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The human remains recovered from Upper Cave at Zhoukoudian are the richest and best preserved late Pleistocene human fossils ever found in east Asia. For decades, as the representative of the late Pleistocene human in east Asia, the Upper Cave skulls have played an important role in research on the origins of modern Mongoloids and American Indians. Recently, more attention has been paid to the details and mechanisms for late Pleistocene human evolution and the formation of modern human populations. Both the origin and diversification of modern humans have been stressed in research. Some studies further the debates on the evolutionary position of Upper Cave Man and this group’s role in the formation of modern human populations in east Asia. To further explore these problems, we examined and compared 12 non-metric features on three Upper Cave skulls and modern Chinese unearthed from two archaeological sites in North China. Our results indicate that 8 features are expressed differently between Upper Cave Man and modern Chinese. We believe that more primitive characteristics define Upper Cave Man when compared to modern Chinese populations. These findings and some problems on late Pleistocene human evolution including intra2group variation and the standard for modern human populations, are discussed.  相似文献   

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This article highlights how the loose definition of the term ‘refugia’ has led to discrepancies in methods used to assess the vulnerability of species to the current trend of rising global temperatures. The term ‘refugia’ is commonly used without distinguishing between macrorefugia and microrefugia, ex situ refugia and in situ refugia, glacial and interglacial refugia or refugia based on habitat stability and refugia based on climatic stability. It is not always clear which definition is being used, and this makes it difficult to assess the appropriateness of the methods employed. For example, it is crucial to develop accurate fine‐scale climate grids when identifying microrefugia, but coarse‐scale macroclimate might be adequate for determining macrorefugia. Similarly, identifying in situ refugia might be more appropriate for species with poor dispersal ability but this may overestimate the extinction risk for good dispersers. More care needs to be taken to properly define the context when referring to refugia from climate change so that the validity of methods and the conservation significance of refugia can be assessed.  相似文献   

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《人类学学报》2021,40(01):12
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民族考古学曾运用相似性概念对许多地区狩猎采集者的行为进行了研究,相关的民族考古学资料为研究旧石器时代晚期现代人的迁移性提供了可能。随着东北亚地区出土黑曜岩遗物遗址的增加,相应的黑曜岩产地分析研究也日益增多,目前有关长白山黑曜岩产地研究的资料已显著累积。本文参考了现今狩猎采集者的民族学资料,以产自长白山的黑曜岩遗物及分布于特定区域的有柄尖刃器为研究对象,发现晚更新世时期(MIS 2)东北亚现代人拥有广大的直接或间接活动范围。对现代人迁移性的研究不仅为区域石器制作技术的对比分析提供了便利,也为了解古人类的生存环境及适应策略提供了重要资料。  相似文献   

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The human frontal bone from al’a, Slovak Republic, has previously entered into discussions of the morphological patterns of Central European Neandertals and the origins of early modern humans in that region. A morphological reassessment of its supraorbital region and a morphometric analysis of its overall proportions indicate that it falls well within expected ranges of variation of Late Pleistocene Neandertals and is separate from European earlier Upper Paleolithic early modern human crania. It is similar to the Qafzeh-Skhul sample in some metrical and supraorbital robusticity measures, but it contrasts with them in mid-sagittal curvature and supraorbital torus morphology. In the context of its probable oxygen isotope stage 5 age based on inferred biostratigraphic associations, it should not be employed directly for arguments relating to the emergence of modern humans in Central Europe.  相似文献   

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山顶洞人化石是迄今在东亚地区发现的数量最为丰富、保存状态最为完好的更新世晚期人类化石。多年来,山顶洞人作为东亚地区更新世晚期人类的代表,在研究东亚地区现代蒙古人种及美洲印第安人起源方面发挥着重要作用。随着对现代人起源与演化研究的深入,学术界对更新世晚期人类演化及现代人群形成过程的许多细节及演化机制予以了越来越多的注意,提出了现代人群出现时间及现代人群分化时间的概念。一些研究对山顶洞人的演化程度及其在东亚地区现代人群形成上的作用也提出了不同看法。为了深入探讨这些问题,本文对12项颅骨非测量特征在山顶洞人与现代中国人的表现情况进行了对比研究。发现有8项特征在山顶洞人与现代中国人之间具有不同的表现,作者认为山顶洞人在颅骨特征表现上较现代中国人具有更多的原始性。在此基础上,作者就更新世晚期人群内部变异、现代人群特征标准等问题进行了讨论。  相似文献   

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Predicting past distributions of species climatic niches, hindcasting, by using climate envelope models (CEMs) is emerging as an exciting research area. CEMs are used to examine veiled evolutionary questions about extinctions, locations of past refugia and migration pathways, or to propose hypotheses concerning the past population structure of species in phylogeographical studies. CEMs are sensitive to theoretical assumptions, to model classes and to projections in non-analogous climates, among other issues. Studies hindcasting the climatic niches of species often make reference to these limitations. However, to obtain strong scientific inferences, we must not only be aware of these potential limitations but we must also overcome them. Here, I review the literature on hindcasting CEMs. I discuss the theoretical assumptions behind niche modelling, i.e. the stability of climatic niches through time and the equilibrium of species with climate. I also summarize a set of 'recommended practices' to improve hindcasting. The studies reviewed: (1) rarely test the theoretical assumptions behind niche modelling such as the stability of species climatic niches through time and the equilibrium of species with climate; (2) they only use one model class (72% of the studies) and one palaeoclimatic reconstruction (62.5%) to calibrate their models; (3) they do not check for the occurrence of non-analogous climates (97%); and (4) they do not use independent data to validate the models (72%). Ignoring the theoretical assumptions behind niche modelling and using inadequate methods for hindcasting CEMs may well entail a cascade of errors and naïve ecological and evolutionary inferences. We should also push integrative research lines linking macroecology, physiology, population biology, palaeontology, evolutionary biology and CEMs for a better understanding of niche dynamics across space and time.  相似文献   

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Aim Climate changes are thought to be responsible for the retreat and eventual extinction of subtropical lauroid species that covered much of Europe and North Africa during the Palaeogene and early Neogene; little is known, however, of the spatial and temporal patterns of this demise. Herein we calibrate ecological niche models to assess the climatic requirements of Laurus L. (Lauraceae), an emblematic relic from the Tethyan subtropical flora, subsequently using these models to infer how the range dynamics of Laurus were affected by Plio‐Pleistocene climate changes. We also provide predictions of likely range changes resulting from future climatic scenarios. Location The Mediterranean Basin and Macaronesian islands (Canaries, Madeira, Azores). Methods We used a maximum‐entropy algorithm (Maxent) to model the relationship between climate and Laurus distribution over time. The models were fitted both to the present and to the middle Pliocene, based on fossil records. We employed climatic reconstructions for the mid‐Pliocene (3 Ma), the Last Glacial Maximum (21 ka) and a CO2‐doubling future scenario to project putative species distribution in each period. We validated the model projections with Laurus fossil and present occurrences. Results Laurus preferentially occupied warm and moist areas with low seasonality, showing a marked stasis of its climatic niche. Models fitted to Pliocene conditions successfully predicted the current species distribution. Large suitable areas existed during the Pliocene, which were strongly reduced during the Pleistocene, but humid refugia within the Mediterranean Basin and Macaronesian islands enabled long‐term persistence. Future climate conditions are likely to re‐open areas suitable for colonization north of the current range. Main conclusions The climatic requirements of Laurus remained virtually unchanged over the last 3 Myr. This marked niche conservatism imposed largely deterministic range dynamics driven by climate conditions. This species's relatively high drought tolerance might account for the survival of Laurus in continental Europe throughout the Quaternary whilst other Lauraceae became extinct. Climatic scenarios for the end of this century would favour an expansion of the species's range towards northern latitudes, while severely limiting southern populations due to increased water stress.  相似文献   

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The essential characteristics of the vegetation dynamics of tropical Africa remain only partially known. This study assesses the succession of vegetation-types over Central Africa during the last two glacial/interglacial cycles. Analysis of core KZai 02, which contains pollen from the Zaire River watershed (latitudes 9°N–13°S), allows the investigation of long-term patterns of plant ecosystem development and their climatic causes. Core KZai 02 (18.20 m long) was recovered from 6°24.20′S/9°54.10′E in the uppermost axial edifice of the Zaire deep sea fan. The chronology of this sedimentary archive was established using nannofossils and correlations of pollen and total organic carbon signals with the nearby core GeoB1008. The pollen record indicates that: (i) glacials (MIS 6, 4, 2) are marked by the development of afromontane (Podocarpus) forest at high altitudes when central basin lowlands were occupied by Cyperaceae marshes and savannah; (ii) during interglacials (MIS 1, 5) lowland forests were developed, marked by the successive expansion of pioneer, warm-temperate, rain forests, and mangrove indicating sea-level rise; (iii) glacial-interglacial transitions (MIS 6/5, 2/1) display similar vegetation dynamics. The strong evidence of afromontane forest and the opening of the vegetation during glacials suggest a reduced latitudinal distribution of rainfall by the strengthening of the trade wind system. West African monsoon systems were enhanced during interglacials, allowing the progressive development of lowland forests. The development of rain and pioneer forests during glacial Heinrich stadials suggests an enhancement of water availability in tropical Africa associated with these high-latitude events. However, no augmentation of wind activity described by previous studies is evidenced by our pollen record. Similar vegetation successions during glacial/interglacial transitions suggest the diachronous and stepped intervention of CO2 (emphasizing the influence of temperature on plant ecosystems) and water availability.  相似文献   

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In 2012,a human occipital bone fossil was discovered by Zhou Yi,from the Museum of Dingcun,in a quarry (35°45.963′ N,111°25.310′ E) near Shigou village,Xiangfen County,Shanxi Province in North China. The quarry is located about 10 km southeast of Xiangfen County,on the west bank of the Fenhe River,at an altitude of about 412 m above sea level. It is located on the third terrace of the Fenhe River valley. According to Zhou Yi and Wang Chongfa,the quarry owner,the occipital bone was recovered from the gravel mound after the sandy gravel matrix was sifted by workers,so the fossil should be from the sand-gravel layer. Since the quarry was excavated,the stratigraphic section only retained part of the gravel layer and the underlying strata. A bunker located 104m south of the quarry that also occurred on the third terrace retained a complete section. The complete exposed strata of the quarry includes: Malan loess,reddish soil,gray silty layer,gravel layer,marly silt layer,sand-gravel layer,marly silt layer and fine sandy layer. The geological age of the sandgravel layer where the human fossil was located is late Middle Pleistocene. The fossil remains include part of the occipital squama specifically the right cerebral fossa,a portion of the left cerebral fossa,missing the basioccipital and exoccipital. A transverse suture is approximately 52.0mm at the superior border of the occipital squama and it indicates an Inca bone should exist between the parietal bones and the occipital bone. Considering the open occipital-mastoid suture and roughness of the outer surface,the occipital bone might belong to a young individual about 16~26 years of age. The wall of the cerebral fossa is about 6.5mm thick,within the range of variation in modern humans. The highest nuchal line is visible in the left part of the occipital squama,while the superior nuchal line,the highest nuchal line and the occipital torus are absent on the right side. In Homo erectus and archaic Homo sapiens fossils from China,the occipital torus is characteristic and strong developed,while the superior nuchal line and the highest nuchal line are absent. The occipital torus is absent or less developed in early modern humans,while the superior nuchal line and the highest nuchal line do exist. So the morphology of the Shigou occipital bone is more derived than Homo erectus and archaic Homo sapiens,and more similar to modern humans. It indicates that the Shigou human may belong to early modern humans. Inca bones are common in Pleistocene human fossils from China,such as Homo erectus pekinensis from Zhoukoudian and archaic Homo sapiens from Dali in Shaanxi,and from Xujiayao and Dingcun in Shanxi. This feature is also seen in early modern humans of Chuandong in Guizhou. The presence of an Inca bone at Shigou provide more evidence that the Inca bone is a regional characteristic of Pleistocene East Asians,which supports the hypothesis of continuity of human evolution in Pleistocene East Asia.  相似文献   

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王幼平 《人类学学报》2019,38(4):525-535
本文首先简要梳理了晚更新世华北地区石片石器发展历程;进而探讨石片石器与南邻的砾石工业,北部边疆地区新发现的莫斯特文化遗存,以及更晚来自西北方向的石叶/细石器技术的交流互动。在此基础上,重点讨论晚更新世华北石片石器与现代人在该地区出现与发展历程之间的关系,提出石片石器是华北地区旧石器文化发展的主流,亦是追溯该地区现代人出现与发展课题至关重要的考古学证据。  相似文献   

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Temperate forests across the globe are migrating as a result of global warming, but little is known about how changes in climate and host geographic distributions will affect the obligate symbionts of these forests. Analysis of past events can provide insight into how these symbionts have responded to previous climatic changes and inform predictions for contemporary and future climate change events. The Madrean Sky Islands Archipelago (MSIA) comprises mountain “islands” whose Pine-Oak forests appear in stark contrast to the surrounding “sea” of Sonoran Desert vegetation. The archipelago formed due to a post-Pleistocene warming climate that resulted in the expansion of the Sonoran Desert and migration of forests to fragmented, higher elevation areas. Rhizopogon (Boletales) consists of obligate ectomycorrhizal (EcM) symbionts that form truffle sporocarps and associate exclusively with Pinaceae. As such, the MSIA-Rhizopogon system represents a natural experiment of how fungal symbionts responded to climatic change and host migration. Rhizopogon was sampled from nine islands at two sites (one Pinus site and one Pseudotsuga site) per island, and diversity was characterized using the ITS rRNA gene determined from both sporocarps and bioassay-based EcM root tips derived from soil samples collected at each site. We described the biodiversity of Rhizopogon within and among sky islands of the MSIA, and tested whether symbiont species richness and community structure were determined by host association, island identity, geographic distance, or some interaction among these factors. Twenty-five OTUs at 99% similarity in the genus Rhizopogon were identified across nine sky islands with a range of 5–15 OTUs per island. While differential host association with Pinus and Pseudotsuga was a significant driver of community composition, our results supported an even stronger island effect. Furthermore, Rhizopogon communities associated with Pinus forest sites were characterized by random phylogenetic structures across sky islands and are not structured by geographic distance. Our results supported a strong isolation effect that involved historical habitat fragmentation of sky islands in response to past climate changes, and that both host association and stochastic processes, e.g., ecological drift, played a role in shaping Rhizopogon communities of the MSIA.  相似文献   

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Environmental processes govern demography, species movements, community turnover and diversification and yet in many respects these dynamics are still poorly understood at high latitudes. We investigate the combined effects of climate change and geography through time for a widespread Holarctic shrew, Sorex tundrensis. We include a comprehensive suite of closely related outgroup taxa and three independent loci to explore phylogeographic structure and historical demography. We then explore the implications of these findings for other members of boreal communities. The tundra shrew and its sister species, the Tien Shan shrew (Sorex asper), exhibit strong geographic population structure across Siberia and into Beringia illustrating local centres of endemism that correspond to Late Pleistocene refugia. Ecological niche predictions for both current and historical distributions indicate a model of persistence through time despite dramatic climate change. Species tree estimation under a coalescent process suggests that isolation between populations has been maintained across timeframes deeper than the periodicity of Pleistocene glacial cycling. That some species such as the tundra shrew have a history of persistence largely independent of changing climate, whereas other boreal species shifted their ranges in response to climate change, highlights the dynamic processes of community assembly at high latitudes.  相似文献   

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Previous research revealed complex diversification patterns in the parthenogenetic weevil Naupactus cervinus. To understand the origin of clonal diversity and successful spreading of this weevil, we investigated its geographic origin and possible dispersal routes and whether parthenogens can persist in habitats under unsuitable environmental conditions. This study is based on samples taken throughout a broad area of the species’ range. We used both mitochondrial and nuclear markers and applied phylogenetic and network analyses to infer possible relationships between haplotypes. Bayesian phylogeographic analyses and ecological niche modeling were used to investigate the processes that shaped genetic diversity and enabled the colonization of new geographic areas. Southeastern Brazil emerges as the original distribution area of Ncervinus. We detected two range expansions, one along natural corridors during the Pleistocene and the other in countries outside South America during recent times. Isolation due to climate shifts during the early Pleistocene led to diversification in two divergent clades, which probably survived in different refugia of the Paranaense Forest and the Paraná River delta. The origin of the clonal diversity was probably a complex process including mutational diversification, hybridization, and secondary colonization. The establishment of Ncervinus in areas outside its native range may indicate adaptation to drier and cooler conditions. Parthenogenesis would be advantageous for the colonization of new environments by preventing the breakup of successful gene combinations. As in other insect pests, the present distribution of Ncervinus results from both its evolutionary history and its recent history related to human activities.  相似文献   

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Statistical species distribution models (SDMs) are widely used to predict the potential changes in species distributions under climate change scenarios. We suggest that we need to revisit the conceptual framework and ecological assumptions on which the relationship between species distributions and environment is based. We present a simple conceptual framework to examine the selection of environmental predictors and data resolution scales. These vary widely in recent papers, with light inconsistently included in the models. Focusing on light as a necessary component of plant SDMs, we briefly review its dependence on aspect and slope and existing knowledge of its influence on plant distribution. Differences in light regimes between north‐ and south‐facing aspects in temperate latitudes can produce differences in temperature equivalent to moves 200 km polewards. Local topography may create refugia that are not recognized in many climate change SDMs using coarse‐scale data. We argue that current assumptions about the selection of predictors and data resolution need further testing. Application of these ideas can clarify many issues of scale, extent and choice of predictors, and potentially improve the use of SDMs for climate change modelling of biodiversity.  相似文献   

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