Breakup of pangaea and isolation of relict mammals in australia, South america, and madagascar

The composition of aboriginal land mammal faunas in Australia and New Guinea (prototherians and metatherians), South America (metatherians and eutherians) and Madagascar (eutherians only) is reconsidered in light of continental drift reconstructions of Mesozoic-Tertiary world paleogeography It is proposed that these three faunas represent successively detached samples of the evolving world mammal fauna as it existed when each of these land masses became faunally isolated from the rest of the world as a result of the progressive fragmentation of Pangaea. Isolation of aboriginal prototherians and metatherians in Australia and New Guinea may date from the Upper JurassicLower Cretaceous; isolation of aboriginal metatherians and eutherians in South America may date from the Middle Cretaceous-Upper Cretaceous; isolation of aboriginal eutherians in Madagascar may date from the Paleocene-Eocene.     

Aleuts: Ecosystem, Holocene Historys, and Siberian Origin: Soviet and U.S. scientists join in a study of the origins of the first Americans

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.     

Cnidocyte mechanoreceptors are tuned to the movements of swimming prey by chemoreceptors

Cnidocytes, the stinging cells of cnidarians, discharge nematocysts in response to physical contact accompanied by the stimulation of specific chemoreceptors. Cnidocytes in fishing tentacles of a sea anemone are now found to discharge nematocysts preferentially into targets vibrating at 30, 55, and 65 to 75 hertz. Moreover, in the presence of submicromolar concentrations of known chemosensitizers, such as N-acetylated sugars and mucin, these optima shift to 5, 15, 30, and 40 hertz, frequencies that correspond to the movements of swimming prey. Hence, chemoreceptors for these substances tune cnidocyte mechanoreceptors to frequencies that match the movements of the prey.     

Diadema antillarum Was Not a Keystone Predator in Cryptic Reef Environments

The ecological impact of the disappearance of a major predator depends on the responsiveness of the prey. Mass mortality of the most abundant grazer in Caribbean cryptic reef environments, the sea urchin Diadema antilarum, selectively decreased rates of mortality of encrusting organisms by half, yet community composition hardly changed because alternative species failed to become established.     

从外来物到原生物——台湾原住民烟草文化的人类学考察

烟草自十七世纪由荷兰人及迁台汉人传入台湾原住民社会。在之后的两三百年里,台湾原住民学会栽培烟草,制作烟具,形成独特的烟草文化习俗,烟草从外来物转变为原住民部落具有特定社会价值和文化意义的原生物。人类学界在认知与建构台湾原住民传统社会的核心物质文化内涵时将烟草纳入其中。     

A major ecosystem shift in the northern Bering Sea

Until recently, northern Bering Sea ecosystems were characterized by extensive seasonal sea ice cover, high water column and sediment carbon production, and tight pelagic-benthic coupling of organic production. Here, we show that these ecosystems are shifting away from these characteristics. Changes in biological communities are contemporaneous with shifts in regional atmospheric and hydrographic forcing. In the past decade, geographic displacement of marine mammal population distributions has coincided with a reduction of benthic prey populations, an increase in pelagic fish, a reduction in sea ice, and an increase in air and ocean temperatures. These changes now observed on the shallow shelf of the northern Bering Sea should be expected to affect a much broader portion of the Pacific-influenced sector of the Arctic Ocean.     

广西沿海地区作物种质资源土著知识调查

采用国际通用的种质资源土著知识调查方法,对广西沿海地区作物种质资源土著知识进行了调查研究。结果表明：随着优良品种的大量推广,作物种质资源更新速度加快,老的农家品种越来越少;为适应沿海地区自然气候环境,当地人对作物品种资源有一些特殊的需求,因而保留了一些古老的农家品种,形成独特的作物种质资源保护与利用土著知识,如医疗保健用法、传统习惯用法以及宗教用法等;通过调查共收集到各种作物种质资源146份,开创了广西作物种质资源保护与利用土著知识研究新领域。针对目前广西沿海地区在作物种质资源保护上存在的保护意识不强、相关体制机制不健全、对作物种质资源保护和利用土著知识研究不够等问题,提出了制定专项研究计划并给予资助,设立作物种质资源保护和利用土著知识研究实验区,以及建立健全相关法律制度和运行机制等建议,以促进广西作物种质资源的有效保护与可持续利用。     

Regulation of keystone predation by small changes in ocean temperature

Key species interactions that are sensitive to temperature may act as leverage points through which small changes in climate could generate large changes in natural communities. Field and laboratory experiments showed that a slight decrease in water temperature dramatically reduced the effects of a keystone predator, the sea star Pisaster ochraceus, on its principal prey. Ongoing changes in patterns of cold water upwelling, associated with El Nino events and longer term geophysical changes, may thus have far-reaching impacts on the composition and diversity of these rocky intertidal communities.     

Rational choice, context dependence, and the value of information in European starlings (Sturnus vulgaris)

Both human and nonhuman decision-makers can deviate from optimal choice by making context-dependent choices. Because ignoring context information can be beneficial, this is called a "less-is-more effect." The fact that organisms are so sensitive to the context is thus paradoxical and calls for the inclusion of an ecological perspective. In an experiment with starlings, adding cues that identified the context impaired performance in simultaneous prey choices but improved it in sequential prey encounters, in which subjects could reject opportunities in order to search instead in the background. Because sequential prey encounters are likely to be more frequent in nature, storing and using contextual information appears to be ecologically rational on balance by conditioning acceptance of each opportunity to the relative richness of the background, even if this causes context-dependent suboptimal preferences in (less-frequent) simultaneous choices. In ecologically relevant scenarios, more information seems to be more.     

海南岛史前采集渔猎经济及其技术的发展

Hainan Island was advantaged for the rich ecological environmental resources, and the fishing and hunting economic activities were very and rich and colorful. The collecting activities originated along the seashores,and then extended into mesas and hunmmocks. The terrestrial collecting developed from ground into underground, from potherb, leaf and fruit collecting into earthnut collecting, and the aquatic collecting from slow animals emptyhanded collecting at the shallow sea into tooled halieutics. As with the long coastline, wide maritime space and abundant sea-born mollusks in the island, tooled halieutics developed rather later. Hunting played a very import antrole in the economy of the aboriginal in the island, their hunting technology was gradually improved, Becanse of different geographical conditions, the inhabitants in the middle of the mountainous area gave priority to collecting and hunting and their halieutics was not advanced, while in the littoral they gave priority to halieutics and collecting but their hunting lagged behind. The island was advantaged for the abundant natural resources and sparsely populated, the inhabitants relied on the natural resources and their collecting, fishing and hunting had lasted very long, therefore, their agriculture in the history was not yet mature.     

太平洋褶柔鱼摄食行为观察研究

鱿鱼类是摄食极为凶猛的海洋动物。实验条件下对太平洋褶柔鱼(Todarodes pacificus)的摄食行为进行观察与描述,实验分3种不同的太平洋褶柔鱼群体大小(3尾,7~12尾,以及44尾)在循环水水槽中进行,实验用太平洋褶柔鱼平均胴长为20 cm。用高感录像机对太平洋褶柔鱼摄食过程进行记录,同时观察太平洋褶柔鱼对饵料鱼的攻击行为。观察认为,发现、进攻目标饵料鱼阶段的角度范围分别为广分布和窄分布,大多数对饵料鱼的进攻阶段开始于二者相对距离为1到6个胴长间。太平洋褶柔鱼在攻击阶段时其体色表现出暗色模式。在个体多的太平洋褶柔鱼群体中,太平洋褶柔鱼追逐较大的饵料鱼,且有观察到几尾太平洋褶柔鱼共同分食一尾饵料鱼的现象。研究认为,太平洋褶柔鱼摄食行为与自身个体大小、群体大小以及饵料鱼大小等密切相关。     

Paleodemography of the libben site, Ottawa county, ohio

The Libben site, a Late Woodland ossuary and occupation site from the Great Black Swamp of northern Ohio has yielded a well-preserved skeletal sample of 1327 articulated individuals. The outstanding preservation and completeness of the site and the utilization of an exhaustive aging methodology make this the largest and most comprehensively censused North American prehistoric cemetery. Survivorship data indicate a robust, successful population. Life expectancy at birth was 20 years. Among adults, male mortality was consistently higher than female, a condition possibly related to high interpersonal and intergroup aggression. Infant mortality was generally low, and a general hypothesis concerning the elevation of infant mortality and the simultaneous depression of adult mortality among aboriginal peoples after European contact is suggested.     

Abnormal hemoglobin studies in Taiwan aborigines

No abnormal hemoglobins were detected in a survey of blood samples from three of the largest aboriginal tribes of Taiwan. Samples from 655 individuals of the Ami, Paiwan, and Atayal tribes were examined by Smithies' method of vertical starch gel electrophoresis at pH 9.0. Only the A hemoglobins were found.     

大口黑鲈鱼苗摄食天然饵料和配合饲料的研究

本文报导了以浮游动物和浮游动物加配合饲料饲养大口黑鲈Micropterus salmoides鱼苗的研究结果。大口黑鲈鱼苗开口摄食轮虫类和无节幼体，其后依次为枝角类和桡足幼体，枝角类和桡足类成体，对食物具有明显的阶段性和选择性。投喂浮游动物加配合饲料组的生长优于浮游动物组。体长和体重日平均增长分别为1．3mm、1．23mm和24．69mg、20．35mg，t检验差异显著。其成活率分别为64．4％和51．5％，二者相差12．9％。可见浮游动物加配合饲料对促进大口黑鲈鱼苗生长和提高成活率都有明显效果。     

大口黑鲈鱼苗摄食天然饵料和配合饲料的研究

本文报导了以浮游动物和浮游动物加配合饲料饲养大口黑鲈Micropterus salmoides鱼苗的研究结果。大口黑鲈鱼苗开口摄食轮虫类和无节幼体，其后依次为枝角类和桡足幼体，枝角类和桡足类成体，对食物具有明显的阶段性和选择性。投喂浮游动物加配合饲料组的生长优于浮游动物组。体长和体重日平均增长分别为1．3mm、1．23mm和24．69mg、20．35mg，t检验差异显著。其成活率分别为64．4％和51．5％，二者相差12．9％。可见浮游动物加配合饲料对促进大口黑鲈鱼苗生长和提高成活率都有明显效果。     

腹管食螨瓢虫对桔全爪螨种群空间数量及时间动态的反应

腹管食螨瓢虫对其猎物桔全爪螨种群空间,数量及时间动态有明显的反应。在空间上,捕食者集中分布于猎物密度高的外层树冠,除其幼虫集中分布于树冠的中上部外,其余各虫态及其猎物种群在树冠各位点皆无显著的差异。捕食者能在果园内有效地搜索并趋集于猎物密度高的树上,对猎物种群聚集扩散趋势显示出有规则的反应。在数量上,捕食者在田间建立种群后,其数量消长将随猎物种群数量而起伏。捕食者对猎物种群空间及数量动态的反应都有10天左右的时滞。腹管食螨瓢虫对桔全爪螨自然控制效能高,经人工大量繁殖释放和助迁引进,是桔全爪螨综合治理的一个重要途径。     

Radiocarbon dating of coastal peat, barrow, alaska

A buried, frozen section of peat from sea level yielded radiocarbon dates between 700 and 2600 B.C.; it suggests burial by a transgressing sea.     

原生态丹寨硒米中Zn·Cr含量及其生理功能研究

利用微波消解火焰原子吸收光谱法（FAAS法）测定产地为黔东南林区丹寨县的原生态硒米中微量元素Zn、Cr的含量,并讨论这2种元素在人体内的生理功能。     

Ecological change, group territoriality, and population dynamics in Serengeti lions

Territorial behavior is expected to buffer populations against short-term environmental perturbations, but we have found that group living in African lions causes a complex response to long-term ecological change. Despite numerous gradual changes in prey availability and vegetative cover, regional populations of Serengeti lions remained stable for 10- to 20-year periods and only shifted to new equilibria in sudden leaps. Although gradually improving environmental conditions provided sufficient resources to permit the subdivision of preexisting territories, regional lion populations did not expand until short-term conditions supplied enough prey to generate large cohorts of surviving young. The results of a simulation model show that the observed pattern of "saltatory equilibria" results from the lions' grouping behavior.     

冬季大叶藻与幼参混养效果的模拟研究

在实验室条件下对冬季大叶藻Zosteramarina与刺参却ostichopttsjaponicas当年生幼苗的生态混养效果进行了研究,分析了大叶藻对养殖水体中氨氮、硝酸盐、亚硝酸盐、磷酸盐的控制作用以及大叶藻对幼参生长的集聚效果。试验设置大叶藻与幼参混养组、幼参单养组和大叶藻单养空白组,每组设5个重复。试验幼参为2010年培育的秋苗（体长2．90cm±0．04cm,体质量0．69g±0．02g）,试验总水体75L,幼参放养密度为1个／L,水温为（15±1）℃,盐度为31～32,光照强度为（271±14）lx,试验共进行30d。结果表明：大叶藻单养组氨氮、硝酸盐、亚硝酸盐、磷酸盐含量最高;幼参摄食大叶藻碎屑,对水体营养盐起到一定的控制作用,混养组各种营养盐含量居中;幼参单养组各种营养盐含量最低。试验期间,底质情况良好,水质对幼参的生长无影响;大叶藻可为幼参提供附着基,对幼参的集聚效果良好,超过80％的幼参栖息在大叶藻叶片上。