“海洋2号”：北京海洋馆——从“海洋2号”看大海

科学界对“生物圈2号”褒贬不一,但这一尝试的最重要意义是使人类知道,大自然系统难以被人工完全模拟。海洋馆尝试为海洋生物提供一个人工环境,可以类比为“海洋2号”。它告诉人们：大海是一个极其复杂的系统,人类对它的认识永远是冰山一角。这对走入21世纪开发海洋的人类,是一个重要的启示。     

应改为"淀粉遇碘变蓝"

《生物学通报》2 0 0 0年第 5期“‘唾液淀粉酶对淀粉的消化作用’一节探索课的尝试”一文中写道 :“如在设计‘唾液淀粉酶对淀粉的消化作用’实验中 ,启发学生思考实验的原理 ,即淀粉遇碘酒变蓝。唾液中有唾液淀粉酶 ,它能消化淀粉为麦芽糖 ,而麦芽糖遇碘酒不变色。”文中出现“淀粉遇碘酒变蓝”、“麦芽糖遇碘酒不变色”的说法值得商确。“碘酒 ,碘汀俗称 ,是碘和碘化钾的稀酒精溶液 ,在溶液中 I- I2 I-3 。在溶液中极微量的碘与淀粉相遇立即形成深蓝色的加合物 ,这是定性检验碘的灵敏方法。淀粉是由许多葡萄糖分子缩合而成的多糖 ,分子…     

国际基因组完成人类21号染色体DNA序列测定

21号染色体占人类基因组的 1 %～ 1 .5% ,是人类染色体组中最小的常染色体 ,也是自人类基因组计划实施以来第一个被绘制出致密连锁图、酵母人工染色体 (YAC)物理图谱和限制性内切酶 Not 图谱的常染色体 .今年 5月《自然》杂志刊登了日、德、法、美、英和瑞士等国 1 3个研究单位署名文章“人类 2 1号染色体DNA序列”,测定序列覆盖了 2 1号染色体的 99.7% ,序列测定的准确度达 99.995% .根据他们公布的结果 ,2 1号染色体长臂 (2 1 q) DNA由 33546361 bp组成 ,其中只剩下 3个小的克隆裂隙和 7个序列裂隙 (约 1 0 0kb)尚未确定其序列 .2 1号…     

人类与海洋—讨论海洋生态环境的有关问题

自然环境和资源是人类生存和发展的最基本的物质条件。占人类赖以生存的地球表面积71%的海洋,是地球上一切生命的摇篮。在人类数千年的文明历史进程中,海洋一直受到人们极大的关注,它不但调节着全球的气候,蕴藏着丰富的动力、矿产、生物、化学等资源,而且也是天然日交通“大道”。因此,在人类当前面临着人口、资源,环境三大问题中,如何做到既要开发利用海洋这个自然资源宝库,又要保护好海洋环境,这是人们非常关注的重     

能在天外再造一个家吗

地球如果真的有一天要完蛋了,人类能不能在天外造个家?"杞人忧天"的事情还真有人去做,这就是举世闻名的"生物圈2号"(Biosphere 2)试验。要想在天外造个家,就先在地球上造一个试试看。"生物圈2号"实际上就是一个模拟地球生物圈的试验,它相对于地球生物圈——"生物圈1号"——而得名,设计者想建造一个完全封闭的环境,来模拟地球生态系统中的能量流动和物质循环,让一个封闭的"生物圈"运转起来,这也是未来人类在太空建造长期生存空间的必然模式。这是个非常     

人类起源于海洋吗?

生物进化论在我国已得到普及,人类起源于古猿的知识早已家喻户晓了。可是近年来有一种冠以“新学说”的人类起源于海洋动物的怪论,在我国的一些报刊上时有出现,四处流传。据说这“新学说”是一位英国人提出来的。有人认为只要是外国的新理论,就盲目地加以宣传。“新学说”主张人类不是起源于古猿,而是起源于海洋动物(海豹、海豚等)。其论据是人类与海兽有下列共同特征:身体外表面无     

仿生学简介

仿生学是一门新兴的学科,它研究并摹仿生物系统,为工程技术系统提供新的设计思想。相传春秋战国时代(公元前450-500年),鲁班上山伐木途中,手指为茅草划破,从而受到启发,经反复实践,终于制成人类史上第一架带有锯齿的木工锯。这可算是最早的仿生学工作了。另据“韩非子”记载,鲁班用竹木做了一个木鸟,“成而飞之,三日不下”。文艺复兴时代,意大利人达·芬奇也试图摹仿鸟的飞翔动作,制造扑翼机。这些发明和尝试,在人类文明史上犹如点点星火,一闪而灭,始终未能形成一门独立的学科。其根本原因,正如恩格斯指出的:“科学的发生和发展一开始就是由生产决定     

环游海底世界走进北京海洋馆

北京海洋馆坐落于北京动物园长河北岸,占地12万平方米,建筑面积4．2万平方米,是世界最大的内陆水族馆。其整体设计别具一格,空中俯瞰,好似一个巨大的蓝色海螺静静地躺在绿树环抱中的沙滩上。而馆内则是神秘而生机勃勃的海洋世界,这里生活的海洋和淡水鱼类、哺乳动物及其它水生物达千余种、数万尾。北京海洋馆是集观赏、娱乐,科普于一体的海洋生物博物馆,它以认识海洋的展示理念,按游览路线顺序为人们巧妙展示了“雨林奇观”、“触摸池”、“海底环游”、“鲨鱼馆”、“鲸豚湾”、“海洋剧院”等六个主题的景观：     

新时代中国海洋科技新作为

作为人类生存环境的重要组成部分,海洋在调节气候变化、提供可再生资源和维持生态平衡中起着举足轻重的作用。人类对海洋战略地位及其价值的认识随海洋研究、开发和保护事业的发展而不断深化。纵观漫长的历史过程,两千多年前的古罗马哲学家西塞罗就预言:“谁控制了海洋,谁就控制了世界。”而今,海洋对人类社会的重要作用和价值,已从早期的“兴渔盐”“通舟楫”等,发展成为连接世界的大通道、人类社会赖以生存发展的战略空间和资源宝库。     

"3+综合"——生物教学面临的机遇与挑战

今年浙江、江苏、山西、吉林 4省普通高校招生入学考试“3 X”科目设置采用“3 综合”形式 ,对于理科考生加考的“综合”为“理科综合”科目 ,它是由物理、化学和生物 3门学科组成的。生物学科与理、化相比有一个不同之处 ,它是在几年前被取消高考的科目。众所周知 ,由于高考指挥棒的作用 ,在中学 ,哪门学科不被列入高考科目 ,就会失去学校、学生以及家长的重视。其实 ,在近代从西方传入的各种学科中 ,生物学一开始就非常引人注目。当 2 1世纪即将到来的时候 ,生物学再次引起重视。随着世界人口的急剧增加 ,粮食危机日渐突出 ;同时人类生存…     

On the origin of the Hirudinea and the demise of the Oligochaeta

The phylogenetic relationships of the Clitellata were investigated with a data set of published and new complete 18S rRNA gene sequences of 51 species representing 41 families. Sequences were aligned on the basis of a secondary structure model and analysed with maximum parsimony and maximum likelihood. In contrast to the latter method, parsimony did not recover the monophyly of Clitellata. However, a close scrutiny of the data suggested a spurious attraction between some polychaetes and clitellates. As a rule, molecular trees are closely aligned with morphology-based phylogenies. Acanthobdellida and Euhirudinea were reconciled in their traditional Hirudinea clade and were included in the Oligochaeta with the Branchiobdellida via the Lumbriculidae as a possible link between the two assemblages. While the 18S gene yielded a meaningful historical signal for determining relationships within clitellates, the exact position of Hirudinea and Branchiobdellida within oligochaetes remained unresolved. The lack of phylogenetic signal is interpreted as evidence for a rapid radiation of these taxa. The placement of Clitellata within the Polychaeta remained unresolved. The biological reality of polytomies within annelids is suggested and supports the hypothesis of an extremely ancient radiation of polychaetes and emergence of clitellates.     

On the ontogeny of the haptor and the evolution of the Monogenea

Data on the ontogeny of the posterior haptor of monogeneans were obtained from more than 150 publications and summarised. These data were plotted into diagrams showing evolutionary capacity levels based on the theory of a progressive evolution of marginal hooks, anchors and other attachment components of the posterior haptor in the Monogenea (Malmberg, 1986). 5 + 5 unhinged marginal hooks are assumed to be the most primitive monogenean haptoral condition. Thus the diagrams were founded on a 5 + 5 unhinged marginal hook evolutionary capacity level, and the evolutionary capacity levels of anchors and other haptoral attachement components were arranged according to haptoral ontogenetical sequences. In the final plotting diagram data on hosts, type of spermatozoa, oncomiracidial ciliation, sensilla pattern and protonephridial systems were also included. In this way a number of correlations were revealed. Thus, for example, the number of 5 + 5 marginal hooks correlates with the most primitive monogenean type of spermatozoon and with few sensillae, many ciliated cells and a simple protonephridial system in the oncomiracidium. On the basis of the reviewed data it is concluded that the ancient monogeneans with 5 + 5 unhinged marginal hooks were divided into two main lines, one retaining unhinged marginal hooks and the other evolving hinged marginal hooks. Both main lines have recent representatives at different marginal hook evolutionary capacity levels, i.e. monogeneans retaining a haptor with only marginal hooks. For the main line with hinged marginal hooks the name Articulon-choinea n. subclass is proposed. Members with 8 + 8 hinged marginal hooks only are here called Proanchorea n. superord. Monogeneans with unhinged marginal hooks only are here called Ananchorea n. superord. and three new families are erected for its recent members: Anonchohapteridae n. fam., Acolpentronidae n. fam. and Anacanthoridae n. fam. (with 7 + 7, 8 + 8 and 9 + 9 unhinged marginal hooks, respectively). Except for the families of Articulonchoinea (e.g. Acanthocotylidae, Gyrodactylidae, Tetraonchoididae) Bychowsky's (1957) division of the Monogenea into the Oligonchoinea and Polyonchoinea fits the proposed scheme, i.e. monogeneans with unhinged marginal hooks form one old group, the Oligonchoinea, which have 5 + 5 unhinged marginal hooks, and the other group form the Polyonchoinea, which (with the exception of the Hexabothriidae) has a greater number (7 + 7, 8 + 8 or 9 + 9) of unhinged marginal hooks. It is proposed that both these names, Oligonchoinea (sensu mihi) and Polyonchoinea (sensu mihi), will be retained on one side and Articulonchoinea placed on the other side, which reflects the early monogenean evolution. Except for the members of Ananchorea [Polyonchoinea], all members of the Oligonchoinea and Polyonchoinea have anchors, which imply that they are further evolved, i.e. have passed the 5 + 5 marginal hook evolutionary capacity level (Malmberg, 1986). There are two main types of anchors in the Monogenea: haptoral anchors, with anlages appearing in the haptor, and peduncular anchors, with anlages in the peduncle. There are two types of haptoral anchors: peripheral haptoral anchors, ontogenetically the oldest, and central haptoral anchors. Peduncular anchors, in turn, are ontogenetically younger than peripheral haptoral anchors. There may be two pairs of peduncular anchors: medial peduncular anchors, ontogentically the oldest, and lateral peduncular anchors. Only peduncular (not haptoral) anchors have anchor bars. Monogeneans with haptoral anchors are here called Mediohaptanchorea n. superord. and Laterohaptanchorea n. superord. or haptanchoreans. All oligonchoineans and the oldest polyonchoineans are haptanchoreans. Certain members of Calceostomatidae [Polyonchoinea] are the only monogeneans with both (peripheral) haptoral and peduncular anchors (one pair). These monogeneans are here called Mixanchorea n. superord. Polyonchoineans with peduncular anchors and unhinged marginal hooks are here called the Pedunculanchorea n. superord. The most primitive pedunculanchoreans have only one pair of peduncular anchors with an anchor bar, while the most advanced have both medial and lateral peduncular anchors; each pair having an anchor bar. Certain families of the Articulonchoinea, the Anchorea n. superord., also have peduncular anchors (parallel evolution): only one family, the Sundanonchidae n. fam., has both medial and lateral peduncular anchors, each anchor pair with an anchor bar. Evolutionary lines from different monogenean evolutionary capacity levels are discussed and a new system of classification for the Monogenea is proposed.In agreeing to publish this article, I recognise that its contents are controversial and contrary to generally accepted views on monogenean systematics and evolution. I have anticipated a reaction to the article by inviting senior workers in the field to comment upon it: their views will be reported in a future issue of this journal. EditorIn agreeing to publish this article, I recognise that its contents are controversial and contrary to generally accepted views on monogenean systematics and evolution. I have anticipated a reaction to the article by inviting senior workers in the field to comment upon it: their views will be reported in a future issue of this journal. Editor