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1.
Melissa Ann Millar Margaret Byrne 《Biological journal of the Linnean Society. Linnean Society of London》2013,108(4):871-881
Genetic structure among disjunct population groups of Pultenaea pauciflora was assessed to determine the evolutionary history of this species as a basis for conservation management strategies. Analysis of individuals from all extant populations using 1737 amplified length polymorphism markers revealed two highly divergent genetic entities with strong geographical structuring. Populations located at Narrogin and Brookton clustered together in Bayesian assignment analysis with every individual optimally placed in a single cluster with complete membership. Genetic differentiation between populations in these two areas was very low. Populations at Boddington were highly divergent from those located at Narrogin and Brookton. All individuals from Boddington populations were optimally placed into a second cluster with complete membership. Populations located at Boddington maintain lower levels of allelic diversity, yet greater levels of mean heterozygosity than populations located at Narrogin and Brookton. The degree of genetic differentiation and different patterns of genetic diversity strongly suggest historical divergence and separate evolutionary influences on the two lineages that occur in different ecological habitat. These Evolutionary Significant Units are likely to represent two cryptic sister taxa in the extant populations currently recognized as P. pauciflora, and the reassessment of taxonomic and conservation status of both lineages is required. © 2013 State of Western Australia. Biological Journal of the Linnean Society © 2013 The Linnean Society of London 相似文献
2.
C. MORITZ 《Molecular ecology》1994,3(4):401-411
Patterns of variation in mitochondrial DNA (mtDNA) increasingly are being investigated in threatened or managed species, but not always with clearly defined goals for conservation. In this review I identify uses of mtDNA analysis which fall into two different areas: (i) 'gene conservation' - the identification and management of genetic diversity, and (ii) 'molecular ecology' - the use of mtDNA variation to guide and assist demographic studies of populations. These two classes of application have different conceptual bases, conservation goals and time-frames. Gene conservation makes extensive use of phylogenetic information and is, in general, most relevant to long-term planning. Appropriate uses here include identification of Evolutionarily Significant Units and assessment of conservation priority of taxa or areas from an evolutionary perspective. Less appropriate are inferences about fitness from within-population diversity and about species boundaries. Molecular ecology makes more use of allele frequencies and provides information useful for short-term management of populations. Powerful applications are to identify Management Units and to define and use naturally occurring genetic tags. Estimating demographic parameters, e.g migration rate and population size, from patterns of mtDNA diversity is fraught with difficulty, particularly where populations are fluctuating, and is unlikely to produce quantitative estimates sufficiently accurate to be useful for practical management of contemporary populations. However, through comparative studies, mtDNA analysis can provide qualitative signals of population changes, allowing efficient targeting of resource-intensive ecological studies. Thus, there are some relatively straightforward uses of mtDNA, preferably in conjunction with assays of nuclear variation, that can make a significant contribution to the long-term planning and short-term execution of species recovery plans. 相似文献
3.
Abstract. The leaf beetles Cryptocephalus coryli, C. decemmaculatus and C. nitidulus are of conservation concern and are included on the UK Biodiversity Action Plan. The distinctiveness of the disjunct remaining populations of these beetles was compared to that of more continuously distributed Cryptocephalus species. This was carried out with a view to defining evolutionary significant units (ESUs) in the rare species. A portion of the cytochrome b gene, an intergenic spacer and partial tRNA was analysed from 93 specimens of Cryptocephalus beetle (Coleoptera: Chrysomelidae). Considerable sequence divergence was apparent in all the species, even at an intersite scale when the distances between sampled localities were very small (< 1 km). Intrapopulation, intersite and interpopulation divergence observed in the rare species was reflected in the species that have a more continuous distribution, implying that dispersal ability in these species is poor and gene flow can be impeded by relatively trivial barriers to dispersal. The evidence suggests that the disjunct populations of the rare Cryptocephalus species can, tentatively, be considered as ESUs. This has important implications for management strategies and reintroductions. 相似文献
4.
John B. A. Okello Christian Noirard Pierre Joly Silvester Nyakaana Vincent B. Muwanika Nicolas Alcala Séverine Vuilleumier Hans R. Siegismund Luca Fumagalli 《Molecular ecology》2015,24(10):2507-2520
Over the past two decades, an increasing amount of phylogeographic work has substantially improved our understanding of African biogeography, in particular the role played by Pleistocene pluvial–drought cycles on terrestrial vertebrates. However, still little is known on the evolutionary history of semi‐aquatic animals, which faced tremendous challenges imposed by unpredictable availability of water resources. In this study, we investigate the Late Pleistocene history of the common hippopotamus (Hippopotamus amphibius), using mitochondrial and nuclear DNA sequence variation and range‐wide sampling. We documented a global demographic and spatial expansion approximately 0.1–0.3 Myr ago, most likely associated with an episode of massive drainage overflow. These events presumably enabled a historical continent‐wide gene flow among hippopotamus populations, and hence, no clear continental‐scale genetic structuring remains. Nevertheless, present‐day hippopotamus populations are genetically disconnected, probably as a result of the mid‐Holocene aridification and contemporary anthropogenic pressures. This unique pattern contrasts with the biogeographic paradigms established for savannah‐adapted ungulate mammals and should be further investigated in other water‐associated taxa. Our study has important consequences for the conservation of the hippo, an emblematic but threatened species that requires specific protection to curtail its long‐term decline. 相似文献
5.
The phylogeographic pattern of mitochondrial DNA variation in water voles (Arvicola terrestris) from 57 localities across the United Kingdom and representative samples from Spain, France, Switzerland and Finland was determined from sequence variation in the central portion of the control region. Twenty-seven different haplotypes were resolved which formed two distinct phylogenetic clades. This major division separated haplotypes found in Scotland from those found in England and Wales. Nested clade analysis of haplotypes indicated that such a division was a consequence of allopatric fragmentation. The haplotypes found in Switzerland, France and Spain clustered with Scottish haplotypes, whereas the haplotype from Finland clustered with the English/Welsh haplotypes. These patterns indicate that contemporary Scottish populations are derived from an Iberian glacial refugium, whereas English and Welsh populations are derived from an eastern European refugium. As such, the postglacial recolonization of the United Kingdom must have involved two colonization events, either in different localities with no subsequent contact, or as two waves separated over time, with the second wave of colonizers displacing the first. An analysis of molecular variance (AMOVA) identified significant population genetic divergence within both the major clades, indicative of restricted gene flow and regional population isolation. The implications of both phylogeographical and population genetic structure are discussed in context with the conservation of water voles in Britain. 相似文献
6.
Remote cameras are a common method for surveying wildlife and recently have been promoted for implementing large‐scale regional biodiversity monitoring programs. The use of camera‐trap data depends on the correct identification of animals captured in the photographs, yet misidentification rates can be high, especially when morphologically similar species co‐occur, and this can lead to faulty inferences and hinder conservation efforts. Correct identification is dependent on diagnosable taxonomic characters, photograph quality, and the experience and training of the observer. However, keys rooted in taxonomy are rarely used for the identification of camera‐trap images and error rates are rarely assessed, even when morphologically similar species are present in the study area. We tested a method for ensuring high identification accuracy using two sympatric and morphologically similar chipmunk (Neotamias) species as a case study. We hypothesized that the identification accuracy would improve with use of the identification key and with observer training, resulting in higher levels of observer confidence and higher levels of agreement among observers. We developed an identification key and tested identification accuracy based on photographs of verified museum specimens. Our results supported predictions for each of these hypotheses. In addition, we validated the method in the field by comparing remote‐camera data with live‐trapping data. We recommend use of these methods to evaluate error rates and to exclude ambiguous records in camera‐trap datasets. We urge that ensuring correct and scientifically defensible species identifications is incumbent on researchers and should be incorporated into the camera‐trap workflow. 相似文献
7.
Ellen Cheng Karen E. Hodges José Melo‐Ferreira Paulo C. Alves L. Scott Mills 《Molecular ecology》2014,23(12):2929-2942
With climate warming, the ranges of many boreal species are expected to shift northward and to fragment in southern peripheral ranges. To understand the conservation implications of losing southern populations, we examined range‐wide genetic diversity of the snowshoe hare (Lepus americanus), an important prey species that drives boreal ecosystem dynamics. We analysed microsatellite (8 loci) and mitochondrial DNA sequence (cytochrome b and control region) variation in almost 1000 snowshoe hares. A hierarchical structure analysis of the microsatellite data suggests initial subdivision in two groups, Boreal and southwestern. The southwestern group further splits into Greater Pacific Northwest and U.S. Rockies. The genealogical information retrieved from mtDNA is congruent with the three highly differentiated and divergent groups of snowshoe hares. These groups can correspond with evolutionarily significant units that might have evolved in separate refugia south and east of the Pleistocene ice sheets. Genetic diversity was highest at mid‐latitudes of the species' range, and genetic uniqueness was greatest in southern populations, consistent with substructuring inferred from both mtDNA and microsatellite analyses at finer levels of analysis. Surprisingly, snowshoe hares in the Greater Pacific Northwest mtDNA lineage were more closely related to black‐tailed jackrabbits (Lepus californicus) than to other snowshoe hares, which may result from secondary introgression or shared ancestral polymorphism. Given the genetic distinctiveness of southern populations and minimal gene flow with their northern neighbours, fragmentation and loss of southern boreal habitats could mean loss of many unique alleles and reduced evolutionary potential. 相似文献
8.
Recent years have seen a debate over various methods that could objectively prioritize conservation value below the species level. Most prominent among these has been the evolutionarily significant unit (ESU). We reviewed ESU concepts with the aim of proposing a more unified concept that would reconcile opposing views. Like species concepts, conflicting ESU concepts are all essentially aiming to define the same thing: segments of species whose divergence can be measured or evaluated by putting differential emphasis on the role of evolutionary forces at varied temporal scales. Thus, differences between ESU concepts lie more in the criteria used to define the ESUs themselves rather than in their fundamental essence. We provide a context-based framework for delineating ESUs which circumvents much of this situation. Rather than embroil in a befuddled debate over an optimal criterion, the key to a solution is accepting that differing criteria will work more dynamically than others and can be used alone or in combination depending on the situation. These assertions constitute the impetus behind adaptive evolutionary conservation. 相似文献
9.
Roxiris A. Azuaje-Rodríguez Jason D. Weckstein Janice H. Dispoto Swati Patel Joseph A. Cacioppo John M. Bates Sofia Marques Silva Alexandre Aleixo 《Ibis》2020,162(1):119-136
Hylexetastes woodcreepers are endemic to the terra firme forests of the Amazon basin. Currently, most taxonomic sources recognize two species of Hylexetastes (H. perrotii and H. stresemanni), each divided into three subspecies. Some authors maintain that the H. perrotii subspecies should be elevated to full species status. In particular, Hylexetastes perrotii brigidai is endemic to the eastern Amazon, the second Amazonian area of endemism (Xingu) most affected by deforestation and habitat degradation. Consequently, the taxonomic status of H. p. brigidai is of particular concern for conservation. Thus far, only morphological characters have been evaluated for the taxonomic delimitation of species and subspecies of Hylexetastes. We present a molecular phylogenetic analysis of all subspecies to help delimit Hylexetastes interspecific limits. Fragments of two mitochondrial (Cytb and ND2) and three nuclear genes (FGB5, G3PDH and MUSK) from 57 Hylexetastes specimens were sequenced. An ecological niche model was estimated to describe more accurately the potential distributions of taxa and to evaluate their vulnerability to ongoing deforestation. Phylogenetic analyses support the paraphyly of the polytypic H. perrotii as currently delimited and the elevation of Hylexetastes perrotii uniformis to full species rank, as well as the presence of three evolutionary significant units (ESUs) within this newly delimited species, including one grouping all H. p. brigidai specimens. Alternatively, under lineage-based species concepts, our results support at least five evolutionary species in Hylexetastes: H. stresemanni, H. undulatus, H. perrotii, H. uniformis and H. brigidai. Each of these taxa and ESUs are distributed in different interfluvial areas of the Amazon basin, which have different degrees of disturbance. Because they occupy the most heavily impacted region among all Hylexetastes ESUs, regular assessments of the conservation statuses of H. p. brigidai and both H. uniformis ESUs are paramount. 相似文献
10.
Rivers provide an excellent system to study interactions between patterns of biodiversity structure and ecological processes. In these environments, gene flow is restricted by the spatial hierarchy and temporal variation of connectivity within the drainage network. In the Australian arid zone, this variability is high and rivers often exist as isolated waterholes connected during unpredictable floods. These conditions cause boom/bust cycles in the population dynamics of taxa, but their influence on spatial genetic diversity is largely unknown. We used a landscape genetics approach to assess the effect of hydrological variability on gene flow, spatial population structure and genetic diversity in an Australian freshwater fish, Macquaria ambigua. Our analysis is based on microsatellite data of 590 samples from 26 locations across the species range. Despite temporal isolation of populations, the species showed surprisingly high rates of dispersal, with population genetic structure only evident among major drainage basins. Within drainages, hydrological variability was a strong predictor of genetic diversity, being positively correlated with spring-time flow volume. We propose that increases in flow volume during spring stimulate recruitment booms and dispersal, boosting population size and genetic diversity. Although it is uncertain how the hydrological regime in arid Australia may change under future climate scenarios, management strategies for arid-zone fishes should mitigate barriers to dispersal and alterations to the natural flow regime to maintain connectivity and the species' evolutionary potential. This study contributes to our understanding of the influence of spatial and temporal heterogeneity on population and landscape processes. 相似文献
11.
Maarten van Zonneveld Evert Thomas Nora P. Castañeda‐Álvarez Veerle Van Damme Carolina Alcazar Judy Loo Xavier Scheldeman 《Diversity & distributions》2018,24(6):718-729
Background
Humans threat the populations of tree species by overexploitation, deforestation, land use change, and climate change. We present a novel threat assessment at intraspecific level to support the conservation of genetic resources of 80 socioeconomically viable tree species in South America. In this assessment, we evaluate the threat status of Ecogeographic Range Segments (ERSs). ERSs are groups of populations of a specific species in a certain ecological zone of a particular grid cell of a species’ geographic occupancy.Methods
We used species location records to determine the species distributions and species‐specific ERSs. We distinguished eight threat situations to assess the risk of extirpation of the ERSs of all 80 species. These threat situations were determined by large or little tree cover, low or high human pressure, and low or high climate change impact. Available layers of tree cover and threats were used to determine the levels of fragmentation and direct human pressure. Maxent niche modelling with two Global Circulation Models helped determining climate change impact by the 2050s.Results
When all 80 species are considered, in total, 59% of the ERSs are threatened by little tree cover or high human pressure. When climate change is also considered, then 71‐73% of the ERSs are threatened. When an increased risk of extirpation of populations outside protected areas is considered, then 84–86% of the ERSs are threatened. Seven species warrant special attention because all their ERSs are threatened across their whole distribution in South America: Balfourondendron riedelianum, Cariniana legalis, Dalbergia nigra, Handroanthus pulcherrimus, Pachira quintana, Prosopis flexuosa, and Prosopis pallida.Conclusions
Our results confirm the urgency to set up a regional action plan for the conservation of tree genetic resources in South America. With this threat assessment, we aim to support governments and organizations who are taking up this task.12.
分子系统学在生物保护中的意义 总被引：7，自引：1，他引：7
本文综述了近年来分子系统学的原理和方法及其在生物多样性保护中的应用和发展。分子系统学方法可以很好地确定物种保护的基本单元——进化显著性单元,并可用于推测群体的发展状态,从而为物种的保护提供了一项新的具很强操作性的科学手段。 相似文献
13.
Violeta Muñoz‐Fuentes Chris T. Darimont Robert K. Wayne Paul C. Paquet Jennifer A. Leonard 《Journal of Biogeography》2009,36(8):1516-1531
Aim Limited population structure is predicted for vagile, generalist species, such as the grey wolf (Canis lupus L.). Our aims were to study how genetic variability of grey wolves was distributed in an area comprising different habitats that lay within the potential dispersal range of an individual and to make inferences about the impact of ecology on population structure. Location British Columbia, Canada – which is characterized by a continuum of biogeoclimatic zones across which grey wolves are distributed – and adjacent areas in both Canada and Alaska, United States. Methods We obtained mitochondrial DNA control region sequences from grey wolves from across the province and integrated our genetic results with data on phenotype, behaviour and ecology (distance, habitat and prey composition). We also compared the genetic diversity and differentiation of British Columbia grey wolves with those of other North American wolf populations. Results We found strong genetic differentiation between adjacent populations of grey wolves from coastal and inland British Columbia. We show that the most likely factor explaining this differentiation is habitat discontinuity between the coastal and interior regions of British Columbia, as opposed to geographic distance or physical barriers to dispersal. We hypothesize that dispersing grey wolves select habitats similar to the one in which they were reared, and that this differentiation is maintained largely through behavioural mechanisms. Main conclusions The identification of strong genetic structure on a scale within the dispersing capabilities of an individual suggests that ecological factors are driving wolf differentiation in British Columbia. Coastal wolves are highly distinct and representative of a unique ecosystem, whereas inland British Columbia grey wolves are more similar to adjacent populations of wolves located in Alaska, Alberta and Northwest Territories. Given their unique ecological, morphological, behavioural and genetic characteristics, grey wolves of coastal British Columbia should be considered an Evolutionary Significant Unit (ESU) and, consequently, warrant special conservation status. If ecology can drive differentiation in a highly mobile generalist such as the grey wolf, ecology probably drives differentiation in many other species as well. 相似文献
14.
Andrew R. Weeks Carla M. Sgro Andrew G. Young Richard Frankham Nicki J. Mitchell Kim A. Miller Margaret Byrne David J. Coates Mark D. B. Eldridge Paul Sunnucks Martin F. Breed Elizabeth A. James Ary A. Hoffmann 《Evolutionary Applications》2011,4(6):709-725
Translocations are being increasingly proposed as a way of conserving biodiversity, particularly in the management of threatened and keystone species, with the aims of maintaining biodiversity and ecosystem function under the combined pressures of habitat fragmentation and climate change. Evolutionary genetic considerations should be an important part of translocation strategies, but there is often confusion about concepts and goals. Here, we provide a classification of translocations based on specific genetic goals for both threatened species and ecological restoration, separating targets based on ‘genetic rescue’ of current population fitness from those focused on maintaining adaptive potential. We then provide a framework for assessing the genetic benefits and risks associated with translocations and provide guidelines for managers focused on conserving biodiversity and evolutionary processes. Case studies are developed to illustrate the framework. 相似文献
15.
《Global Change Biology》2018,24(6):2262-2271
The inability of organisms to cope in changing environments poses a major threat to their survival. Rising carbon dioxide concentrations, recently exceeding 400 μatm, are rapidly warming and acidifying our oceans. Current understanding of organism responses to this environmental phenomenon is based mainly on relatively short‐ to medium‐term laboratory and field experiments, which cannot evaluate the potential for long‐term acclimation and adaptation, the processes identified as most important to confer resistance. Here, we present data from a novel approach that assesses responses over a centennial timescale showing remarkable resilience to change in a species predicted to be vulnerable. Utilising museum collections allows the assessment of how organisms have coped with past environmental change. It also provides a historical reference for future climate change responses. We evaluated a unique specimen collection of a single species of brachiopod (Calloria inconspicua) collected every decade from 1900 to 2014 from one sampling site. The majority of brachiopod shell characteristics remained unchanged over the past century. One response, however, appears to reinforce their shell by constructing narrower punctae (shell perforations) and laying down more shell. This study indicates one of the most calcium‐carbonate‐dependent species globally to be highly resilient to environmental change over the last 120 years and provides a new insight for how similar species might react and possibly adapt to future change. 相似文献
16.
17.
现存物种的分布格局、遗传结构是当前因素和历史因素共同作用的结果。人类的过度开发、全球变暖等当前因素造成的生境片段化是目前许多报春花属植物濒危的一大原因。该文总结了近年来报春花属内的保育遗传学研究进展,期望以此为更好地保护报春花属植物提供一定的理论基础。应用亲缘地理学研究方法可以弥补古生物学难以研究报春花植物历史成因的不足,因此也总结该方法在报春花属内的研究进展,并初步整理不同地区间的报春花属植物的分化式样,同时期望这些研究成果能为为研究报春花属植物在应对全球气候变化的响应机制方面提供一些参考。 相似文献
18.
With advances in sequencing technology, research in the field of landscape genetics can now be conducted at unprecedented spatial and genomic scales. This has been especially evident when using sequence data to visualize patterns of genetic differentiation across a landscape due to demographic history, including changes in migration. Two recent model‐based visualization methods that can highlight unusual patterns of genetic differentiation across a landscape, SpaceMix and EEMS, are increasingly used. While SpaceMix's model can infer long‐distance migration, EEMS’ model is more sensitive to short‐distance changes in genetic differentiation, and it is unclear how these differences may affect their results in various situations. Here, we compare SpaceMix and EEMS side by side using landscape genetics simulations representing different migration scenarios. While both methods excel when patterns of simulated migration closely match their underlying models, they can produce either un‐intuitive or misleading results when the simulated migration patterns match their models less well, and this may be difficult to assess in empirical data sets. We also introduce unbundled principal components (un‐PC), a fast, model‐free method to visualize patterns of genetic differentiation by combining principal components analysis (PCA), which is already used in many landscape genetics studies, with the locations of sampled individuals. Un‐PC has characteristics of both SpaceMix and EEMS and works well with simulated and empirical data. Finally, we introduce msLandscape, a collection of tools that streamline the creation of customizable landscape‐scale simulations using the popular coalescent simulator ms and conversion of the simulated data for use with un‐PC, SpaceMix and EEMS. 相似文献
19.
Roberto E. Vogler Ariel A. Beltramino Ellen E. Strong Juana G. Peso Alejandra Rumi 《Zoological Journal of the Linnean Society》2015,174(3):487-499
Aylacostoma Spix, 1827, contains species that are the subject of focused conservation efforts under the auspices of the ‘Aylacostoma Project’, the only ex situ conservation programme for freshwater gastropods in South America. Two species from the High Paraná River (Argentina–Paraguay) are included in this programme (Aylacostoma chloroticum Hylton Scott, 1954 and Aylacostoma brunneum Vogler & Peso, 2014), as their habitats have disappeared as a consequence of the filling of the Yacyretá Reservoir in the 1990s. At present, A. chloroticum is restricted to only one known wild population in a small and fragile habitat, and wild populations of A. brunneum are presumed to have gone extinct. We used partial sequences of the cytochrome oxidase subunit I gene to provide the first phylogeographical perspective on these species from a limited dataset containing representatives of several wild populations that are successfully being bred in captivity. We found low genetic diversity and two haplotypes in A. chloroticum, and absence of variation with one haplotype in A. brunneum. The reservoir's entry zone was identified to be of great interest for conservation, and is where we suggest re‐introductions and translocations should be targeted, to preserve the future evolutionary potential of the extant diversity. © 2015 The Linnean Society of London 相似文献
20.
Species and their geographical distributions, tabulated either from regional faunal and floral monographs or directly from natural history collections, often are used as the basic units of analysis by ecologists and biogeographers. It has been argued that in order for species to be operationally useful units for evolutionary and ecological studies, they need to be recognizable and identifiable as distinct entities. A growing body of molecular phylogeographic studies demonstrates that currently recognized species often are unreliable in their approximation of fundamental evolutionary and geographical units, leading, for example, to proposed usage of molecular-based evolutionarily significant units in lieu of species in conservation biology. We argue that ecologists and bio- geographers should likewise employ evolutionarily significant units as basic units of analysis when evidence clearly indicates that a formally recognized species either fails to convey important evolutionary and geographical information (i.e. includes multiple geographically distinct evolu- tionary lineages) or fails to delineate a natural entity (i.e. does not represent a monophyletic set of populations). We demonstrate the limitations of current species as evolutionary, geographical, and conservation units within the ecologically well-studied North American desert rodent assemblage. We suggest that biotic surveys should be designed to allow the efficient assembly and dissemination of molecular phylogeographic data from ecologically and biogeographically representative systems. 相似文献