首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
This article presents an analysis of the relationship between historical memory and the emergence and reproduction of a specific model of unionism. I argue that in order to understand the militant particularism of the Spanish engine drivers, we need to look at the historical representations that it is embedded in. Recourse to a generational framework makes possible the sustained presentation of the union as a case of successful workers’ organizing, in spite of evidence to the contrary. The historical ethnographic analysis of SEMAF, the Spanish engine drivers’ union, contributes to the analysis of historical memory within the contemporary anthropology of class. The article contributes to theoretical debates in the anthropology of class by reclaiming Michel Trouillot’s conceptualization of the historical process. Two aspects of Trouillot’s work are singled out: his dynamic understanding of the process of historical production and the corollary formulation of the overlapping capacities in which people participate in it (as agents, actors, and subjects) and his emphasis on the importance of expanding scholarly views of the field of historical production.  相似文献   

2.
In Europe, forests have been strongly influenced by human land-use for millennia. Here, we studied the importance of anthropogenic historical factors as determinants of understorey species distributions in a 967 ha Danish forest complex using 156 randomly placed 100-m2 plots, 15 environmental, 9 spatial, and 5 historical variables, and principal components analysis (PCA), redundancy analysis (RDA) as well as indicator species analysis. The historical variables were status as ancient (1805 AD) high forest, reclaimed bogs, ≤100 m from Bronze Age burial mounds, or former conifer plantation, and stand age. The PCA results showed that the main gradients in species composition were strongly related to the explanatory variables. Forward variable selection and variation partitioning using RDA showed that although modern environment was the dominant driver of species composition, anthropogenic historical factors were also important. The pure historical variation fraction constituted 13% of the variation explained. The RDA results showed that ancient-forest status and, secondarily, reclaimed bog status were the only significant historical variables. Many typical forest interior species, with poor dispersal and a strong literature record as ancient-forest species, were still concentrated in areas that were high forest in 1805. Among the younger forests, there were clear floristic differences between those on reclaimed bogs and those not. Apparently remnant populations of wet-soil plants were still present in the reclaimed bog areas. Our results emphasize the importance of historical factors for understanding modern vegetation patterns in forested landscapes.  相似文献   

3.
The statistical analysis of Bowman et al. ( Journal of Biogeography , 2008, 35 , 1976–1988) revealed the weak relationship between the rate of woody cover encroachment onto the freshwater floodplains in the central section of Kakadu National Park (KNP) over a 40-year period and estimates of proximate water buffalo ( Bubalus bubalis ) density. The analysis relied on detailed mapping of buffalo tracks, the best historical record of spatial variation of buffalo density in KNP. In their reply, Petty & Werner ( Journal of Biogeography , 2009, doi: [DOI link] ) prefer to privilege an amalgam of historical sources to claim that buffalo removal is the primary driver of the woody expansion on floodplains. The contrasting weight placed on data analysis and differences of interpretation underscore a tension between statistically based historical ecology approaches and environmental history narratives, a tension that forms part of the broader cultural clash between the Sciences and Humanities.  相似文献   

4.
Qian H  Ricklefs RE 《The American naturalist》2004,163(5):773-9; discussion 780-5
We comment on a recent paper by Francis and Currie that reports a globally consistent relationship between plant family diversity in large geographic grid cells and factors in the physical environment. This relationship was interpreted as demonstrating local ecological determination of diversity, leaving little room for regional and historical effects. We suggest that using family richness to describe patterns of diversity reduces regional effects owing to the lower endemism of plants at the family compared with the species level. Regardless of the taxonomic level of analysis, we further point out that unless regional effects are tested explicitly, statistically significant differences in diversity between regions can be overlooked. Finally, even correlations between diversity and physical conditions of the environment can have primarily historical and evolutionary origins when lineages diversify within ecological zones of origin and spread more slowly to diverse environments. Thus, local ecological determinism should not have primacy over evolutionary-historical explanations for patterns of diversity between or within regions. Ecologists must evaluate patterns in local diversity within historical and geographic, as well as ecological, contexts.  相似文献   

5.
The fragmentation of a population may have important consequences for population genetic diversity and structure due to the effects of genetic drift and reduced gene flow. We studied the genetic consequences of the fragmentation of the Spanish imperial eagle (Aquila adalberti) population into small patches through a temporal analysis. Thirty‐four museum individuals representing the population predating the fragmentation were analysed for a 345‐bp segment of the mitochondrial control region and a set of 10 nuclear microsatellite loci. Data from a previous study on the current population (N = 79) were re‐analysed for this subset of 10 microsatellite markers and results compared to those obtained from the historical sample. Three shared mitochondrial haplotypes were found in both populations, although fluctuations in haplotype frequencies and the occurrence of a fourth haplotype in the historical population resulted in lower current levels of haplotype and nucleotide diversity. However, microsatellite markers revealed undiminished levels of nuclear diversity. No evidence for genetic structure was observed for the historical Spanish imperial eagle population, suggesting that the current pattern of structure is the direct consequence of population fragmentation. Temporal fluctuations in mitochondrial and microsatellite allelic frequencies were found between the historical and the current population as well as for each pairwise comparison between historical and current Centro and historical and current Parque Nacional de Doñana nuclei. Our results indicate an ancestral panmictic situation for the species that management policies should aim to restore. A historical analysis like the one taken here provides the baseline upon which the relative role of recent drift in shaping current genetic patterns in endangered species can be evaluated and this knowledge is used to guide conservation actions.  相似文献   

6.
Aim To demonstrate that parsimony analysis of endemicity (PAE) is not analogous to a cladistic biogeographical analysis. Location We used six data sets from previously published studies from around the world. Methods In order to test the efficiency of PAE in recovering historical relationships among areas, we performed an empirical comparison of nodes recovered with PAE, primary Brooks parsimony analysis (BPA), and an event‐based method using three models (maximum codivergence, reconciled trees, and the default model of the treefitter program) for six data sets. We measured the performance of PAE in recovering historical area relationships by counting the number and examining the content of nodes recovered by PAE and by historical methods. The dispersal/vicariance ratio was calculated to assess the prevalence of dispersal or vicariance in each reconstruction and its relationship to the performance of PAE. Results Our results show that PAE recovers an average of 17.25% of historical nodes. PAE and BPA tend to provide similar results; however, in relation to the event‐based models, PAE performance was poor under all the tested scenarios. Although in some cases PAE reconstructions are more resolved than historical reconstructions, this does not necessarily mean that PAE produces more informative answers. These additional nodes correspond to unsupported statements that are based solely on the distributional data of taxa and not on their phylogenetic history. In other words, these nodes were not found by the historical methods, which take phylogenetics into account. The number of historical nodes recovered using PAE was in general negatively correlated with the dispersal/vicariance ratio. Main conclusions Our results show that PAE is unable to recover historical patterns and therefore does not fit into the current paradigm of historical biogeography. These findings raise doubts regarding conclusions derived from biogeographical studies that interpret PAE trees as area cladograms. We acknowledge that PAE aims to describe but does not explain the current distribution of organisms. It is therefore a useful tool in other biogeographical or ecological analyses for exploring the distribution of taxa or for establishing hypotheses of primary homology between areas.  相似文献   

7.
In a previous paper (Swedlund et al., 1984) we have described the population structure of the historical Connecticut River Valley of Massachusetts in terms of matrimonial migration matrices. Using procedures described by Morton (1973), Harpending and Jenkins (1974), Jorde (1980), and others the exchanges between subdivisions which make up the matrices are made column stochastic and analyzed to predict genetic kinship. Subsequently the kinship estimates within and between subdivisions can be interpreted as genetic covariance and compared to the actual geographic distances between the respective subdivisions using a principal components analysis. In the present paper we extend these results by applying nonmetric multidimensional scaling to the migration matrices, and to isonymy matrices based on the same communities. We demonstrate that the multidimensional scaling configurations of marital migration represent the actual geographic relationships between the communities quite effectively for this particular case study from historical Massachusetts. Moreover, we argue that while these migration data may provide good estimates of social and genetic exchange between the subdivisions, surname analysis may also be informative of processes not revealed in the migration matrices alone.  相似文献   

8.
Collections of historical tissue samples from fish (e.g. scales and otoliths) stored in museums and fisheries institutions are precious sources of DNA for conducting retrospective genetic analysis. However, in some cases, only external tags used for documentation of spatial dynamics of fish populations have been preserved. Here, we test the usefulness of fish tags as a source of DNA for genetic analysis. We extract DNA from historical tags from cod collected in Greenlandic waters between 1950 and 1968. We show that the quantity and quality of DNA recovered from tags is comparable to DNA from archived otoliths from the same individuals. Surprisingly, levels of cross‐contamination do not seem to be significantly higher in DNA from external (tag) than internal (otolith) sources. Our study therefore demonstrates that historical tags can be a highly valuable source of DNA for retrospective genetic analysis of fish.  相似文献   

9.
A frequently advocated approach for forecasting the population‐level impacts of climate change is to project models based on historical, observational relationships between climate and demographic rates. Despite the potential pitfalls of this approach, few historically based population models have been experimentally validated. We conducted a precipitation manipulation experiment to test population models fit to observational data collected from the 1930s to the 1970s for six prairie forb species. We used the historical population models to predict experimental responses to the precipitation manipulations, and compared these predictions to ones generated by a statistical model fit directly to the experimental data. For three species, a sensitivity analysis of the effects of precipitation and grass cover on forb population growth showed consistent results for the historical population models and the contemporary statistical models. Furthermore, the historical population models predicted population growth rates in the experimental plots as well or better than the statistical models, ignoring variation explained by spatial random effects and local density‐dependence. However, for the remaining three species, the sensitivity analyses showed that the historical and statistical models predicted opposite effects of precipitation on population growth, and the historical models were very poor predictors of experimental responses. For these species, historical observations were not well replicated in space, and for two of them the historical precipitation‐demography correlations were weak. Our results highlight the strengths and weaknesses of observational and experimental approaches, and increase our confidence in extrapolating historical relationships to predict population responses to climate change, at least when the historical correlations are strong and based on well‐replicated observations.  相似文献   

10.
Human‐environmental relationships have long been of interest to a variety of scientists, including ecologists, biologists, anthropologists, and many others. 1 , 2 In anthropology, this interest was especially prevalent among cultural ecologists of the 1970s and earlier, who tended to explain culture as the result of techno‐environmental constraints. 3 More recently researchers have used historical ecology, an approach that focuses on the long‐term dialectical relationship between humans and their environments, as well as long‐term prehuman ecological datasets. 4 - 7 An important contribution of anthropology to historical ecology is that anthropological datasets dealing with ethnohistory, traditional ecological knowledge, and human skeletal analysis, as well as archeological datasets on faunal and floral remains, artifacts, geochemistry, and stratigraphic analysis, provide a deep time perspective (across decades, centuries, and millennia) on the evolution of ecosystems and the place of people in those larger systems. Historical ecological data also have an applied component that can provide important information on the relative abundances of flora and fauna, changes in biogeography, alternations in food webs, landscape evolution, and much more.  相似文献   

11.
Parsimony analysis of endemicity (PAE) has been widely criticized in the recent literature based on methodology rather than on theory. Here I argue that most of the criticisms of PAE result from confusion between the dynamic and static approaches of PAE, by both users and critics of the method. Originally, PAE (the dynamic approach) was proposed primarily for historical comparisons of biotic distributions based on geological and stratigraphical information; that is, the stratigraphical record of the biota within two or more horizons was used to evaluate changes (layer by layer) in their distributional patterns. This led to an analysis of the biota throughout space and through time. On the other hand, the static approach excluded the temporal component and based the analysis on a single geological horizon. Most problems exemplified and discussed in the literature refer to the static approach. In addition to this defence of the original PAE, I present some new criticisms regarding the application of PAE using artificially delimited areas (for example areas defined by geopolitical boundaries), which may lead to incorrect interpretations. Recently, several variations of static PAE have appeared: some designed to accommodate ecological data (e.g. parsimony analysis of distributions – PAD); others that incorporate phylogenetic content (e.g. cladistic analysis of distributions and endemism – CADE); and some that have been integrated with other historical methods (e.g. panbiogeography) in order to detect and evaluate hypotheses of biogeographical homologies. Biogeographers, both ecological and historical, should be aware of the problems and limitations of both dynamic and static PAE and evaluate new variations of PAE (PAD, CADE, etc.). Finally, I argue in favour of an independent and pluralist discipline of biogeography that treats biogeography as related to systematics but not dependent on it, as some scholars have assumed.  相似文献   

12.
Organisms are historical entities in that their past history plays an important role in shaping the properties they exhibit today. While this fact is widely acknowledged, little attempt has been made to develop a testable approach to the analysis of the historical factor in evolutionary morphology. The analysis of extrinsic environmental factors may reveal the limits imposed by the environment on biological design, but the intrinsic phylogenetic component of design may severely constrain the directions of structural modification that can occur. The importance of history can be assessed with (1) a phylogenetic hypothesis of genealogical relationship, (2) the use of emergent structural or functional attributes with general properties, and (3) the testing of historical hypotheses by the comparison of general properties between monophyletic lineages. The synthesis of a structural/phylogenetic approach to historical morphology with the analysis of extrinsic limits to form may provide the level of resolution needed to generate testable mechanistic hypotheses regarding the distribution of extant organismal forms in the hyperspace of possible morphologies.  相似文献   

13.
On the basis of the reconstruction of general nutritional patterns by trace element data on historic populations, an examination on occupational Ba intakes in the skeleton was carried out for a historical metallurgy population. The concentrations of the trace elements Ba, Sr, and Pb as well as the matrix element Ca were determined by AAS analysis. Their correlations within the population were analysed statistically. Evidence of a correlation between Ba and Sr concentrations and the lack of a correlation between Ba and Pb concentrations is interpreted as evidence for a probably solely dietary-related Ba intake in the skeleton. Ba intake from working in ore smelting plants is therefore unlikely or at least insignificant. These conclusions are supported by analysis results of modern food items from the catchment area of the historical population. A sufficient Ba supply through rye was determined, thereby explaining the concentration of Ba in the bone material of the historic population.  相似文献   

14.
Wikipedia is a huge global repository of human knowledge that can be leveraged to investigate interwinements between cultures. With this aim, we apply methods of Markov chains and Google matrix for the analysis of the hyperlink networks of 24 Wikipedia language editions, and rank all their articles by PageRank, 2DRank and CheiRank algorithms. Using automatic extraction of people names, we obtain the top 100 historical figures, for each edition and for each algorithm. We investigate their spatial, temporal, and gender distributions in dependence of their cultural origins. Our study demonstrates not only the existence of skewness with local figures, mainly recognized only in their own cultures, but also the existence of global historical figures appearing in a large number of editions. By determining the birth time and place of these persons, we perform an analysis of the evolution of such figures through 35 centuries of human history for each language, thus recovering interactions and entanglement of cultures over time. We also obtain the distributions of historical figures over world countries, highlighting geographical aspects of cross-cultural links. Considering historical figures who appear in multiple editions as interactions between cultures, we construct a network of cultures and identify the most influential cultures according to this network.  相似文献   

15.
新疆地处欧亚大陆东西方交汇处,公元前200年以后的人群迁徙、融合历程能够反映丝绸之路沿线地区不同族群的形成历史和多元文化的互动模式。拉甫却克墓地是东疆哈密地区首次发掘的历史时期墓葬群。本文基于该墓地10例成年人颅面部测量数据,采用多元统计及生物距离的方法来评估拉甫却克墓地的人群结构,并对哈密绿洲地带青铜时代晚期到历史时期的人群变迁进行初步探索。结果显示:1)拉甫却克人群呈现出明显的异质性,既有与欧亚大陆东部人群颅面部特征相近的个体,也有表现出东西方混合特征的个体;2)青铜时代晚期至早期铁器时代(公元前2000年至公元前1000年),哈密人群在体质特征上存在连续性;而早期铁器时代到历史时期(公元前1000年以后),随着欧亚大陆东部人群遗传贡献的增加,哈密人群体质特征发生明显变化。结合考古证据和历史记录,新的人骨标本让我们对哈密历史时期的人群迁徙和融合有了初步认识,也使后续可以针对这一问题展开更详细的多学科研究。  相似文献   

16.
Quantifying the roles of historical versus contemporary constraints in determining species diversity is a central issue in island biogeography, and the phylogenetic beta diversity between islands is an essential measure specifying the influence of historical barriers on insular assemblages. In this study, using phylogenetic information for 513 tree species on 26 islands in the subtropical Ryukyu Archipelago, phylogenetic beta diversity between islands was calculated, and effects of historical factors (gaps as surrogate measures of historical barriers) and current ones (distance, area and elevation) on the phylogenetic structure of tree assemblages were examined. The pattern of phylogenetic beta diversity demonstrated that the Tokara Gap and geographical distance were consistently important for characterizing tree assemblages in the Ryukyus relative to other historical and current factors, which suggests that the Tokara Gap and distance‐limited dispersal from the two adjacent source islands have left a deep imprint on the phylogenetic structure of the current tree flora of the islands.  相似文献   

17.
Reducing the number of animal subjects used in biomedical experiments is desirable for ethical and practical reasons. Previous reviews of the benefits of reducing sample sizes have focused on improving experimental designs and methods of statistical analysis, but reducing the size of control groups has been considered rarely. We discuss how the number of current control animals can be reduced, without loss of statistical power, by incorporating information from historical controls, i.e. subjects used as controls in similar previous experiments. Using example data from published reports, we describe how to incorporate information from historical controls under a range of assumptions that might be made in biomedical experiments. Assuming more similarities between historical and current controls yields higher savings and allows the use of smaller current control groups. We conducted simulations, based on typical designs and sample sizes, to quantify how different assumptions about historical controls affect the power of statistical tests. We show that, under our simulation conditions, the number of current control subjects can be reduced by more than half by including historical controls in the analyses. In other experimental scenarios, control groups may be unnecessary. Paying attention to both the function and to the statistical requirements of control groups would result in reducing the total number of animals used in experiments, saving time, effort and money, and bringing research with animals within ethically acceptable bounds.  相似文献   

18.
Aim To examine how the employment of both community‐ and population‐level approaches can provide a wider view of the importance of contemporary and historical factors on current species distribution. We posit that community ecology should provide more information about contemporary factors, whereas population genetics should provide better information about historical factors. Location Rivers of the western Mediterranean Basin, including four subregions differing in geological history: the Iberian Plate, Transitional, Betic and Rif. Methods For a community‐level approach, Trichoptera richness and community composition were compared between subregions using species accumulation curves and a correspondence analysis. For a population‐level approach, the mtDNA cytochrome C oxidase subunit I (COI) gene of specimens of the Trichoptera midstream‐lowland species Chimarra marginata (L.) was sequenced and analysed using phylogeographical methods. Results The community approach revealed that historical events had more influence on headwater communities than contemporary ecological factors, whereas historical events had negligible influence on midstream‐lowland communities. In midstream‐lowland sites, however, the population approach showed that the genetic structure of C. marginata differed significantly between subregions and revealed patterns of historical gene migration. In terms of species richness, the Rif subregion had the lowest value per basin due to local climatic features and isolation. Main conclusions Both community‐ and population‐level approaches yielded information about the effects of historical factors on species distribution. However, the importance of historical events on current Trichoptera communities depends on the river zonation. Unlike headwater sites, midstream‐lowland sites showed signs of historical events at the population level but not at the community level at the scale used, indicating that both approaches should be employed together in biogeographical studies. Lack of detection of historical events at the community level does not necessarily mean that they are negligible. Most likely, the organizational level used is not appropriate. We also stress the importance of implementing conservation measures for rivers in the western Mediterranean, especially under future scenarios of climate change and human disturbances in the Mediterranean Basin.  相似文献   

19.
Population genetics theory predicts loss in genetic variability because of drift and inbreeding in isolated plant populations; however, it has been argued that long-distance pollination and seed dispersal may be able to maintain gene flow, even in highly fragmented landscapes. We tested how historical effective population size, historical migration and contemporary landscape structure, such as forest cover, patch isolation and matrix resistance, affect genetic variability and differentiation of seedlings in a tropical palm (Euterpe edulis) in a human-modified rainforest. We sampled 16 sites within five landscapes in the Brazilian Atlantic forest and assessed genetic variability and differentiation using eight microsatellite loci. Using a model selection approach, none of the covariates explained the variation observed in inbreeding coefficients among populations. The variation in genetic diversity among sites was best explained by historical effective population size. Allelic richness was best explained by historical effective population size and matrix resistance, whereas genetic differentiation was explained by matrix resistance. Coalescence analysis revealed high historical migration between sites within landscapes and constant historical population sizes, showing that the genetic differentiation is most likely due to recent changes caused by habitat loss and fragmentation. Overall, recent landscape changes have a greater influence on among-population genetic variation than historical gene flow process. As immediate restoration actions in landscapes with low forest amount, the development of more permeable matrices to allow the movement of pollinators and seed dispersers may be an effective strategy to maintain microevolutionary processes.  相似文献   

20.
Abstract

Croizat’s radical attack on traditional modes of biological inquiry has produced strongly polarised responses. Instead of arguing for or against the panbiogeographic approach I attempt to analyse some basic assumptions shared by both its defenders and critics. Although their emphasis is quite different both sides rely on two central oppositions. In evolutionary arguments selective explanations are opposed to those emphasising phylogenetic constraint (orthogenesis). In biogeographic arguments ecological explanations are opposed to historical explanations. I discuss how the legendary opposition between nature and nurture was resolved by reformulating the way in which causation was viewed. I suggest that the selection/constraint opposition shares many features in common with the nature/nurture opposition and argue that it can be resolved in a similar manner. Conflicts between ecological and historical explanations in biogeography are explored by contrasting Diamond’s analysis of New Guinea bird distributions with that of Croizat’s. By again drawing on the resolution of the nature/nurture dispute a way of synthesising ecological and historical explanations is outlined.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号