共查询到20条相似文献，搜索用时 15 毫秒
1.
Kate L. Sanders Arne R. Rasmussen Mumpuni Johan Elmberg Anslem de Silva Michael L. Guinea Michael S. Y. Lee 《Molecular ecology》2013,22(10):2742-2759
The viviparous sea snakes (Hydrophiinae) are a young radiation of at least 62 species that display spectacular morphological diversity and high levels of local sympatry. To shed light on the mechanisms underlying sea snake diversification, we investigated recent speciation and eco‐morphological differentiation in a clade of four nominal species with overlapping ranges in Southeast Asia and Australia. Analyses of morphology and stomach contents identified the presence of two distinct ecomorphs: a ‘macrocephalic’ ecomorph that reaches >2 m in length, has a large head and feeds on crevice‐dwelling eels and gobies; and a ‘microcephalic’ ecomorph that rarely exceeds 1 m in length, has a small head and narrow fore‐body and hunts snake eels in burrows. Mitochondrial sequences show a lack of reciprocal monophyly between ecomorphs and among putative species. However, individual assignment based on newly developed microsatellites separated co‐distributed specimens into four significantly differentiated clusters corresponding to morphological species designations, indicating limited recent gene flow and progress towards speciation. A coalescent species tree (based on mitochondrial and nuclear sequences) and isolation‐migration model (mitochondrial and microsatellite markers) suggest between one and three transitions between ecomorphs within the last approximately 1.2 million to approximately 840 000 years. In particular, the macrocephalic ‘eastern’ population of Hydrophis cyanocinctus and microcephalic H. melanocephalus appear to have diverged very recently and rapidly, resulting in major phenotypic differences and restriction of gene flow in sympatry. These results highlight the viviparous sea snakes as a promising system for speciation studies in the marine environment. 相似文献
2.
《Insect Conservation and Diversity》2018,11(4):363-369
- Global climate change causes range shifts in many insects. Urban areas and south‐facing slopes may provide a warmer environment for newcomers adapted to warmer climatic conditions. The German wasp (Vespula germanica, Fabricius, 1793), which is native to central and southern Europe, has been expanding its range into Southern Finland since 2001.
- The association between the German wasp and its sister species, the common wasp (V. vulgaris Linnaeus, 1758), with urban areas was studied in three cities in Finland. In addition, the numbers of German wasp catches during 7 years on south‐ and north‐facing riverbank slopes in SW‐Finland were compared and the association with spring temperature was analysed.
- The newcomer German wasp seemed to be associated with urban areas, while its sister species was associated with rural areas in two of the cities and urban areas in one of the three studied cities. In addition, the German wasp was more common in south‐facing than in north‐facing slopes of the river valley, while the direction of the slope was less important for the common wasp. Finally, the abundance of the German wasp but not the common wasp has increased with an increase in spring temperature.
- The preference of the German wasp for urban habitats and south‐facing slopes in Finland may be because those habitats are usually warmer than their surroundings and the species is well adapted for urban environments. These environments can act as stepping stones in species’ range shifts driven by climate change.
3.
Thomas J. Givnish Daniel Spalink Mercedes Ames Stephanie P. Lyon Steven J. Hunter Alejandro Zuluaga Alfonso Doucette Giovanny Giraldo Caro James McDaniel Mark A. Clements Mary T. K. Arroyo Lorena Endara Ricardo Kriebel Norris H. Williams Kenneth M. Cameron 《Journal of Biogeography》2016,43(10):1905-1916
4.
Melita Vamberger Louise Durkin Chamnan Kim Markus Handschuh Rattanak Seng Uwe Fritz 《Journal of Zoological Systematics and Evolutionary Research》2017,55(2):167-174
Cambodia is known to harbour three distinct species of Southeast Asian leaf turtles (Cyclemys spp.), which are heavily traded and common in seizures of wildlife. Confiscated leaf turtles are often released to natural habitats. Thus, an exact knowledge of the distribution of the individual species is of great importance to avoid the introduction of non‐native turtles, posing the risk of competition and hybridization. In this study, we examine a recently discovered leaf turtle population from Phnom Kulen National Park using external morphology, 17 unlinked microsatellite loci and the mitochondrial cytochrome b gene. Leaf turtles from the Phnom Kulen National Park morphologically resemble C. oldhamii, but harbour mitochondrial haplotypes of C. atripons. With respect to microsatellite loci, the turtles are distinct from C. atripons. Unfortunately no material of C. oldhamii was available from Cambodia. We propose that the Phnom Kulen population represents either a natural hybrid swarm of C. atripons and C. oldhamii or a distinct undescribed species with introgressed mitochondria of C. atripons. This underlines that genetic differentiation of wild leaf turtle populations in Cambodia is complex and suggests that this differentiation pattern becomes increasingly threatened by translocations of confiscated individuals. For drawing a definite conclusion about the taxonomic status of the Phnom Kulen population, denser sampling of other Cambodian leaf turtle populations would be required, in particular of C. oldhamii. 相似文献
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Parm Viktor von Oheimb Katharina C. M. von Oheimb Takahiro Hirano Tu Van Do Hao Van Luong Jonathan Ablett Sang Van Pham Fred Naggs 《Ecology and evolution》2018,8(8):4136-4149
The insular limestone karsts of northern Vietnam harbor a very rich biodiversity. Many taxa are strongly associated with these environments, and individual species communities can differ considerably among karst areas. The exact processes that have shaped the biotic composition of these habitats, however, remain largely unknown. In this study, the role of two major processes for the assembly of snail communities on limestone karsts was investigated, interspecific competition and filtering of taxa due to geographical factors. Communities of operculate land snails of the genus Cyclophorus were studied using the dry and fluid‐preserved specimen collections of the Natural History Museum, London. Phylogenetic distances (based on a Bayesian analysis using DNA sequence data) and shell characters (based on 200 semilandmarks) were used as proxies for ecological similarity and were analyzed to reveal patterns of overdispersion (indicating competition) or clustering (indicating filtering) in observed communities compared to random communities. Among the seven studied karst areas, a total of 15 Cyclophorus lineages were found. Unique communities were present in each area. The analyses revealed phylogenetic overdispersion in six and morphological overdispersion in four of seven karst areas. The pattern of frequent phylogenetic overdispersion indicated that competition among lineages is the major process shaping the Cyclophorus communities studied. The Coastal Area, which was phylogenetically overdispersed, showed a clear morphological clustering, which could have been caused by similar ecological adaptations among taxa in this environment. Only the community in the Cuc Phuong Area showed a pattern of phylogenetic clustering, which was partly caused by an absence of a certain, phylogenetically very distinct group in this region. Filtering due to geographical factors could have been involved here. This study shows how museum collections can be used to examine community assembly and contributes to the understanding of the processes that have shaped karst communities in Vietnam. 相似文献
6.
Shifting cultivation is a widespread land‐use in the tropics that is considered a major threat to rainforest diversity and structure. In the Philippines, a country with rich biodiversity and high rates of species endemism, shifting cultivation, locally termed as kaingin, is a major land‐use and has been for centuries. Despite the potential impact of shifting cultivation on forests and its importance to many people, it is not clear how biodiversity and forest structure recover after kaingin abandonment in the country, and how well these post‐kaingin secondary forests can complement the old‐growth forests. We investigated parameters of forest diversity and structure along a fallow age gradient in secondary forests regenerating after kaingin abandonment in Leyte Island, the Philippines (elevation range: 445–650 m asl). We first measured the tree diversity and forest structure indices in regenerating secondary forests and old‐growth forest. We then measured the recovery of tree diversity and forest structure parameters in relation to the old‐growth forest. Finally, using linear mixed effect models (LMM), we assessed the effect of different environmental variables on the recovery of forest diversity and structure. We found significantly higher species density in the oldest fallow sites, while Shannon’s index, species evenness, stem number, basal area, and leaf area index were higher in the old‐growth forest. A homogeneous species composition was found across the sites of older fallow age. Multivariate analysis revealed patch size as a strong predictor of tree diversity and forest structure recovery after shifting cultivation. Our study suggests that, secondary forests regenerating after shifting cultivation abandonment can recover rapidly. Although recovery of forest structure was not as rapid as the tree diversity, our older fallow sites contained a similar number of species as the old‐growth forest. Many of these species are also endemic to the Philippines. Novel and emerging ecosystems like tropical secondary forests are of high conservation importance and can act as a refuge for dwindling tropical forest biodiversity. 相似文献
7.
Benjamin J. Wainwright Geoffrey L. Zahn Joshua Zushi Nicole Li Ying Lee Jillian Lean Sim Ooi Jen Nie Lee Danwei Huang 《Ecology and evolution》2019,9(19):11288-11297
Marine fungal biodiversity remains vastly understudied, and even less is known of their biogeography and the processes responsible for driving these distributions in marine environments. We investigated the fungal communities associated with the seagrass Enhalus acoroides collected from Singapore and Peninsular Malaysia to test the hypothesis that fungal communities are homogeneous throughout the study area. Seagrass samples were separated into different structures (leaves, roots, and rhizomes), and a sediment sample was collected next to each plant. Amplicon sequencing of the fungal internal transcribed spacer 1 and subsequent analysis revealed significant differences in fungal communities collected from different locations and different structures. We show a significant pattern of distance decay, with samples collected close to each other having more similar fungal communities in comparison with those that are more distant, indicating dispersal limitations and/or differences in habitat type are contributing to the observed biogeographic patterns. These results add to our understanding of the seagrass ecosystem in an understudied region of the world that is also the global epicenter of seagrass diversity. This work has implications for seagrass management and conservation initiatives, and we recommend that fungal community composition be a consideration for any seagrass transplant or restoration programme. 相似文献
8.
Brittney Kajdacsi Federico Costa Chaz Hyseni Fleur Porter Julia Brown Gorete Rodrigues Helena Farias Mitermayer G. Reis James E. Childs Albert I. Ko Adalgisa Caccone 《Molecular ecology》2013,22(20):5056-5070
Throughout the developing world, urban centres with sprawling slum settlements are rapidly expanding and invading previously forested ecosystems. Slum communities are characterized by untended refuse, open sewers and overgrown vegetation, which promote rodent infestation. Norway rats (Rattus norvegicus) are reservoirs for epidemic transmission of many zoonotic pathogens of public health importance. Understanding the population ecology of R. norvegicus is essential to formulate effective rodent control strategies, as this knowledge aids estimation of the temporal stability and spatial connectivity of populations. We screened for genetic variation, characterized the population genetic structure and evaluated the extent and patterns of gene flow in the urban landscape using 17 microsatellite loci in 146 rats from nine sites in the city of Salvador, Brazil. These sites were divided between three neighbourhoods within the city spaced an average of 2.7 km apart. Surprisingly, we detected very little relatedness among animals trapped at the same site and found high levels of genetic diversity, as well as structuring across small geographical distances. Most FST comparisons among sites were statistically significant, including sites <400 m apart. Bayesian analyses grouped the samples in three genetic clusters, each associated with distinct sampling sites from different neighbourhoods or valleys within neighbourhoods. These data indicate the existence of complex genetic structure in R. norvegicus in Salvador, linked to the heterogeneous urban landscape. Future rodent control measures need to take into account the spatial and temporal linkage of rat populations in Salvador, as revealed by genetic data, to develop informed eradication strategies. 相似文献
9.
Gabriele Marranci 《The Australian journal of anthropology》2015,26(2):276-292
In recent years discussion about female genital mutilation (FGM) has expanded and the UN has recently called for a universal ban of the practice. The practice in Southeast Asia is widespread among Malay Muslims and, although different styles and practices exist, procedures conducted in medical clinics are extremely minor and, according to gynaecological research, have no effect on sexuality due to the clitoris being left totally untouched. One of the states in which Malay Muslims maintain such a tradition is Singapore. Nonetheless, Singapore is rarely mentioned in academic studies or even in reports discussing the ritual. Even inside Singapore, only Malays tend to know of the tradition, while other ethnic groups remain oblivious to the fact that Singapore is among the states that allow such an operation. The present article does not discuss FGM per se and avoids contributing to the diatribe about labels and values, although these are, of course, extremely relevant. Instead it focuses on the reasons for the practice remaining hidden and undiscussed in Singapore, so much so that some respondents did not know that they had been circumcised. 相似文献
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Sophie L. Rasmussen Thomas B. Berg Torben Dabelsteen Owen R. Jones 《Ecology and evolution》2019,9(23):13174-13187
- European hedgehog (Erinaceus europaeus) populations are widespread across diverse habitats but are declining in Western Europe. Drastic declines have been described in the UK, with the most severe declines occurring in rural areas. Hedgehogs are widely distributed in Denmark, but their status remains unknown.
- Fieldwork on hedgehogs has tended to focus on rural areas, leaving their ecology in suburban habitats largely unexplored, with clear implications for conservation initiatives. Here, we study the ecology of 35 juvenile hedgehogs using radio tracking during their first year of life in the suburbs of western Copenhagen.
- We use radio‐tracking data to estimate (a) home range sizes in autumn and spring/summer, (b) survival during their first year of life, (c) the body mass changes before, during, and after hibernation, and (d) the hibernation behavior of the juvenile hedgehogs.
- We show that males and females have small home ranges compared with previous studies. The 95% MCP home range sizes in autumn were 1.33 ha (95% CI = 0.88–2.00) for males and 1.40 ha (95% CI = 0.84–2.32) for females; for spring/summer they were 6.54 ha (95% CI = 3.76–11.38) for males and 1.51 ha (95% CI = 0.63–3.63) for females. The juvenile survival probabilities during the study period from September 2014 to July 2015 were .56 for females and .79 for males. All healthy individuals gained body mass during the autumn and survived hibernation with little body mass loss thus demonstrating that the juveniles in the study were capable of gaining sufficient weight in the wild to survive their first hibernation.
- The climate is changing, but there is a lack of knowledge on how this affects mammal ecology. The exceptionally mild autumn of 2014 caused the juvenile hedgehogs to delay hibernation for up to a month compared with previous studies in Denmark.
12.
Potential declines in native pollinator communities and increased reliance on pollinator‐dependent crops have raised concerns about native pollinator conservation and dispersal across human‐altered landscapes. Bumble bees are one of the most effective native pollinators and are often the first to be extirpated in human‐altered habitats, yet little is known about how bumble bees move across fine spatial scales and what landscapes promote or limit their gene flow. In this study, we examine regional genetic differentiation and fine‐scale relatedness patterns of the yellow‐faced bumble bee, Bombus vosnesenskii, to investigate how current and historic habitat composition impact gene flow. We conducted our study across a landscape mosaic of natural, agricultural and urban/suburban habitats, and we show that B. vosnesenskii exhibits low but significant levels of differentiation across the study system (FST = 0.019, Dest = 0.049). Most importantly, we reveal significant relationships between pairwise FST and resistance models created from contemporary land use maps. Specifically, B. vosnesenskii gene flow is most limited by commercial, industrial and transportation‐related impervious cover. Finally, our fine‐scale analysis reveals significant but declining relatedness between individuals at the 1–9 km spatial scale, most likely due to local queen dispersal. Overall, our results indicate that B. vosnesenskii exhibits considerable local dispersal and that regional gene flow is significantly limited by impervious cover associated with urbanization. 相似文献
13.
Brigitte Fiala Konstans Wells Julia Haubenreisser Andreas Pittroff Sinan Kaya‐Zeeb Arthur Y. C. Chung Rosli Bin Hashim Alexander Keller 《Biological journal of the Linnean Society. Linnean Society of London》2015,116(3):558-570
Thrips (Thysanoptera) have been recorded as pollinators of various plant species, but they are mostly regarded to be of low ecological relevance. In Southeast Asia, thrips were recently discovered to pollinate flowers of several taxonomic sections of the pioneer tree genus Macaranga (Euphorbiaceae), which is particularly well known as an ant‐plant, and for its importance in early forest succession. The lack of taxonomic treatment and of knowledge about systematic relationships among extant thrips, however, has prevented firm conclusions on the specificity of this plant–pollinator interaction. Here, results from sequencing of the mitochondrial cytochrome oxidase subunit support our previous morphospecies concept of Macaranga flower thrips, and confirm the genetic identity of five recently described species. They were remarkably all assigned to the genus Dolichothrips (Phlaeothripidae), which typically consists of phytophagous species. In addition, the molecular data revealed one cryptic species. A first phylogenetic tree of the Dolichothrips associated with Macaranga provides insights into their systematic position. In particular, we identify monophyly of all important Macaranga pollinator species, all species being largely specific to particular taxonomic host plant sections. Our results suggest a closely matched diversification of pollinating thrips with Macaranga trees. This adds a novel type of association to thrips pollinator–plant interactions, which have been so far documented as single‐species interactions or generalist thrips species visiting multiple plant taxa. 相似文献
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Amy M. Savage Britn Hackett Benoit Gunard Elsa K. Youngsteadt Robert R. Dunn 《Insect Conservation and Diversity》2015,8(3):216-228
- Global urbanisation is rapidly expanding and most of the world's humans now live in cities. Most ecological studies have, however, focused on protected areas.
- To address this issue, we tested predictions from studies of protected areas in urban ecosystems.
- Because most cities are heterogeneous habitat mosaics which include habitats with varying levels of chronic environmental stress, we focused on predictions from studies of less modified ecosystems about community‐wide responses to variation in chronic stress.
- We sampled ants across Manhattan's urban habitat mosaic, at sites with varying levels of chronic environmental stress.
- Many predictions derived from less modified ecosystems were supported by our findings: despite being the most intensively sampled habitat, high stress urban medians had less variability in ant composition –both within and among sites – than either urban parks or urban forests, the lowest stress habitat – urban forests‐had significantly more accumulated species and a higher number of unique species than higher stress habitats, and urban parks, which have intermediate levels of chronic environmental stress, also had intermediate levels of variation in among‐site species composition, accumulated species richness, and the incidence of unique species. The most common species also differed across Manhattan's urban habitat mosaic.
- Nevertheless, the prediction that exotic species would occur more frequently in higher stress habitats was not supported; exotic species were equally common across all habitats.
- These findings suggest that fine‐scale heterogeneity in the chronic stress of urban habitats may be an underappreciated, but important structuring force for urban animal communities.
17.
SIMONE FATTORINI 《Insect Conservation and Diversity》2011,4(4):307-315
Abstract. 1. Urbanisation is an obvious cause of insect extinction, but few studies have investigated insect species loss in urban areas, and the importance of urban environment in conservation biology is controversial. 2. Urban Rome offered a unique possibility to study whether species rarity predisposes a species to extinction, and how urban green spaces are important in insect conservation. On the basis of records collected in more than one century, tenebrionid beetle extinction in Rome was related to a multidimensional characterisation of species rarity based on geographical range, ecological tolerance and local abundance. From these measures, a vulnerability index was derived. All measures of rarity and the vulnerability index were correlated with species decline: rare species disappeared earlier. 3. Identification of ecological correlates of extinction proneness is an important task in conservation biology, yet few studies have addressed this issue for insects. Tenebrionid extinction in urban Rome indicates that vulnerability measures based on rarity traits are strong predictors of species decline. 4. Most of tenebrionids living in urban Rome are not rare and the urban area is an important hold for few species of conservation concern. This suggests that contrary to current practice, insect conservation programmes in an urban area should be more addressed to single species action plans than protection of as many areas as possible. 相似文献
18.
Due to anthropogenic activities, tropical rain forests face many challenges in sustaining biodiversity and maintaining global climates. This study explores how forest successional stage, tree composition, and stratum affect communities of saproxylic cerambycid beetles—concealed feeders that play important roles in forest nutrient cycling. Forty trees in five families (Fabaceae, Lecythidaceae, Malvaceae, Moraceae, and Sapotaceae) were sampled in a mosaic of old‐growth and secondary forest on the Osa Peninsula, Costa Rica. Bait branches yielded 3549 cerambycid individuals in 49 species. Species richness was almost identical in old‐growth and secondary forest, and both yielded specialists, but abundance was higher in old‐growth forest. Overall community structure was most strongly influenced by host plant species; within most plant families it was also impacted by forest successional status. Moraceae was the exception, presumably because the focal tree species was abundant in both old‐growth and secondary forest. Several host and old‐growth specialist species reached high densities within patches of old‐growth forest, but seldom colonized apparently suitable trees within secondary forest. This suggests that even small areas of old‐growth forest can act as refuges, but that secondary forest may act as a barrier to dispersal. The vulnerability of specialized saproxylic insects to land use change will be linked to the ability of their preferred hosts to disperse to and persist in successional habitats; rearing studies may provide the most accurate method to monitor community changes over time. 相似文献
19.
The taxonomic history of the diatom genus Amphora is one of a broad early morphological concept resulting in the inclusion of a diversity of taxa, followed by an extended period of revision and refinement. The introduction of molecular systematics has increased the pace of revision and has largely resolved the relationships between the major lineages, indicating homoplasy in the evolution of amphoroid symmetry. Within the two largest monophyletic lineages, the genus Halamphora and the now taxonomically refined genus Amphora, the intrageneric morphological and ecological relationships have yet to be explored within a phylogenetic framework. Critical among this is whether the range of morphological features exhibited within these diverse genera are reflective of evolutionary groupings or, as with many previously studied amphoroid features, are nonhomologous when examined phylogenetically. Presented here is a four‐marker molecular phylogeny that includes 31 taxa from the genus Amphora and 77 taxa from the genus Halamphora collected from fresh, brackish, and salt waters from coastal and inland habitats of the United States and Japan. These phylogenies illustrate complex patterns in the evolution of frustule morphology and ecology within the genera and the implications of this on the taxonomy, classification, and organization of the genera are discussed. 相似文献
20.
The false spider crabs of the family Hymenosomatidae are one of the most poorly known group of brachyuran crabs in Southeast Asia. This is largely attributed to their small size and cryptic behaviour. Despite the many studies of decapods in Southeast Asia, only eleven species of hymenosomatids are known. Of these, two genera and six species were only described in the last two years. From Singapore the largest number of species (five) has been reported probably because it has been the best explored, while from Thailand three species and Peninsular Malaysia two species are known. There are no published records of hymenosomatids from Borneo or Java. The hymenosomatid fauna is perhaps best known in Australia and New Zealand. It is anticipated that when proper collections are made and studies implemented, the Southeast Asian hymenosomatid fauna will prove to be more diverse than what has been reported. The ecology of the Southeast Asian species is reviewed, especially in the view that two species are completely freshwater, one of which is a troglobite. Most species are littoral or sublittoral in habit and very sensitive to human activities (e.g. pollution). 相似文献