共查询到20条相似文献，搜索用时 15 毫秒
1.
Prochilodus magdalenae is an endemic freshwater fish that occurs in the Magdalena, Sinú and Atrato hydrographic basins. It has an important economic role and is a food resource for the artisanal fishing communities. Its socioeconomic importance contrasts with the current status of its fisheries, where stocks are being depleted. Considering its importance and lack of information on its genetic structure, we used seven microsatellite markers to assess the genetic structure of wild populations of P. magdalenae. The genetic diversity was assessed and the population genetic structure was estimated through Fst, analysis of molecular variance and Bayesian analysis. A total of 290 alleles were found in all loci throughout all population. The high polymorphism contrasts with the levels of observed heterozygosity (Ho = 0.276), which are the lowest values recorded for the family. We found three populations of bocachico coexisting throughout the studied system, contradicting the hypothesis that freshwater migratory fish form panmictic populations. These results on the genetic structure of P. magdalenae constitute tools for a better understanding of the behavior and biology of this species, contributing to fish management and conservation programs. 相似文献
2.
JORGE GONZÁLEZ-ASTORGA REW P. VOVIDES PABLO OCTAVIO-AGUILAR DANIEL AGUIRRE-FEY FERNANDO NICOLALDE-MOREJÓN CARLOS IGLESIAS 《Botanical journal of the Linnean Society. Linnean Society of London》2006,152(4):533-544
The genetic diversity and structure of four populations of the cycad Zamia loddigesii were studied throughout its range in Mexico. Allozyme electrophoresis of 15 loci was conducted. The mean number of alleles per locus was 1.80 ± 0.09, the percentage of polymorphic loci was 66.6 ± 5.4, and the expected heterozygosity was 0.266 ± 0.02. The results indicated that the genetic diversity was relatively higher, with respect to tropical tree species and other cycads. The genetic variation explained by differences among populations was 18%. On average, gene flow between paired populations was similar ( Nm = 1.6) to other tropical forest trees and cycad species. Our results indicated that the geographical isolation among populations of Z. loddigesii generated allele loss, as well as a clinal variation in the frequencies of two loci ( MDH and MNR2 ), in relation to the latitudinal distribution of populations. The populations have become fragmented due to increasingly higher pressure of habitat conversion and disturbance. The importance of the establishment of sanctuaries and protected areas and a reduction in deforestation is highlighted in this research as a way of preserving the high genetic diversity of this and other endemic species. © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 152 , 533–544. 相似文献
3.
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
4.
评世界保护联盟新的物种受威胁分类系统草案 总被引：2，自引：0，他引：2
王献溥 《植物资源与环境学报》1994,3(4):55-58
为了进一步了解物种受威胁的情况和发展,以加强物种保护工作,世界保护联盟制定了一个新的物种受威胁分类系统草案,把物种受威胁的程度分为９个级别,即绝灭种、野生状态下的绝灭种、极危种、濒危种、渐危种、敏感种、安全的／危险性小的种、不充分了解的种和未估价的种。本文对这个分类系统草案作了简略的评介。 相似文献
5.
Brumfield RT 《Molecular ecology》2010,19(23):5079-5083
The negative effects of human‐induced habitat disturbance and modification on multiple dimensions of biological diversity are well chronicled ( Turner 1996 ; Harding et al. 1998 ; Lawton et al. 1998 ; Sakai et al. 2001 ). Among the more insidious consequences is secondary contact between formerly allopatric taxa ( Anderson & Hubricht 1938 ; Perry et al. 2002 ; Seehausen 2006 ). How the secondary contact will play out is unpredictable ( Ellstrand et al. 2010 ), but if the taxa are not fully reproductively isolated, hybridization is likely, and if the resulting progeny are fertile, the eventual outcome is often devastating from a conservation perspective ( Rhymer & Simberloff 1996 ; Wolf et al. 2001 ; McDonald et al. 2008 ). In this issue of Molecular Ecology, Steeves et al. (2010) present an analysis of hybridization between two avian species, one of which is critically endangered and the other of which is invasive. Their discovery that the endangered species has not yet been hybridized to extinction is promising and not what one would necessarily expect from theory. 相似文献
6.
Rain forests are expected to be amongst the ecosystem types most affected by fragmentation due to their high species diversity, high endemism, complexity of interactions, and contrast with surrounding altered matrix. Due to their shorter life cycles and dependence on canopy cover, rain forest understory herbs are expected to indicate the effects of recent fragmentation more rapidly than canopy trees. This study investigated all four known species of the genus Romnalda , all of which are rare rain forest herbaceous species, to investigate the possible effects of habitat fragmentation and isolation on genetic diversity and gene flow. Allozymes were used as genetic markers and regional remnant vegetation maps were used to compare landscape fragmentation. We found that R. strobilacea populations in a highly fragmented landscape were genetically depauperate compared with those of its congeneric species that are found within continuous rain forest habitats and that allelic diversity decreased with decreasing population size but not geographic distance in R. strobilacea . Given the similarity among the species, our results indicate that all Romnalda species are potentially susceptible to loss of genetic diversity due to habitat fragmentation within relatively short timeframes. The results indicate that populations are not highly genetically differentiated and there is little evidence of genetic provenance where the species have restricted geographic ranges. Thus, species recovery programs would be better to focus on maintaining population size and genetic diversity rather than population differentiation. 相似文献
7.
Brian Tilston Smith Robert W. Bryson Jr. Derek D. Houston John Klicka 《Ecology letters》2012,15(11):1318-1325
The Tropical Niche Conservatism hypothesis is a leading explanation for why biodiversity increases towards the equator. The model suggests that most lineages have tropical origins, with few dispersing into temperate regions. However, biotas are comprised of lineages with differing geographical origins, thus it is unclear whether lineages that originated on different continents will exhibit similar patterns of niche conservatism. Here, we summarised biogeographical patterns of New World vertebrates and compared species diversity patterns between families that originated in North and South America. Overall, families with southern origins exhibit niche conservatism with many lineages restricted to the Neotropics, whereas many northern‐origin families are distributed across the Neotropics and the Nearctic. Consequently, northern lineages have contributed to high tropical biodiversity, but southern lineages have contributed relatively little to temperate biodiversity in North America. The asymmetry in niche conservatism between northern and southern lineages is an important contributor to the biodiversity gradient. 相似文献
8.
Tian-Tian Xue Xu-Dong Yang Qin Liu Fei Qin Wen-Di Zhang Steven B. Janssens Sheng-Xiang Yu 《植物分类学报：英文版》2023,61(4):682-697
A significant fraction of higher plants in China are threatened due to dramatic landscape transformation and increasing climate change. However, the conservation effectiveness of threatened higher plants (THPs) and their response to climate change are still underexplored to date. Based on the latest list of THPs in China, we obtained 102 593 occurrence records with latitude and longitude for 3858 THPs. By integrating the distribution patterns of three biodiversity indexes (i.e., species richness, species complementarity, and weighted endemism) and 10 plant categories, we identified hotspots for THPs and calculated the conservation effectiveness of nature reserves. We then selected 1959 THPs to project the shift of species richness and range sizes under climate change (representative concentration pathway [RCP] 2.6 and RCP 8.5). In total, 16 hotspot areas covering 7.38% of Chinese land area and containing 91.73% of THPs were identified. Current nature reserves protected 35.05% of hotspots, 73.07% of all THPs, and 56.64% of narrow-ranged species. By the 2070s, the species richness of THPs were predicted to decrease in Southeast and Central China, and 42.42% (RCP 2.6) and 51.40% (RCP 8.5) of the 1959 THPs would confront habitat contraction. Future conservation efforts should focus on the conservation gaps and carry out targeted conservation for THPs with narrow distribution range. In order to cope with climate change, the hotspots with relatively low species loss can serve as important areas to contain current species diversity and the areas with high species gain offer opportunities for ex-situ conservation of THPs. 相似文献
9.
10.
Kristen C. Ruegg Eric C. Anderson Kristina L. Paxton Vanessa Apkenas Sirena Lao Rodney B. Siegel David F. DeSante Frank Moore Thomas B. Smith 《Molecular ecology》2014,23(23):5726-5739
Neotropic migratory birds are declining across the Western Hemisphere, but conservation efforts have been hampered by the inability to assess where migrants are most limited—the breeding grounds, migratory stopover sites or wintering areas. A major challenge has been the lack of an efficient, reliable and broadly applicable method for measuring the strength of migratory connections between populations across the annual cycle. Here, we show how high‐resolution genetic markers can be used to identify genetically distinct groups of a migratory bird, the Wilson's warbler (Cardellina pusilla), at fine enough spatial scales to facilitate assessing regional drivers of demographic trends. By screening 1626 samples using 96 highly divergent single nucleotide polymorphisms selected from a large pool of candidates (~450 000), we identify novel region‐specific migratory routes and timetables of migration along the Pacific Flyway. Our results illustrate that high‐resolution genetic markers are more reliable, precise and amenable to high throughput screening than previously described intrinsic marking techniques, making them broadly applicable to large‐scale monitoring and conservation of migratory organisms. 相似文献
11.
12.
C. Benítez‐Benítez M. Escudero F. Rodríguez‐Sánchez P. Jiménez‐Mejías 《Molecular ecology》2018,27(7):1696-1713
Estimating species ability to adapt to environmental changes is crucial to understand their past and future response to climate change. The Mediterranean Basin has experienced remarkable climatic changes since the Miocene, which have greatly influenced the evolution of the Mediterranean flora. Here, we examine the evolutionary history and biogeographic patterns of two sedge sister species (Carex, Cyperaceae) restricted to the western Mediterranean Basin, but with Pliocene fossil record in central Europe. In particular, we estimated the evolution of climatic niches through time and its influence in lineage differentiation. We carried out a dated phylogenetic–phylogeographic study based on seven DNA regions (nDNA and ptDNA) and fingerprinting data (AFLPs), and modelled ecological niches and species distributions for the Pliocene, Pleistocene and present. Phylogenetic and divergence time analyses revealed that both species form a monophyletic lineage originated in the late Pliocene–early Pleistocene. We detected clear genetic differentiation between both species with distinct genetic clusters in disjunct areas, indicating the predominant role of geographic barriers limiting gene flow. We found a remarkable shift in the climatic requirements between Pliocene and extant populations, although the niche seems to have been relatively conserved since the Pleistocene split of both species. This study highlights how an integrative approach combining different data sources and analyses, including fossils, allows solid and robust inferences about the evolutionary history of a plant group since the Pliocene. 相似文献
13.
Haigen Xu Mingchang Cao Zhi Wang Yi Wu Yun Cao Jun Wu Zhifang Le Peng Cui Hui Ding Wanggu Xu Hua Peng Jianping Jiang Yuhu Wu Xuelong Jiang Zhiyun Zhang Dingqi Rao Jianqiang Li Fumin Lei Nianhe Xia Lianxian Han Wei Cao Jiayu Wu Xin Xia Yimin Li 《Ecology and evolution》2018,8(12):6290-6298
Protected areas are considered as an essential strategy to halt the decline of biodiversity. Ecological representation in protected areas is crucial for assessment on the progress toward conservation targets. Although China has established a large number of protected areas since the 1950s, ecological representation of protected areas is poorly understood. Here, we performed the complementarity analysis to evaluate ecological representation of protected areas in China. We used a database of the geographical distribution for 10,396 woody plant species, 2,305 fern species, 406 amphibian species, 460 reptile species, 1,364 bird species, and 590 mammal species from 2,376 counties across China. We identified complementary sets of counties for all species or threatened species of plant and vertebrate species using a complementarity algorithm. We evaluated ecological representation of 3,627 protected areas and discerned conservation gaps by comparing the distribution of protected areas with complementary sets. The results show that the spatially representative and complementary sites for biodiversity are poorly covered, and a fairly large proportion of protected areas is not designed to efficiently represent biodiversity at the national scale. Our methodology can serve as a generic framework for assessment on ecological representation of protected areas at the national scale. 相似文献
14.
Karoliny de Oliveira;Roberto Leonan M. Novaes;Marcelo M. Weber;Ricardo Moratelli; 《Ecology and evolution》2024,14(6):e11419
Myotis originated during the Oligocene in Eurasia and has become one of the most diverse bat genera, with over 140 species. In the case of neotropical Myotis, there is a high degree of phenotypic conservatism. This means that the taxonomic and geographic limits of several species are not well understood, which constrains detailed studies on their ecology and evolution and how to effectively protect these species. Similar to other organisms, bats may respond to climate change by moving to different areas, adapting to new conditions, or going extinct. Ecological niche models have become established as an efficient and widely used method for interpolating (and sometimes extrapolating) species' distributions and offer an effective tool for identifying species conservation requirements and forecasting how global environmental changes may affect species distribution. How species respond to climate change is a key point for understanding their vulnerability and designing effective conservation strategies in the future. Thus, here, we assessed the impacts of climate change on the past and future distributions of two phylogenetically related species, Myotis ruber and Myotis keaysi. The results showed that the species are influenced by changes in temperature, and for M. ruber, precipitation also becomes important. Furthermore, M. ruber appears to have been more flexible to decreases in temperature that occurred in the past, which allowed it to expand its areas of environmental suitability, unlike M. keaysi, which decreased and concentrated these areas. However, despite a drastic decrease in the spatial area of environmental suitability of these species in the future, there are areas of potential climate stability that have been maintained since the Pleistocene, indicating where conservation efforts need to be concentrated in the future. 相似文献
15.
Ludmilla Moura de Souza Aguiar Renato Oliveira Lopes da Rosa Gareth Jones Ricardo Bomfim Machado 《Austral ecology》2015,40(7):836-844
Ecological niche models have become very popular for analysing the potential distribution of species. Nevertheless, models are strongly influenced by many factors, such as spatial resolution, environmental variables and the quality of distribution records. In this paper, we evaluated how ecological niche models changed with the addition of records accumulated over four decades. Our model species was the stripe‐headed round‐eared bat (Tonatia saurophila). Thus, with data organized in chronological order, we could observe how the models changed in predicting distributions over time in comparison with all known point locations. We tested if partial models could predict the occurrence of new unpublished records for savannah areas in central Brazil, considering that the species is typically associated with forest environments. Our results indicate a high omission rate for models built with point localities from the 1970s and 1980s (58.5% and 50.0% of all known points respectively), and predicted that the species could occur in central Brazil. Although T. saurophila has indeed been recorded recently in central Brazil, it was found in places different from those predicted by the models using these restricted earlier data. Nevertheless, the environmental suitability of such areas is significantly different from sites largely described in earlier records from the Amazonia region, as shown by principal components analysis. We argue that populations of T. saurophila that occupy open habitats in central South America (including Caatinga, Cerrado, Chaco and semi‐deciduous interior forests) deserve further study at the genetic level to determine if bats in these very different habitats are taxonomically distinct from Amazonian populations. Our results also suggest that models based on very limited datasets for species occurrence can lead conservationists or decision makers to wrong conclusions. 相似文献
16.
P. C. Almada-Villela 《Journal of fish biology》1990,37(SA):197-199
17.
18.
Among various potential consequences of rarity is genetic erosion. Neutral genetic theory predicts that rare species will have lower genetic diversity than common species. To examine the association between genetic diversity and rarity, variation at eight DNA microsatellite markers was documented for 14 Acropora species that display different patterns of distribution and abundance in the Indo-Pacific Ocean. Our results show that the relationship between rarity and genetic diversity is not a positive linear association because, contrary to expectations, some rare species are genetically diverse and some populations of common species are genetically depleted. Our data suggest that inbreeding is the most likely mechanism of genetic depletion in both rare and common corals, and that hybridization is the most likely explanation for higher than expected levels of genetic diversity in rare species. A significant hypothesis generated from our study with direct conservation implications is that as a group, Acropora corals have lower genetic diversity at neutral microsatellite loci than may be expected from their taxonomic diversity, and this may suggest a heightened susceptibility to environmental change. This hypothesis requires validation based on genetic diversity estimates derived from a large portion of the genome. 相似文献
19.
全球气候变化与人为活动等因素导致的生物多样性丧失,引起了全球各界对生物多样性保护的高度关注。传统生物多样性保护主要对物种、特有种、受威胁物种的种类组成及其分布模式开展研究,忽视了进化历史在生物多样性保护中的作用。云南是全球生物多样性热点地区的交汇区,生物多样性的保护历来受到广泛关注,为了更好地探讨云南生物多样性的保护措施,该研究以云南被子植物菊类分支物种为研究对象,基于物种间的演化关系,结合其地理分布,从进化历史的角度探讨物种、特有种、受威胁物种的种类组成及系统发育组成的分布格局,并整合自然保护地的空间分布,识别生物多样性的重点保护区域。结果表明：云南被子植物菊类分支的物种、特有种及受威胁物种的物种密度与系统发育多样性均显著正相关;通过零模型分析发现,由南向北标准化系统发育多样性逐渐降低;云南南部、东南部、西北部是云南被子植物菊类分支的重点保护区域,加强这些区域的保护,将最大化地保护生物多样性的进化历史和进化潜能。由此可见,融合进化历史信息的植物多样性格局分析不仅有助于更加深入地理解植物多样性的形成与演变,也为生物多样性保护策略的制定提供更多的思路。 相似文献
20.
E. A. Myers J. A. Rodríguez‐Robles D. F. DeNardo R. E. Staub A. Stropoli S. Ruane F. T. Burbrink 《Molecular ecology》2013,22(21):5418-5429
Phylogeographic inference can determine the timing of population divergence, historical demographic processes, patterns of migration, and when extended to multiple species, the history of communities. Single‐locus analyses can mislead interpretations of the evolutionary history of taxa and comparative analyses. It is therefore important to revisit previous single‐locus phylogeographic studies, particularly those that have been used to propose general patterns for regional biotas and the processes responsible for generating inferred patterns. Here, we employ a multilocus statistical approach to re‐examine the phylogeography of Lampropeltis zonata. Using nonparametic and Bayesian species delimitation, we determined that there are two well‐supported species within L. zonata. Ecological niche modelling supports the delimitation of these taxa, suggesting that the two species inhabit distinct climatic environments. Gene flow between the two taxa is low and appears to occur unidirectionally. Further, our data suggest that gene flow was mediated by females, a rare pattern in snakes. In contrast to previous analyses, we determined that the divergence between the two lineages occurred in the late Pliocene (c. 2.07 Ma). Spatially and temporally, the divergence of these lineages is associated with the inundation of central California by the Monterey Bay. The effective population sizes of the two species appear to have been unaffected by Pleistocene glaciation. Our increased sampling of loci for L. zonata, combined with previously published multilocus analyses of other sympatric species, suggests that previous conclusions reached by comparative phylogeographic studies conducted within the California Floristic Province should be reassessed. 相似文献