In this paper,we focus on the influences of various parameters in the niching genetic algorithm inversion procedure on the results,such as various objective functions,the number of the models in each subpopulation,and...In this paper,we focus on the influences of various parameters in the niching genetic algorithm inversion procedure on the results,such as various objective functions,the number of the models in each subpopulation,and the critical separation radius.The frequency-waveform integration（F-K） method is applied to synthesize three-component waveform data with noise in various epicentral distances and azimuths.Our results show that if we use a zero-th-lag cross-correlation function,then we will obtain the model with a faster convergence and a higher precision than other objective functions.The number of models in each subpopulation has a great influence on the rate of convergence and computation time,suggesting that it should be obtained through tests in practical problems.The critical separation radius should be determined carefully because it directly affects the multiextreme values in the inversion.We also compare the inverted results from full-band waveform data and surfacewave frequency-band（0.02-0.1 Hz） data,and find that the latter is relatively poorer but still has a higher precision,suggesting that surface-wave frequency-band data can also be used to invert for the crustal structure.展开更多
Optimization implies the minimization or maximization of an objective function. Some problems have sev-eral optimum points which all, should be computed. Niching method is presented to do so. However, its efficiency c...Optimization implies the minimization or maximization of an objective function. Some problems have sev-eral optimum points which all, should be computed. Niching method is presented to do so. However, its efficiency can be improved via combining it with Memetic algorithm. Therefore, in this paper, Memetic method is used to improve this method in terms of convergence rate and diversity. In the proposed methods, genetic algorithm, PSO, and learning automata are used as a local search algorithm of Memetic method. The result of simulations demonstrates that proposed methods are more effective compared with Niching in terms of convergence and diversity.展开更多
This study analyzes drift phenomena of deterministic crowding and probabilistic crowding by using equivalence class model and expectation proportion equations. It is proved that the replacement errors of deterministic...This study analyzes drift phenomena of deterministic crowding and probabilistic crowding by using equivalence class model and expectation proportion equations. It is proved that the replacement errors of deterministic crowding cause the population converging to a single individual, thus resulting in premature stagnation or losing optional optima. And probabilistic crowding can maintain equilibrium multiple subpopulations as the population size is adequate large. An improved niching method using clustering crowding is proposed. By analyzing topology of fitness landscape using hill valley function and extending the search space for similarity analysis, clustering crowding determines the locality of search space more accurately, thus greatly decreasing replacement errors of crowding. The integration of deterministic and probabilistic replacement increases the capacity of both parallel local hill climbing and maintaining multiple subpopulations. The experimental results optimizing various multimodal functions show that,the performances of clustering crowding, such as the number of effective peaks maintained, average peak ratio and global optimum ratio are uniformly superior to those of the evolutionary algorithms using fitness sharing, simple deterministic crowding and probabilistic crowding.展开更多
To solve the combinatorial optimization problem of outer layout and inner connection integrated schemes in the design of hydraulic manifold blocks （ HMB）, a hybrid genetic simulated annealing algo- rithm based on ni...To solve the combinatorial optimization problem of outer layout and inner connection integrated schemes in the design of hydraulic manifold blocks （ HMB）, a hybrid genetic simulated annealing algo- rithm based on niche technology is presented. This hybrid algorithm, which combines genetic algorithm, simulated annealing algorithm and niche technology, has a strong capability in global and local search, and all extrema can be found in a short time without strict requests for preferences. For the complex restricted solid spatial layout problems in HMB, the optimizing mathematical model is presented. The key technologies in the integrated layout and connection design of HMB, including the realization of coding, annealing operation and genetic operation, are discussed. The framework of HMB optimal design system based on hybrid optimization strategy is proposed. An example is given to testify the effectiveness and feasibility of the algorithm.展开更多
[Objective]Implementation of the Ten-Year Fishing Ban policy may alter fish diversity and niche characteristics of dominant species in spawning grounds within the National Nature Reserve for Rare and Endemic Fish in t...[Objective]Implementation of the Ten-Year Fishing Ban policy may alter fish diversity and niche characteristics of dominant species in spawning grounds within the National Nature Reserve for Rare and Endemic Fish in the Upper Yangtze River.This study initiated continuous monitoring of natural spawning habitats from February 2022 to assess these ecological changes.[Methods]Environmental DNA(eDNA)metabarcoding was employed to analyze fish species composition,biodiversity patterns,and niche parameters of dominant species.Water sampling followed the CEN/TS 19461 standard across five monitoring transects(ZT1-ZT5).[Results]The eDNA analysis detected 45 species of fish belonging to 38 genera,13 families,and 3 orders were detected through environmental DNA(eDNA)in this survey,including 10 species endemic to the upper reaches of the Yangtze River,such as Procypris rabaudi and Myxocyprinus asiaticus.The fish community was mainly composed of bottom-dwelling,settling ovum-producing,omnivorous fish.The variation ranges of the Chao1 index,ACE index,Shannon index,and Simpson index are 736~996,719~965,1.58~3.23,and 0.83~0.99,respectively,indicating that fish species in spawning sites are abundant and community distribution uniformity is high.All indexes are highest at ZT1 monitoring points.Cluster analysis showed that,at a certain similarity level,fish community types in spawning sites could be basically divided into two groups:ZT1,ZT3,and ZT5 clustered together,and ZT2 and ZT4 clustered together,indicating similar fish community habitats.There are 9 dominant fish species in typical deep pool habitats in the reserve,with niche widths(Bi)ranging from 1.13 to 3.87.The dominant fish species are broad and medium niche fish,such as Cyprinus carpio and Hemiculter tchangi,with the niche overlap index(Oik)of some dominant fish species reaching more than 0.95.This indicates fierce competition for resources among the fish in this spawning ground.[Conclusion]The Zhutuo spawning ground demonstrates high species richness with homogeneous community structure and intense resource competition.This study establishes an eDNA-based monitoring framework that enhances conventional survey method,providing critical baseline data for adaptive management under the fishing moratorium regime.展开更多
Predicting whether alien species will invade a native community is a key challenge in invasion ecology.One factor that may help predict invasion success is phylogenetic relatedness.Darwin proposed that closely related...Predicting whether alien species will invade a native community is a key challenge in invasion ecology.One factor that may help predict invasion success is phylogenetic relatedness.Darwin proposed that closely related species tend to share similar niches,although this relationship may be influenced by various ecological and evolutionary factors.To test this,we classified alien Asteraceae species in China into three categories based on their invasion status and the extent of ecological damage:introduced,naturalized,and invasive.We then compared the genetic relationships and niche overlap between alien and native Asteraceae species.We found that invasive Asteraceae species are more closely related to native Asteraceae species than are introduced and naturalized species.However,alien Asteraceae species(including introduced,naturalized,and invasive species)exhibited relatively low niche overlap with native Asteraceae species.These findings suggest that the main premise underlying Darwin’s naturalization conundrum,namely,the universality of phylogenetic niche conservatism,may not hold true.Instead,our findings indicate that alien species are more likely to invade successfully when they are more closely related to native plants,exhibit less niche overlap,and maintain conservative niches during the invasion process.These findings provide new insights into the mechanisms of alien plant invasions,highlight the relationship between alien species invasions and native community vulnerability,and offer important insights into the development of effective biological invasion management strategies.展开更多
Animals living in syntopy share acoustic space.Asian horned frogs are well known for their sympatric distribution,but little is known about their strategies to avoid acoustic niche competition.This study focused on th...Animals living in syntopy share acoustic space.Asian horned frogs are well known for their sympatric distribution,but little is known about their strategies to avoid acoustic niche competition.This study focused on three sympatric Boulenophrys frog species from southern China—B.nanlingensis,B.ombrophila,and B.shimentaina,with the former two species call in similar frequencies but breed in different seasons.First,we checked the call variation during the change of individual body size and the ambient air temperature in three species.We have found call frequencies were the most static parameters in each species that were associated with body size and contributed most to species identifcation.Temporal call parameters shift with temperature but are mostly infuenced by low temperatures.Second,we checked the interactions between the environment and call properties.The calling site preferences of each species corresponded well with the prediction of the acoustic adaptation hypothesis(in view of higher frequency better transmission in open habitat),and species with similar call frequencies have some aspects of common calling sites.Third,we checked the species–species interaction by using playback tests with male B.nanlingensis.Results from playback experiments showed species that call at similar frequencies could hardly share the same habitat during the same season.These fndings expanded the knowledge of acoustic coexistence in closely related anuran species and provided insights into the vocal behavior of Asian horned frogs.展开更多
The future distribution of invading species depends on the climate space available and certain life history traits that facilitate invasion.Here,to predict the spread potential of plant species introduced in North Ame...The future distribution of invading species depends on the climate space available and certain life history traits that facilitate invasion.Here,to predict the spread potential of plant species introduced in North America north of Mexico(NAM),we compiled distribution and life history data(i.e.,seed size,life form,and photosynthetic pathways)for 3021 exotic plant species introduced to NAM.We comparatively examined the species’range size and climate space in both native and exotic regions and the role of key life history traits.We found that large climate space for most exotic plants is still available in NAM.The range sizes in global exotic regions could better predict the current range sizes in NAM than those in global native regions or global native plus exotic regions.C3 species had larger ranges on average than C4 and CAM plants,and herbaceous species consistently showed stronger relationships in range size between native and exotic regions than woody species,as was the case within the C3 species group.Seed size was negatively related to range size both in native regions and in NAM.However,seed size surprisingly showed a positive correlation with global exotic range size and no correlation with the current actual global(native plus exotic)range size.Our findings underline the importance of species’native distribution and life history traits in predicting the spread of exotic species.Future studies should continue to identify potential climate space and use underappreciated species traits to better predict species invasions under changing climate.展开更多
Habitat fragmentation poses a significant threat to bird communities, especially those in open and semi-open ecosystems such as steppes. This study investigates how steppe birds adapt to and utilize fragmented habitat...Habitat fragmentation poses a significant threat to bird communities, especially those in open and semi-open ecosystems such as steppes. This study investigates how steppe birds adapt to and utilize fragmented habitats by combining niche modeling with ecological trait analysis. We conducted standardized point surveys to examine the habitat preferences of 32 bird species in Inner Mongolia, China, and quantified their habitat niche parameters using the Outlying Mean Index (OMI). Our results reveal distinct habitat preferences among species, with some thriving in intact environments while others are better adapted to fragmented areas. Grassland species showed high specialization along the fragmentation gradient, while others exhibited adaptability to varying levels of fragmentation. Using a Generalized Additive Model (GAM), we identified three key traits influencing habitat occupancy: hand-wing index, body mass, and range size. Specifically, species with medium hand-wing indices, moderate body mass, and larger range sizes were more likely to occupy heavily fragmented habitats. These findings provide empirical evidence on how habitat fragmentation affects bird species in steppe ecosystems. The study highlights the importance of functional traits in understanding avian responses to habitat fragmentation and offers a foundation for developing effective conservation strategies to preserve biodiversity in fragmented landscapes.展开更多
Accurate capture and presentation of the interactive feedback relationships among various objectives in multi-objective reservoir operation is essential for maximizing operational benefits.In this study,the niche theo...Accurate capture and presentation of the interactive feedback relationships among various objectives in multi-objective reservoir operation is essential for maximizing operational benefits.In this study,the niche theory of ecology was innovatively applied to the field of reservoir operation,and a novel state-relationship(S-R)measurement analysis method was developed for multi-objective reservoir operation.This method enables the study of interaction among multiple objectives.This method was used to investigate the relationship among the objectives of power generation,water supply,and ecological protection for cascade reservoir operation in the Wujiang River Basin in China.The results indicated that the ecological protection objective was the most competitive in acquiring and capturing resources like flow and water level,while the water supply objective was the weakest.Power generation competed most strongly with ecological protection and relatively weakly with water supply.These findings facilitate decision-making throughout the reservoir operation process in the region.The S-R method based on the niche theory is convenient,efficient,and intuitive,allowing for the quantification of feedback relationships among objectives without requiring the solution of the Pareto frontier of a multi-objective problem in advance.This method provides a novel and feasible idea for studying multi-objective interactions.展开更多
The transformation of natural habitats into human-modified landscapes has far-reaching consequences for species distribution and abundance.As species adapt to these changing environments,shifts in distribution pattern...The transformation of natural habitats into human-modified landscapes has far-reaching consequences for species distribution and abundance.As species adapt to these changing environments,shifts in distribution patterns,niche dynamics,and interspecies interactions may occur,impacting biodiversity at multiple levels and potentially leading to ecosystem imbalances.This study aims to assess the impact of variations in vegetation composition and human disturbance on the distribution of sympatric breeding birds and to determine the extent of niche overlap or differentiation among these species.We conducted field surveys and collected data on bird distribution,vegetation composition,and level of human disturbance in eastern Inner Mongolian grasslands.We focused on the six most frequently co-occurring breeding birds,representing a mix of sparrows,larks,and corvids.Generalized Additive Models revealed varying responses of species occurrence along habitat gradients.Species like the Eurasian Skylark(Alauda arvensis),Mongolian Lark(Melanocorypha mongolica),and Asian Shorttoed Lark(Calandrella cheleensis),increased in larger and more connected habitats,while others,like the Tree Sparrow(Passer montanus),Eurasian Magpie(Pica pica),and Barn Swallow(Hirundo rustica),adapted to more fragmented habitats.Niche analysis indicated habitat generalists tended to occupy larger niches than grassland specialists.Substantial niche overlap was also found among the six co-occurring bird species.Conservation efforts should consider the specific needs of specialist species and strive to maintain or restore critical grassland habitats.Additionally,promoting sustainable agricultural practices that balance the needs of birds and human activities can contribute to the coexistence of generalist and specialist bird species in modified landscapes.展开更多
The formation of pantropical intercontinental disjunction(PID)in plants has generally been attributed to vicariance,boreotropical migration,and long-distance dispersal.However,this pattern has primarily been examined ...The formation of pantropical intercontinental disjunction(PID)in plants has generally been attributed to vicariance,boreotropical migration,and long-distance dispersal.However,this pattern has primarily been examined in herbs,shrubs,and trees,and less commonly studied in interlayer plant taxa.Here we examined evolutionary processes that resulted in the PID of a pantropical woody liana,Uncaria(Rubiaceae).We first constructed a comprehensive phylogeny by employing 73 plastid protein-coding sequences from 29 accessions of Uncaria(including 16 newly sequenced)from different continents.We then inferred divergence time,history and ecological niche evolution of this genus.Our results showed that Uncaria consisted of four well-supported clades that belonged to two geographically distinct lineages:the Asia-Oceania lineage and the Afro-Neotropical lineage.Biogeographic reconstruction showed this genus likely originated in Asia during the early Miocene(ca.19.03 Ma)and the Middle Miocene Climatic Optimum may have triggered the early diversification of Uncaria.Due to its recent origin and small seeds with long wings,wind or water-mediated long-distance dispersal may have contributed to the distribution of Uncaria in tropical Oceania(via stepping-stone dispersal)and tropical Africa and America(by transoceanic dispersal).Our findings also indicate that diversification of Uncaria was primarily driven by ecological niche divergence,particularly climatic factors.Our study emphasizes the dual role of climatic niche divergence and long-distance dispersal in shaping the PID of Uncaria,providing references for many other extant lineages with similar distributions.展开更多
Background:The traditional Chinese medicine compound Sancao decoction(SCD)is a folk prescription for regulating immunity.It is composed of 8 Chinese herbal medicines,such as Prunellae Spica(Xiakucao),Houttuyniae Herba...Background:The traditional Chinese medicine compound Sancao decoction(SCD)is a folk prescription for regulating immunity.It is composed of 8 Chinese herbal medicines,such as Prunellae Spica(Xiakucao),Houttuyniae Herba(Yuxingcao),Lysimachiae Herba(Jinqiancao)and so on.In cancer,the interleukin-6(IL-6)/the signal transducer and the activator of transcription 3(STAT3)pathway directly promotes the proliferation,survival and angiogenesis of cancer cells,and arginase-1(ARG-1)is a key enzyme for myeloid-derived suppressor cells(MDSCs)to exert immunosuppressive function.It is not clear whether SCD regulates the expression of ARG-1 in MDSCs through the IL-6/STAT3 pathway.Therefore,we explored the effect and mechanism of SCD on lung metastasis of breast cancer.Methods:The components in SCD have been analyzed by HPLC-MS.A spontaneous metastasis model of breast cancer was established by injecting 4T1 cells into the mammary fat pad of BALB/c mice.Pre-metastatic niche(PMN)formation and the role of SCD on PMN were evaluated by lung metastasis nodules,lung pathology tests and immunofluorescence for 2–4 weeks.Serum tests and hematoxylin-eosin staining(H&E)were used to evaluate the side effects of cisplatin.Western blot and ELISA were used to detect proteins and cytokines of the STAT3 signaling pathway in mouse lung tissue.Results:Compared with SCD or cisplatin treatment alone,SCD/cisplatin(CP)synergistic administration not only significantly inhibited orthotropic breast tumor growth,but also reduced lung metastasis and alleviated the hepatorenal toxicity induced by CP in vivo.Remarkably,the combination effectively inhibited PMN formation and the accumulation of MDSCs in the lung PMN,accompanied by the significant infiltration of CD4+T and CD8+T-lymphocytes in the lung PMN and spleen.In addition,the SCD/CP combination downregulated protein expression levels of STAT3,p-STAT3,IL-6 and ARG-1 in the lung PMN of breast cancer mice.Conclusion:The synergistic effect of SCD and cisplatin inhibited MDSCs aggregation and the immunosuppressive function of pulmonary PMN,thereby remodeling the immunosuppressive tumor microenvironment and enhancing anti-tumor immunity,leading to remission of orthotopic breast cancer and lung metastases and amelioration of cisplatin-induced liver and kidney toxicity.展开更多
Subterranean environments are buffered from external climatic fluctuations due to the absence of light and a delayed thermal response to surface conditions(Mammola 2019).Terrestrial salamanders are often found in subt...Subterranean environments are buffered from external climatic fluctuations due to the absence of light and a delayed thermal response to surface conditions(Mammola 2019).Terrestrial salamanders are often found in subterranean habitats,but few studies have assessed the influence of climatic effects on their long-term spatial distribution and niche breadth.In this study,we investigated the variability over 29 consecutive years of the spatial niche in a terrestrial salamander population inhabiting an artificial subterranean habitat.We hypothesized that juvenile salamanders,which are typically active near cave entrances and more exposed to climatic variability and dehydration(Peterman et al.2013),would exhibit an earlier and more variable behavioral adaptation to increasing external temperatures compared to adults.展开更多
Long-term niche differentiation will lead to the evolution of diverse adaptive strategies for species in diverse environments. The present study selected two Forsythia species, Forsythia mandshurica(Fm)-which naturall...Long-term niche differentiation will lead to the evolution of diverse adaptive strategies for species in diverse environments. The present study selected two Forsythia species, Forsythia mandshurica(Fm)-which naturally occurs in a cold temperate zone and Forsythia suspensa(Fs)-which thrives in a warm temperate zone-to reveal their differential chilling defense mechanisms by integrating morpho-physiological,transcriptomic, and metabolomic data. Transcriptome results show that Fm has evolved in a series of adaptive mechanisms designed to help the plants to cope with chilling stress by enhancing sugar, amino acid, hormone, polyamine, and phenol content to improve cell osmotic potential and to mitigate petal browning. Metabolomic data suggested the increased chilling resistance of Fm relies on in the plant being rich in a-linolenic acid, linoleic acid, as well as two amino acids, Phe and Trp, and has low levels of cinnamic acid and gramine in flowers compared to Fs. A higher abundance of glutathione disulfide and NADPH regulated by glutathione peroxidases and NADPH improved the ability of the cellular antioxidant and reduction-oxidation system stability in Fm;Additionally, the elevated levels of pyruvate, a-ketoglutaric acid, and oxaloacetic acid in Fm contributed to a significantly enhanced ATP production in mitochondria. Through Ka/Ks and gene expression analysis,four transcription factors, EVM0025036(bHLH), EVM0010639 and EVM0007275(AP2), and EVM0025908(bZIP) were identified that may contribute to the high cold tolerance of Fm. These adaptations highlight the intricate interplay between genetic and physiological processes that shape the survival strategies of plants in response to their specific ecological niches.展开更多
Comprehensive phylogeographic insights require the integration of evidence across diverse taxa,ecosystems,and geographical regions.However,our understanding of the arid biota of the vast Asian drylands remains limited...Comprehensive phylogeographic insights require the integration of evidence across diverse taxa,ecosystems,and geographical regions.However,our understanding of the arid biota of the vast Asian drylands remains limited.Accordingly,this study combined phylogeographic analyses with ecological niche modeling to investigate patterns of diversification and demography of the Central Asian racerunner(Eremias vermiculata),a widespread lizard inhabiting arid eastern-Central Asia(AECA).Mitochondrial DNA(mtDNA)sequences were obtained from 876 individuals across 113 localities,while three nuclear genes-CGNL1,MAP1A,andβ-fibint7-were sequenced from 204,170,and 138 individuals,respectively.Analyses identified four distinct mtDNA lineages corresponding to specific geographic subregions within the AECA,reflecting the topographic and ecological heterogeneity of the region.The detection of mito-nuclear discordance indicated the presence of complex evolutionary dynamics.Divergence dating placed the initial lineage splits at approximately 1.18 million years ago,coinciding with major tectonic activity and climatic aridification that likely promoted allopatric divergence.In particular,lineage diversification within the Tarim Basin suggests that recent environmental shifts may have contributed to genetic divergence.Demographic reconstructions revealed signatures of population expansion or range shifts across all lineages during the Last Glacial Maximum,signifying the combined influence of the unique topography and climate dynamics of the AECA on diversification and demographic change.These results highlight the need for fine-scale genomic investigations to clarify the mechanisms underlying mito-nuclear discordance and local adaptation.Such efforts are essential for advancing understanding of how genetic diversity in dryland taxa responds to environmental change,providing insights into the evolutionary adaptability of species in dynamic landscapes.展开更多
Siberian taimen Hucho taimen(Pallas,1773)is a broadly distributed and popular sport fish with high economic value.However,low abundance and hard-to-reach habitat make the Siberian taimen a relatively understudied spec...Siberian taimen Hucho taimen(Pallas,1773)is a broadly distributed and popular sport fish with high economic value.However,low abundance and hard-to-reach habitat make the Siberian taimen a relatively understudied species.Here we describe the morphological variability of two size groups of Siberian taimen juveniles from the eastern(Amur River basin)and western(Kama River basin)parts of the species distribution.The largest morphological differentiation of Siberian taimen juveniles was observed at the inter-basin level.In the Amur River basin,Siberian taimen juveniles also differed morphologically even at sites located at a distance of 20 km from each other,which may be explained by a small home-range inhabitation of juveniles leading to the formation of their morphotype determined by local environmental conditions.The pattern of allometry varies in taimen from different rivers,which could be related to the ontogenetic shift of ecological niches and the level of heterogeneity of the river environment.展开更多
基金supported by the National Natural Science Foundation of China (Nos.41274059,40974021 and 40774044)Beijing Natural Scientific Foundation (Nos.8122039 and 8092028) to J.Lei
文摘In this paper,we focus on the influences of various parameters in the niching genetic algorithm inversion procedure on the results,such as various objective functions,the number of the models in each subpopulation,and the critical separation radius.The frequency-waveform integration（F-K） method is applied to synthesize three-component waveform data with noise in various epicentral distances and azimuths.Our results show that if we use a zero-th-lag cross-correlation function,then we will obtain the model with a faster convergence and a higher precision than other objective functions.The number of models in each subpopulation has a great influence on the rate of convergence and computation time,suggesting that it should be obtained through tests in practical problems.The critical separation radius should be determined carefully because it directly affects the multiextreme values in the inversion.We also compare the inverted results from full-band waveform data and surfacewave frequency-band（0.02-0.1 Hz） data,and find that the latter is relatively poorer but still has a higher precision,suggesting that surface-wave frequency-band data can also be used to invert for the crustal structure.
文摘Optimization implies the minimization or maximization of an objective function. Some problems have sev-eral optimum points which all, should be computed. Niching method is presented to do so. However, its efficiency can be improved via combining it with Memetic algorithm. Therefore, in this paper, Memetic method is used to improve this method in terms of convergence rate and diversity. In the proposed methods, genetic algorithm, PSO, and learning automata are used as a local search algorithm of Memetic method. The result of simulations demonstrates that proposed methods are more effective compared with Niching in terms of convergence and diversity.
文摘This study analyzes drift phenomena of deterministic crowding and probabilistic crowding by using equivalence class model and expectation proportion equations. It is proved that the replacement errors of deterministic crowding cause the population converging to a single individual, thus resulting in premature stagnation or losing optional optima. And probabilistic crowding can maintain equilibrium multiple subpopulations as the population size is adequate large. An improved niching method using clustering crowding is proposed. By analyzing topology of fitness landscape using hill valley function and extending the search space for similarity analysis, clustering crowding determines the locality of search space more accurately, thus greatly decreasing replacement errors of crowding. The integration of deterministic and probabilistic replacement increases the capacity of both parallel local hill climbing and maintaining multiple subpopulations. The experimental results optimizing various multimodal functions show that,the performances of clustering crowding, such as the number of effective peaks maintained, average peak ratio and global optimum ratio are uniformly superior to those of the evolutionary algorithms using fitness sharing, simple deterministic crowding and probabilistic crowding.
基金Supported by the National Natural Science Foundation of China （No. 50375023）.
文摘To solve the combinatorial optimization problem of outer layout and inner connection integrated schemes in the design of hydraulic manifold blocks （ HMB）, a hybrid genetic simulated annealing algo- rithm based on niche technology is presented. This hybrid algorithm, which combines genetic algorithm, simulated annealing algorithm and niche technology, has a strong capability in global and local search, and all extrema can be found in a short time without strict requests for preferences. For the complex restricted solid spatial layout problems in HMB, the optimizing mathematical model is presented. The key technologies in the integrated layout and connection design of HMB, including the realization of coding, annealing operation and genetic operation, are discussed. The framework of HMB optimal design system based on hybrid optimization strategy is proposed. An example is given to testify the effectiveness and feasibility of the algorithm.
文摘[Objective]Implementation of the Ten-Year Fishing Ban policy may alter fish diversity and niche characteristics of dominant species in spawning grounds within the National Nature Reserve for Rare and Endemic Fish in the Upper Yangtze River.This study initiated continuous monitoring of natural spawning habitats from February 2022 to assess these ecological changes.[Methods]Environmental DNA(eDNA)metabarcoding was employed to analyze fish species composition,biodiversity patterns,and niche parameters of dominant species.Water sampling followed the CEN/TS 19461 standard across five monitoring transects(ZT1-ZT5).[Results]The eDNA analysis detected 45 species of fish belonging to 38 genera,13 families,and 3 orders were detected through environmental DNA(eDNA)in this survey,including 10 species endemic to the upper reaches of the Yangtze River,such as Procypris rabaudi and Myxocyprinus asiaticus.The fish community was mainly composed of bottom-dwelling,settling ovum-producing,omnivorous fish.The variation ranges of the Chao1 index,ACE index,Shannon index,and Simpson index are 736~996,719~965,1.58~3.23,and 0.83~0.99,respectively,indicating that fish species in spawning sites are abundant and community distribution uniformity is high.All indexes are highest at ZT1 monitoring points.Cluster analysis showed that,at a certain similarity level,fish community types in spawning sites could be basically divided into two groups:ZT1,ZT3,and ZT5 clustered together,and ZT2 and ZT4 clustered together,indicating similar fish community habitats.There are 9 dominant fish species in typical deep pool habitats in the reserve,with niche widths(Bi)ranging from 1.13 to 3.87.The dominant fish species are broad and medium niche fish,such as Cyprinus carpio and Hemiculter tchangi,with the niche overlap index(Oik)of some dominant fish species reaching more than 0.95.This indicates fierce competition for resources among the fish in this spawning ground.[Conclusion]The Zhutuo spawning ground demonstrates high species richness with homogeneous community structure and intense resource competition.This study establishes an eDNA-based monitoring framework that enhances conventional survey method,providing critical baseline data for adaptive management under the fishing moratorium regime.
基金supported by the National Natural Science Foundation of China(32271584 and 31600445)the Natural Science Basic Research Plan in Shaanxi Province of China(2020JM-286)+2 种基金the Fundamental Research Funds for the Central Universities(GK202103072 and GK202103073)the Key Research and Development Program of Shaanxi Province(2025SF-YBXM-514)Special Research Project in Philosophy and Social Sciences of Shaanxi Province(2022HZ1795).
文摘Predicting whether alien species will invade a native community is a key challenge in invasion ecology.One factor that may help predict invasion success is phylogenetic relatedness.Darwin proposed that closely related species tend to share similar niches,although this relationship may be influenced by various ecological and evolutionary factors.To test this,we classified alien Asteraceae species in China into three categories based on their invasion status and the extent of ecological damage:introduced,naturalized,and invasive.We then compared the genetic relationships and niche overlap between alien and native Asteraceae species.We found that invasive Asteraceae species are more closely related to native Asteraceae species than are introduced and naturalized species.However,alien Asteraceae species(including introduced,naturalized,and invasive species)exhibited relatively low niche overlap with native Asteraceae species.These findings suggest that the main premise underlying Darwin’s naturalization conundrum,namely,the universality of phylogenetic niche conservatism,may not hold true.Instead,our findings indicate that alien species are more likely to invade successfully when they are more closely related to native plants,exhibit less niche overlap,and maintain conservative niches during the invasion process.These findings provide new insights into the mechanisms of alien plant invasions,highlight the relationship between alien species invasions and native community vulnerability,and offer important insights into the development of effective biological invasion management strategies.
基金supported by the Project for Endangered Wildlife Investigation,Supervision and Industry Regulation of the National Forestry and Grassland Bureau of China(202407-HN-001)the Project for Endangered Wildlife Protection of Hunan Forestry Bureau of China(HNYB-2024001).
文摘Animals living in syntopy share acoustic space.Asian horned frogs are well known for their sympatric distribution,but little is known about their strategies to avoid acoustic niche competition.This study focused on three sympatric Boulenophrys frog species from southern China—B.nanlingensis,B.ombrophila,and B.shimentaina,with the former two species call in similar frequencies but breed in different seasons.First,we checked the call variation during the change of individual body size and the ambient air temperature in three species.We have found call frequencies were the most static parameters in each species that were associated with body size and contributed most to species identifcation.Temporal call parameters shift with temperature but are mostly infuenced by low temperatures.Second,we checked the interactions between the environment and call properties.The calling site preferences of each species corresponded well with the prediction of the acoustic adaptation hypothesis(in view of higher frequency better transmission in open habitat),and species with similar call frequencies have some aspects of common calling sites.Third,we checked the species–species interaction by using playback tests with male B.nanlingensis.Results from playback experiments showed species that call at similar frequencies could hardly share the same habitat during the same season.These fndings expanded the knowledge of acoustic coexistence in closely related anuran species and provided insights into the vocal behavior of Asian horned frogs.
文摘The future distribution of invading species depends on the climate space available and certain life history traits that facilitate invasion.Here,to predict the spread potential of plant species introduced in North America north of Mexico(NAM),we compiled distribution and life history data(i.e.,seed size,life form,and photosynthetic pathways)for 3021 exotic plant species introduced to NAM.We comparatively examined the species’range size and climate space in both native and exotic regions and the role of key life history traits.We found that large climate space for most exotic plants is still available in NAM.The range sizes in global exotic regions could better predict the current range sizes in NAM than those in global native regions or global native plus exotic regions.C3 species had larger ranges on average than C4 and CAM plants,and herbaceous species consistently showed stronger relationships in range size between native and exotic regions than woody species,as was the case within the C3 species group.Seed size was negatively related to range size both in native regions and in NAM.However,seed size surprisingly showed a positive correlation with global exotic range size and no correlation with the current actual global(native plus exotic)range size.Our findings underline the importance of species’native distribution and life history traits in predicting the spread of exotic species.Future studies should continue to identify potential climate space and use underappreciated species traits to better predict species invasions under changing climate.
基金supported by the National Natural Science Foundation of China(No.32201304)the Fundamental Research Funds for the Central Universities(No.2412022QD026).
文摘Habitat fragmentation poses a significant threat to bird communities, especially those in open and semi-open ecosystems such as steppes. This study investigates how steppe birds adapt to and utilize fragmented habitats by combining niche modeling with ecological trait analysis. We conducted standardized point surveys to examine the habitat preferences of 32 bird species in Inner Mongolia, China, and quantified their habitat niche parameters using the Outlying Mean Index (OMI). Our results reveal distinct habitat preferences among species, with some thriving in intact environments while others are better adapted to fragmented areas. Grassland species showed high specialization along the fragmentation gradient, while others exhibited adaptability to varying levels of fragmentation. Using a Generalized Additive Model (GAM), we identified three key traits influencing habitat occupancy: hand-wing index, body mass, and range size. Specifically, species with medium hand-wing indices, moderate body mass, and larger range sizes were more likely to occupy heavily fragmented habitats. These findings provide empirical evidence on how habitat fragmentation affects bird species in steppe ecosystems. The study highlights the importance of functional traits in understanding avian responses to habitat fragmentation and offers a foundation for developing effective conservation strategies to preserve biodiversity in fragmented landscapes.
基金supported by the National Key Research&Development Project of China(Grant No.2016YFC0402209)and the China Scholarship Council.
文摘Accurate capture and presentation of the interactive feedback relationships among various objectives in multi-objective reservoir operation is essential for maximizing operational benefits.In this study,the niche theory of ecology was innovatively applied to the field of reservoir operation,and a novel state-relationship(S-R)measurement analysis method was developed for multi-objective reservoir operation.This method enables the study of interaction among multiple objectives.This method was used to investigate the relationship among the objectives of power generation,water supply,and ecological protection for cascade reservoir operation in the Wujiang River Basin in China.The results indicated that the ecological protection objective was the most competitive in acquiring and capturing resources like flow and water level,while the water supply objective was the weakest.Power generation competed most strongly with ecological protection and relatively weakly with water supply.These findings facilitate decision-making throughout the reservoir operation process in the region.The S-R method based on the niche theory is convenient,efficient,and intuitive,allowing for the quantification of feedback relationships among objectives without requiring the solution of the Pareto frontier of a multi-objective problem in advance.This method provides a novel and feasible idea for studying multi-objective interactions.
基金supported by the National Natural Science Foundation of China (No.32201304)the Fundamental Research Funds for the Central Universities (No.2412022QD026)。
文摘The transformation of natural habitats into human-modified landscapes has far-reaching consequences for species distribution and abundance.As species adapt to these changing environments,shifts in distribution patterns,niche dynamics,and interspecies interactions may occur,impacting biodiversity at multiple levels and potentially leading to ecosystem imbalances.This study aims to assess the impact of variations in vegetation composition and human disturbance on the distribution of sympatric breeding birds and to determine the extent of niche overlap or differentiation among these species.We conducted field surveys and collected data on bird distribution,vegetation composition,and level of human disturbance in eastern Inner Mongolian grasslands.We focused on the six most frequently co-occurring breeding birds,representing a mix of sparrows,larks,and corvids.Generalized Additive Models revealed varying responses of species occurrence along habitat gradients.Species like the Eurasian Skylark(Alauda arvensis),Mongolian Lark(Melanocorypha mongolica),and Asian Shorttoed Lark(Calandrella cheleensis),increased in larger and more connected habitats,while others,like the Tree Sparrow(Passer montanus),Eurasian Magpie(Pica pica),and Barn Swallow(Hirundo rustica),adapted to more fragmented habitats.Niche analysis indicated habitat generalists tended to occupy larger niches than grassland specialists.Substantial niche overlap was also found among the six co-occurring bird species.Conservation efforts should consider the specific needs of specialist species and strive to maintain or restore critical grassland habitats.Additionally,promoting sustainable agricultural practices that balance the needs of birds and human activities can contribute to the coexistence of generalist and specialist bird species in modified landscapes.
基金funded equally by grants from the National Natural Science Foundation of China(32322006 and 32100187)the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2024QZKK0200)+5 种基金by the Key Projects of the Joint Fund of the National Natural Science Foundation of China(U23A20149)the Key R&D Program of Yunnan Province(202103AF140005 and 202101BC070002)the Yunnan Provincial Science and Technology Talent and Platform Plan(202305AM070005)the Key Specialized Research and Development Breakthrough Program in Henan Province(232102110237)the Natural Science Foundation of Henan Province(242300421572)the Strategic Biological Resources Capacity Building Project of Chinese Academy of Sciences(KFJ-BRP-017-08).
文摘The formation of pantropical intercontinental disjunction(PID)in plants has generally been attributed to vicariance,boreotropical migration,and long-distance dispersal.However,this pattern has primarily been examined in herbs,shrubs,and trees,and less commonly studied in interlayer plant taxa.Here we examined evolutionary processes that resulted in the PID of a pantropical woody liana,Uncaria(Rubiaceae).We first constructed a comprehensive phylogeny by employing 73 plastid protein-coding sequences from 29 accessions of Uncaria(including 16 newly sequenced)from different continents.We then inferred divergence time,history and ecological niche evolution of this genus.Our results showed that Uncaria consisted of four well-supported clades that belonged to two geographically distinct lineages:the Asia-Oceania lineage and the Afro-Neotropical lineage.Biogeographic reconstruction showed this genus likely originated in Asia during the early Miocene(ca.19.03 Ma)and the Middle Miocene Climatic Optimum may have triggered the early diversification of Uncaria.Due to its recent origin and small seeds with long wings,wind or water-mediated long-distance dispersal may have contributed to the distribution of Uncaria in tropical Oceania(via stepping-stone dispersal)and tropical Africa and America(by transoceanic dispersal).Our findings also indicate that diversification of Uncaria was primarily driven by ecological niche divergence,particularly climatic factors.Our study emphasizes the dual role of climatic niche divergence and long-distance dispersal in shaping the PID of Uncaria,providing references for many other extant lineages with similar distributions.
基金supported by Fundamental Research Funds for the Central Universities(ZYN2024075)Chengdu Science and Technology Bureau Technology Innovation R&D Project(2024-YF05-02236-SN)the Applied Basic Research Project of the Sichuan Science Technology Department(2021YJ0256).Peer review information。
文摘Background:The traditional Chinese medicine compound Sancao decoction(SCD)is a folk prescription for regulating immunity.It is composed of 8 Chinese herbal medicines,such as Prunellae Spica(Xiakucao),Houttuyniae Herba(Yuxingcao),Lysimachiae Herba(Jinqiancao)and so on.In cancer,the interleukin-6(IL-6)/the signal transducer and the activator of transcription 3(STAT3)pathway directly promotes the proliferation,survival and angiogenesis of cancer cells,and arginase-1(ARG-1)is a key enzyme for myeloid-derived suppressor cells(MDSCs)to exert immunosuppressive function.It is not clear whether SCD regulates the expression of ARG-1 in MDSCs through the IL-6/STAT3 pathway.Therefore,we explored the effect and mechanism of SCD on lung metastasis of breast cancer.Methods:The components in SCD have been analyzed by HPLC-MS.A spontaneous metastasis model of breast cancer was established by injecting 4T1 cells into the mammary fat pad of BALB/c mice.Pre-metastatic niche(PMN)formation and the role of SCD on PMN were evaluated by lung metastasis nodules,lung pathology tests and immunofluorescence for 2–4 weeks.Serum tests and hematoxylin-eosin staining(H&E)were used to evaluate the side effects of cisplatin.Western blot and ELISA were used to detect proteins and cytokines of the STAT3 signaling pathway in mouse lung tissue.Results:Compared with SCD or cisplatin treatment alone,SCD/cisplatin(CP)synergistic administration not only significantly inhibited orthotropic breast tumor growth,but also reduced lung metastasis and alleviated the hepatorenal toxicity induced by CP in vivo.Remarkably,the combination effectively inhibited PMN formation and the accumulation of MDSCs in the lung PMN,accompanied by the significant infiltration of CD4+T and CD8+T-lymphocytes in the lung PMN and spleen.In addition,the SCD/CP combination downregulated protein expression levels of STAT3,p-STAT3,IL-6 and ARG-1 in the lung PMN of breast cancer mice.Conclusion:The synergistic effect of SCD and cisplatin inhibited MDSCs aggregation and the immunosuppressive function of pulmonary PMN,thereby remodeling the immunosuppressive tumor microenvironment and enhancing anti-tumor immunity,leading to remission of orthotopic breast cancer and lung metastases and amelioration of cisplatin-induced liver and kidney toxicity.
文摘Subterranean environments are buffered from external climatic fluctuations due to the absence of light and a delayed thermal response to surface conditions(Mammola 2019).Terrestrial salamanders are often found in subterranean habitats,but few studies have assessed the influence of climatic effects on their long-term spatial distribution and niche breadth.In this study,we investigated the variability over 29 consecutive years of the spatial niche in a terrestrial salamander population inhabiting an artificial subterranean habitat.We hypothesized that juvenile salamanders,which are typically active near cave entrances and more exposed to climatic variability and dehydration(Peterman et al.2013),would exhibit an earlier and more variable behavioral adaptation to increasing external temperatures compared to adults.
基金supported by the National Natural Science Foundation of China(Grant NO.32360307).
文摘Long-term niche differentiation will lead to the evolution of diverse adaptive strategies for species in diverse environments. The present study selected two Forsythia species, Forsythia mandshurica(Fm)-which naturally occurs in a cold temperate zone and Forsythia suspensa(Fs)-which thrives in a warm temperate zone-to reveal their differential chilling defense mechanisms by integrating morpho-physiological,transcriptomic, and metabolomic data. Transcriptome results show that Fm has evolved in a series of adaptive mechanisms designed to help the plants to cope with chilling stress by enhancing sugar, amino acid, hormone, polyamine, and phenol content to improve cell osmotic potential and to mitigate petal browning. Metabolomic data suggested the increased chilling resistance of Fm relies on in the plant being rich in a-linolenic acid, linoleic acid, as well as two amino acids, Phe and Trp, and has low levels of cinnamic acid and gramine in flowers compared to Fs. A higher abundance of glutathione disulfide and NADPH regulated by glutathione peroxidases and NADPH improved the ability of the cellular antioxidant and reduction-oxidation system stability in Fm;Additionally, the elevated levels of pyruvate, a-ketoglutaric acid, and oxaloacetic acid in Fm contributed to a significantly enhanced ATP production in mitochondria. Through Ka/Ks and gene expression analysis,four transcription factors, EVM0025036(bHLH), EVM0010639 and EVM0007275(AP2), and EVM0025908(bZIP) were identified that may contribute to the high cold tolerance of Fm. These adaptations highlight the intricate interplay between genetic and physiological processes that shape the survival strategies of plants in response to their specific ecological niches.
基金supported by the Central Asia Drug Discovery and Development Centre of Chinese Academy of Sciences(180GJHZ2024036MI)National Natural Science Foundation of China(32070433,32470466,31672270,31872959)+2 种基金Third Xinjiang Scientific Expedition Program(2021xjkk0600)Special Exchange Program of the Chinese Academy of Sciencessponsored by the ANSO Scholarship for Young Talents
文摘Comprehensive phylogeographic insights require the integration of evidence across diverse taxa,ecosystems,and geographical regions.However,our understanding of the arid biota of the vast Asian drylands remains limited.Accordingly,this study combined phylogeographic analyses with ecological niche modeling to investigate patterns of diversification and demography of the Central Asian racerunner(Eremias vermiculata),a widespread lizard inhabiting arid eastern-Central Asia(AECA).Mitochondrial DNA(mtDNA)sequences were obtained from 876 individuals across 113 localities,while three nuclear genes-CGNL1,MAP1A,andβ-fibint7-were sequenced from 204,170,and 138 individuals,respectively.Analyses identified four distinct mtDNA lineages corresponding to specific geographic subregions within the AECA,reflecting the topographic and ecological heterogeneity of the region.The detection of mito-nuclear discordance indicated the presence of complex evolutionary dynamics.Divergence dating placed the initial lineage splits at approximately 1.18 million years ago,coinciding with major tectonic activity and climatic aridification that likely promoted allopatric divergence.In particular,lineage diversification within the Tarim Basin suggests that recent environmental shifts may have contributed to genetic divergence.Demographic reconstructions revealed signatures of population expansion or range shifts across all lineages during the Last Glacial Maximum,signifying the combined influence of the unique topography and climate dynamics of the AECA on diversification and demographic change.These results highlight the need for fine-scale genomic investigations to clarify the mechanisms underlying mito-nuclear discordance and local adaptation.Such efforts are essential for advancing understanding of how genetic diversity in dryland taxa responds to environmental change,providing insights into the evolutionary adaptability of species in dynamic landscapes.
文摘Siberian taimen Hucho taimen(Pallas,1773)is a broadly distributed and popular sport fish with high economic value.However,low abundance and hard-to-reach habitat make the Siberian taimen a relatively understudied species.Here we describe the morphological variability of two size groups of Siberian taimen juveniles from the eastern(Amur River basin)and western(Kama River basin)parts of the species distribution.The largest morphological differentiation of Siberian taimen juveniles was observed at the inter-basin level.In the Amur River basin,Siberian taimen juveniles also differed morphologically even at sites located at a distance of 20 km from each other,which may be explained by a small home-range inhabitation of juveniles leading to the formation of their morphotype determined by local environmental conditions.The pattern of allometry varies in taimen from different rivers,which could be related to the ontogenetic shift of ecological niches and the level of heterogeneity of the river environment.
