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Seasonal migration is an underappreciated driver of animal diversification. Changes in migratory behaviour may favour the establishment of sedentary founder populations and promote speciation if there is sufficient reproductive isolation between sedentary and migratory populations. From a systematic literature review, we here quantify the role of migratory drop-off-the loss of migratory behaviour-in promoting speciation in birds on islands. We identify at least 157 independent colonization events likely initiated by migratory species that led to speciation, including 44 cases among recently extinct species. By comparing, for all islands, the proportion of island endemic species that derived from migratory drop-off with the proportion of migratory species among potential colonizers, we showed that seasonal migration has a larger effect on island endemic richness than direct dispersal. We also found that the role of migration in island colonization increases with the geographic isolation of islands. Furthermore, the success of speciation events depends in part on species biogeographic and ecological factors, here positively associated with greater range size and larger flock sizes. These results highlight the importance of shifts in migratory behaviour in the speciation process and calls for greater consideration of migratory drop-off in the biogeographic distribution of birds.
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Aves , Animais , FilogeniaRESUMO
We created a database of lost and rediscovered tetrapod species, identified patterns in their distribution and factors influencing rediscovery. Tetrapod species are being lost at a faster rate than they are being rediscovered, due to slowing rates of rediscovery for amphibians, birds and mammals, and rapid rates of loss for reptiles. Finding lost species and preventing future losses should therefore be a conservation priority. By comparing the taxonomic and spatial distribution of lost and rediscovered tetrapod species, we have identified regions and taxa with many lost species in comparison to those that have been rediscovered-our results may help to prioritise search effort to find them. By identifying factors that influence rediscovery, we have improved our ability to broadly distinguish the types of species that are likely to be found from those that are not (because they are likely to be extinct). Some lost species, particularly those that are small and perceived to be uncharismatic, may have been neglected in terms of conservation effort, and other lost species may be hard to find due to their intrinsic characteristics and the characteristics of the environments they occupy (e.g. nocturnal species, fossorial species and species occupying habitats that are more difficult to survey such as wetlands). These lost species may genuinely await rediscovery. However, other lost species that possess characteristics associated with rediscovery (e.g. large species) and that are also associated with factors that negatively influence rediscovery (e.g. those occupying small islands) are more likely to be extinct. Our results may foster pragmatic search protocols that prioritise lost species likely to still exist.
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Ecossistema , Extinção Biológica , Animais , Anfíbios , Áreas Alagadas , Mamíferos , Conservação dos Recursos Naturais/métodos , Espécies em Perigo de Extinção , BiodiversidadeRESUMO
The Cuban macaw Ara tricolor (Bechstein, 1811) is an extinct species of large parrots. Its historical distribution and ecology are poorly understood. To date, only three late Quaternary paleontological and one archeozoological (17th-18th centuries) finds of the species have been described from central Cuba. A new (fourth) fossil find of the Cuban macaw is described and is a fragmentary carpometacarpus from Upper Pleistocene layers of the El Abrón Cave in the Pinar del Río province. The find provides the first documented evidence of the species from the western part of Cuba. The associated fauna indicates that the Cuban macaw lived in mosaic, semi-open marshy landscapes, which were probably similar to those in the vicinity of Ciénaga de Zapata in modern times.
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Fósseis , Papagaios , Cuba , AnimaisRESUMO
Bird bones from the Late Pleistocene (31-24 kyr) Ikhine-2 site (Central Yakutia), one of the key Upper Paleolithic sites in northeastern Siberia, have first been studied. This is the northernmost and the oldest bird association in the Pleistocene of Eastern Siberia. Among the bone materials available, the coracoids of the extinct Dyuktai goose (Anser djuktaiensis) and the hooded crane (Grus monacha) are of particular interest. Dyuktai goose is a large representative of the mammoth fauna, originally described from younger deposits (12-13 kyr) in southeastern Yakutia. This is the second find of this species in Russia, which significantly expands our understanding of the geography and time of its distribution. The hooded crane, a rare modern species with a limited habitat area, has first been found in paleontological record. This find indicates the northern distribution of this species during the Late Pleistocene Karginian interstadial. Bones of Anas crecca and Larus canus have also been found at the site.
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Gansos , Mamutes , Animais , Ecossistema , Federação Russa , SibériaRESUMO
Ancient samples present a number of technical challenges for DNA barcoding, including damaged DNA with low endogenous copy number and short fragment lengths. Nevertheless, techniques are available to overcome these issues, and DNA barcoding has now been used to successfully recover parasite DNA from a wide variety of ancient substrates, including coprolites, cesspit sediment, mummified tissues, burial sediments and permafrost soils. The study of parasite DNA from ancient samples can provide a number of unique scientific insights, for example: (1) into the parasite communities and health of prehistoric human populations; (2) the ability to reconstruct the natural parasite faunas of rare or extinct host species, which has implications for conservation management and de-extinction; and (3) the ability to view in 'real-time' processes that may operate over century- or millenial-timescales, such as how parasites responded to past climate change events or how they co-evolved alongside their hosts. The application of DNA metabarcoding and high-throughput sequencing to ancient specimens has so far been limited, but in future promises great potential for gaining empirical data on poorly understood processes such as parasite co-extinction.
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Código de Barras de DNA Taxonômico , DNA Antigo/isolamento & purificação , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Parasitos/genética , Animais , DNA Antigo/análise , Humanos , Doenças Parasitárias/parasitologiaRESUMO
BACKGROUND AND AIMS: Recent developments in DNA sequencing, so-called next-generation sequencing (NGS) methods, can help the study of rare lineages that are known from museum specimens. Here, the taxonomy and evolution of the Malagasy grass lineage Chasechloa was investigated with the aid of NGS. METHODS: Full chloroplast genome data and some nuclear sequences were produced by NGS from old herbarium specimens, while some selected markers were generated from recently collected Malagasy grasses. In addition, a scanning electron microscopy analysis of the upper floret and cross-sections of the rachilla appendages followed by staining with Sudan IV were performed on Chasechloa to examine the morphology of the upper floret and the presence of oils in the appendages. KEY RESULTS: Chasechloa was recovered within tribe Paniceae, sub-tribe Boivinellinae, contrary to its previous placement as a member of the New World genus Echinolaena (tribe Paspaleae). Chasechloa originated in Madagascar between the Upper Miocene and the Pliocene. It comprises two species, one of them collected only once in 1851. The genus is restricted to north-western seasonally dry deciduous forests. The appendages at the base of the upper floret of Chasechloa have been confirmed as elaiosomes, an evolutionary adaptation for myrmecochory. CONCLUSIONS: Chasechloa is reinstated at the generic level and a taxonomic treatment is presented, including conservation assessments of its species. Our study also highlights the power of NGS technology to analyse relictual or probably extinct groups.
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Espécies em Perigo de Extinção , Poaceae/genética , DNA de Plantas/genética , DNA de Plantas/isolamento & purificação , Flores/ultraestrutura , Sequenciamento de Nucleotídeos em Larga Escala , Madagáscar , Microscopia Eletrônica de Varredura , Filogenia , Poaceae/classificação , Poaceae/ultraestruturaRESUMO
It is widely acknowledged that we are currently facing a critical tipping point with regards to global extinction, with human activities driving us perilously close to the brink of a devastating sixth mass extinction. As a promising option for safeguarding endangered species, induced pluripotent stem cells (iPSCs) hold great potential to aid in the preservation of threatened animal populations. For endangered species, such as the northern white rhinoceros (Ceratotherium simum cottoni), supply of embryos is often limited. After the death of the last male in 2019, only two females remained in the world. IPSC technology offers novel approaches and techniques for obtaining pluripotent stem cells (PSCs) from rare and endangered animal species. Successful generation of iPSCs circumvents several bottlenecks that impede the development of PSCs, including the challenges associated with establishing embryonic stem cells, limited embryo sources and immune rejection following embryo transfer. To provide more opportunities and room for growth in our work on animal welfare, in this paper we will focus on the progress made with iPSC lines derived from endangered and extinct species, exploring their potential applications and limitations in animal welfare research.
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Células-Tronco Pluripotentes Induzidas , Feminino , Animais , Masculino , Humanos , Espécies em Perigo de Extinção , Perissodáctilos , Células-Tronco Embrionárias , Diferenciação CelularRESUMO
CRISPR/Cas9 gene technology is transported as RNA from transgenic roots to distal parts of unmodified grafted scion, where it is translated into proteins to induce heritable mutagenesis at desired loci. This technique has the potential to produce transgene-free and genetically stable plants in difficult-to-propagate and near-extinct species.
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The Ethiopian wolf, endemic to Ethiopia, is the most endangered species in the world. As flagship species, a wide range of studies has been conducted on the Ethiopian wolf. However, there is scanty information about the impact of climate change on this globally important species. Thus, this study aimed to predict the current and future suitable habitats of the species based on four Representative Concentration Pathway scenarios of IPCC for the years 2050 and 2070 by using the MaxEnt model. A total of 479 species occurrence records were obtained from the field survey and Global Biodiversity Information Facility. The 19 bioclimatic variables and altitude were downloaded from worldclim and extracted for the study area using GIS software. The Pearson correlation analysis was employed to detect correlation among variables and maintained 10 variables. The prediction potential of the model was evaluated and found excellent to predict the distribution of the species. The result depicted that suitable habitats for Ethiopian wolves will be badly affected by climate change. Currently, about 9.4% of the total landmass of Ethiopia is suitable for wolves. However, it will be lost in the forthcoming couple of decade under all scenarios of global climate change. Consequently, the Ethiopian wolf is highly suspected to be extinct globally in the mid of 21st century, unless corrective measures are done in time. Therefore, enhancing the adaptive capacity of species as well as genetic resource preservation and captive breeding is advisable.
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Although many species have gone extinct, their genetic components might exist in extant species because of ancient hybridization. Via advances in genome sequencing and development of modern population genetics, one can find the legacy of unknown or extinct species in the context of available genomes from extant species. Such discovery can be used as a strategy to search for hidden species or fossils in conservation biology and archeology, gain novel insight into complex evolutionary history, and provide the new sources of genetic variation for breeding and trait improvement in agriculture.
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GenomaRESUMO
A new fossil species, Protanthomyza grimaldii sp. nov. (Diptera, Anthomyzidae), is described from Baltic amber (Eocene, 48-34 Ma) based on two (male and female) inclusions. It is the ninth species of the genus Protanthomyza Hennig, 1965 and subfamily Protanthomyzinae Rohácek, 1998. Adult morphology of P. grimaldii sp. nov. revealed that the rich chaetotaxy of the thoracic pleuron, two anal veins and presence of the anteroventral process of the epandrium are plausibly shared by all species of Protanthomyza. Relationships of the new species, which belongs to a group lacking the ctenidial spine on the fore femur, are discussed.
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Alburnus kotschyi is re-described and a neotype is designated. It is found in a small isolated coastal stream at Arsuz at the eastern Mediterranean coast as well as in the Ceyhan and Seyhan River drainages in southern Anatolia. Alburnus adanensis, from the Seyhan River, seems not to have been found again since its first description in 1944 and might be extinct.
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Cyprinidae , Animais , RiosRESUMO
We describe a late Pleistocene species of extinct rail, Rallus gracilipes n. sp., from Sawmill Sink blue hole on Abaco Island, Little Bahama Bank, The Bahamas. The only other extinct rail known from any Bahamian island is the smaller Rallus cyanocavi, also from late Pleistocene contexts at Sawmill Sink. No fossils of R. gracilipes or R. cyanocavi have been found in Holocene sites on Abaco; the loss of both of these species is likely to be due to changes in climate, habitat, and island area during the Pleistocene-Holocene Transition.
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Aves , Animais , Bahamas , Ecossistema , Fósseis , IlhasRESUMO
In the fossil record, the quantification of continuous morphological variation has become a central issue when dealing with species identification and speciation. In this context, fossil taxa with living representatives hold great promise, because of the potential to characterise patterns of intraspecific morphological variation in extant species prior to any interpretation in the fossil record. The vast majority of catfish families fulfil this prerequisite, as most of them are represented by extant genera. However, although they constitute a major fish group in terms of distribution, and ecological and taxonomic diversity, the quantitative study of their past morphological variation has been neglected, as fossil specimens are generally identified based on the scarcest remains, that is, complete neurocrania that bear discrete characters. Consequently, a part of freshwater catfish history is unprospected and unknown. In this study, we explored the morphological continuous variation of the humeral plate shape in Synodontis catfishes using Elliptic Fourier Analysis (EFA), and compared extant members and fossil counterparts. We analysed 153 extant specimens of 11 Synodontis species present in the Chad basin, in addition to 23 fossil specimens from the Chadian fossiliferous area of Toros Menalla which is dated around 7 Ma. This highly speciose genus, which is one of the most diversified in Africa, exhibits a rich fossil record with several hundred remains mostly identified as Synodontis sp. The analysis of the outline of the humeral plate reveals that some living morphological types were already represented in the Chad Basin 7 My ago, and allows for the discovery of extinct species. Beside illuminating the complex Neogene evolutionary history of Synodontis, these results underline the interest in the ability of isolated remains to reconstruct a past dynamic history and to validate the relevance of EFA as a tool to explore specific diversity through time. J. Morphol. 277:1486-1496, 2016. © 2016 Wiley Periodicals, Inc.