem birds. Its occurrence in the Northern Hemisphere challenges biogeographical hypotheses of a Gondwanan origin of crown birds3, and its relatively small size and possible littoral ecology may corroborate proposed ecological filters4,5,9 that influenced the persistence of crown birds through the end-Cretaceous mass extinction.


Assuntos
Aves/classificação , Fósseis , Filogenia , Animais , Bélgica , Aves/anatomia & histologia , Feminino , Masculino , Crânio/anatomia & histologia
18.
Nature ; 579(7799): 393-396, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32188954

RESUMO

Agricultural practices constitute both the greatest cause of biodiversity loss and the greatest opportunity for conservation1,2, given the shrinking scope of protected areas in many regions. Recent studies have documented the high levels of biodiversity-across many taxa and biomes-that agricultural landscapes can support over the short term1,3,4. However, little is known about the long-term effects of alternative agricultural practices on ecological communities4,5 Here we document changes in bird communities in intensive-agriculture, diversified-agriculture and natural-forest habitats in 4 regions of Costa Rica over a period of 18 years. Long-term directional shifts in bird communities were evident in intensive- and diversified-agricultural habitats, but were strongest in intensive-agricultural habitats, where the number of endemic and International Union for Conservation of Nature (IUCN) Red List species fell over time. All major guilds, including those involved in pest control, pollination and seed dispersal, were affected. Bird communities in intensive-agricultural habitats proved more susceptible to changes in climate, with hotter and drier periods associated with greater changes in community composition in these settings. These findings demonstrate that diversified agriculture can help to alleviate the long-term loss of biodiversity outside natural protected areas1.


Assuntos
Agricultura/métodos , Agricultura/estatística & dados numéricos , Biodiversidade , Aves/classificação , Florestas , Animais , Bovinos , Costa Rica , Produtos Agrícolas/provisão & distribução , Extinção Biológica , Agricultura Florestal/estatística & dados numéricos , Aquecimento Global/estatística & dados numéricos , Controle Biológico de Vetores , Polinização , Dispersão de Sementes , Fatores de Tempo
19.
Nature ; 579(7797): 92-96, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32076267

RESUMO

Colonization, speciation and extinction are dynamic processes that influence global patterns of species richness1-6. Island biogeography theory predicts that the contribution of these processes to the accumulation of species diversity depends on the area and isolation of the island7,8. Notably, there has been no robust global test of this prediction for islands where speciation cannot be ignored9, because neither the appropriate data nor the analytical tools have been available. Here we address both deficiencies to reveal, for island birds, the empirical shape of the general relationships that determine how colonization, extinction and speciation rates co-vary with the area and isolation of islands. We compiled a global molecular phylogenetic dataset of birds on islands, based on the terrestrial avifaunas of 41 oceanic archipelagos worldwide (including 596 avian taxa), and applied a new analysis method to estimate the sensitivity of island-specific rates of colonization, speciation and extinction to island features (area and isolation). Our model predicts-with high explanatory power-several global relationships. We found a decline in colonization with isolation, a decline in extinction with area and an increase in speciation with area and isolation. Combining the theoretical foundations of island biogeography7,8 with the temporal information contained in molecular phylogenies10 proves a powerful approach to reveal the fundamental relationships that govern variation in biodiversity across the planet.


Assuntos
Biodiversidade , Aves/classificação , Ilhas , Modelos Biológicos , Animais , Bases de Dados de Ácidos Nucleicos , Extinção Biológica , Especiação Genética , Filogenia , Filogeografia
20.
BMC Evol Biol ; 20(1): 32, 2020 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-32093609

RESUMO

BACKGROUND: Bird plumage exhibits a diversity of colors that serve functional roles ranging from signaling to camouflage and thermoregulation. However, birds must maintain a balance between evolving colorful signals to attract mates, minimizing conspicuousness to predators, and optimizing adaptation to climate conditions. Examining plumage color macroevolution provides a framework for understanding this dynamic interplay over phylogenetic scales. Plumage evolution due to a single overarching process, such as selection, may generate the same macroevolutionary pattern of color variation across all body regions. In contrast, independent processes may partition plumage and produce region-specific patterns. To test these alternative scenarios, we collected color data from museum specimens of an ornate clade of birds, the Australasian lorikeets, using visible-light and UV-light photography, and comparative methods. We predicted that the diversification of homologous feather regions, i.e., patches, known to be involved in sexual signaling (e.g., face) would be less constrained than patches on the back and wings, where new color states may come at the cost of crypsis. Because environmental adaptation may drive evolution towards or away from color states, we tested whether climate more strongly covaried with plumage regions under greater or weaker macroevolutionary constraint. RESULTS: We found that alternative macroevolutionary models and varying rates best describe color evolution, a pattern consistent with our prediction that different plumage regions evolved in response to independent processes. Modeling plumage regions independently, in functional groups, and all together showed that patches with similar macroevolutionary models clustered together into distinct regions (e.g., head, wing, belly), which suggests that plumage does not evolve as a single trait in this group. Wing patches, which were conserved on a macroevolutionary scale, covaried with climate more strongly than plumage regions (e.g., head), which diversified in a burst. CONCLUSIONS: Overall, our results support the hypothesis that the extraordinary color diversity in the lorikeets was generated by a mosaic of evolutionary processes acting on plumage region subsets. Partitioning of plumage regions in different parts of the body provides a mechanism that allows birds to evolve bright colors for signaling and remain hidden from predators or adapt to local climatic conditions.


Assuntos
Adaptação Fisiológica , Evolução Biológica , Aves/classificação , Cor , Plumas/fisiologia , Adaptação Fisiológica/genética , Animais , Aves/genética , Plumas/química , Interação Gene-Ambiente , Fenótipo , Filogenia , Pigmentação/genética , Clima Tropical , Asas de Animais/química
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