上海科技英语学术论文翻译公司.pdfVIP

- : 131-1089-3071 上海科技英语学术论文翻译公司 手机 【 】 5 10 40% 精诚翻译公司全网最低 元百字起 （市场价格 元，比传统翻译机构低 左 + 5 右，互联网 时代，省去中间的环节，价格低于翻译行业任何家翻译机构， 年 经验保证，首推先翻译后付费模式，无效免单，免费试译，免费修改，为很多 的大型外企和国企翻译过许多专业文件五周年庆，五折优惠中，可以通过以上! 方式咨询！ Spiderstravelacrosswater likeships,usingtheir legsassailsandtheir silkasan anchor,accordingto researchpublishedintheopenaccessjournal BMC EvolutionaryBiology.Thestudy helpsexplain howspidersareableto migrate acrossvast distancesandwhytheyarequickto colonise newareas.Common spidersarefrequentlyobservedtofly usingatechniquecalled ballooning.This involvesusingtheir silkto catchthewindwhichthen liftsthem upintotheair. Ballooningspidersareestimatedto moveupto 30kmperdaywhenwind conditionsaresuitable,helpingintheir questfor newhabitatsand resources. Thisdispersalstrategy, however,involvesasignificant risk.Theairbornespider has littlecontroloverwhere ittravelsandcouldenduplandingonwater,which has beenthoughtto beunsuitablefor itssurvival. Leadauthor MoritoHayashifromthe NaturalHistoryMuseum,London,UK,said: EvenDarwintook noteofflying spidersthat keptdroppingonthe Beaglemiles awayfromtheseashore. Butgiventhatspidersareterrestrial,andthattheydonot havecontroloverwheretheywilltravelwhen ballooning,howcouldevolution allowsuch riskybehaviorto bemaintained? Wevenowfoundthat spidersactivelyadopt posturesthat allowthemto usethe wind directionto controltheirjourney onwater.They evendropsilkandstopon thewater surfacewhentheywant.Thisabilitycompensatesforthe risksof landing onwater afterthe uncontrolledspiderflights. The researcherscollected325adultspiders belongingto 21commonspeciesfrom smallislandsinnaturereservesinNottinghamshire,UK.The spiders behaviorwas observedontrays ofwater in