39 research outputs found

    Spatial genetic structure patterns of phenotype-limited and boundary-limited expanding populations: a simulation study.

    Get PDF
    Range expansions may create a unique spatial genetic pattern characterized by alternate genetically homogeneous domains and allele frequency clines. Previous attempts to model range expansions have mainly focused on the loss of genetic diversity during expansions. Using individual-based models, we examined spatial genetic patterns under two expansion scenarios, boundary-limited range expansions (BLRE) and phenotype-limited range expansions (PhLRE). Our simulation revealed that the genetic diversity within populations lost quickly during the range expansion, while the genetic difference accumulated between populations. Consequently, accompanying the expansions, the overall diversity featured a slow decrease. Specifically, during BLREs, high speed of boundary motion facilitated the maintenance of total genetic diversity and sharpened genetic clines. Very slight constraints on boundary motion of BLREs drastically narrowed the homogeneous domains and increased the allele frequency fluctuations from those levels exhibited by PhLREs. Even stronger constraints, however, surprisingly brought the width of homogeneous domains and the allele frequency fluctuations back to the normal levels of PhLREs. Furthermore, high migration rates maintained a higher total genetic diversity than low ones did during PhLREs. Whereas, the total genetic diversities during BLREs showed a contrary pattern: higher when migration was low than those when migration was high. Besides, the increase of migration rates helped maintain a greater number of homogeneous domains during PhLREs, but their effects on the number of homogeneous domains during BLREs were not monotonous. Previous studies have showed that the homogenous domains can merge to form a few broad domains as the expansion went on, leading to fewer homogeneous domains. Our simulations, meanwhile, revealed that the range expansions could also rebuild homogeneous domains from the clines during the range expansion. It is possible that that the number of homogeneous domains was determined by the interaction of merging and newly emerging homogeneous domains

    Genotyping faeces of red pandas (Ailurus fulgens): implications for population estimation

    No full text
    The red panda (Ailurus fulgens) is an endangered species distributed in the Himalaya and Hengduan Mountains and extremely difficult to monitor because it is elusive, wary and nocturnal. However, recent advances in noninvasive genetics are allowing conservationists to indirectly estimate population size of this animal. Here, we present a pilot study of individual identification of wild red pandas using DNA extracted from faeces. A chain of optimal steps in noninvasive studies were used to maximize genotyping success and minimize error rate across sampling, selection of microsatellite loci, DNA extraction and amplification and data checking. As a result, 18 individual red pandas were identified successfully from 33 faecal samples collected in the field using nine red panda-specific microsatellite loci with a low probability of identity of 1.249 × 10−3 for full siblings. Multiple methods of tracking genotyping error showed that the faecal genetic profiles possessed very few genotyping errors, with an overall error rate of 1.12 × 10−5. Our findings demonstrate the feasibility and reliability of using faeces as an effective source of DNA for estimating and monitoring wild red panda populations

    Characterization of the complete mitochondrial genome of Otus lettia: exploring the mitochondrial evolution and phylogeny of owls (Strigiformes)

    No full text
    Large-scale molecular phylogenetic studies of the avian order Strigiformes have been performed, and numerous mitochondrial genomes have been determined. However, their intergeneric relationships are still controversial, and few comprehensive comparative analyses of mitochondrial genomes have been conducted on Strigiformes. In this study, the mitochondrial genome of Otus lettia was determined and compared with other Strigiformes. The O. lettia mitochondrial genome was 16,951 bp in size. For Strigiformes, atp8 can be used as a suitable molecular marker for population genetic diversity, while cox1 is a candidate barcoding marker for species identification. All protein-coding genes may be under strong purifying selection pressure, and one extra cytosine insertion located in nad3 is common to all owls except Tyto longimembris, T. alba, and Athene noctua. Four different mitochondrial gene arrangement types were found among the Strigiformes mitogenomes, and their evolutionary relationship between each other can be perfectly explained by the tandem duplication and random loss model. The phylogenetic topologies using the mitochondrial genomes showed that target species O. lettia had a closer relationship with O. scops + O. sunia than O. bakkamoena, the genus Glaucidium was paraphyletic, and the Ninox clade was located at the basal position of Strigidae lineage. Our phylogenetic trees also supported the previous recommendations that Sceloglaux albifacies, Ciccaba nigrolineata, and Ketupa flavipes should be transferred to Ninox, Strix, and Bubo, respectively. These findings will be helpful in further unraveling the mitochondrial evolution and phylogeny of Strigiformes

    Metabolic rate of the red panda, Ailurus fulgens, a dietary bamboo specialist.

    No full text
    The red panda (Ailurus fulgens) has a similar diet, primarily bamboo, and shares the same habitat as the giant panda, Ailuropoda melanoleuca. There are considerable efforts underway to understand the ecology of the red panda and to increase its populations in natural reserves. Yet it is difficult to design an effective strategy for red panda reintroduction if we do not understand its basic biology. Here we report the resting metabolic rate of the red panda and find that it is higher than previously measured on animals from a zoo. The resting metabolic rate was 0.290 ml/g/h (range 0.204-0.342) in summer and 0.361 ml/g/h in winter (range 0.331-0.406), with a statistically significant difference due to season and test temperature. Temperatures in summer were probably within the thermal neutral zone for metabolism but winter temperatures were below the thermal neutral zone. There was no difference in metabolic rate between male and female red pandas and no difference due to mass. Our values for metabolic rate were much higher than those measured by McNab for 2 red pandas from a zoo. The larger sample size (17), more natural conditions at the Panda Base and improved accuracy of the metabolic instruments provided more accurate metabolism measurements. Contrary to our expectations based on their low quality bamboo diet, the metabolic rates of red pandas were similar to mammals of the same size. Based on their metabolic rates red pandas would not be limited by their food supply in natural reserves

    Genetic structuring and recent demographic history of red pandas (Ailurus fulgens) inferred from microsatellite and mitochondrial DNA

    No full text
    Clarification of the genetic structure and population history of a species can shed light on the impacts of landscapes, historical climate change and contemporary human activities and thus enables evidence-based conservation decisions for endangered organisms. The red panda (Ailurus fulgens) is an endangered species distributing at the edge of the Qinghai-Tibetan Plateau and is currently subject to habitat loss, fragmentation and population decline, thus representing a good model to test the influences of the above-mentioned factors on a plateau edge species. We combined nine microsatellite loci and 551 bp of mitochondrial control region (mtDNA CR) to explore the genetic structure and demographic history of this species. A total of 123 individuals were sampled from 23 locations across five populations. High levels of genetic variation were identified for both mtDNA and microsatellites. Phylogeographic analyses indicated little geographic structure, suggesting historically wide gene flow. However, microsatellite-based Bayesian clustering clearly identified three groups (Qionglai-Liangshan, Xiaoxiangling and Gaoligong-Tibet). A significant isolation-by-distance pattern was detected only after removing Xiaoxiangling. For mtDNA data, there was no statistical support for a historical population expansion or contraction for the whole sample or any population except Xiaoxiangling where a signal of contraction was detected. However, Bayesian simulations of population history using microsatellite data did pinpoint population declines for Qionglai, Xiaoxiangling and Gaoligong, demonstrating significant influences of human activity on demography. The unique history of the Xiaoxiangling population plays a critical role in shaping the genetic structure of this species, and large-scale habitat loss and fragmentation is hampering gene flow among populations. The implications of our findings for the biogeography of the Qinghai-Tibetan Plateau, subspecies classification and conservation of red pandas are discussed

    A Review of Membrane Computing Models for Complex Ecosystems and a Case Study on a Complex Giant Panda System

    No full text
    Ecosystem modelling based on membrane computing is emerging as a powerful way to study the dynamics of (real) ecological populations. *ese models, providing distributed parallel devices, have shown a great potential to imitate the rich features observed in the behaviour of species and their interactions and key elements to understand and model ecosystems. Compared with differential equations, membrane computing models, also known as P systems, can model more complex biological phenomena due to their modularity and their ability to enclose the evolution of different environments and simulate, in parallel, different interrelated processes. In this paper, a comprehensive survey of membrane computing models for ecosystems is given, taking a giant panda ecosystem as an example to assess the model performance. *is work aims at modelling a number of species using P systems with different membrane structure types to predict the number of individuals depending on parameters such as reproductive rate, mortality rate, and involving processes as rescue or release. Firstly, the computing models are introduced conceptually, describing the main elements constituting the syntax of these systems and explaining the semantics of the rules involved. Next, various modelled species (including endangered animals, plants, and bacteria) are summarized, and some computer tools are presented. *en, a discussion follows on the use of P systems for ecosystem modelling. Finally, a case study on giant pandas in Chengdu Base is analysed, concluding that the study in this field by using PDP systems can provide a valuable tool to deepen into the knowledge about the evolution of the population. *is could ultimately help in the decision-making processes of the managers of the ecosystem to increase the species diversity and modify the adaptability. Besides, the impacts of natural disasters on the population dynamics of the species should also be considered. *e analysis performed throughout the paper has taken into consideration this fact in order to increase the reliability of the prospects making use of the models designed.Ministerio de Economía, Industria y Competitividad TIN2017-89842-P (MABICAP
    corecore