邀请人们进入多姿多彩的生命世界——生物多样性教育进行时

无论你位于地球的哪个点上,你都处在一个生命形态异常丰富的网络之中。从大型动物到最小的微生物,从雨林到珊瑚礁,生物多样性围绕着我们,并触及到我们生活的方方面面。加里曼丹岛(Kalimantanlsland),中国古称婆罗洲,位于东南亚马来群岛中部,是世界第三大岛。这个岛上百分之九十的人都曾经感染过疟疾。1955年,世界卫生组织(WHO)开始喷洒狄氏剂(类似农药滴滴涕)以杀死携带疟疾的蚊虫,几乎将岛上这一可怕的疾病消灭,还杀死了包括生活在人们房子里的     

Chemical evolution: The first stages

The available data on the syntheses of critically important precursor molecules for chemical evolution are reviewed and problems of rates of production versus rates of destruction in the primitive ocean are discussed. It is concluded that many global chemical syntheses would have been improbable in the Earth's oceans and that more attention should be paid to specific environments which would have favored such syntheses. The recent discovery of an accelerating effect of formaldehyde on the oligomerization of HCN as well as the eutectic-concentration mechanism are discussed in relation to a new scenario for chemical evolution on the primitive Earth.     

The lumisphere,a new model of pre-biotic evolution

Lyophilization of the amber-colored, fluorescent oils obtained via thermolysis of amino acid mixtures (Lys, Ala, Gly) leads to a cellular-structured material—with an average cell diameter of 50 μm. The cellular aggregates show a resemblance to epithel tissues. Single cellular entities find their analogs in Fox microspheres as well as in the microfossilsIsuasphaera. Short-wave UV (254 nm) irradiation of the aqueous suspensions destroys the cells, whereas suspension in saline solutions (NaCl) offers protection against dissolution by UV light. The fluorescence spectrum of the microscopic preparations containing the highly fluorescent cellular material (“lumispheres”) was registered.     

The use of rice crop residues as a non-commercial energy source in the developing world: The energy and environmental implications

The potential biomass energy that can be derived from the harvest of rice crop residues is calculated for three methods of crop production. The potential energy available amounts to 3.70 × 10¹⁰ J ha^?1 year^?1 for traditional methods, 7.93 × 10¹⁰ J for the labor-intensive and 8.36 × 10¹⁰ J for the capital-intensive methods. The net energy benefits available for cooking, heating and biogasification are calculated on a per hectare basis taking into account the costs of collection, transportation and processing. The amounts of energy available for cooking and heating range from 3.70 × 10⁹ to 8.33 × 10⁹ J ha^?1, and the amounts of energy for methanol use range from 1.85 × 10⁹ to 4.17 × 10⁹ J ha^?1 year^?1.The ecological problems associated with soil erosion, nutrient loss and pesticide use are evaluated in terms of the compensatory energy costs involved, and the resultant net energy balance for each method of rice production is calculated. The net energy available per hectare for the traditional method is 3.43 × 10¹⁰ J, for the labor-intensive method, 7.25 × 10¹⁰ J and for the capital-intensive method, 7.02 × 10¹⁰ J. The harvest of rice crop residues in the developing world could provide up to 5.80 × 10¹⁸ J year^?1.The use of rice crop residues is investigated within the context of the rural village energy system. The prospects for the use of rice crop residues are evaluated in relation to alternative energy sources and it is concluded that regional residue harvest programs should be implemented cautiously, integrating soil management and environmental planning procedures where appropriate.     

The modern theory of biological evolution: an expanded synthesis

In 1858, two naturalists, Charles Darwin and Alfred Russel Wallace, independently proposed natural selection as the basic mechanism responsible for the origin of new phenotypic variants and, ultimately, new species. A large body of evidence for this hypothesis was published in Darwins Origin of Species one year later, the appearance of which provoked other leading scientists like August Weismann to adopt and amplify Darwins perspective. Weismanns neo-Darwinian theory of evolution was further elaborated, most notably in a series of books by Theodosius Dobzhansky, Ernst Mayr, Julian Huxley and others. In this article we first summarize the history of life on Earth and provide recent evidence demonstrating that Darwins dilemma (the apparent missing Precambrian record of life) has been resolved. Next, the historical development and structure of the modern synthesis is described within the context of the following topics: paleobiology and rates of evolution, mass extinctions and species selection, macroevolution and punctuated equilibrium, sexual reproduction and recombination, sexual selection and altruism, endosymbiosis and eukaryotic cell evolution, evolutionary developmental biology, phenotypic plasticity, epigenetic inheritance and molecular evolution, experimental bacterial evolution, and computer simulations (in silico evolution of digital organisms). In addition, we discuss the expansion of the modern synthesis, embracing all branches of scientific disciplines. It is concluded that the basic tenets of the synthetic theory have survived, but in modified form. These sub-theories require continued elaboration, particularly in light of molecular biology, to answer open-ended questions concerning the mechanisms of evolution in all five kingdoms of life.Dedicated to Prof. Dr. Dr. hc mult. Ernst Mayr on the occasion of his 100th birthdayThis revised version was published online in March 2004, with corrections to the caption of Figure 6.     

Fungal spore germination into yeast or mycelium: possible implications of dimorphism in evolution and human pathogenesis

 The ability of dimorphism in fungi is conventionally regarded as a reversible change between the two vegetative forms, yeast and mycelium, in response to environmental change. A zygomycetous isolate, Benjaminiella poitrasii, exhibited yeast-mycelium transition in response to the change in temperature (37–28  °C) and decrease in glucose concentration. For the first time the presence of dimorphic response during asexual and sexual spore germination is reported under the dimorphism-triggering conditions in B. poitrasii. The zygospores germinated into budding yeast when subjected to yeast-form supporting conditions. The mycelium-form favoring conditions gave rise to true mycelium. Similarly, the asexual spores displayed a dimorphic response during germination. Our observations suggest that dimorphism is an intrinsic ability present in the vegetative, asexual, and sexual forms of the fungus. As dimorphic fungi are intermediate to the unicellular yeast and the filamentous forms, understanding of the dimorphic character could be useful to trace the evolutionary relationships among taxonomically different fungi. Moreover, the implications of spore germination during the onset of pathogenesis and in drug development for human health care are discussed. Received: 4 November 1999 / Accepted in revised form: 28 February 2000     

我校建立灾害经济学学科的重要性

本文回顾了灾害经济学的发展历程,分析了灾害经济学的理论框架及与其他学科的关系,从经济学的角度阐述了建立这一学科的必要性,并探讨了建立这一学科的基础条件.全文从经济学的角度阐述了建立这一学科的必要性.并探讨了建立这一学科所要研究的理论知识.     

The number of queens: An important trait in ant evolution

The pervasive social and ecological differences between ant colonies that have a single queen and those that have multiple queens are defined. The evolutionary tendencies which lead to polygyny and the adaptive significance of multiple queens are examined. The discussion of the ecological consequences of polygyny and monogyny leads to a deeper understanding of territoriality, spacing and species packing in ants.     

当代快速进化的奥秘

在人们的印象里，课本上所讲的进化过程如同冰河运动一样缓慢，时间跨度长达数千年。而当代进化的快速现象，是指几年或几十年内发生的、如同河水泛滥般的进化变迁……[编者按]     

The convoluted evolution of snail chirality

The direction that a snail (Mollusca: Gastropoda) coils, whether dextral (right-handed) or sinistral (left-handed), originates in early development but is most easily observed in the shell form of the adult. Here, we review recent progress in understanding snail chirality from genetic, developmental and ecological perspectives. In the few species that have been characterized, chirality is determined by a single genetic locus with delayed inheritance, which means that the genotype is expressed in the mother's offspring. Although research lags behind the studies of asymmetry in the mouse and nematode, attempts to isolate the loci involved in snail chirality have begun, with the final aim of understanding how the axis of left-right asymmetry is established. In nature, most snail taxa (>90%) are dextral, but sinistrality is known from mutant individuals, populations within dextral species, entirely sinistral species, genera and even families. Ordinarily, it is expected that strong frequency-dependent selection should act against the establishment of new chiral types because the chiral minority have difficulty finding a suitable mating partner (their genitalia are on the 'wrong' side). Mixed populations should therefore not persist. Intriguingly, however, a very few land snail species, notably the subgenus Amphidromus sensu stricto, not only appear to mate randomly between different chiral types, but also have a stable, within-population chiral dimorphism, which suggests the involvement of a balancing factor. At the other end of the spectrum, in many species, different chiral types are unable to mate and so could be reproductively isolated from one another. However, while empirical data, models and simulations have indicated that chiral reversal must sometimes occur, it is rarely likely to lead to so-called 'single-gene' speciation. Nevertheless, chiral reversal could still be a contributing factor to speciation (or to divergence after speciation) when reproductive character displacement is involved. Understanding the establishment of chirality, the preponderance of dextral species and the rare instances of stable dimorphism is an important target for future research. Since the genetics of chirality have been studied in only a few pulmonate species, we also urge that more taxa, especially those from the sea, should be investigated.     

未来对中国与世界至关重要的十年

应对气候变化已经成为全世界共同面对的重要议题 全球数千名科学家合作对温室气体排放与全球平均气温上升之间的关系做了许多模拟和情景预测.研究结果表明,如果按照目前能源利用趋势,2030年全球温室气体排放量将达402亿吨当量,几乎是1990年的两倍.这意味着大气中温室气体的浓度将超过1000 ppm(1ppm为百万分之一),全球气温将上升6摄氏度.6度升温,将导致大规模气候变化,给地球和人类带来难以承受和无法弥补的损害.     

The value of energy efficiency programs for US residential and commercial buildings in a warmer world

US residential and commercial buildings were responsible for about 41 exajoules (EJ) of primary energy use per year in 2002, accounting for approximately 9% of the world fossil-fuel related anthropogenic carbon (C) emissions of 6.7 Gt that contribute to climate change. US Government-sponsored building energy efficiency research and implementation programs are focused on reducing energy consumption in US residential and commercial buildings and reducing these carbon (C) emissions. Although not specifically intended for adaptation to a warmer climate and less effective than under today’s cooler climate, these programs also could help reduce energy demand in a future warmer world. Warming scenarios projected by the United Nations Intergovernmental Panel on Climate Change (IPCC) in 2001 imply net overall decreases in both site energy and primary energy consumption in US residential and commercial buildings, largely because of the reduced need for heating. However, there would be as much as a 25% increase in building space cooling demand and a significant part of the increase could be offset by energy-efficiency improvements in buildings. Overall, in the US, buildings-related energy efficiency programs would reduce site energy consumption in buildings in the US by more than 2 EJ in 2020 and primary energy by more than 3.5 EJ, more than enough to offset the projected growth in cooling energy consumption due to climate change and growth in the US building stock. The savings would have an estimated annual net value at 2005 energy prices of between $45.0 and $47.3 billion to consumers.

Policy options in a worst case climate change world

Climatic changes more rapid and extreme than assessed by the IPCC cannot be excluded, because of the possibility of positive earth system feedbacks and thresholds. Do today’s policy makers have to take these into account, and if so, are the options different from those considered today? The paper briefly summarizes the types of extreme climatic changes noted in the literature and then evaluates the options to address them in a what-if manner. Different from other studies, which usually look at only one type of measure, we consider a broader portfolio of options: drastic emissions reduction programmes, drawing greenhouse gases from the atmosphere (“carbon dioxide removal”), “emergency cooling” through influencing the radiative balance of the atmosphere (“solar radiation management”), and finally adaptation beyond the options considered seriously today. Politics will have to decide on the choice or mix of “emergency” measures, but research can ensure that such decisions are based on the best scientific information. If through concerted international efforts to mitigate greenhouse emissions low stabilization levels could be reached, such decisions may never have to be made. However, research in support of some form of a “plan B” is now warranted, focusing on those options that have the most positive ratio between potential effectiveness and feasibility on the one hand, and environmental and political risks on the other hand. Such plan should not be limited to one set of options such as geo-engineering and should explicitly take into account not only the relationships between the options but also the wide variety in characteristics of the individual options in terms of effectiveness, feasibility, environmental risks, and political implications.     

城市如何可持续发展?——评《绿色城市法则:向可持续发展城市转变》

<正>艾伦·B·雅各布斯认为,城市应该是一个给人提供生活空间的美丽而充满魅力的地方,是社会集体成就的最终体现。在这里,人们可以恣意发挥,最大限度地实现自我价值。自由、爱、创意、激情、平静和欢乐等不同元素在这里交织。——(《美好城市:沉思与遐想》)随着个人对城市生活的向往和社会经济发展的需要,世界正在经历大规模的城镇化进程。2008年,城市人口已经占到总人口的50%;根据第六次全国人口普查,中国在2010年的城市化率也达到了49.7%,并以每年近一个百分点的速度飞快增长。城镇化是21世纪的特征,正在重