Guo Moruo (Kuo Mojo, 1892-1978), specialist in Chinese history, philologist, writer and social activist. His original name was Kuo Kaizhen and his self-styled name was Shangwu. On November 16 1892, he was born in the ...Guo Moruo (Kuo Mojo, 1892-1978), specialist in Chinese history, philologist, writer and social activist. His original name was Kuo Kaizhen and his self-styled name was Shangwu. On November 16 1892, he was born in the town of Shawan in Leshan County, Sichuan Province.From the autumn.of 1907 to the summer of 1913, he was a pupil at the Jiadingfu Middle School and the展开更多
Founder events influence recessive diseases in highly endogamous populations.Several Indian populations have experienced significant founder events due to strict endogamy.However,the clinical implications of it remain...Founder events influence recessive diseases in highly endogamous populations.Several Indian populations have experienced significant founder events due to strict endogamy.However,the clinical implications of it remain underexplored.Therefore,we perform whole-exome sequencing of 281 individuals from four South Indian populations,characterized by high IBD scores.Our study reveals a high inbreeding rate of 59%across the populations.We identify∼29.2%of the variants that are exclusively present in a single population and uncover 1284 unreported exonic variants,underscoring the underrepresentation of Indian populations in global databases.Among these,23 are predicted to be deleterious,all of which are present in a heterozygous state;they may be pathogenic when homozygous,an expected phenomenon in endogamous populations.Approximately 16%-33%of the identified pathogenic variants showed significantly higher occurrence rates compared with the South Asian populations from 1000 Genomes dataset.Pharmacogenomic analysis revealed distinct allele frequencies of variants in CYP450 and non-CYP450 genes,highlighting heterogeneous drug responses and associated risks.We report a high prevalence of ankylosing spondylitis in Reddy population,linked to the HLA-B∗27:04 allele and strong founder effect.Our findings highlight the need for extensive genomic research in understudied Indian populations for a better understanding of disease risk and evolving strategies for precision and preventive medicine.展开更多
Recent estimates indicate that one-fifth of botanical species worldwide are considered at risk of becoming extinct in the wild. One available strategy for conserving many rare plant species is reintroduction, which ho...Recent estimates indicate that one-fifth of botanical species worldwide are considered at risk of becoming extinct in the wild. One available strategy for conserving many rare plant species is reintroduction, which holds much promise especially when carefully planned by following guidelines and when monitored long-term. We review the Center for Plant Conservation Best Reintroduction Practice Guidelines and highlight important components for planning plant reintroductions. Before attempting reintroductions practitioners should justify them, should consider alternative conservation strategies, understand threats, and ensure that these threats are absent from any recipient site. Planning a reintroduction requires considering legal and logistic parameters as well as target species and recipient site attributes.Carefully selecting the genetic composition of founders, founder population size, and recipient site will influence establishment and population growth. Whenever possible practitioners should conduct reintroductions as experiments and publish results. To document whether populations are sustainable will require long-term monitoring for decades, therefore planning an appropriate monitoring technique for the taxon must consider current and future needs. Botanical gardens can play a leading role in developing the science and practice of plant reintroduction.展开更多
Translocations, especially assisted colonizations, of animals are increasingly used as a conservation management tool. In many cases, however, limited funding and other logistic challenges limit the number of individu...Translocations, especially assisted colonizations, of animals are increasingly used as a conservation management tool. In many cases, however, limited funding and other logistic challenges limit the number of individuals available for transloeation. In conservation genetics, small populations are predicted to rapidly lose genetic diversity which can deteriorate population survival. Thus, how worried should we be about the loss of genetic diversity when introducing small, isolated populations？ Historical species introductions provide a means to assess these issues. Here we review 13 studies of ＂assisted colonization-like＂ introductions of animals, where only a small known number of founders established an isolated population without secondary contact to the source population. We test which factors could be important in retaining genetic diversity in these cases. In many cases, loss in heterozygosity （-12.1%） was detected, and more seriously the loss in allelic richness （-27.8 %）. Number of founders seemed to have an effect but it also indicated that high population growth rate could help to retain genetic diversity, i.e. future management actions could be effective even with a limited number of founders if population growth would be enhanced. On the contrary, translocated organisms with longer generation times did not seem to retain more genetic diversity. We advocate that, where possible, future studies on translocated animals should report the loss of genetic diversity （both heterozygosity and allelic richness）, which is essential for meta-analyses like this one for deepening our understanding of the genetic consequences of assisted colonization, and justifying management decisions [Current Zoology 61 （5）： 827-834, 2015].展开更多
Since late 2011,outbreaks of pseudorabies virus(PRV)have occurred in southern China causing major economic losses to the pig industry.We previously reported that variant PRV forms and recombination in China could be t...Since late 2011,outbreaks of pseudorabies virus(PRV)have occurred in southern China causing major economic losses to the pig industry.We previously reported that variant PRV forms and recombination in China could be the source of continued epidemics.Here,we analyzed samples from intensive pig farms in eastern China between 2017 and 2019,and sequenced the main glycoproteins(gB,gC,gD,and gE)to study the evolution characteristics of PRV.Based on the gC gene,we found that PRV variants belong to clade 2 and detected a founder effect during by the PRV epidemic.In addition,we detected inter-and intra-clade recombination;in particular,inter-clade recombination in the gB genes of strains FJ-ZXF and FJ-W2,which were recombinant with clade 1 strains.We also found specific amino-acid changes and positively selected sites,possibly associated with functional changes.This analysis of the emergence of PRV in China illustrates the need for continuous monitoring and the development of vaccines against specific variants of PRV.展开更多
U-Pb zircon age, geochemical, and Sr-Nd-Pb isotopic data of mafic dykes from eastern Shandong Province, eastern China is reported herein. Laser ablation inductively coupled plasma mass spectrometry （LA-ICP-MS） U-Pb ...U-Pb zircon age, geochemical, and Sr-Nd-Pb isotopic data of mafic dykes from eastern Shandong Province, eastern China is reported herein. Laser ablation inductively coupled plasma mass spectrometry （LA-ICP-MS） U-Pb zircon analyses of two samples from the investigated mafic dykes yield consistent ages ranging from 121.9 Ma ± 0.47 Ma to 122.9 Ma ± 0.61 Ma. The mafic dykes are characterized by high （87Sr/86Sr） i ranging from 0.7087 to 0.7089, low εNd（t） values ranging from -16.9 to -17.8, 206Pb/204Pb = 17.15 to 17.17, 207Pb/204Pb = 15.45 to 15.47, and 208Pb/204Pb = 37.59 to 37.68. Results from the current study suggest that the mafic dykes are derived from partial melting of ancient lithospheric mantle that was variably hybridized by melts derived from foundered lower crustal eclogite. The mafic dykes may have been generated through subsequent insignificant crystal fractionation and very minor crustal contamination during magma ascent. Combined with previous studies, the current findings provide new evidence that the intense lithospheric thinning beneath the eastern Shandong Province of eastern China occurred at ~120 Ma, and that this condition was caused by the removal of the lower lithosphere （mantle and lower crust）.展开更多
On the bases of archaeological discoveries, the earliest domestication of rice has been confirmed in the middle and lower Changjiang River basin, while in the region wild rice populations are found in shallow swamps u...On the bases of archaeological discoveries, the earliest domestication of rice has been confirmed in the middle and lower Changjiang River basin, while in the region wild rice populations are found in shallow swamps under a climate with freezing winter cold. These findings lead us to-examine the past ideas about domestication and differentiation of rice. Historically, in 1930s two sub-species, indica and japonica, were proposed on the basis of sterility in F1 hybrids between them. Soon after that, the two types were classified by the associations of a number of genetically independent traits. The characteristic associations of traits have been explained by the hybrid sterility or reproductive barriers which were assumed to comprise a set of duplicate recessive lethal genes and to be an inner genetic mechanism to lead to the varietal differentiations In 1980s, the hybrid sterility between Indica and Japonica types was analyzed, and Indica, Japonica, and wide-compatibility type which gives fertile hybrids when cross to Indica and Japonica types, are proved to contain an allele, S5＇, S5＇ and S5^n, respectively at a locus on chromosome 6. And those gametes having Sj allele are found to be partially aborted in the hybrid genotypes of S5＇/S5＇ while no gamete abortion occurs in S5＇/S5^n and S5＇/S5^n genotypes. Since then, the gene S5^n has been used in hybrid rice breeding to obtain fertile and vigorous hybrids between subspecies, and the long-disputed problem of hybrid sterility has been solved. Also in such studies the characteristic association of traits found in each of vadetal groups is better explained by founder effects. On the other hand, a large number of native cultivars of rice were surveyed with enzyme polymorphism in 1980s and later with molecular markers. As a result, profound genetic diversity is found in cultivated rice as well as in wild rice. These findings seem to lead us to the idea of multiple independent domestications of rice. However, before reaching such a conclusion, at least two factors, i.e., long-distance-dissemination of some genotypes and the possibilities of introgression by local wild rice to primitive cultivars need to be examined. Taking the two factors as well as the historical events into consideration, it is considered here that the perennial japonica cultivars which are close to wild rice in the Changjiang River basin were disseminated to East India through Assam or along the Bengal Bay, where they were transformed under the introgressions of local wild rice and formed a secondary center, from which some genotypes seem to be disseminated to colonies in Southeast Asia under the influence of Hinduism. Later some of the genotypes were introduced into China and constituted so called Indica type. This may be a reasonable picture for the varietal differentiation.展开更多
Reintroductions of rare plants require detailed knowledge of habitat requirements, species interactions,and restoration techniques. Thus, incremental experimentation over many years may be required to develop adequate...Reintroductions of rare plants require detailed knowledge of habitat requirements, species interactions,and restoration techniques. Thus, incremental experimentation over many years may be required to develop adequate knowledge and techniques for successful reintroduction. To determine drivers of extinction in historical reintroductions of a federally endangered perennial(Astragalus bibullatus), we developed a reintroduction experiment to disentangle the relative importance of habitat quality, herbivores, and restoration technique on reintroduction success. In a factorial design, we manipulated access to vertebrate herbivores across different habitat types(mesic ecotone vs. xeric barren), and used founder populations comprised of more transplants and genetic sources than previous reintroduction attempts.In mesic ecotones where historical reintroductions failed, excluding herbivores, thinning woody encroachment to improve habitat quality, outplanting across a greater array of microhabitats, and increasing founder population size did not improve demographic rates over previous attempts.Compared to mesic ecotones, transplant survival rates and cumulative fruit production were more than two and ten times greater, respectively, in a xeric barren ecotone characterized by open, grassy, and dry microenvironmental conditions. Across all sites, herbivores decreased probabilities of survival and flowering of larger adult plants. Flowering rates were 80% greater inside relative to outside herbivore exclusion cages. Over a four-year period, only a single uncaged plant produced fruit. Our study demonstrates that habitat quality and vertebrate herbivory are key drivers of long-term persistence in rare plant reintroductions. Using incremental experiments that build on previous knowledge gained from long-term monitoring can improve reintroduction outcomes.展开更多
Considering the severe impacts of genetic bottlenecks and small numbers of founders in populations of reintroduced animals, it is necessary to study inbreeding and its effect on fitness in species of conservation conc...Considering the severe impacts of genetic bottlenecks and small numbers of founders in populations of reintroduced animals, it is necessary to study inbreeding and its effect on fitness in species of conservation concern. Pere David＇s deer is one of few large mammal species extinct in the wild but safely preserved in captivity. Its specific background gives us the opportunity to study the relationships between heterozygosity and neonatal fitness in relocated populations. We employed five microsatellite loci to explore heterozygosity-fitness correlations in a population of Pere David＇s deer at the Beijing Milu Ecological Research Center. We observed associations between microsatellite-based variables sMLH, IR, MD^2 and HL, and two components of fitness ex- pressed early in life （birth weight and the neonatal mortality of 123 Pere David＇s deer calves born over six consecutive years）. We found that neonatal mortality was 19.1% - 7.6%, not higher than the 19% or 18% reported in other ungulates. The heterozygosity of calves was not associated with neonatal mortality, nor birth weight. Our study implies that low genetic variability of microsa- l：ellite loci has no overt effect on birth weight and neonatal mortality in reintroduced populations of P^re David＇s deer [Current Zoology 59 （2）： 249-256, 2013].展开更多
Recent empirical and theoretical studies suggest that personality and locomotory performance traits linked to dispersal abilities are crucial components of the dispersal syndromes,and that they can evolve during range...Recent empirical and theoretical studies suggest that personality and locomotory performance traits linked to dispersal abilities are crucial components of the dispersal syndromes,and that they can evolve during range expansions and colonization processes.Island colonization is one of the best characterized processes in dispersal biogeography,and its implication in the evolution of phenotypic traits has been investigated over a wide range of temporal scales.However,the effect of island colonization on personality and performance traits of natural populations,and how these traits could drive island colonization,has been little explored.Noteworthy,no studies have addressed these processes in the context of late Pleistocene range expansions.Here,we investigated the contribution of island colonization triggered by postglacial range expansions to intraspecific variation in personality and locomotory performance traits.We compared boldness,exploration,jumping performance,and stickiness abilities in populations from 3 equidistant areas of the Tyrrhenian tree frog Hyla sarda,2 from the main island(Corsica Island),and 1 from the recently colonized island of Elba.Individuals from Elba were significantly bolder than individuals from Corsica,as they emerged sooner from a shelter(P=0.028),while individuals from Corsica showed markedly higher jumping and stickiness performance(both P<0.001),resulting as more performing than those of Elba.We discuss these results in the context of the major microevolutionary processes at play during range expansion,including selection,spatial sorting,founder effects,and their possible interaction with local adaptation processes.展开更多
Founder parents have contributed significantly to the improvement of wheat breeding and production. In order to investigate the genetic characteristics of founder parents and widely planted cultivars, Mazhamai(M), Biy...Founder parents have contributed significantly to the improvement of wheat breeding and production. In order to investigate the genetic characteristics of founder parents and widely planted cultivars, Mazhamai(M), Biyumai(B) and six sibling lines(BM1–6) derived from the cross M×B were phenotyped for eight yield-related traits over multiple years and locations and genotyped using the the wheat 90 K single nucleotide polymorphism(SNP) assay. BM4 has been used as a founder parent, and BM1 has been widely planted, whereas BM2, 3, 5, and 6 have not been used extensively for breeding or planting in China. Phenotypic comparisons revealed that BM4 and BM1 displayed a better overall performance than the other sibling lines. BM1 showed higher thousand-grain weight than BM4, whereas BM4 exhibited lower coefficient of variation for most of the yield-related traits across different years and locations, indicating that BM4 was widely adaptable and more stable in different environments. SNP analysis revealed that BM4 and BM1 inherited similar proportions of the M genome but are dissimilar to BM2, 3, 5, and 6. Both BM1 and BM4 have specific alleles that differ from the other BM lines, and most of these alleles are concentrated in specific chromosomal regions that are found to associate with favorable QTLs, these SNPs and their surrounding regions may carry the genetic determinants important for the superior performance of the two lines. But BM4 has more genetic diversity than BM1 with more specific alleles and pleiotropic regions, indicating that the genome of BM4 may be more complex than the other sibling lines and has more favorable gene resources. Our results provide valuable information that can be used to select elite parents for wheat and self-pollinating crop breeding.展开更多
Sexual isolation resulting from differences in mate choice behaviors is a hallmark of rapidly-speciating lineages. When present, asymmetrical sexual isolation may provide insights into the mechanisms responsible for t...Sexual isolation resulting from differences in mate choice behaviors is a hallmark of rapidly-speciating lineages. When present, asymmetrical sexual isolation may provide insights into the mechanisms responsible for the evolutionary change in mate signaling traits. In particular, Kaneshiro＇s hypothesis suggests that divergence in sexual characters between populations may arise in allopatry when ＇derived＇ founding populations are subject to severe population bottlenecks, accompanied by a relaxation of sexual selection relative to ＇ancestral＇ source populations. In the present study, we tested predictions of asymmetrical sexual isolation between two allopatric species of Hawaiian Laupala crickets, representing ＇ancestral＇ （L. makaio） and ＇derived＇ （L. nigra） taxa. While crickets in this genus are notable for rapid divergence of male courtship songs, these species share similar song types, thus suggesting that patterns of sexual isolation are likely due to other mating cues. Analysis of behavioral responses in conspeci- fic and heterospecific ＇no-choice＇ mating trials revealed pronounced asymmetrical isolation in the direction predicted by Kane- shiro＇s hypothesis, wherein we observed a significant reduction in mating success for crosses involving ＇derived＇ males paired with ＇ancestral＇ females, compared to the reciprocal heterospecific and both conspecific pairings. Further dissection of courtship behaviors suggested this difference did not reflect male mate choice, but rather, marked reduced spermatophore acceptance rates by ＇ancestral＇ females paired with ＇derived＇ males. The results are discussed with respect to founder effect models of speciatiou and the potential role of chemosensory signals in mate choice in these species [Current Zoology 59 （2）： 230-238, 2013].展开更多
Past studies discussing the origins of agriculture have mainly emphasized changes in environmental and human-behavior factors as possible explanations for the shift from foraging to farming. This paper focuses on how ...Past studies discussing the origins of agriculture have mainly emphasized changes in environmental and human-behavior factors as possible explanations for the shift from foraging to farming. This paper focuses on how increase in the biological fitness of both farmers and crops enabled the rapid evolution and success of farmers and agriculture. It is shown that the first plants under domestication achieved their superior fitness mainly as a consequence of some of their genetic and life-history traits. It led these species to be extensively integrated into human subsistence and eventually dominate the farmers’ fields. Concurrently, the first farmers gained their enhanced fitness by producing food surplus and by acquiring extra social prestige and power, while materializing the tendency to higher reproduction rate, and eventually to the expansion of farming populations. The unbreakable dependence between high fitness crops and high fitness man, namely their coevolution is a key issue and a promising research area in the understanding of the human story and the origins of agriculture.展开更多
"The year of 2013 is marked by the soaring of China’s cross-border ecommerce industry,"Wang Shutong,founder and CEO of DHgate which is known as one of the earliest B2B(Business to Business)cross-border ecom..."The year of 2013 is marked by the soaring of China’s cross-border ecommerce industry,"Wang Shutong,founder and CEO of DHgate which is known as one of the earliest B2B(Business to Business)cross-border ecommerce platforms,said展开更多
Exhibition Date:2014.3.5-5.1 Exhibition Address:50B Fengxian Road close Shimen Er Road,Shanghai The original idea of this project came from a private dialogue between Liu Gang and Deng Yeming,the founder of AM Art Spa...Exhibition Date:2014.3.5-5.1 Exhibition Address:50B Fengxian Road close Shimen Er Road,Shanghai The original idea of this project came from a private dialogue between Liu Gang and Deng Yeming,the founder of AM Art Space two years ago.Liu Gang came up with two thorough questions that why Deng Yeming started the space and展开更多
文摘Guo Moruo (Kuo Mojo, 1892-1978), specialist in Chinese history, philologist, writer and social activist. His original name was Kuo Kaizhen and his self-styled name was Shangwu. On November 16 1892, he was born in the town of Shawan in Leshan County, Sichuan Province.From the autumn.of 1907 to the summer of 1913, he was a pupil at the Jiadingfu Middle School and the
基金supported by the DBT JRF-SRF research fellowship.KT was supported the J C Bose Fellowship from Science and Engineering Research Board(SERB),Department of Science and Technology,Government of India(JCB/2019/000027)CSIR Bhatnagar Fellowship,from Council of Scientific and Industrial Research(CSiR),Ministry of Science and Technology,Government of India.
文摘Founder events influence recessive diseases in highly endogamous populations.Several Indian populations have experienced significant founder events due to strict endogamy.However,the clinical implications of it remain underexplored.Therefore,we perform whole-exome sequencing of 281 individuals from four South Indian populations,characterized by high IBD scores.Our study reveals a high inbreeding rate of 59%across the populations.We identify∼29.2%of the variants that are exclusively present in a single population and uncover 1284 unreported exonic variants,underscoring the underrepresentation of Indian populations in global databases.Among these,23 are predicted to be deleterious,all of which are present in a heterozygous state;they may be pathogenic when homozygous,an expected phenomenon in endogamous populations.Approximately 16%-33%of the identified pathogenic variants showed significantly higher occurrence rates compared with the South Asian populations from 1000 Genomes dataset.Pharmacogenomic analysis revealed distinct allele frequencies of variants in CYP450 and non-CYP450 genes,highlighting heterogeneous drug responses and associated risks.We report a high prevalence of ankylosing spondylitis in Reddy population,linked to the HLA-B∗27:04 allele and strong founder effect.Our findings highlight the need for extensive genomic research in understudied Indian populations for a better understanding of disease risk and evolving strategies for precision and preventive medicine.
基金Guangxi Chairman's Foundation grant #09203-04 to Hong Liu and colleagues supported JM attendance at the IABG conference possiblefunding from the U.S. Fish and Wildlife Service(1448-40181-99-G173)+4 种基金Florida Department of Agriculture and Consumer Services (#20161,021010,022647)Miami-Dade County Natural Areas Management and Environmentally Endangered Lands Program (R-80807)Arizona Department of TransportationU.S. Forest ServiceU.S. National Park Service
文摘Recent estimates indicate that one-fifth of botanical species worldwide are considered at risk of becoming extinct in the wild. One available strategy for conserving many rare plant species is reintroduction, which holds much promise especially when carefully planned by following guidelines and when monitored long-term. We review the Center for Plant Conservation Best Reintroduction Practice Guidelines and highlight important components for planning plant reintroductions. Before attempting reintroductions practitioners should justify them, should consider alternative conservation strategies, understand threats, and ensure that these threats are absent from any recipient site. Planning a reintroduction requires considering legal and logistic parameters as well as target species and recipient site attributes.Carefully selecting the genetic composition of founders, founder population size, and recipient site will influence establishment and population growth. Whenever possible practitioners should conduct reintroductions as experiments and publish results. To document whether populations are sustainable will require long-term monitoring for decades, therefore planning an appropriate monitoring technique for the taxon must consider current and future needs. Botanical gardens can play a leading role in developing the science and practice of plant reintroduction.
文摘Translocations, especially assisted colonizations, of animals are increasingly used as a conservation management tool. In many cases, however, limited funding and other logistic challenges limit the number of individuals available for transloeation. In conservation genetics, small populations are predicted to rapidly lose genetic diversity which can deteriorate population survival. Thus, how worried should we be about the loss of genetic diversity when introducing small, isolated populations？ Historical species introductions provide a means to assess these issues. Here we review 13 studies of ＂assisted colonization-like＂ introductions of animals, where only a small known number of founders established an isolated population without secondary contact to the source population. We test which factors could be important in retaining genetic diversity in these cases. In many cases, loss in heterozygosity （-12.1%） was detected, and more seriously the loss in allelic richness （-27.8 %）. Number of founders seemed to have an effect but it also indicated that high population growth rate could help to retain genetic diversity, i.e. future management actions could be effective even with a limited number of founders if population growth would be enhanced. On the contrary, translocated organisms with longer generation times did not seem to retain more genetic diversity. We advocate that, where possible, future studies on translocated animals should report the loss of genetic diversity （both heterozygosity and allelic richness）, which is essential for meta-analyses like this one for deepening our understanding of the genetic consequences of assisted colonization, and justifying management decisions [Current Zoology 61 （5）： 827-834, 2015].
基金financially supported by the National Key Research and Development Program of China (2017YFD0500101)the Natural Science Foundation of Jiangsu Province (BK20170721)the China Association for Science and Technology Youth Talent Lift Project (2017-2019)
文摘Since late 2011,outbreaks of pseudorabies virus(PRV)have occurred in southern China causing major economic losses to the pig industry.We previously reported that variant PRV forms and recombination in China could be the source of continued epidemics.Here,we analyzed samples from intensive pig farms in eastern China between 2017 and 2019,and sequenced the main glycoproteins(gB,gC,gD,and gE)to study the evolution characteristics of PRV.Based on the gC gene,we found that PRV variants belong to clade 2 and detected a founder effect during by the PRV epidemic.In addition,we detected inter-and intra-clade recombination;in particular,inter-clade recombination in the gB genes of strains FJ-ZXF and FJ-W2,which were recombinant with clade 1 strains.We also found specific amino-acid changes and positively selected sites,possibly associated with functional changes.This analysis of the emergence of PRV in China illustrates the need for continuous monitoring and the development of vaccines against specific variants of PRV.
基金supported by Opening Project(201206)of the State Key Laboratory of Ore deposit Geochemistry,Chinese Academia of Sciencesthe National Nature Science Foundation of China(40773020,40972071,90714010,and 40634020)
文摘U-Pb zircon age, geochemical, and Sr-Nd-Pb isotopic data of mafic dykes from eastern Shandong Province, eastern China is reported herein. Laser ablation inductively coupled plasma mass spectrometry （LA-ICP-MS） U-Pb zircon analyses of two samples from the investigated mafic dykes yield consistent ages ranging from 121.9 Ma ± 0.47 Ma to 122.9 Ma ± 0.61 Ma. The mafic dykes are characterized by high （87Sr/86Sr） i ranging from 0.7087 to 0.7089, low εNd（t） values ranging from -16.9 to -17.8, 206Pb/204Pb = 17.15 to 17.17, 207Pb/204Pb = 15.45 to 15.47, and 208Pb/204Pb = 37.59 to 37.68. Results from the current study suggest that the mafic dykes are derived from partial melting of ancient lithospheric mantle that was variably hybridized by melts derived from foundered lower crustal eclogite. The mafic dykes may have been generated through subsequent insignificant crystal fractionation and very minor crustal contamination during magma ascent. Combined with previous studies, the current findings provide new evidence that the intense lithospheric thinning beneath the eastern Shandong Province of eastern China occurred at ~120 Ma, and that this condition was caused by the removal of the lower lithosphere （mantle and lower crust）.
文摘On the bases of archaeological discoveries, the earliest domestication of rice has been confirmed in the middle and lower Changjiang River basin, while in the region wild rice populations are found in shallow swamps under a climate with freezing winter cold. These findings lead us to-examine the past ideas about domestication and differentiation of rice. Historically, in 1930s two sub-species, indica and japonica, were proposed on the basis of sterility in F1 hybrids between them. Soon after that, the two types were classified by the associations of a number of genetically independent traits. The characteristic associations of traits have been explained by the hybrid sterility or reproductive barriers which were assumed to comprise a set of duplicate recessive lethal genes and to be an inner genetic mechanism to lead to the varietal differentiations In 1980s, the hybrid sterility between Indica and Japonica types was analyzed, and Indica, Japonica, and wide-compatibility type which gives fertile hybrids when cross to Indica and Japonica types, are proved to contain an allele, S5＇, S5＇ and S5^n, respectively at a locus on chromosome 6. And those gametes having Sj allele are found to be partially aborted in the hybrid genotypes of S5＇/S5＇ while no gamete abortion occurs in S5＇/S5^n and S5＇/S5^n genotypes. Since then, the gene S5^n has been used in hybrid rice breeding to obtain fertile and vigorous hybrids between subspecies, and the long-disputed problem of hybrid sterility has been solved. Also in such studies the characteristic association of traits found in each of vadetal groups is better explained by founder effects. On the other hand, a large number of native cultivars of rice were surveyed with enzyme polymorphism in 1980s and later with molecular markers. As a result, profound genetic diversity is found in cultivated rice as well as in wild rice. These findings seem to lead us to the idea of multiple independent domestications of rice. However, before reaching such a conclusion, at least two factors, i.e., long-distance-dissemination of some genotypes and the possibilities of introgression by local wild rice to primitive cultivars need to be examined. Taking the two factors as well as the historical events into consideration, it is considered here that the perennial japonica cultivars which are close to wild rice in the Changjiang River basin were disseminated to East India through Assam or along the Bengal Bay, where they were transformed under the introgressions of local wild rice and formed a secondary center, from which some genotypes seem to be disseminated to colonies in Southeast Asia under the influence of Hinduism. Later some of the genotypes were introduced into China and constituted so called Indica type. This may be a reasonable picture for the varietal differentiation.
基金supported by the United States Department of Interior National Park Service Challenge Cost-Share Program (Grant: H55901000010)the Tennessee Department of Environment and Conservation-Division of Natural Areas (Grants: 32701-00385, 32701-0899, and 32701-01236)
文摘Reintroductions of rare plants require detailed knowledge of habitat requirements, species interactions,and restoration techniques. Thus, incremental experimentation over many years may be required to develop adequate knowledge and techniques for successful reintroduction. To determine drivers of extinction in historical reintroductions of a federally endangered perennial(Astragalus bibullatus), we developed a reintroduction experiment to disentangle the relative importance of habitat quality, herbivores, and restoration technique on reintroduction success. In a factorial design, we manipulated access to vertebrate herbivores across different habitat types(mesic ecotone vs. xeric barren), and used founder populations comprised of more transplants and genetic sources than previous reintroduction attempts.In mesic ecotones where historical reintroductions failed, excluding herbivores, thinning woody encroachment to improve habitat quality, outplanting across a greater array of microhabitats, and increasing founder population size did not improve demographic rates over previous attempts.Compared to mesic ecotones, transplant survival rates and cumulative fruit production were more than two and ten times greater, respectively, in a xeric barren ecotone characterized by open, grassy, and dry microenvironmental conditions. Across all sites, herbivores decreased probabilities of survival and flowering of larger adult plants. Flowering rates were 80% greater inside relative to outside herbivore exclusion cages. Over a four-year period, only a single uncaged plant produced fruit. Our study demonstrates that habitat quality and vertebrate herbivory are key drivers of long-term persistence in rare plant reintroductions. Using incremental experiments that build on previous knowledge gained from long-term monitoring can improve reintroduction outcomes.
文摘Considering the severe impacts of genetic bottlenecks and small numbers of founders in populations of reintroduced animals, it is necessary to study inbreeding and its effect on fitness in species of conservation concern. Pere David＇s deer is one of few large mammal species extinct in the wild but safely preserved in captivity. Its specific background gives us the opportunity to study the relationships between heterozygosity and neonatal fitness in relocated populations. We employed five microsatellite loci to explore heterozygosity-fitness correlations in a population of Pere David＇s deer at the Beijing Milu Ecological Research Center. We observed associations between microsatellite-based variables sMLH, IR, MD^2 and HL, and two components of fitness ex- pressed early in life （birth weight and the neonatal mortality of 123 Pere David＇s deer calves born over six consecutive years）. We found that neonatal mortality was 19.1% - 7.6%, not higher than the 19% or 18% reported in other ungulates. The heterozygosity of calves was not associated with neonatal mortality, nor birth weight. Our study implies that low genetic variability of microsa- l：ellite loci has no overt effect on birth weight and neonatal mortality in reintroduced populations of P^re David＇s deer [Current Zoology 59 （2）： 249-256, 2013].
基金supported by a grant from the Italian Ministry of Education,University and Research(PRIN project 2017KLZ3MA).
文摘Recent empirical and theoretical studies suggest that personality and locomotory performance traits linked to dispersal abilities are crucial components of the dispersal syndromes,and that they can evolve during range expansions and colonization processes.Island colonization is one of the best characterized processes in dispersal biogeography,and its implication in the evolution of phenotypic traits has been investigated over a wide range of temporal scales.However,the effect of island colonization on personality and performance traits of natural populations,and how these traits could drive island colonization,has been little explored.Noteworthy,no studies have addressed these processes in the context of late Pleistocene range expansions.Here,we investigated the contribution of island colonization triggered by postglacial range expansions to intraspecific variation in personality and locomotory performance traits.We compared boldness,exploration,jumping performance,and stickiness abilities in populations from 3 equidistant areas of the Tyrrhenian tree frog Hyla sarda,2 from the main island(Corsica Island),and 1 from the recently colonized island of Elba.Individuals from Elba were significantly bolder than individuals from Corsica,as they emerged sooner from a shelter(P=0.028),while individuals from Corsica showed markedly higher jumping and stickiness performance(both P<0.001),resulting as more performing than those of Elba.We discuss these results in the context of the major microevolutionary processes at play during range expansion,including selection,spatial sorting,founder effects,and their possible interaction with local adaptation processes.
基金supported by grants from the National Basic Research Program of China(973 Program,2011CB100104)the National Natural Science Foundation of China(31471174)
文摘Founder parents have contributed significantly to the improvement of wheat breeding and production. In order to investigate the genetic characteristics of founder parents and widely planted cultivars, Mazhamai(M), Biyumai(B) and six sibling lines(BM1–6) derived from the cross M×B were phenotyped for eight yield-related traits over multiple years and locations and genotyped using the the wheat 90 K single nucleotide polymorphism(SNP) assay. BM4 has been used as a founder parent, and BM1 has been widely planted, whereas BM2, 3, 5, and 6 have not been used extensively for breeding or planting in China. Phenotypic comparisons revealed that BM4 and BM1 displayed a better overall performance than the other sibling lines. BM1 showed higher thousand-grain weight than BM4, whereas BM4 exhibited lower coefficient of variation for most of the yield-related traits across different years and locations, indicating that BM4 was widely adaptable and more stable in different environments. SNP analysis revealed that BM4 and BM1 inherited similar proportions of the M genome but are dissimilar to BM2, 3, 5, and 6. Both BM1 and BM4 have specific alleles that differ from the other BM lines, and most of these alleles are concentrated in specific chromosomal regions that are found to associate with favorable QTLs, these SNPs and their surrounding regions may carry the genetic determinants important for the superior performance of the two lines. But BM4 has more genetic diversity than BM1 with more specific alleles and pleiotropic regions, indicating that the genome of BM4 may be more complex than the other sibling lines and has more favorable gene resources. Our results provide valuable information that can be used to select elite parents for wheat and self-pollinating crop breeding.
文摘Sexual isolation resulting from differences in mate choice behaviors is a hallmark of rapidly-speciating lineages. When present, asymmetrical sexual isolation may provide insights into the mechanisms responsible for the evolutionary change in mate signaling traits. In particular, Kaneshiro＇s hypothesis suggests that divergence in sexual characters between populations may arise in allopatry when ＇derived＇ founding populations are subject to severe population bottlenecks, accompanied by a relaxation of sexual selection relative to ＇ancestral＇ source populations. In the present study, we tested predictions of asymmetrical sexual isolation between two allopatric species of Hawaiian Laupala crickets, representing ＇ancestral＇ （L. makaio） and ＇derived＇ （L. nigra） taxa. While crickets in this genus are notable for rapid divergence of male courtship songs, these species share similar song types, thus suggesting that patterns of sexual isolation are likely due to other mating cues. Analysis of behavioral responses in conspeci- fic and heterospecific ＇no-choice＇ mating trials revealed pronounced asymmetrical isolation in the direction predicted by Kane- shiro＇s hypothesis, wherein we observed a significant reduction in mating success for crosses involving ＇derived＇ males paired with ＇ancestral＇ females, compared to the reciprocal heterospecific and both conspecific pairings. Further dissection of courtship behaviors suggested this difference did not reflect male mate choice, but rather, marked reduced spermatophore acceptance rates by ＇ancestral＇ females paired with ＇derived＇ males. The results are discussed with respect to founder effect models of speciatiou and the potential role of chemosensory signals in mate choice in these species [Current Zoology 59 （2）： 230-238, 2013].
文摘Past studies discussing the origins of agriculture have mainly emphasized changes in environmental and human-behavior factors as possible explanations for the shift from foraging to farming. This paper focuses on how increase in the biological fitness of both farmers and crops enabled the rapid evolution and success of farmers and agriculture. It is shown that the first plants under domestication achieved their superior fitness mainly as a consequence of some of their genetic and life-history traits. It led these species to be extensively integrated into human subsistence and eventually dominate the farmers’ fields. Concurrently, the first farmers gained their enhanced fitness by producing food surplus and by acquiring extra social prestige and power, while materializing the tendency to higher reproduction rate, and eventually to the expansion of farming populations. The unbreakable dependence between high fitness crops and high fitness man, namely their coevolution is a key issue and a promising research area in the understanding of the human story and the origins of agriculture.
文摘"The year of 2013 is marked by the soaring of China’s cross-border ecommerce industry,"Wang Shutong,founder and CEO of DHgate which is known as one of the earliest B2B(Business to Business)cross-border ecommerce platforms,said
文摘Exhibition Date:2014.3.5-5.1 Exhibition Address:50B Fengxian Road close Shimen Er Road,Shanghai The original idea of this project came from a private dialogue between Liu Gang and Deng Yeming,the founder of AM Art Space two years ago.Liu Gang came up with two thorough questions that why Deng Yeming started the space and
