共查询到20条相似文献，搜索用时 46 毫秒
1.
Rasmussen M Guo X Wang Y Lohmueller KE Rasmussen S Albrechtsen A Skotte L Lindgreen S Metspalu M Jombart T Kivisild T Zhai W Eriksson A Manica A Orlando L De La Vega FM Tridico S Metspalu E Nielsen K Ávila-Arcos MC Moreno-Mayar JV Muller C Dortch J Gilbert MT Lund O Wesolowska A Karmin M Weinert LA Wang B Li J Tai S Xiao F Hanihara T van Driem G Jha AR Ricaut FX de Knijff P Migliano AB Gallego Romero I Kristiansen K Lambert DM Brunak S Forster P Brinkmann B Nehlich O Bunce M Richards M Gupta R 《Science (New York, N.Y.)》2011,334(6052):94-98
We present an Aboriginal Australian genomic sequence obtained from a 100-year-old lock of hair donated by an Aboriginal man from southern Western Australia in the early 20th century. We detect no evidence of European admixture and estimate contamination levels to be below 0.5%. We show that Aboriginal Australians are descendants of an early human dispersal into eastern Asia, possibly 62,000 to 75,000 years ago. This dispersal is separate from the one that gave rise to modern Asians 25,000 to 38,000 years ago. We also find evidence of gene flow between populations of the two dispersal waves prior to the divergence of Native Americans from modern Asian ancestors. Our findings support the hypothesis that present-day Aboriginal Australians descend from the earliest humans to occupy Australia, likely representing one of the oldest continuous populations outside Africa. 相似文献
2.
Traverse A 《Science (New York, N.Y.)》1987,236(4807):1469-1472
Palynological studies of the nonmarine Newark Supergroup of eastern North America and of rift basins in the northern Gulf of Mexico facilitate correlation with well-dated marine sections of Europe. New information emphasizes the chronological link between the Newark basins and a Gulf of Mexico basin and their common history in the rifting of North America from Pangea. Shales from the subsurface South Georgia Basin are shown to be of late Karnian age (early Late Triassic). The known time of earliest sedimentation in the Culpeper Basin is extended from Norian (late Late Triassic) to mid-Karnian, and the date of earliest sedimentation in the Richmond and Deep River basins is moved to at least earliest Karnian, perhaps Ladinian. The subsurface Eagle Mills Formation in Texas and Arkansas has been dated palynologically as mid- to late Karnian. The oldest parts of the Newark Supergroup, and the Eagle Mills Formation, mostly began deposition in precursor rift basins that formed in Ladinian to early Karnian time. In the southern Newark basins, sedimentation apparently ceased in late Karnian but continued in the northern basins well into the Jurassic, until genesis of the Atlantic ended basin sedimentation. 相似文献
3.
目前家养骆驼在中国最早出自新疆轮台县群巴克墓地,年代在公元前800年左右,可确认最迟在西周晚期中国新疆北部地区已驯养有双峰驼。与中亚地区相比,中国相关考古材料年代明显偏晚,结合国内外已有的考古学证据和分子生物学研究成果,中国家养双峰驼的起源从境外传入的可能性较大。具体传入路线方面,新疆北部可能并非最初传入地点,相反内蒙古和甘青地区值得重点关注。 相似文献
4.
《Science (New York, N.Y.)》1976,191(4226):459
The last two sentences of "Chicano and Native American Scientists Meet" (Science, 7 Nov. 1975, p. 546) should have read "Individual members, most of whom are Ph.D.'s in the natural sciences, are all committed ... to improving the scientific training and counseling that is available to Chicano and Native American students. At the meeting ... members ... planned activities for the coming year that will increase the number of Chicanos and Native Americans entering science and the visibility of their accomplishments." 相似文献
5.
苦楝不同种源苗期生长性状和生长节律研究 总被引：6，自引：0，他引：6
通过观测苦楝10个种源生长性状,分析苗高、地径和冠幅的生长节律,采用Logistic方程拟合其苗高、地径和冠幅生长过程。结果表明,拟合方程的决定系数为0.969~0.998,符合"S"型生长曲线;不同苦楝种源在苗高、地径和冠幅的物候期和生长参数上存在比较明显的差异,各种源前期生长量小于后期;不同种源速生期起始时间变动幅度为5—6月,最早与最晚时间在种源间相差20 d左右;速生期结束时间变动幅度为8—10月,最早与最晚时间在种源间相差50 d左右;速生期生长量占总生长量的比例均在58%以上,速生期生长量最大种源约为最小种源的2倍左右;地径和冠幅速生期起始时间相差不大,且均早于苗高;冠幅速生期结束最早,其次是苗高,最晚为地径;在速生期起始时间上,北方种源早于南方种源,在速生期结束时间上,北方种源晚于南方种源。 相似文献
6.
Elizabeth Atwood Lawrence 《Agriculture and Human Values》1998,15(2):133-138
Because Plains Indians, as well as some other groups of Native Americans, generally perceived people and animals as closely related, medical therapies and preventive regimes in human and veterinary medical practice often overlapped. The sense of partnership that mounted people shared with their horses dictated that it was appropriate for certain equine remedies to be similar to those used for themselves. Horses, as well as people, could possess useful knowledge in the realm of curing. Reciprocity between humankind and nature was expressed by the interactive healing powers of people and horses as well as by recorded examples of the connection that existed between human and equine health maintenance measures and medical procedures. 相似文献
7.
新中式景观风格是目前中国风景园林发展的一种形式。它是将现代的处理手法、新的技术、材料、工艺等与中国传统的造园思想、手法及元素相结合形成的一种融合中华民族的传统文化又符合现代人审美的景观风格。对新中式景观风格的概念进行界定,分析其产生的原因,并从空间布局、景观要素、造景手法、造景手段4个方面分析它的特征及其应用。 相似文献
8.
Abi-Rached L Jobin MJ Kulkarni S McWhinnie A Dalva K Gragert L Babrzadeh F Gharizadeh B Luo M Plummer FA Kimani J Carrington M Middleton D Rajalingam R Beksac M Marsh SG Maiers M Guethlein LA Tavoularis S Little AM Green RE Norman PJ Parham P 《Science (New York, N.Y.)》2011,334(6052):89-94
Whole genome comparisons identified introgression from archaic to modern humans. Our analysis of highly polymorphic human leukocyte antigen (HLA) class I, vital immune system components subject to strong balancing selection, shows how modern humans acquired the HLA-B*73 allele in west Asia through admixture with archaic humans called Denisovans, a likely sister group to the Neandertals. Virtual genotyping of Denisovan and Neandertal genomes identified archaic HLA haplotypes carrying functionally distinctive alleles that have introgressed into modern Eurasian and Oceanian populations. These alleles, of which several encode unique or strong ligands for natural killer cell receptors, now represent more than half the HLA alleles of modern Eurasians and also appear to have been later introduced into Africans. Thus, adaptive introgression of archaic alleles has significantly shaped modern human immune systems. 相似文献
9.
Mellars P 《Science (New York, N.Y.)》2006,313(5788):796-800
The pattern of dispersal of biologically and behaviorally modern human populations from their African origins to the rest of the occupied world between approximately 60,000 and 40,000 years ago is at present a topic of lively debate, centering principally on the issue of single versus multiple dispersals. Here I argue that the archaeological and genetic evidence points to a single successful dispersal event, which took genetically and culturally modern populations fairly rapidly across southern and southeastern Asia into Australasia, and with only a secondary and later dispersal into Europe. 相似文献
10.
White TD 《Science (New York, N.Y.)》1980,208(4440):175-176
Hominid footprints discovered at the Pliocene (3.6 to 3.8 million years ago) site of Laetoli in northern Tanzania represent the earliest evidence of bipedalism in human evolution. This new evidence emphasizes the mosaic pattern of human evolution. 相似文献
11.
Laughlin WS 《Science (New York, N.Y.)》1975,189(4202):507-515
An original objective of these multidisciplinary studies was to determine the position of the Aleuts in the Aleutian ecosystem with time depth. This has been done in a variety of ways (7, 14, 20, 21). One of the most useful approaches is the construction of life expectancy tables. The greater longevity of Aleuts compared with Eskimos represents an effective biological and cultural human adaptation within this ecosystem. The Aleuts defined their ecosystem by expanding to the limits of the area they could effectively exploit with their complex technology, population structure, and population deployment system. Their intellectual achievements played a tangible role in their longevity in the pre-Russian period, and their sophisticated knowledge of human anatomy is both a causal and a consequential correlate of their longevity. From the Aleut point of view, the food resources were diverse, abundant, and accessible, and they also provided fabricational materials necessary for their complex material culture. The Aleuts successfully hunted the world's largest range of sea mammals, from the sea otter to the whales. At the same time, extensive use of invertebrates easily available on the ice-free strandflats enabled disadvantaged sectors of the population to make important contributions to their own food supply and thus improve life expectancy. The rich food and fabricational materials antedate the Holocene history of Nikolski Bay and the arrival of the ancestral Aleuts. The natural resources of this area are fundamentally related to the former peninsular extension of Beringia and the permanent upwelling system in Samalga Pass (22). Sea otters, seals, and sea lions were present when the first Aleuts came to the area. Nikolski Bay has been an ideal place to obtain samples representing the entire Holocene Epoch. The earliest Asiatic migrants came from Siberia and traversed the southern coastline of Beringia. They established a large and permanent village on the northern arm of Nikolski Bay and remained there while expanding to the far ends of the Aleutian domain in the sixth millennium of their residence. The record of cultural change spans a lithic revolution. It begins with a conservative unifacial core and blade industry that preserves several Asiatic traits but includes stone lamps, dishes, an image of the deity, and the use of red ochre. Between 7000 and 6000 years ago bifacially flaked and stemmed points appear, with some continuing elements of the old unifacial industry. This transition culture continues to about 4500 years ago, when the standard sequence seen in the old midden of Chaluka takes form. This culture continues, adding and subtracting various elements but always maintaining a distinctive configuration through time, to the present Aleuts, whose connection with the first Anangula settlement includes having remembered an older Aleut designation, "the place of the blades," and collecting eggs on its flanks. The dating of events inside Nikolski Bay and the identification of the Asiatic elements do throw light on human migration from Siberia into Alaska. The Aleuts and Eskimos may well have been a part of a single population system of Bering Sea Mongoloids who expanded along the Siberian coasts and across the southern Beringian coasts. The population that reached Nikolski Bay became Aleuts. Those closer to the old mouth of the Kuskokwim River and further north became Eskimos. The rise of sea level presented no problems to marine-adapted people. Instead it presented more opportunities in the form of more coastline to exploit. The ancestors of the American Indians migrated earlier through the interior of Beringia. The double-thumb hypothesis of Hrdlicka (23) is useful now for interpreting human migration into the New World. He suggested that if the Eskimos were physically related to the Indians as the thumb of one hand is to the fingers, then a second thumb is necessary to represent the Aleuts, who are also distinctive. The Bering Sea Mongoloids as a group (Aleuts, Eskimos, Chukchi, Koryaks, and probably Kamchadals) are distinguished from the Indians by both genetic traits such as the presence of blood group B, which is absent in the Indians, and morphological configurations such as the unusually broad, low ascending portions of the mandible. This magnitude of difference fits very well with a geographic difference in point of origin, separate route of entry into the New World across Beringia, and the maintenance of separation by many geographic, economic, and cultural barriers. Earlier investigators in the Aleutians compiled invaluable bodies of information. The Russian W. J. Jochelson worked in the Aleutians and the American A. Hrdlicka in Siberia. The problems common to both sides of the Bering Sea have now been studied by Soviet and American scholars at the same time, in the same place, and with the same specimens. It has been pleasant and informative to work directly with the Siberian authorities on Siberia in the Aleutians. In summary, I submit the following eight conclusions: 1) Increased longevity, rather than rapid population turnover, served as a major form of population adaptation and resource management among the Aleuts. Because people lived longer, genetic and cultural wastage was minimized. 2) Cranial vault change, from narrow to broad, has been the result of evolution within the population. 3) The Aleuts have continuously occupied Nikolski Bay, Umnak Island, for 8700 years. During this time sea level has risen and the coastline configuration has changed. 4) Siberian characteristics of the Anangula core and blade industry have been identified, and a transition culture, which links the earliest Anangula tool tradition with the later Aleut culture of Chaluka, has been discovered. 5) Organic remains of human occupation have been used to precisely date geological events of the Holocene Epoch for 8700 of its 10,000 years. Major volcanic eruptions occurred, at exponentially increasing intervals, 10,000, 9000, 7000 and 3000 years ago. 6) The earliest Aleut culture has preserved its Asiatic template because of the coastal entry route from Siberia and subsequent isolation of the population. The abundant lithic remains indicate a complex and diverse material culture. 7) The known similarity of Aleuts to Asiatic populations plus our Holocene time scale suggest a slower rate of human evolution than was assumed when a later date of entry into the Aleutians was accepted. 8) In the broadest perspective, these findings are relevant to understanding the entry of man (Aleuts, Eskimos, and Indians) into the New World in that other migrant populations originating in Siberia may also have entered the New World with a sophisticated and complex culture. 相似文献
12.
13.
It is particularly important for us not to lose sight of the fact that people have been around for a long time and that they achieved remarkable technical skills long before Western science was developed. An anonymous writer from the Food and Agriculture Organization has observed: "It is a commonplace that the fundamental discoveries which made civilization possible-fire- making, tool-making, agriculture, building, calculating, writing, money-were all apparently made outside the area which has given us the marvels of modern science" (19). The writer might well have added that it is also commonly overlooked that food technology was not suddenly developed in the 20th century but has been very much a part of the lives of people everywhere ever since they began doing more to their food than gathering it and eating it raw. Lamb's "Essay on Roast Pig" may not be an accurate account of the first conjunction of fire and food, but cooking is a rather ancient practice. Fermentation is another complicated processing technology which is a traditional part of most cultures, particularly those in warm climates-beer, yogurt, cheese, the fish pastes and sauces of Asia, the palm wine of Africa, and soy sauce, are butsome examples. Native Americans, besides accomplishing marvels in plant genetics and crop development, also developed water extraction methods for treating acorns to render the flour palatable and edible, and the alkali method of processing maize. Furthermore, they developed a cure for scurvy-by making a water extraction of pine needles which are rich in ascorbic acid-long before it was first reported by Jacques Cartier in the 16th century. Similarly, calcium-deficient diets of pregnant and nursing women were traditionally successfully supplemented by calcium-rich powdered deer antlers in northern China. Among the Chinese and Greeks, goiter was cured by eating certain kinds of seaweed centuries before the disease was traced to a lack of iodine, and Kenyans learned to suck salt-rich earth to avoid salt depletion symptoms after arduous exertion in tropical heat long before "modern science" learned why (20). The enumeration of examples could go on, but this was not meant to be an essay in folklore. The point is that all so-called primitive societies developed technologies, techniques, and a store of practical knowledge of a wide range of sophistication, by what must be admitted to be the scientific method, and neither their accomplishments and skills nor those of societies "en voie de développement" should be ignored or discounted. We are confident that modern food science and technology has much to contribute to helping the food-deficit nations eat adequately. First, we must find a way of using the best of Western technology without losing sight of the reality of the situation in the third world and without failing to take into account, better than we have done so far, the secondary and tertiary implications of the changes suggested. Second, we must encourage the examination of local problems in terms of the use and improvement of local technologies which are often quite sophisticated and the result of centuries of development. And third, we must inject a greater component of cultural awareness in the education of students to make them more creative in their application of scientific knowledge to local problems and more adaptable to the conditions that exist in developing countries. We should not lose sight of the fact that because of the precarious nature of their food supply, very often developing countries have much more rigid rules governing the production, preparation, and consumption of food than usually is the case in food-surplus societies, and disturbing these rules is a very serious matter. The time is past when "West is best" can be taken for granted; "adapt and adopt" is surely less offensively arrogant and much more to the point. 相似文献
14.
Current biogeographic models hypothesize that brown bears migrated from Asia to the New World ~100 to 50 thousand years ago but did not reach areas south of Beringia until ~13 to 12 thousand years ago, after the opening of a mid-continental ice-free corridor. We report a 26-thousand-year-old brown bear fossil from central Alberta, well south of Beringia. Mitochondrial DNA recovered from the specimen shows that it belongs to the same clade of bears inhabiting southern Canada and the northern United States today and that modern brown bears in this region are probably descended from populations that persisted south of the southern glacial margin during the Last Glacial Maximum. 相似文献
15.
Dumond DE 《Science (New York, N.Y.)》1980,209(4460):984-991
The proposed existence of a biotically productive tundra-steppe on the exposed Bering Land Bridge of the late Pleistocene aids conceptualization of the migrations of early Asian hunters. But clear knowledge of the human occupants of north-westernmost America before 11,000 years ago is elusive. Evidence indicates that at that time the Alaskan peoples had a culture generally based on microliths that, while obviously derived from Asia, were not sufficiently similar to the tools of the earliest widely distributed hunters of more southerly North America to support any direct and close relation between the two cultures. 相似文献
16.
Late triassic naticid drillholes: carnivorous gastropods gain a major adaptation but fail to radiate
Infaunal and reclining bivalves of the Late Triassic Cassian Formation of northern Italy contain drillholes that closely resemble those produced by modern naticid gastropods. The oldest drillholes previously reported are from the late Early Cretaceous; this suggests that the drilling adaptation was lost soon after its appearance in the Late Triassic and originated independently in another naticid clade 120 million years later. The perceived selective value of such an adaptation may thus not always be a good predictor of its long-term survival, which is ultimately governed by factors that affect the speciation and extinction rates of the clade that carries it. 相似文献
17.
A Homo erectus calvarium [Sambungmacan 4 (Sm 4)] was recovered from Pleistocene sediments at Sambungmacan in central Java. Micro-computed tomography analysis shows a modern human-like cranial base flexion associated with a low platycephalic vault, implying that the evolution of human cranial globularity was independent of cranial base flexion. The overall morphology of Sm 4 is intermediate between that of earlier and later Javanese Homo erectus; apparent morphological specializations are more strongly expressed in the latter. This supports the hypothesis that later Pleistocene Javanese populations were substantially isolated and made minimal contributions to the ancestry of modern humans. 相似文献
18.
黔东南原生态民族文化多样性与糯稻遗传多样性资源保护 总被引：6，自引：0，他引：6
黔东南原生态民族文化是该地区众多民族在长期与自然环境的交流和交融及其抗争中形成的一种稳定的生活方式和经济文化类型。黔东南原生态民族文化与糯稻遗传多样性资源极其丰富,糯稻文化在黔东南各民族的日常生活、生产、风俗习惯和宗教信仰等方面中都有充分的体现。这说明黔东南糯稻品种的遗传多样性形成并保持着强大的生命力,除了依赖于自身的生物条件和对自然生态的适应外,还主要取决于黔东南原生态民族文化的多样性。然而,随着环境的恶化、外来文化冲击和新栽培稻种的推广,黔东南原生态民族文化和糯稻的遗传多样性资源都受到了严重的威胁。为传承和保护这种原生态民族文化并促进糯稻遗传多样性资源的保护与利用,应从以下几个方面采取措施：一是要充分挖掘和发扬原生态民族文化;二是要用传统与现代生物技术相结合的方法全面研究该地区的糯稻（特别是糯禾）遗传多样性资源;三是要结合该地区的自然环境和人文环境,探索适合于糯稻遗传多样性资源的新型农家管理保护模式。正确认识原生态民族传统文化多样性在糯稻遗传多样性资源保护与利用中的重要作用与地位,为寻找更多的新途径来保护稻种遗传多样性资源具有重要的意义。 相似文献
19.
世界现代田园城市美学价值的应用及其意境的探析和设计——以成都市为例 总被引：1，自引：1，他引：0
探讨了世界现代田园城市的起源与发展,结合世界现代田园城市思想与成都文化底蕴与特色,研究和分析了世界田园城市美学价值的应用及其意境设计的方法。研究发现,成都具有大面积的绿色视野、独特的休闲文化气息等美学价值,并具有构建田园意象与自然文化统一的打造潜力。成都在构建世界现代田园城市的设计中应以城市绿地系统规划为基础,以＂一群三区＂为构建体系,以城市民俗文化、物流交通、信息等网络为依托,做到＂自然之美、社会公正、城乡一体＂。 相似文献
20.
Human tissues have carbon-isotope ratios (13C/12C) that reflect dietary ratios. This observation has been used to determine the extent of metabolic turnover of DNA in cells of the adult human cerebellum (90 percent of which are neuronal). If adult human neuronal DNA were metabolically stable, its 13C/12C would reflect that in the maternal diet during fetal development as nearly all neurons are formed during maturation of the fetal brain and do not undergo cell division thereafter. The 13C/12C ratios in the food chains and body tissues of Europeans differ from corresponding American ratios by about 50 parts per million on the average. Therefore, turnover was studied by comparing 13C/12C ratios in cerebellar DNA of American-born Americans, European-born Americans, and European-born Europeans. The 13C/12C ratios in cerebellar DNA from European-born Americans were closer to 13C/12C ratios in cerebellar DNA from European-born Europeans than from American-born Americans, indicating that there was little or no turnover of neuronal DNA. 相似文献