111Lesson17Insectswon’ttakeovertheearth,theyownitnow.leadingbiologistexplainswhybugsaremostsuccessfuldesign.解釋為什么昆蟲是世界上最成功的設計。Theyincorporateastonishinglysophisticateddesignfeatures,bothstructurallyandfunctionally,whichrenderthemespeciallywellsuitedforsurvivalonthis無論在結構上還是機能上，它們具有令人驚訝的設計能力特征，來展示出它們在這個星球上的適應性。There’snodenyingit:BugsRule.Therearecurrently200millioninsectsforeveryman,womanandchild.Ofthespeciesidentified,morethanhalfareinsects.不可否認的是：昆蟲法則。當前每一個人都對應2被人所識別，其中一半以上為昆蟲。Wehumansmaynotliketheidea,isnodenyingit:BugsRule.Estimateshaveitthattherearesomebugsnowaliveontheplanet.Itisnotonlytheirsheernumber,butalsotheirdiversitythatisstaggering:Ofthetotal millionspeciesofanimals,plantsandmicroorganismsthathavebeenidentified,morethan222half—oroverinsects.Andwhilenewofinsectsarebeingdiscovereddaily,over10millionmayyetremainunknown.1018們的物種多樣性令人驚愕：總共有150微生物80的昆蟲被發現，超過1000萬的物種仍然未知。WhatmakesinsectsthemostsuccessfulinhabitantsoftheearthOneansweristhattheyaresmall,whichhasmadeitpossibleforthemtocolonizeliterallyeverynookandcranny.Butthereisanotherreason:Insectsarebuiltlast. Itisthesefeaturesthathaveallowedthemtogaintheevolutionaryadvantagetheyhaveachieved.Thesuitofarmorthatinsectsareencasedinprovidesthemwithprotectionfrompredatorsandkeepsthemfromdryingout,thelatterbeingofconsiderableconcern,giventheirtinysize.Withouttheiroutercasing,theywouldneverhavemasteredlifeintheopen.Theinsect333isappropriatelyhingedinplacestoprovideformobility.Likeourown,theirlegshaveflexiblejoints,butsodotheirprincipalbodyparts—theirhead,thoraxandabdomen.Eventhewingsoftheinsect,whichcanbeatatfrequenciesofhundredsoftimespersecond,arenomorethanflaplikeelaborationsoftheirskeleton.Itisthankstothecombinedmotorcapacityoftheirlegsandwingsthatinsectsareabletoachievethefeatsofagilityforwhichtheyarefamous.(Thinkofahouseflyevadingswatsorcockroachesinyourkitchen,scurryingforcoverwhenyouturnonthelights.)Potentially,becauseofitsrigidity,theinsectskeletonimposeslimitsongrowth.Insectssolvetheproblembymolting:Astheygettoolargefortheirarmor,theysimplyshedit.它們的盔甲是為了提供防止被捕食的保護和保持干燥，后者是相當的不安，給它們微小的體形。沒有外殼，它們無法生存。昆蟲骨架是在適當的地方連接提供流動性，就像我們自己的，它們的腿具有柔性接頭，但這樣做的主要身體部位是頭部，胸腔和腹部。即使昆蟲有每秒數百次擊打的頻率的翅膀，都比不上它們像折翼狀的骨骼。多虧了它們的腿和翅膀機動能力的結合，昆蟲有了它們有名的靈敏性（想象一下家蠅或者蟑螂在廚房躲避拍擊，當你打開燈時它們急速跑到角落的情形）潛在的，因其剛度，昆444脫皮它們的外殼越來越大時，他們很容易就脫殼了。Agilityinanimalscorrelateswithhighrespiratorydemand,andinsectshavearemarkablewayofdeliveringoxygentotheirinternalorgans.Airflowsintotheinsectbodythroughaseriesofopeningscalledspiraclesthatleadinwardintotubes,ortracheae.Insteadofconveyingoxygenbywayofblood,insectsprovideordirectaerationoftheirtissues.Theflightmusclesofinsectscouldfunctionnearlyaseffectivelywithoutsuchaquickofoxygendelivery.呼吸管通風能沒有一個這樣的快速有效的手段進行氧氣傳遞。Insectsoccupyvirtuallyeveryfeedingniche.Putinanotherway,thismeansthattheyareabletoeatliterallyanything.Theirsuccessinthisregardderivesfromtheextraordinarydiversificationoftheirmouthparts.Beetlesandcaterpillarshavejawsforcuttingandtearing,mosquitoeshaveslenderstyletsforpiercingskin555suckingbloodandbutterflieshavecoiledtubesforimbibingnectar.實際上昆蟲占領著每一個合適喂養的地方毛蟲為穿刺皮膚和吸血，蝴蝶有來連續管來吸收甘露。Insectshaveextraordinarysensorycapacities.Theireyes,whichmaytaketheformofenormoushemispheresbulgingfromtheirhead,typicallyconsistofhundredstiny,tightlyopposedunits,calledfacets.Eachfacetpointsinoneparticulardirection,withtheresultthatthetwoeyesseeinvirtuallyalldirections.Foranaerialhuntersuchasarobberfly,thismeansbeingabletospotpreyinstantlyfromwhereveritmayappear.Insectscanalsoseeacolor—ultraviolet—towhichweareblind.Flowersareoftenadornedwithultravioletpatternsthatareinvisibletous,butvisibleandattractivetothepollinatinginsect.昆蟲有非凡的感官能力，它們的眼睛，這可能在它們的頭上需要巨大的半球形，眼形一般包括數以百計的小而緊緊反對的單位，稱為小眼面。每一個小眼面分在一個特定的方向，其結果是兩只眼睛幾乎看到所有的方向。一個空中獵人就像盜蠅在飛，這意味666它們是看不見的，但我們可見，用來吸引授粉昆蟲。Insectsarealsothebestdefendedofanimals.Theirchemicalweaponsareprodigious.Some,suchasbombardierbeetles,dischargeirritatingchemicalscalledquinoneswhendisturbed.Theymakethequinonesinspecialglandsbymixingchemicalsandcausinganexplosion.Theexplosionisofsuchmagnitudethatthequinonesareexpelledboilinghot,at100degreescentigrade.Otherinsectsarenoremarkable.CertainAustralianbeetlelarvaeandEuropeanmothsemithydrogencyanide,theinfamouspoisonofdetectivenovels.TherearecockroachesinNewZealandthatsprayethylacrolein,ateargas.Anyonewhocollectsinsectsasamatterofroutineknowsthatpickingthembyhandcanbehazardous.Manybite,othersstingandstillothers,suchasseveralstrainsofcaterpillar,havehairsthatcauseitchinguponcontact.Insectslackingsuchdefensesmaybeotherwiseprotected.Somemaybesowellcamouflagedastobevirtuallyundetectable.Asoneexpect,camouflagedinsectsareoftencompletelymotionlessbydayandactiveatnight.777苯醌腺體中混合一些化學物質從而引起一場爆100幼蟲和歐洲的蛀蟲發出氰化氫物質正如預期一樣，通常是在白天偽裝成完全靜止，在夜晚活動。Insectsasagrouphaveachievedsomethingthathaseludedhumans.Theyhavemasteredsustainabledevelopment.Insectsaretheprimaryconsumersofplantson