酷想大晒台

正热心肠的大象邦德得知企鹅夏洛特总学不会游泳,疣猪总是因为犯傻而沦为其他动物的盘中餐,便火速赶来帮忙。不过,以它好心办坏事的习惯,帮忙的过程注定不一般。邦德:"夏洛特,我帮你学游泳吧!"夏洛特:"不要!我不学游泳!"邦德:"来嘛来嘛!"夏洛特:"那你怎么教我游泳?"邦德:"我把你卷起来放到水里,你划动四肢,我慢慢走动,你就会游泳了!"     

鹦鹉蓝蓝:因"爱"生"害"

“蓝蓝”是一只来自南美洲的雄性紫蓝金刚鹦鹉。别看它头不大,却很会动脑子,经常耍些小聪明。比如,有时候它刚刚从地上捡了游客投喂的食物,看见饲养员或志愿者来了,就会马上把食物藏到舌头下面,装出若无其事的样子,对着人点头哈腰地打招呼。等人不看它时,它再飞到笼子里你够不着的地方吃起来,因为它知道捡拾游客投喂的食物会挨批评。为了它的健康和安全,我们经常要从蓝蓝的嘴里把它不该吃或不能多吃的东西抠出来。     

基因的力量

如果你愿意花上一个下午在动物园里,你就会看到一只虎妈妈和它的孩子正在草地上嬉戏。不过,等等,一只白色的虎妈妈和她橘黄色的儿子……在其他方面,它们都是那么相似——黑色的斑纹、大大的爪子、锋利的指甲和长长的尾巴;那么,虎妈妈为什么会有白色的毛皮呢?原来,那是因为一个不同的基因。     

寄生虫的生存之道

人们常常对寄生虫嗤之以鼻，其实它是一种极其奇特的生物。草原上的食肉动物会把你杀死并就地吃掉，而寄生虫会让你一直活着，因为这更加有利于它将你变成舒适的寄生天堂。它在其中按照自己的速度生长，吮吸着人体多汁并富有营养的组织，不断进行增殖。     

胖胖松鼠小豆豆

<正>瞧!这个长着圆鼻头和黑葡萄眼睛的毛球,就是我最要好的朋友——小松鼠豆豆。怎么形容豆豆的身材呢?唔,引用加菲猫的一句名言吧:球状也是身材!如果豆豆把耳朵贴在脑袋上,再把尾巴卷起来,就会立刻变成一个标准的圆球,没准,还能在地上滚着前进呢!和大部分的小宠伙伴一样,豆豆超级贪吃!只要一看到我拿着坚果走过来,它就会焦急地在笼子里上蹿下跳,并发出吱吱吱吱的声音,仿佛在说:"坚果坚果,我的!我的!"豆豆吃东西的模样很有趣——它会用两只小爪子抱着食物,一小口一小口啃着吃,吃完了,还会舔舔留在爪子上的坚果油呢!可爱的豆豆是我们小区的明星,只要我带着豆豆下楼遛弯,就会有一群小伙伴围上来,你看看,我瞧瞧,甭提多喜欢豆豆了!而明星豆豆也很友好,时常扭着胖球般的身体,给大家表演松鼠跳。什么?你也想看豆豆表演松鼠跳?嘿嘿,没问题!不过,你得先用一颗坚果讨好讨好它!因为,没有坚果,豆豆可是会耍大牌拒演的哦!     

馋猫咪咪心眼多

<正>姥姥家有一只超可爱的小花猫,名曰:咪咪。咪咪有一个爱好,就是吃。概括为三个词就是:贪吃,能吃,会吃。真应了一句老话:馋猫。在咪咪的档案里,有一件不光彩的事:偷吃火腿肠。那次,我把一根未开封的火腿肠放在桌子上,去干别的事。吃饭时,我去拿火腿肠,却看见咪咪正鬼鬼祟祟地啃火腿肠的外衣。哎,没办法,火腿肠只好归它了!上个周末我去姥姥家,姥姥对我说:"它还认识你哟,你来了,它连红薯也不吃了,等你喂它好吃的!"听到这话,咪咪像不好意思似的,钻到桌子下边去了。不过我不得不承认,咪咪很聪明,可它的聪明劲都用到吃上去了。吃饼干时,如果饼干块太大,它就会用两个前爪把饼干抱起来再吃。饼干碎裂发出"吃吃吃"的声音,好像在给咪咪伴奏:"我吃,我吃,我吃吃吃!"吃完后,它就冲我"喵"地一叫,问我要餐后冷饮。我把一杯凉水端给它,它大喝一气后,一拍屁股就走"猫",只留下"餐桌"上的一片狼藉等我收拾。哼,不讲理!     

协调人与生物圈 保护生命共同体 专家视点回眸之山地

正丁宗一:(中国医学科学院/协和医科大学研究生院教授、博士生导师,中国医师协会儿童健康专业委员会主任委员。摘编自本刊2013年第6期《仰望珠穆朗玛》)矗立在世界之巅,给人类留下了永不磨灭的丰碑。那,就是珠穆朗玛。她是喜马拉雅造山运动的杰作。只要你走进珠穆朗玛,你就会感觉到珠穆朗玛具有一个"场"。这个"场"会让你感到苍茫的宇宙,正在包裹缠绕着你,正在向你呼唤,那就是生     

马的进化

1.一提到马,人们就会联想起它那高大威武的形象,四蹄腾空风驰电掣般前进的雄姿。然而你可知道,在很早很早以前,马的祖先还是徘徊于沼泽丛林中的一个很不显眼的小角色哩!     

看,尾巴在说话

如果你家里养了一只小狗,你一定常常幻想能够听懂它的语言,了解它的心情吧。来来来,我教你一招就可以帮你实现这个愿望。首先请你走到狗狗身后,然后仔细盯着它的屁股看5秒,有答案了吗?还是一头雾水啊,嘿嘿!秘密就在这尾巴里面呢。当小狗感到兴奋、高兴的时候,它们会将尾巴向右摇摆;当它感到恐惧、害怕的时候,尾巴则会向左摇摆。别     

敏狐控诉野蛮邻居

有两句俗语在敏狐的世界完全行不通。一句是:远亲不如近邻。每次听到这句话,敏狐都会很气愤:"啊呸,忽悠谁呢,瞧我的邻居,一个比一个可恶!"另一句是:敌人的敌人就是朋友。"啊呸,忽悠谁呢,血的教训告诉我们,敌人的敌人是更强大的敌人!"把敏狐的处境用一句话来形容,那就是:邻居的日子好过了,它的日子就会难过。所以敏狐们把一首曾经的流行歌曲给改成这样了:"只要你过得比我好,我就受不了……"在北美洲大草原,敏狐到底过着怎样"水深火热"的生活呢?且听它控诉自己的两个恶邻——红狐 and 郊狼。     

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