LessonsixTheoriginandDiversityofLife生命的起源和多樣性2025/8/131BigBang[bigb??]大爆炸AnexplosionproducingapressureoscillationoftheorderofamillibarormoreatadistantpointontheEarth.e.g.,theeruptionofKrakatoain1883.Largenuclearfusionexplosionsarecomparable.explosion[iks‘pl?u??n]爆炸pressureoscillation[,?s?'lei??n]壓力波動(dòng),沖擊波oftheorder

大約

millibar['milibɑ:][物]毫巴

2025/8/132eruption[i'r?p??n]爆發(fā)Krakatoa喀拉喀托火山(印度尼西亞一火山島)nuclearfusion核聚變,核融合comparable[‘k?mp?r?bl]可比較的,比得上的binomialsystemofnomenclature[bai'n?umi?l'n??m?n,kleit??

]雙名法UsestwoLatinnames,genusandspecies,foreachtypeoforganism.genus['d?i:n?s](復(fù)genera

['d?en?r?]

)屬,2025/8/133clade[kleid]進(jìn)化枝Inacladisticclassification,organismsareplacedintotaxonomicgroupscalledcladeswhentheyshare

characteristicsthatarethoughttoindicatecommonancestry.cladistic[kl?‘distik]

進(jìn)化枝的classification[,kl?sifi'kei??n]分類,分級taxonomic[t?ks?'n?mik]分類學(xué)的

ancestry['?nsistri]祖先2025/8/134class綱Agroupusedintheclassificationoflivingorganisms.Aclassconsistsofanumberofsimilarorcloselyrelatedordersoroccasionallyofonlyoneorder.Classesareusuallylargeandeasilyrecognizedgroups.order目group群體closelyrelated關(guān)系相近的2025/8/135coacervate[k?u‘?s?veit]團(tuán)聚體，凝聚層Acollectionoforganicmacromoleculessurroundedbywatermoleculesthatarealignedtoformasphere.collection集成,聚積

macromolecule[,m?kr?u'm?likju:l]高分子align排列sphere[sfi?]球體2025/8/136continentaldrift[,k?nt?‘nentl

drift]大陸漂移Thetheorythatthepresentcontinentsresultfromthebreak-upofalargercontinentandhavemovedindependentlytotheirpresentpositions.resultfrom由...產(chǎn)生break-up分裂破碎core[k?:]核心ThecoreoftheEarthisthatpartlyingbelowthemantle.2025/8/137mantle[‘m?ntl]地幔crust[kr?st]地殼ThecrustoftheEarthistheoutershelloftheEarth,definedbyitscompositionandthepropertiesofsomeseismicwaves.composition成分，合成物seismicwaves['saizmik]震波2025/8/138division[di'vi??n]門Aunitusedintheclassificationofplants.Adivisionconsistsofanumberofclasses,oroccasionallyofonlyoneclass,withcertainimportantcharacteristicsincommon.characteristic[,k?rikt?‘ristik]特性2025/8/139family

科Aunitusedintheclassificationofplantsandanimals.Afamilyconsistsofanumberofcloselyrelatedorsimilargeneraoroccasionallyofonlyonegenus.Familynamesendin-aceaeor-aeinbotanyandin-ideaeinzoology.genera[‘d?en?r?]

屬genus['d?i:n?s]botany[‘b?t?ni]植物學(xué)zoology[z??'?l?d?i:]動(dòng)物學(xué),生態(tài)2025/8/1310genus['d?i:n?s]屬(plural,genera)Aunitusedintheclassificationofplantsandanimals.Agenusconsistsofanumberofcloselyrelatedspecies,andmembersofthesamegenusoftenhaveanumberofobviouscharacteristicsincommonbywhichtheycanclearlybeseentoberelated.plural['plu?r?l]復(fù)數(shù)的2025/8/1311kingdom[‘ki?d?m]界Inbiology,amajorcategoryintowhichlivingmaterialisclassified.category[‘k?tiɡ?ri]種類,別,范疇livingmaterial生活物質(zhì),活質(zhì)liposome['lip?us?um]脂質(zhì)體Avesicleformedbythehomogenization(emulsification)ofphospholipidsindilutesaltsolutions.Liposomesaretheprototypesofmembrane-boundbiologicstructures.2025/8/1312vesicle['vesikl]小囊泡homogenization[,h??m?d??na?'zei??n]均質(zhì)化emulsification[i,m?lsifi'kei??n]乳化,乳化作用phospholipid[,f?sf?u'lipid]磷脂dilute[dai‘lju:t]沖淡,稀釋solution[s?'lu:??n]溶液prototype['pr?ut?taip]原型,典型membrane-bound膜結(jié)合的,膜約束的2025/8/1313interior[in‘ti?ri?]內(nèi)部core核心order目Aunitusedintheclassificationofplantsandanimals.Anorderconsistsofanumberofsimilarorcloselyrelatedfamiliesoronlyonefamily.Namesofordersendtypicallyin–alesinplantsandin-ainanimals.ozonelayer[‘?uz?un

'lei?

]臭氧層Alayeroftheatmosphere,about20-50kmabovethesurface,whichcontainsozoneproducedbyultravioletradiation.2025/8/1314ultravioletradiation[,?ltr?‘vai?lit

,reidi'ei??n]紫外輻射phylum['fail?m]

{復(fù)phyla['fail?]

}門Aunitusedintheclassificationofanimals.Aphylumconsistofanumberofclasses,oroccasionallyofonlyoneclass,withcertainimportantcharacteristicsincommon,implyingthatallmembersaredescendedfromacommonancestor.descendedfrom從...下來

imply暗示,意味ancestor祖先,祖宗

2025/8/1315proteinoid[,pr?u'tin?id]類蛋白(質(zhì))Aproteinlikestructureofbranchedaminoacidchainsthatisthebasicstructureofamicrosphere.branched分枝的microsphere微球體species['spi:?i:z]物種種Aunitusedintheclassificationofplantsandanimals.Ideallyaspeciesisdefinedasagroupoforganismsthatinterbreedwitheachothertoproducefertileoffspring.2025/8/1316ideally理想地在觀念上地define定義,詳細(xì)說明group群體interbreed[,int?'bri:d](使)異種交配,(使)混種fertile[‘f?:tail]能繁殖的taxon['t?ks?n](復(fù)taxa['t?ks?])分類單位，分類群Aunitofclassificationofanyrankinthehierarchicalscale.hierarchical[,hai?‘rɑ:kik?l]分等級的2025/8/1317scale衡量,測量,刻度taxonomy[t?k's?n?mi:]分類學(xué)Thestudyofthetheory,procedure,andrulesofclassificationoforganismsaccordingtothesimilaritiesanddifferencesbetweenthem.procedure程序,手續(xù)2025/8/1318Ahomeforlife:Formationof

thesolarsystemandplanetearth

Thestoryoflife’soriginsbeginswiththeformationoftheearth.生命起源于地球的形成。Thesequenceofeventsthatgaverisetoourplanetbegan,inturn,withthecosmicexplosion

physicistscalltheBigBang.我們行星的形成開始于宇宙物理學(xué)家所命名的大爆炸。2025/8/1319

Thesun

atthecenterofoursolarsystem

condensedfromacloudofprimordialmatterroughly5billionyearsago;theplanets,includingtheearth,condensedabout4.6billionyearsago.

太陽，位于太陽系中心，在大約50億年前，由原始物質(zhì)濃縮形成;行星,包括地球在內(nèi),生成于大約46億年前。2025/8/1320

Theearthiscomposedofanumberoflayers:asolidcrust,asemisolidmantle,andalargelymolten(liquid)corethathasasolidcenter.

地球由多層組成：堅(jiān)硬的地殼，半流體的地幔和一個(gè)很大的熔解狀態(tài)的(液體)地核,地核有一個(gè)固體的中心。2025/8/1321

BasicphysicalfeaturesofEarththatmayhavemadetheemergenceoflifepossibleincludetheplanet’ssize,temperature,composition,anddistancefromthesun.

地球的基本物理特征(使生命起源成為可能)，包括行星的大小，溫度，組成以及離太陽的距離。2025/8/1322

Themajorcurrenthypothesisholdsthatlifearosespontaneouslyontheearlyearth

bymeansofchemicalevolutionfromnonlivingsubstances.當(dāng)前主要假設(shè)認(rèn)為，在早期地球上,生命自發(fā)的形成于非生命物質(zhì)的化學(xué)進(jìn)化。2025/8/1323

Evidenceforprelifestagesofchemicalorganizationcomesfrom

laboratoryexperiments

thattrytoduplicatethephysicalenvironmentandchemicalresourcesoftheearlyearth.

通過模擬早期地球的自然條件和化學(xué)資源，科學(xué)家在實(shí)驗(yàn)室中已經(jīng)獲得了化學(xué)有機(jī)體的生命前階段的證據(jù)。（化學(xué)有機(jī)體的生命前階段的證據(jù)來源于實(shí)驗(yàn)室試驗(yàn)）2.Theemergenceoflife:organicandbiologicalmoleculesonaprimitiveplanet2025/8/1324

Theseexperiment,includingthepioneeringworkofMillerandUrey,havesuccessfullyproducedorganicmonomersincludingaminoacids,simplesugars,andnucleicacidbases.這些實(shí)驗(yàn)包括米勒等早期所做工作，成功地產(chǎn)出了有機(jī)單體，包括氨基酸，單糖，核酸堿基。2025/8/1325

Theprobablenextsteptowardlifewasthespontaneouslinkingofsuchmonomersintopolymerssuchasproteinoidsandnucleiacids.

這些單體自發(fā)的連接成多聚體，如類蛋白和核酸，使進(jìn)入生命狀態(tài)成為可能。（使進(jìn)入生命狀態(tài)成為可能的下一個(gè)步驟）Currentresearchsuggeststhatlikelysitesforthispolymerizationwereclayorrocksurfaces.目前的研究認(rèn)為這些聚合作用可能發(fā)生在泥土或巖石表面。2025/8/1326

Researchershavefoundthat,whenenergyisavailabletoasystem,theycangeneratethreekindsoforganicmolecular

aggregates.研究發(fā)現(xiàn)當(dāng)一個(gè)系統(tǒng)獲得能量時(shí)，可能發(fā)生3種有機(jī)分子的聚集體。

TheRussianAleksandr

Oparinobtainedpolymer-richdroplets,calledcoacervates,fromsolutionsofpolymers.俄國科學(xué)家從多聚物的溶液中獲得了富含多聚物的小液滴，即凝聚物。2025/8/1327

SidneyFoxgenerated

proteinoid

microspheresfrommixturesofaminoacidandwater.Fox從氨基酸和水的混合液中獲得了類蛋白微球體。Athirdlaboratorystructureistheliposome,asphericallipidbilayerthatformsfromphospholipids.實(shí)驗(yàn)室第三個(gè)結(jié)構(gòu)物質(zhì)是脂質(zhì)體，即由磷脂形成的球形液體脂雙層結(jié)構(gòu)。2025/8/1328

Astructuresimilartooneormoreoftheseaggregatesmayhavebeentheprecursoroftruecells.與這些聚集體類似的結(jié)構(gòu)可能是生命細(xì)胞的前體.

FurtherstepsintheappearanceofcellsontheearthincludedthedevelopmentofRNAandDNAasbiologicalinformationmolecules.

地球上生命發(fā)生的下一階段就是作為生物信息分子的RNA和DNA的形成。2025/8/1329EvidencesuggeststhatRNA,whichcanformspontaneouslyunderconditionsmimickingthoseoftheearlyearth,wasthefirstinformationmolecule.

有證據(jù)表明,在實(shí)驗(yàn)室模擬早期地球自然條件下自發(fā)生成的RNA是最早的信息分子。2025/8/1330ThediscoveryofRNAribozymes—RNAthatcanactasanenzymelikecatalyst—suggeststhatsuchcatalyticRNAalsocouldhaveassemblednewRNAsfromearlynucleotides.

RNA核酶-RNA可以作為類似酶的催化劑-的發(fā)現(xiàn)表明它可以催化早期核甘酸形成新的RNA。CertaincatalyticRNAscanalsocarryoutsexlikeexchangesofpiecesofRNA.某些催化性的RNA分子也能進(jìn)行RNA片段間性交換的。2025/8/1331

Following

thedevelopmentofalipid-proteinsurfacelayerandreplicatingRNAandDNAinformationalmolecules,theeventsleadingtotheemergenceoflivingcellswouldhavetheoriginofthegeneticcode,thesequesteringofRNAorDNAintocell-likestructures,andthedevelopmentofmetabolicpathways.接下來脂蛋白表層的形成，信息分子RNA和DNA的的復(fù)制，最后導(dǎo)致活細(xì)胞發(fā)生，包括最初的遺傳密碼的確立，RNA或DNA被包裹進(jìn)細(xì)胞樣的結(jié)構(gòu)中,及代謝途徑的建立。2025/8/1332

Theoldestfossilsthatmayrepresentlivingcellsarefoundinrocksthatareabout3.5billionyearsold.能說明活細(xì)胞存在的最古老化石大約有35億年了。Thefirstcellswereprobablyanaerobicheterotrops,withautotrophsarisingmuchlater.最早出現(xiàn)的細(xì)胞可能是厭氧異養(yǎng)生物，很久后自養(yǎng)生物出現(xiàn)。3.Theearliestcells2025/8/1333

ThefirstautotrophsproducedtheirownnutrientsandreleasedO2—ametabolicby-productthathadacrucialimpactonlaterlifeforms.

最早的自養(yǎng)生物可以制造營養(yǎng)物質(zhì)并釋放氧氣-這個(gè)新陳代謝副產(chǎn)品對后期生命的形成有一個(gè)深遠(yuǎn)的影響。(這個(gè)是對后期生命的形成有一個(gè)深遠(yuǎn)的影響新陳代謝副產(chǎn)品。)Theresultingozonelayerintheearth’satmospherereducedthepenetrationofultravioletlight.地球大氣層中的臭氧層的出現(xiàn)減少了紫外線的照射。2025/8/1334

Asaresult,cellswouldsurviveinshallowwaterandonthelandsurface.

結(jié)果，細(xì)胞就能夠在淺水區(qū)和陸地上生存了。Theincreasingquantityofatmosphericoxygenalsopermittedtheevolutionofaerobiccellsandcellularrespiration,whichinturnsignaledthebeginningoftheglobalcarboncycle.大氣中氧氣數(shù)量的增加使得需氧細(xì)胞和細(xì)胞呼吸得以進(jìn)化，這預(yù)示著全球碳循環(huán)的開始。2025/8/1335

Althoughtheearliestcellswereallprokaryotes,byabout1.5billionyearsagoeukaryotesappeared.雖然最早期的細(xì)胞都是原核生物，但是在大約15億年前，真核細(xì)胞出現(xiàn)了。2025/8/13364.ThechangingfaceofplanetearthChangesinlandmasses,theseas,andclimatehavegreatlyaffectedtheevolutionoflifeontheearth.大陸板塊，海洋和氣候的變化對地球生命的進(jìn)化有深遠(yuǎn)的影響。Thebasicpartsoftheplanetincludealight,solidcrustoverahot,semisolidmantleandaninner,partiallymoltencore.地球的最基本的組分包括堅(jiān)硬的地殼，半流體的地幔和熔解態(tài)的地核．2025/8/1337Massivesegmentsorplatesofthecrustmoveoverthemantleintheprocessofcontinentaldrift.大板快地殼擠壓地幔形成大陸漂移。Overthepast500millionyears,continentaldrifthas

sculptedtheearth’scruststoproducetheformand

distributionofpresent-daycontinents.在過去的５億年里，大陸漂移雕塑了地殼的外觀，從而形成了現(xiàn)在的大陸。2025/8/1338Climaticchangesthatgreatlyaffectedlivingorganismsaccompaniedtheseplatemovements;theperiodwasmarkedby

occasionalwavesofmassextinctionsoflivingcreatures.伴隨板塊運(yùn)動(dòng)，氣候改變對生物有深遠(yuǎn)影響，在特定時(shí)期的生物大滅絕就是這個(gè)時(shí)期的見證。2025/8/1339Organismswerealsoaffectedbyperiodsofglaciation

thatfollowedvariationsintheearth’sorbitandintheoutputofenergybythesun.生物也受冰河期影響，在冰河期，地球軌道和太陽能的輸出都發(fā)生了很大變化。2025/8/13405.taxonomy:categorizingthevarietyoflivingthingsBiologistsusethebinomialsystemofnomenclaturedevelopedbyLinnaeustocategorizethevarietiesoflifeontheearth.

生物學(xué)家利用林奈提出的雙名法對地球上的生物進(jìn)行分類。

Thesystemassignseachtypeoforganismtoagenusandspecies.該系統(tǒng)可以將每種生物劃分到屬和種．2025/8/1341Organismsarethenfurtherclassifiedintohighertaxonomic

categories—family,order,class,division(plants),phylum(animals),andkingdom.然后將生物進(jìn)一步劃分到更高級類別中，即科，目，綱，門，界。2025/8/1342Evidencefrommanysubfieldsofbiology,suchasbio