首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到18条相似文献,搜索用时 125 毫秒
1.
人类颞骨因其复杂的表面及内部结构成为演化研究的重要解剖部位之一,然而由于缺乏对现代人颞骨形态与变异的细致研究及对比数据,对颞骨一些特征的定义和鉴定价值还存在争议。迄今为止,尚无学者对现代中国人群颞骨形态与变异做过专门研究。有鉴于此,本文对颞骨乳突后部一些典型性状的形态变异在现代中国人及部分古人类的表现情况进行了研究。研究结果表明:1)除乳突旁隆起的发育水平存在性别差异外(不受地区差异影响),乳突切迹、枕乳嵴、枕动脉沟的出现率和发育水平既不受地区差异影响,又无性别差异。2)现代中国人乳突后部形态总体表现为窄而深的乳突切迹、明显的乳突旁隆起、以及发育程度较弱的枕动脉沟和枕乳嵴;3)在本文所研究的性状中,乳突切迹、乳突切迹前端隆起、乳突旁隆起、枕乳嵴和枕动脉沟均呈现不同程度的个体变异;4)一些被认为属于尼安德特人衍生特征的性状在中国古人类和现代中国人的乳突后部都有出现;5)本文研究的颞骨乳突后部形态特征在中国更新世晚期人类的表现与现代中国人接近。  相似文献   

2.
中国全新世人群颞下颌关节尺寸的时代变化   总被引:1,自引:0,他引:1  
本文通过对中国北方地区新石器时代(54例)、青铜铁器时代(189例) 和近代(92例) 成年男性颞下颌关节的多项测量项目的对比、分析, 对中国全新世人群颞下颌关节测量性状的变异问题进行了研究。结果显示近7000年来颞下颌关节的不同部位在全新世不同阶段有不同的变化特点。髁突、冠突在全新世厚度变薄, 髁突的变薄主要在新石器-青铜铁器时代, 冠突的变薄主要在青铜铁器-近代。髁突面积在全新世也在缩小, 在新石器-青铜铁器时代缩小的幅度更大。髁突顶缘弧度的变平、下颌窝的变浅主要发生在新石器-青铜铁器时代。髁突面积/下颌窝面积, 其变化主要发生在青铜铁器时代。这些变化可能与生活环境、食物结构改变、下颌骨与头骨不同的演化速率等有关。  相似文献   

3.
吕锦燕 《人类学学报》2007,26(2):128-137
研究证实人类骨性[眶形态具有明显的]化变化,在现代人群之间的表现也有一定程度的差别,因而[眶形态是研究人类]化及现代人群关系的重要特征之一。但是,学术界对与眼眶形态有关的许多问题还不是很清楚,或有争议。基于这一情况,本文对3项代表眼眶形态的性状在五组全新世近代—现代人群中的表现情况进行了观测,并结合对比了部分更新世晚期人类化石标本。本文研究发现:在中国地区,人类[眶的高低变异在]化过程中具有明显的时代变化,从新石器时代起出现了区域性的差异,并一直延续到现代;方形眼眶应该是中国人群较稳定的连续性特征,其高出现率从更新世一直延续到现代;在中国人群中,眼眶外下侧缘圆钝这一特征应该也是从更新世一直延续到现代的,但是其高出现率则只维持到新石器时代为止。  相似文献   

4.
宋述慧  滕徐菲  肖景发 《遗传》2018,40(11):1048-1054
随着人类基因组计划和国际千人基因组计划的实施,已公开数百个中国人个体的全基因组数据。建立高精度的中国人群参考基因组序列,发现并解析中国人群特有的序列变异,是我国未来精准医学研究的基础。为满足未来精准医学研究中国人基因组数据持续增长的科学管理和深入研究的需求,中国科学院北京基因组研究所发展并建立了基于中国人群全基因组测序数据的虚拟中国人基因组数据库(Virtual Chinese Genome Database, VCGDB)和中国人群基因组变异数据库(Genome Variation Map, GVM),面向国内外用户提供数据检索、共享、下载和在线分析服务。本文重点介绍了这两个数据库的特点和功能,以及未来发展与应用前景,以期为中国人群参考基因组及基因组变异图谱资源库的推广使用、发展完善提供有益信息。  相似文献   

5.
通过对532枚中国北方地区新石器时代到青铜时代和铁器时代人类上、下颌骨第一臼齿(M1和M1)齿冠面积和齿尖面积的测量和分析, 得到以下关于中国北方近代人群牙齿尺寸的准确数据和变异情况的结果: 两性M1和M1齿冠面积存在显著性差异, 男性齿冠面积大于女性齿冠面积, 齿尖相对面积不存在性别差异; 从新石器时代到青铜时代男性M1和M1分别缩小了1.16%和4.96%, 女性分别缩小了5.68%和6.11%,青铜时代到铁器时代齿冠面积无明显变化; M1颊侧尖相对基底面积大于舌侧尖, 形成齿尖大小差异的原因很可能是在人类演化过程中, 齿冠面积整体缩小的趋势下, 为使咬合面最大化使用, 各齿尖朝着更利于扩大咬合面基底面积的方式进化的结果; 世界各地区近代人群M1和M1各齿尖大小顺序基本一致, 其中M1为原尖>前尖>后尖>次尖, M1下原尖最大, 下次小尖最小, 其他三个齿尖面积非常接近, 不存在明显大小变化。  相似文献   

6.
陈淳 《人类学学报》1983,2(4):331-408
通过中国十个重要细石器遗址中细石核的观察,对中国细石核的类型和工艺技术作一初步的区分和综合的比较,以探讨中国细石器传统在时间和空间上的分布特点。同时与发现于东北亚、西北美的细石核进行对比,从它们之间的异同来看这一地区在文化上的传承关系。  相似文献   

7.
金鱼外部形态的变异   总被引:1,自引:0,他引:1  
金鱼与鲫鱼在外部形态上有着极大的差异,几乎没有一个单一形状不发生变异.对金鱼外部形态的变异作了较全面的介绍,并论述了金鱼的变异在进化上的意义.  相似文献   

8.
目的建立高精度低误差的《Mus和Rattus属鼠类下颌骨形态特征测量分析系统》。方法运用Microsoft Visual Basic6.0语言设计程序,自动测量、计算、分析下颌骨形态特征。实例运行评估其可操作性。结果本系统可提高测量精度28倍,减少计算误差40余倍。可适用于Mus和Rattus属的野生动物、实验动物的下颌骨形态特征测量分析。结论《Mm和Rottus属鼠类下颌骨形态特征测量分析系统》具有成为可操作的遗传检测方法。  相似文献   

9.
现代中国人身高的变异   总被引:8,自引:7,他引:8  
张振标 《人类学学报》1988,7(2):112-120
本文依据16个省汉族和23个少数民族身高平均值,运用方差分析法分析和讨论了当代中国人身高的地理变化,男女两性身高的群体变化趋势。  相似文献   

10.
根据花粉模拟的中国植被及6000aBP植被制图的初步探讨   总被引:4,自引:0,他引:4  
通过建立现代植物花粉与植被的类比关系,运用花粉植被化模拟技术进行植被类型模拟和制图。首先利用中国表土花粉资料,设计了以生态学原理为基础的功能型植物,并组合成植被型,以运行植被模型。该实验能够模拟出中国现代的主要植被类型,其地理分布与实际植被有较好一致性。进一步对中全新世花粉资料运行,初步模拟了112个花粉样点上的植被类型,并做出了中全新世的植被分布图。该图能够与已有的研究成果相对比,它为恢复古植被提供了一个较客观地制图法。它的精度可以随着资料密度和花粉类型的增加而不断提高。该研究对国际性的全球古植被制图和对比气候模型驱动的植被模型有着较大的参考价值。  相似文献   

11.
Palaeoecological investigations of a small mire in Ötztal, Tyrol, Austria, situated about 50 m above the potential tree-line, indicates that human impact on the landscape started with burning of heath at approximately 5300 B.P. At about 4800 B.P. a weak increase in important apophytes may reflect the local presence of domestic animals. Between 4000 and 3500 B.P. a clear decline in pastoral activity occurred. From 3000 B.P. a strong increase in the representation of apophytes suggests local summer settlement, while in the interval 2600–2200 B.P. anthropogenic activity declined. After 2150 B.P. there was a marked increase in summer farm activity. Fresh information is presented on tree-line fluctuations during the Holocene: Pinus cembra forest ascended above the present potential tree-line by more than 50–100 m between 9000–8000 B.P., 6000–5500 B.P., and 3800–3000 B.P. A Betula maximum between 7000 and 5500 B.P. is probably due to succession in nearby avalanche tracks, as well as to a higher tree-line. Low humification and low loss-on-ignition values around 6000 B.P. may reflect the Frosnitz stadial (6900–6000 B.P.). The Rootmoos I stadial (5400 B.P.) and probably the early Sub-Atlantic stadial maximum (3000–2300) are also reflected in the physical properties of the peat profile.  相似文献   

12.
哈克地区全新世生态环境演变与人类文化的发展轨迹   总被引:1,自引:0,他引:1  
哈克遗址是呼伦贝尔地区一处重要的细石器遗址,对划分和确立东北地区细石器文化的类型及其渊源具有重要的价值。遗址位于海拉尔河东、北、南三面环绕而形成的半封闭式高平台小岛上,自下而上基本存在着四个时期的文化堆积,其中,包含细石器文化遗存的堆积物的厚度最大。岩性、岩相、碳酸钙含量检测和植物孢粉分析等方面的综合信息表明,全新世以来地层垂直沉积和气候变迁波动是同步发展的。人类依环境优劣而留居或迁徙,其文化发展从早到晚经历了新石器、辽至蒙元、明清时期的历史演变,变化始终伴随着气候的波动,表现出以适应为特征的生存与繁衍轨迹。  相似文献   

13.
Neurons in the anterior ventral (AV) thalamic nucleus of human adults were impregnated by Golgi-Kopsch impregnation method. Results showed that at least three morphological types of neurons could be recognized in the human AV thalamic nucleus. Type I neurons were medium to large with rich dendritic arborization. Both tufted and radiating dendritic branching patterns were seen in almost every neuron of this type. Only the initial axonal segments of these cells were impregnated suggesting that these axons were heavily myelinated. Type II neurons were medium in size with poor to moderate dendritic arborization. Many of these cells possess a few dendritic grape-like appendages. Long segments (up to 300 μm) of their axons were impregnated suggesting that these axons were either unmyelinated or thinly myelinated. These axons change their direction and form loops very often. No local branches were seen for these axons suggesting that they could be projection axons. Type III neurons were small with only one or two dendrites with poor arborization. No axons for these cells were seen in this study. The three neuronal types in the human AV thalamic nucleus were compared with neuronal types already described in other thalamic nuclei of human and non-human species. The results of this study might provide a morphological basis for further electrophysiological and / or pathological studies.  相似文献   

14.
目的:通过手术显微镜对前交通动脉复合体及穿支进行解剖和测量,进一步熟悉和掌握该复合体的结构及毗邻血管的走行,为前交通动脉瘤手术提供解剖学依据.方法:用红色乳胶经颈内动脉对15例(30侧)福尔马林固定的湿性尸头进行灌注,然后在手术显微镜下对前交通动脉复合体进行解剖观测,所得结果用SPSS17.0软件进行统计分析.测量大脑前动脉A1和A2段、前交通动脉、Heubner回返动脉、A1段和前交通动脉穿支的长度、直径和各种形态变异.结果:未经选择的标本双侧A1发育无明显差异;术中对Heubner回返动脉、A1段穿支、前交通动脉穿支应仔细分辨加以保护;A1中1/3段穿支少,可作为前交通动脉瘤手术时临时阻断A1的部位;血管造影时前交通动脉不易看清与多种因素有关.结论:前交通动脉复合体复杂多变,熟悉前交通动脉复合体及穿支的解剖特点,对外科医生处理该区疾病至关重要.
Abstract:
Objective:To investigate the anatomy structure and adjacent vessels by investigating the anterior communicating artery complex and its perforating branches under an surgery microscope, in order to, to provide anatomical datas for anterior communicating aneurysms. Method: A total of 15 adult cadaveric heads (30 cerebral hemispheres) fixed with formalin were used, red latex was injected into internal carotid artery. Anterior communicating artery complexes were dissected, detected by surgery microscope.The results were analyzed with SPSS 17.0 statistical software. The lengthes, diameters and variations of the anterior cerebral artery(ACA)A 1 segment, A2 segment, anterior communicating artery (AComA), Heubner recurrent artery(HRA), perforating branches of A1 segment and AcomA were measured. Result:There were no statistically significant differences between two sides of A1 segment in length and diameter. HRA, perforating branches of Al segment and AComA should be carefully recognized and protected during the operation on anterior communicating aneurysms. The middle 1/3 of A1 segment which had less perforating branches was the best position for temporary occlusion during the operation on anterior communicating aneurysms. It is difficult to distinguish AComA in cerebral angiography. Conclusion: The anterior communicating artery complex was regarded as the most complex. Being familiar with the anatomy of the anterior communicating artery complex and the perforating branches enabled neurosurgeons to handle the diseases in this area efficiently.  相似文献   

15.
Several studies on craniofacial morphology showed that most Paleoindians, who were the first settlers of the New World, clearly differ from modern Amerindians and East Asians, their supposed descendants and sister group, respectively. Here we present new evidence supporting this view from the Late Pleistocene/Early Holocene horizon from Mexico, as well as from the most complete set of dated Paleoindian remains. We analyzed the phenotypic resemblance of early Mexicans with other South Paleoamerican and modern human series. Two independent approaches to the data were used. In the first case, individual specimens were tested for morphological similarity with a set of modern reference samples. In the second analysis, Mexican specimens were treated as a sample in order to compute minimum genetic distances. Results from both approaches tend to associate early Mexican skulls with Paleoindians from Brazil, an Archaic sample from Colombia, and several circum-Pacific populations. These results give support to a model in which morphologically generalized groups of non-Northeast Asian descent (the so-called Paleoamericans) entered the continent first, and then dispersed from North to South America through Central America. The large geographic dispersal of Paleoamericans, and their presence in Mexico in the Early Holocene, raise new issues about the continent's settlement scenario.  相似文献   

16.
Erhard Schulz 《Hydrobiologia》1991,214(1):359-365
Palynological investigations of corings in the sebkhas of Taoudenni (N-Mali) and Segedim (N-Niger), archaeological excavations in the Acacus Mts. (SW-Libya) and charcoal records in the central Ténéré (Niger) give evidence for a northward shift of the desert-savanna boundary to 22°–20° N during the middle Holocene. Between Niger and S-Libya there was a ecological gradient from the sudanian, sahelian and saharan savannas to a denser saharan desert vegetation. After a transition phase between 6000 and 4000 BP the saharan desert vegetation was finally established in the Taoudenni and Segedim region and this degraded from ca. 2000 BP to its present condition.During the middle Holocene the central Sahara had a monsoonal summer rain climate with an effective rainfall of 250–300 mm per year near the desert-savanna boundary (ca. 22° N). Interaction between the monsoon and the atlantic cyclones also allowed rainfall in other periods of the year.  相似文献   

17.
目的:通过手术显微镜对前交通动脉复合体及穿支进行解剖和测量,进一步熟悉和掌握该复合体的结构及毗邻血管的走行,为前交通动脉瘤手术提供解剖学依据。方法:用红色乳胶经颈内动脉对15例(30侧)福尔马林固定的湿性尸头进行灌注,然后在手术显微镜下对前交通动脉复合体进行解剖观测,所得结果用SPSS17.0软件进行统计分析。测量大脑前动脉A1和A2段、前交通动脉、Heubner回返动脉、A1段和前交通动脉穿支的长度、直径和各种形态变异。结果:未经选择的标本双侧A1发育无明显差异;术中对Heubner回返动脉、A1段穿支、前交通动脉穿支应仔细分辨加以保护;A1中1/3段穿支少,可作为前交通动脉瘤手术时临时阻断A1的部位;血管造影时前交通动脉不易看清与多种因素有关。结论:前交通动脉复合体复杂多变,熟悉前交通动脉复合体及穿支的解剖特点,对外科医生处理该区疾病至关重要。  相似文献   

18.
We consider and compare the various different kinds of flow that may take place in the anterior chamber of a human eye. The physical mechanisms responsible for causing such flows may be classified as follows: (i) buoyancy-driven flow arising from the temperature difference between the anterior surface of the cornea and the iris, (ii) flow generated by the aqueous production of the ciliary body, (iii) flow generated by the interaction between buoyancy and gravity while sleeping while sleeping in a face-up position, (iv) flow generated by phakodenesis (lens tremor), (v) flow generated by Rapid Eye Movement (REM) during sleep. Each flow is studied using a traditional fluid mechanics/asymptotic analysis approach. We also assess the veracity of a hypothesis that was recently advanced [see Maurice, D.M., 1998. The Von Sallman Lecture 1996: An ophthalmological explanation of REM sleep. Exp. Eye. Res. 66, 139–145, for details] to suggest that, contrary to previous opinion, the purpose of REM during sleep is to ensure corneal respiration in the absence of the buoyant mixing that routinely takes place due to (i) above during waking conditions.  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