Patterns of body size variation along geographical gradients have long been searched for and generalized into eco-geographical rules.However,no rodent species has yet been analyzed in relation to the 3 dimensions of l...Patterns of body size variation along geographical gradients have long been searched for and generalized into eco-geographical rules.However,no rodent species has yet been analyzed in relation to the 3 dimensions of latitude,longitude and altitude.We analyzed geographical clines and dimorphism of body and skull size in the herb field mouse(Apodemus uralensis)across the species range,based on field data and on data from the literature.Sexual dimorphism in adult A.uralensis was not expressed at a large scale,while local patterns were inconsistent.Age-dependent size changes were most expressed in adult individuals:most characters of adults exceeded in size those of subadults,while subadult-juvenile size differences were only significant in body weight and length,zygomatic skull width,length of cranial diastema and breadth of braincase.Despite central morphological niches along the clines being separated,A.uralensis populations showed a high degree of size overlap in morphological space.We found the species to be characterized by high size variability,with the largest individuals inhabiting the eastern and southern edges of the distribution range.Tail,hind foot and ear lengths were largest in the southern part of the range,in agreement with Allen’s rule.The main measurements that we analyzed,namely body mass,zygomatic skull width and condylobasal skull length,show the presence of 3 clines in the size of adult A.uralensis:(i)a decreasing south-north cline,opposing Bergmann’s rule;(ii)an increasing west-east cline,in accordance with Murphy’s rule;and(iii)an increasing altitudinal cline.展开更多
Most species have clearly defined distribution ranges and ecological niches.The genetic and ecological causes of species differentiation and the mechanisms that maintain species boundaries between newly evolved taxa a...Most species have clearly defined distribution ranges and ecological niches.The genetic and ecological causes of species differentiation and the mechanisms that maintain species boundaries between newly evolved taxa and their progenitors are,however,less clearly defined.This study investigated the genetic structure and clines in Pinus densata,a pine of hybrid origin on the southeastern Tibetan Plateau,to gain an understanding of the contemporary dynamics of species barriers.We analyzed genetic diversity in a range-wide collection of P.densata and representative populations of its progenitors,Pinus tabuliformis and Pinus yunnanensis,using exome capture sequencing.We detected four distinct genetic groups within P.densata that reflect its migration history and major gene-flow barriers across the landscape.The demographies of these genetic groups in the Pleistocene were associated with regional glaciation histories.Interestingly,population sizes rebounded rapidly during interglacial periods,suggesting persistence and resilience of the species during the Quaternary ice age.In the contact zone between P.densata and P.yunnanensis,3.36%of the analyzed loci(57849)showed exceptional patterns of introgression,suggesting their potential roles in either adaptive introgression or reproductive isolation.These outliers showed strong clines along critical climate gradients and enrichment in a number of biological processes relevant to high-altitude adaptation.This indicates that ecological selection played an important role in generating genomic heterogeneity and a genetic barrier across a zone of species transition.Our study highlights the forces that operate to maintain species boundaries and promote speciation in the Qinghai-Tibetan Plateau and other mountain systems.展开更多
Species may exhibit similar traits via different mechanisms： environmental filtering and local adaptation （geography） and shared evolutionary history （phylogeny） can each contribute to the resemblance of traits a...Species may exhibit similar traits via different mechanisms： environmental filtering and local adaptation （geography） and shared evolutionary history （phylogeny） can each contribute to the resemblance of traits among species. Parsing trait variation into geographic and phylogenetic sources is important, as each suggests different constraints on trait evolution. Here, we explore how phylogenetic distance, geographic distance, and geographic variation in climate shape physiological tolerance of high and low temperatures using a global dataset of ant thermal tolerances. We found generally strong roles for evolutionary history and geographic variation in temperature, but essen- tially no detectable effects of spatial proximity per se on either upper or lower thermal tolerance. When we compared the relative importance of the factors shaping upper and lower tolerances, we found a much stronger role for evolutionary history in shaping upper versus lower tolerance, and a moderately weaker role for geographic variation in temperature in shaping upper tolerance when compared with lower tolerance. Our results demonstrate how geographic variation in climate and evolutionary history may have differential effects on the upper and lower endpoints of physiological tolerance. This Janus effect, where the relative contributions of geographic variation in climate and evolutionary history are reversed for lower versus upper physiological tolerances, has gained some support in the literature, and our results for ant physiological tolerances provide further evidence of this pa^ern. As the climate continues to change, the high phylogenetic conservatism of upper tolerance may suggest potential constraints on the evolution of tolerance of high temperatures.展开更多
Hybrid zone is a very critical concept within the evolutionary biology, because it would offer us a better insight to understand the evolutionary role of gene flow and hybridization based on the cline model. This mini...Hybrid zone is a very critical concept within the evolutionary biology, because it would offer us a better insight to understand the evolutionary role of gene flow and hybridization based on the cline model. This minireview presents an expatiation of history perspectives and research developments upon basic concepts including hybrid zones, hybridization, hybrid and its the genetic cline model. Moreover, by figuring out the existing problem around the hybrids within conservative theory and practices, it suggests that the theory of hybrid zone be introduced into conservation biology and it would be provide a broader and more open theoretical background for conservative research and practices.展开更多
Understanding what environmental factors are genetically linked to a phenologic al event is critical for predicting responses to climate change.Photo synthetic phenology often varies among a species of evergreen conif...Understanding what environmental factors are genetically linked to a phenologic al event is critical for predicting responses to climate change.Photo synthetic phenology often varies among a species of evergreen conifers due to local adaptation.However,few empirical studies have revealed relevant relationships between climatic factors in provenance environments and photosynthetic phenology.This study evaluated the effects of environmental conditions of the growing site and seed source provenance on the seasonal changes in maximal photochemical quantum yield of photo systemⅡ(Fv/Fm)in a common garden experiment with 2-year-old seedlings of Sakhalin fir(Abies sachalinensis),a representative species with local adaptation,from four seed source provenances.A logistic model was constructed to explain the seasonal variation of Fv/Fmfrom July to October and the relationships between the estimated model parameters and representative factors featuring provenance environments were evaluated.The landscape gradient of the detected model parameters responsible for the provenance environments was visualized in a map of the distribution area.The lowest temperature was the most plausible factor in the growing environment to explain the seasonal changes of Fv/Fm.Among the representative meteorological factors of provenance environments,the lowest temperatures in July showed significant relationships with two model parameters,explaining the lower limit of Fv/Fmand the higher sensitivity of autumn Fv/Fmdecline.The estimated spatial maps of model parameters consistently showed that the higher the lowest temperature in July in the provenance environment,the lower the Fv/Fmin October and the greater the decrease in the autumn Fv/Fmdecline.Therefore,the lowest summer temperature could be associated with the local adaptation of autumn photosynthetic phenology in A.sachalinensis.展开更多
Introgression,the incorporation of genetic material from one(sub)species into the gene pool of another by means of hybridization and backcrossing,is a common phenomenon in birds and can provide important insights into...Introgression,the incorporation of genetic material from one(sub)species into the gene pool of another by means of hybridization and backcrossing,is a common phenomenon in birds and can provide important insights into the speciation process.In the last decade,the toolkit for studying introgression has expanded together with the development of molecular markers.In this review,we explore how genomic data,the most recent step in this methodological progress,impacts different aspects in the study of avian introgression.First,the detection of hybrids and backcrosses has improved dramatically.The most widely used software package is STRUCTURE.Phylogenetic discordance(i.e.different loci resulting in discordant gene trees) is another means for the detection of introgression,although it should be regarded as a starting point for further analyses,not as a definitive proof of introgression.Specifically,disentangling introgression from other biological processes,such as incomplete lineage sorting,remains a challenging endeavour,although new techniques,such as the D-statistic,are being developed.In addition,phylogenetics might require a shift from trees to networks.Second,the study of hybrid zones by means of geographical or genomic cline analysis has led to important insights into the complex interplay between hybridization and speciation.However,because each hybrid zone study is just a single snapshot of a complex and continuously changing interaction,hybrid zones should be studied across different temporal and/or spatial scales.A third powerful tool is the genome scan.The debate on which evolutionary processes underlie the genomic landscape is still ongoing,as is the question whether loci involved in reproductive isolation cluster together in ‘islands of speciation' or whether they are scattered throughout the genome.Exploring genomic landscapes across the avian tree of life will be an exciting field for further research.Finally,the findings from these different methods should be incorporated into specific speciation scenarios,which can consequently be tested using a modelling approach.All in all,this genomic perspective on avian hybridization and speciation will further our understanding in evolution in general.展开更多
We study the relative properties of(b,c)-inverses with respect to a ring endomorphism.A new class of generalized inverses namedα-(b,c)-inverse is introduced and studied in a more general setting.We show by giving an ...We study the relative properties of(b,c)-inverses with respect to a ring endomorphism.A new class of generalized inverses namedα-(b,c)-inverse is introduced and studied in a more general setting.We show by giving an example that(b,c)-inverses behave quite differently fromα-(b,c)-inverses.The condition that anα-(b,c)-invertible element is precisely a(b,c)-invertible element is investigated.We also study the strongly clean decompositions forα-(b,c)-inverses.Some well-known results on(b,c)-inverses are extended and unified.展开更多
Understanding the occurrence of multiple distinct phenotypes in a population of a species,i.e.,polymorphism,is one of the challenges encountered in evolutionary biology.Egg color polymorphism in birds is one example o...Understanding the occurrence of multiple distinct phenotypes in a population of a species,i.e.,polymorphism,is one of the challenges encountered in evolutionary biology.Egg color polymorphism in birds is one example of morphological polymorphism and disruptive selection has been proposed as a hypothetical mechanism to explain its occurrence.We studied how polymorphic egg colors(immaculate blue and white) occur in Korean populations of the Vinous-throated Parrotbill(Paradoxornis webbianus).Egg color ratios(the proportion of nests with blue eggs in a population) were monitored over a large spatial scale and egg colors were quanti ed using a spectrophotometer.We found egg color ratios to vary spatially among populations.Interestingly,there was a latitudinal morph-ratio cline in egg color ratios.e proportion of nests with blue eggs increased considerably with the latitude declined towards the southern part of the Korean peninsula.ere were some quantitative variations in egg colors among populations.However,the pattern of variations was not consistent with those of the population egg color ratios.Based on these results,we discuss a potential scenario for the evolution of egg color polymorphism in the Vinous-throated Parrotbill.展开更多
The novel Ready Player One shows Ernest Cline’s ability of space construction,and demonstrates charm and artistic value of the virtual fantasy space it depicts.It is a science fiction with perfect combination of ideo...The novel Ready Player One shows Ernest Cline’s ability of space construction,and demonstrates charm and artistic value of the virtual fantasy space it depicts.It is a science fiction with perfect combination of ideological content and artistic form.This thesis aims to discuss the Ernest Cline’s construction of the virtual pace and the real space in Ready Player One and the function of their construction.In real space,the environment is awful and dilapidated,and people’s lives are depressed.While in the virtual space,the world is colorful and people have varied ways of entertainment to fulfill their mind.This Thesis summarizes the effects brought by both the real space and virtual space for Ready Player One.With such a strong contrast,the conflict between the two spaces promotes the narrative process and also highlights the theme of the novel.展开更多
文摘Patterns of body size variation along geographical gradients have long been searched for and generalized into eco-geographical rules.However,no rodent species has yet been analyzed in relation to the 3 dimensions of latitude,longitude and altitude.We analyzed geographical clines and dimorphism of body and skull size in the herb field mouse(Apodemus uralensis)across the species range,based on field data and on data from the literature.Sexual dimorphism in adult A.uralensis was not expressed at a large scale,while local patterns were inconsistent.Age-dependent size changes were most expressed in adult individuals:most characters of adults exceeded in size those of subadults,while subadult-juvenile size differences were only significant in body weight and length,zygomatic skull width,length of cranial diastema and breadth of braincase.Despite central morphological niches along the clines being separated,A.uralensis populations showed a high degree of size overlap in morphological space.We found the species to be characterized by high size variability,with the largest individuals inhabiting the eastern and southern edges of the distribution range.Tail,hind foot and ear lengths were largest in the southern part of the range,in agreement with Allen’s rule.The main measurements that we analyzed,namely body mass,zygomatic skull width and condylobasal skull length,show the presence of 3 clines in the size of adult A.uralensis:(i)a decreasing south-north cline,opposing Bergmann’s rule;(ii)an increasing west-east cline,in accordance with Murphy’s rule;and(iii)an increasing altitudinal cline.
基金supported by grants from the Swedish Research Council(VR 2017-04686)T4F program,Sweden.
文摘Most species have clearly defined distribution ranges and ecological niches.The genetic and ecological causes of species differentiation and the mechanisms that maintain species boundaries between newly evolved taxa and their progenitors are,however,less clearly defined.This study investigated the genetic structure and clines in Pinus densata,a pine of hybrid origin on the southeastern Tibetan Plateau,to gain an understanding of the contemporary dynamics of species barriers.We analyzed genetic diversity in a range-wide collection of P.densata and representative populations of its progenitors,Pinus tabuliformis and Pinus yunnanensis,using exome capture sequencing.We detected four distinct genetic groups within P.densata that reflect its migration history and major gene-flow barriers across the landscape.The demographies of these genetic groups in the Pleistocene were associated with regional glaciation histories.Interestingly,population sizes rebounded rapidly during interglacial periods,suggesting persistence and resilience of the species during the Quaternary ice age.In the contact zone between P.densata and P.yunnanensis,3.36%of the analyzed loci(57849)showed exceptional patterns of introgression,suggesting their potential roles in either adaptive introgression or reproductive isolation.These outliers showed strong clines along critical climate gradients and enrichment in a number of biological processes relevant to high-altitude adaptation.This indicates that ecological selection played an important role in generating genomic heterogeneity and a genetic barrier across a zone of species transition.Our study highlights the forces that operate to maintain species boundaries and promote speciation in the Qinghai-Tibetan Plateau and other mountain systems.
文摘Species may exhibit similar traits via different mechanisms： environmental filtering and local adaptation （geography） and shared evolutionary history （phylogeny） can each contribute to the resemblance of traits among species. Parsing trait variation into geographic and phylogenetic sources is important, as each suggests different constraints on trait evolution. Here, we explore how phylogenetic distance, geographic distance, and geographic variation in climate shape physiological tolerance of high and low temperatures using a global dataset of ant thermal tolerances. We found generally strong roles for evolutionary history and geographic variation in temperature, but essen- tially no detectable effects of spatial proximity per se on either upper or lower thermal tolerance. When we compared the relative importance of the factors shaping upper and lower tolerances, we found a much stronger role for evolutionary history in shaping upper versus lower tolerance, and a moderately weaker role for geographic variation in temperature in shaping upper tolerance when compared with lower tolerance. Our results demonstrate how geographic variation in climate and evolutionary history may have differential effects on the upper and lower endpoints of physiological tolerance. This Janus effect, where the relative contributions of geographic variation in climate and evolutionary history are reversed for lower versus upper physiological tolerances, has gained some support in the literature, and our results for ant physiological tolerances provide further evidence of this pa^ern. As the climate continues to change, the high phylogenetic conservatism of upper tolerance may suggest potential constraints on the evolution of tolerance of high temperatures.
文摘Hybrid zone is a very critical concept within the evolutionary biology, because it would offer us a better insight to understand the evolutionary role of gene flow and hybridization based on the cline model. This minireview presents an expatiation of history perspectives and research developments upon basic concepts including hybrid zones, hybridization, hybrid and its the genetic cline model. Moreover, by figuring out the existing problem around the hybrids within conservative theory and practices, it suggests that the theory of hybrid zone be introduced into conservation biology and it would be provide a broader and more open theoretical background for conservative research and practices.
基金Japan Society for the Promotion of Science,KAKENHI(18J2013908)。
文摘Understanding what environmental factors are genetically linked to a phenologic al event is critical for predicting responses to climate change.Photo synthetic phenology often varies among a species of evergreen conifers due to local adaptation.However,few empirical studies have revealed relevant relationships between climatic factors in provenance environments and photosynthetic phenology.This study evaluated the effects of environmental conditions of the growing site and seed source provenance on the seasonal changes in maximal photochemical quantum yield of photo systemⅡ(Fv/Fm)in a common garden experiment with 2-year-old seedlings of Sakhalin fir(Abies sachalinensis),a representative species with local adaptation,from four seed source provenances.A logistic model was constructed to explain the seasonal variation of Fv/Fmfrom July to October and the relationships between the estimated model parameters and representative factors featuring provenance environments were evaluated.The landscape gradient of the detected model parameters responsible for the provenance environments was visualized in a map of the distribution area.The lowest temperature was the most plausible factor in the growing environment to explain the seasonal changes of Fv/Fm.Among the representative meteorological factors of provenance environments,the lowest temperatures in July showed significant relationships with two model parameters,explaining the lower limit of Fv/Fmand the higher sensitivity of autumn Fv/Fmdecline.The estimated spatial maps of model parameters consistently showed that the higher the lowest temperature in July in the provenance environment,the lower the Fv/Fmin October and the greater the decrease in the autumn Fv/Fmdecline.Therefore,the lowest summer temperature could be associated with the local adaptation of autumn photosynthetic phenology in A.sachalinensis.
文摘Introgression,the incorporation of genetic material from one(sub)species into the gene pool of another by means of hybridization and backcrossing,is a common phenomenon in birds and can provide important insights into the speciation process.In the last decade,the toolkit for studying introgression has expanded together with the development of molecular markers.In this review,we explore how genomic data,the most recent step in this methodological progress,impacts different aspects in the study of avian introgression.First,the detection of hybrids and backcrosses has improved dramatically.The most widely used software package is STRUCTURE.Phylogenetic discordance(i.e.different loci resulting in discordant gene trees) is another means for the detection of introgression,although it should be regarded as a starting point for further analyses,not as a definitive proof of introgression.Specifically,disentangling introgression from other biological processes,such as incomplete lineage sorting,remains a challenging endeavour,although new techniques,such as the D-statistic,are being developed.In addition,phylogenetics might require a shift from trees to networks.Second,the study of hybrid zones by means of geographical or genomic cline analysis has led to important insights into the complex interplay between hybridization and speciation.However,because each hybrid zone study is just a single snapshot of a complex and continuously changing interaction,hybrid zones should be studied across different temporal and/or spatial scales.A third powerful tool is the genome scan.The debate on which evolutionary processes underlie the genomic landscape is still ongoing,as is the question whether loci involved in reproductive isolation cluster together in ‘islands of speciation' or whether they are scattered throughout the genome.Exploring genomic landscapes across the avian tree of life will be an exciting field for further research.Finally,the findings from these different methods should be incorporated into specific speciation scenarios,which can consequently be tested using a modelling approach.All in all,this genomic perspective on avian hybridization and speciation will further our understanding in evolution in general.
基金Supported by the National Natural Science Foundation of China(Grant No.12161049)。
文摘We study the relative properties of(b,c)-inverses with respect to a ring endomorphism.A new class of generalized inverses namedα-(b,c)-inverse is introduced and studied in a more general setting.We show by giving an example that(b,c)-inverses behave quite differently fromα-(b,c)-inverses.The condition that anα-(b,c)-invertible element is precisely a(b,c)-invertible element is investigated.We also study the strongly clean decompositions forα-(b,c)-inverses.Some well-known results on(b,c)-inverses are extended and unified.
文摘Understanding the occurrence of multiple distinct phenotypes in a population of a species,i.e.,polymorphism,is one of the challenges encountered in evolutionary biology.Egg color polymorphism in birds is one example of morphological polymorphism and disruptive selection has been proposed as a hypothetical mechanism to explain its occurrence.We studied how polymorphic egg colors(immaculate blue and white) occur in Korean populations of the Vinous-throated Parrotbill(Paradoxornis webbianus).Egg color ratios(the proportion of nests with blue eggs in a population) were monitored over a large spatial scale and egg colors were quanti ed using a spectrophotometer.We found egg color ratios to vary spatially among populations.Interestingly,there was a latitudinal morph-ratio cline in egg color ratios.e proportion of nests with blue eggs increased considerably with the latitude declined towards the southern part of the Korean peninsula.ere were some quantitative variations in egg colors among populations.However,the pattern of variations was not consistent with those of the population egg color ratios.Based on these results,we discuss a potential scenario for the evolution of egg color polymorphism in the Vinous-throated Parrotbill.
文摘The novel Ready Player One shows Ernest Cline’s ability of space construction,and demonstrates charm and artistic value of the virtual fantasy space it depicts.It is a science fiction with perfect combination of ideological content and artistic form.This thesis aims to discuss the Ernest Cline’s construction of the virtual pace and the real space in Ready Player One and the function of their construction.In real space,the environment is awful and dilapidated,and people’s lives are depressed.While in the virtual space,the world is colorful and people have varied ways of entertainment to fulfill their mind.This Thesis summarizes the effects brought by both the real space and virtual space for Ready Player One.With such a strong contrast,the conflict between the two spaces promotes the narrative process and also highlights the theme of the novel.
