Don'twashthosefossils! StandardmuseumpracticecanwashawayDNA. 1.Washing,brushingandvarnishingfossils—allstandardconservationtreatmentsusedbymanyfossilhuntersandmuseumcuratorsalike—vastlyreducesthechancesofrecoveringancientDNA. 2.Instead,excavatorsshouldbehandlingatleastsomeoftheirbountywithgloves,andfreezingsamplesastheyarefound,dirtandall,concludesapaperintheProceedingsoftheNationalAcademyofSciencestoday. 3.AlthoughmanypalaeontologistsknowanecdotallythatthisisthebestwaytouptheoddsofextractinggoodDNA,Eva-MariaGeigloftheJacquesMonodInstituteinParis,France,andhercolleagueshavenowshownjusthowimportantconservationpracticescanbe.Thisinformation,theysay,needstobehammeredhomeamongthepeoplewhoareactuallyoutinthefielddiggingupbones. 4.Geiglandhercolleagueslookedat3,200-year-oldfossilbonesbelongingtoasingleindividualofanextinctcattlespecies,calledanaurochs.ThefossilsweredugupatasiteinFranceattwodifferenttimes—eitherin1947,andstoredinamuseumcollection,orin2004,andconservedinsterileconditionsat-20oC. 5.Theteam'sattemptstoextractDNAfromthe1947bonesallfailed.Thenewlyexcavatedfossils,however,allyieldedDNA. 6.Becausetheboneshadbeenburiedforthesameamountoftime,andinthesameconditions,theconservationmethodhadtobetoblamesaysGeigl."AsmuchDNAwasdegradedinthese57yearsasinthe3,200yearsbefore,"shesays. Washin,washout 7.Becausemanypalaeontologistsbasetheirworkontheshapeoffossilsalone,theirmethodsofconservationarenotdesignedtopreserveDNA,Geiglexplains. 8.Thebiggestproblemishowtheyarecleaned.Fossilsareoftenwashedtogetheron-siteinalargebath,whichcanallowwater—andcontaminantsintheformofcontemporaryDNA—topermeateintotheporousbones."NotonlyistheauthenticDNAgettingwashedout,butcontaminationisgettingwashedin,"saysGeigl. 9.MostancientDNAspecialistsknowthisalready,saysHendrikPoinar,anevolutionarygeneticistatMcMasterUniversityinOntario,Canada.Butthatdoesn'tmeanthatbestpracticehasbecomewidespreadamongthosewhoactuallyfindthefossils. 10.GettingholdoffossilsthathavebeenpreservedwiththeirDNAinmindreliesoncloserelationshipsbetweenlab-basedgeneticistsandtheexcavators,sayspalaeogeneticistSvantePbooftheMaxPlanckInstituteforEvolutionaryAnthropologyinLeipzig,Germany.Andthatonlyoccursinexceptionalcases,hesays. 11.Pbo'steam,whichhasbeensequencingNeanderthalDNA,continuallyfacestheseproblems."WhenyouwanttostudyancienthumanandNeanderthalremains,there'sabigissueofcontaminationwithcontemporaryhumanDNA,"hesays. 12.Thisdoesn'tmeanthatallmuseumspecimensarefatallyflawed,notesPbo.TheNeanderthalfossilsthatwererecentlysequencedinhisownlab,forexample,hadbeenpartofamuseumcollectiontreatedinthetraditionalway.ButPboiskeentoseesamplesoffossilsfromeverymajorfindpreservedinlinewithGeigl'srecommendations—justincase. Warmandwet 13.Geiglherselfbelievesthat,withcooperationbetweenbenchandfieldresearchers,preservingfossilsproperlycouldopenupavenuesofdiscoverythathavelongbeenassumedclosed. 14.Muchhumanculturaldevelopmenttookplaceintemperateregions.DNAdoesnotsurvivewellinwarmenvironmentsinthefirstplace,andcanvanishwhenfossilsarewashedandtreated.Forthisreason,Geiglsays,mostancientDNAstudieshavebeendoneonpermafrostsamples,suchasthewoollymammoth,oronremainsshelteredfromtheelementsincoldcaves—includingcavebearandNeanderthalfossils. 15.Betterconservationmethods,andafocusonfreshfossils,couldboostDNAextractionfrommoredelicatespecimens,saysGeigl.Andthatcouldshedmorelightonthestoryofhumanevolution. (640wordsnature) Glossary Palaeontologists古生物学家 Aurochs欧洲野牛 Neanderthal(人类学)尼安德特人，旧石器时代的古人类。 Permafrost(地理)永冻层 Questions1-6 AnswerthefollowingquestionsbyusingNOMORETHANTHREEWORDSforeachanswer. 1.Howdidpeopletraditionallytreatfossils? 2.WhatsuggestionsdoGeiglandhercolleaguesgiveonwhatshouldbedonewhenfossilsarefound? 3.Whatproblemsmaybeposediffossilbonesarewashedon-site?NameONE. 4.WhatcharacteristicdofossilboneshavetomakethemsusceptibletobecontaminatedwithcontemporaryDNAwhentheyarewashed? 5.Whatcouldbebetterunderstoodwhenconservationtreatmentsareimproved? 6.Thepassagementionedseveralanimalspeciesstudiedbyresearchers.Howmanyofthemarementioned? Questions7-11 Dothefollowingstatementsagreewiththeinformationgiveninthepassage?PleasewriteTRUEifthestatementagreeswiththewriterFALSEifthestatementdoesnotagreewiththewriterNOTGIVENifthereisnoinformationaboutthisinthepassage. 7.IntheirpaperpublishedintheProceedingsoftheNationalAcademyofSciences，GeiglandhercolleagueshaveshownwhatconservationpracticesshouldbefollowedtopreserveancientDNA. 8.ThefossilbonesthatGeiglandhercolleaguesstudiedareallfromthesameaurochs. 9.Geneticistsdon'thavetoworkonsite. 10.OnlynewlyexcavatedfossilbonesusingnewconservationmethodssuggestedbyGeiglandhercolleaguescontainancientDNA. 11.Paaboisstillworriedaboutthepotentialproblemscausedbytreatmentsoffossilsintraditionalway. Questions12-13 CompletethefollowingthestatementsbychoosingletterA-Dforeachanswer. 12.“Thisinformation”inparagraph3indicates: [A]ItiscriticaltofollowproperpracticesinpreservingancientDNA. [B]ThebestwayofgettinggoodDNAistohandlefossilswithgloves. [C]Fossilhuntersshouldwearhome-madehammerswhilediggingupbones. [D]Manypalaeontologistsknowhowoneshoulddointreatingfossils. 13.ThestudyconductedbyGeiglandhercolleaguessuggests: [A]thefactthatancientDNAcannotberecoveredfromfossilbonesexcavatedinthepast. [B]thecorrelationbetweentheamountofburyingtimeandthatoftherecoveredDNA. [C]thepaceatwhichDNAdegrades. [D]thecorrelationbetweenconservationpracticesanddegradationofDNA.-查字典考试网

试题预览

Don'twashthosefossils!

StandardmuseumpracticecanwashawayDNA.

1.Washing,brushingandvarnishingfossils—allstandardconservationtreatmentsusedbymanyfossilhuntersandmuseumcuratorsalike—vastlyreducesthechancesofrecoveringancientDNA.

2.Instead,excavatorsshouldbehandlingatleastsomeoftheirbountywithgloves,andfreezingsamplesastheyarefound,dirtandall,concludesapaperintheProceedingsoftheNationalAcademyofSciencestoday.

3.AlthoughmanypalaeontologistsknowanecdotallythatthisisthebestwaytouptheoddsofextractinggoodDNA,Eva-MariaGeigloftheJacquesMonodInstituteinParis,France,andhercolleagueshavenowshownjusthowimportantconservationpracticescanbe.Thisinformation,theysay,needstobehammeredhomeamongthepeoplewhoareactuallyoutinthefielddiggingupbones.

4.Geiglandhercolleagueslookedat3,200-year-oldfossilbonesbelongingtoasingleindividualofanextinctcattlespecies,calledanaurochs.ThefossilsweredugupatasiteinFranceattwodifferenttimes—eitherin1947,andstoredinamuseumcollection,orin2004,andconservedinsterileconditionsat-20oC.

5.Theteam'sattemptstoextractDNAfromthe1947bonesallfailed.Thenewlyexcavatedfossils,however,allyieldedDNA.

6.Becausetheboneshadbeenburiedforthesameamountoftime,andinthesameconditions,theconservationmethodhadtobetoblamesaysGeigl."AsmuchDNAwasdegradedinthese57yearsasinthe3,200yearsbefore,"shesays.

Washin,washout

7.Becausemanypalaeontologistsbasetheirworkontheshapeoffossilsalone,theirmethodsofconservationarenotdesignedtopreserveDNA,Geiglexplains.

8.Thebiggestproblemishowtheyarecleaned.Fossilsareoftenwashedtogetheron-siteinalargebath,whichcanallowwater—andcontaminantsintheformofcontemporaryDNA—topermeateintotheporousbones."NotonlyistheauthenticDNAgettingwashedout,butcontaminationisgettingwashedin,"saysGeigl.

9.MostancientDNAspecialistsknowthisalready,saysHendrikPoinar,anevolutionarygeneticistatMcMasterUniversityinOntario,Canada.Butthatdoesn'tmeanthatbestpracticehasbecomewidespreadamongthosewhoactuallyfindthefossils.

10.GettingholdoffossilsthathavebeenpreservedwiththeirDNAinmindreliesoncloserelationshipsbetweenlab-basedgeneticistsandtheexcavators,sayspalaeogeneticistSvantePbooftheMaxPlanckInstituteforEvolutionaryAnthropologyinLeipzig,Germany.Andthatonlyoccursinexceptionalcases,hesays.

11.Pbo'steam,whichhasbeensequencingNeanderthalDNA,continuallyfacestheseproblems."WhenyouwanttostudyancienthumanandNeanderthalremains,there'sabigissueofcontaminationwithcontemporaryhumanDNA,"hesays.

12.Thisdoesn'tmeanthatallmuseumspecimensarefatallyflawed,notesPbo.TheNeanderthalfossilsthatwererecentlysequencedinhisownlab,forexample,hadbeenpartofamuseumcollectiontreatedinthetraditionalway.ButPboiskeentoseesamplesoffossilsfromeverymajorfindpreservedinlinewithGeigl'srecommendations—justincase.

Warmandwet

13.Geiglherselfbelievesthat,withcooperationbetweenbenchandfieldresearchers,preservingfossilsproperlycouldopenupavenuesofdiscoverythathavelongbeenassumedclosed.

14.Muchhumanculturaldevelopmenttookplaceintemperateregions.DNAdoesnotsurvivewellinwarmenvironmentsinthefirstplace,andcanvanishwhenfossilsarewashedandtreated.Forthisreason,Geiglsays,mostancientDNAstudieshavebeendoneonpermafrostsamples,suchasthewoollymammoth,oronremainsshelteredfromtheelementsincoldcaves—includingcavebearandNeanderthalfossils.

15.Betterconservationmethods,andafocusonfreshfossils,couldboostDNAextractionfrommoredelicatespecimens,saysGeigl.Andthatcouldshedmorelightonthestoryofhumanevolution.

(640wordsnature)

Glossary

Palaeontologists古生物学家

Aurochs欧洲野牛

Neanderthal(人类学)尼安德特人，旧石器时代的古人类。

Permafrost(地理)永冻层

Questions1-6

AnswerthefollowingquestionsbyusingNOMORETHANTHREEWORDSforeachanswer.

1.Howdidpeopletraditionallytreatfossils?

2.WhatsuggestionsdoGeiglandhercolleaguesgiveonwhatshouldbedonewhenfossilsarefound?

3.Whatproblemsmaybeposediffossilbonesarewashedon-site?NameONE.

4.WhatcharacteristicdofossilboneshavetomakethemsusceptibletobecontaminatedwithcontemporaryDNAwhentheyarewashed?

5.Whatcouldbebetterunderstoodwhenconservationtreatmentsareimproved?

6.Thepassagementionedseveralanimalspeciesstudiedbyresearchers.Howmanyofthemarementioned?

Questions7-11

Dothefollowingstatementsagreewiththeinformationgiveninthepassage?PleasewriteTRUEifthestatementagreeswiththewriterFALSEifthestatementdoesnotagreewiththewriterNOTGIVENifthereisnoinformationaboutthisinthepassage.

7.IntheirpaperpublishedintheProceedingsoftheNationalAcademyofSciences，GeiglandhercolleagueshaveshownwhatconservationpracticesshouldbefollowedtopreserveancientDNA.

8.ThefossilbonesthatGeiglandhercolleaguesstudiedareallfromthesameaurochs.

9.Geneticistsdon'thavetoworkonsite.

10.OnlynewlyexcavatedfossilbonesusingnewconservationmethodssuggestedbyGeiglandhercolleaguescontainancientDNA.

11.Paaboisstillworriedaboutthepotentialproblemscausedbytreatmentsoffossilsintraditionalway.

Questions12-13

CompletethefollowingthestatementsbychoosingletterA-Dforeachanswer.

12.“Thisinformation”inparagraph3indicates:

[A]ItiscriticaltofollowproperpracticesinpreservingancientDNA.

[B]ThebestwayofgettinggoodDNAistohandlefossilswithgloves.

[C]Fossilhuntersshouldwearhome-madehammerswhilediggingupbones.

[D]Manypalaeontologistsknowhowoneshoulddointreatingfossils.

13.ThestudyconductedbyGeiglandhercolleaguessuggests:

[A]thefactthatancientDNAcannotberecoveredfromfossilbonesexcavatedinthepast.

[B]thecorrelationbetweentheamountofburyingtimeandthatoftherecoveredDNA.

[C]thepaceatwhichDNAdegrades.

[D]thecorrelationbetweenconservationpracticesanddegradationofDNA.

查看答案

纠错

正确答案：

1.washing, brushing, varnishing 见第一段。

2.handling with gloves / freezing samples ( any one of the two ) 见第二段。

3.losing authentic DNA / being contaminated / contamination ( any one of the three) 见第八段“Not only is the authentic DNA getting washed out, but contamination is getting washed in”(答being contaminated或 contamination比较保险)

4.they are porous porous 的意思是多孔的。见第八段“...which can allow water — and contaminants in the form of contemporary DNA — to permeate into the porous bones.”

5.human evolution 见第十五段。其中“shed light on sth”的意思是使某事显得非常清楚，使人了解某事。

6.4 分别为第四段的“an extinct cattle species, called an aurochs”，即欧洲野牛，已经绝迹;第十一段“Neanderthal”，是人类学用语，尼安德特人，旧石器时代的古人类;第十四段“woolly mammoth”和“cave bear”，其中mammoth是猛犸，一种古哺乳动物。

7.T 见第二段。

8.T 见第四段“Geigl and her colleagues looked at 3,200-year-old fossil bones belonging to a single individual of an extinct cattle species, called an aurochs.”即他们研究的骨化石是一头欧洲野牛身上的。

9.NG

10.F 见第十二段第一、二句话。

11.T 见第十二段末句“But P bo is keen to see samples of fossils from every major find preserved in line with Geigl's recommendations — just in case.”意即为保险起见，Paabo还是非常希望见到用Geigl建议的方法保存的化石样本。“just in case” 的意思是以防万一，就是Paabo对用传统保存处理的化石不放心的意思。

12.A 见第三段。This information就是前一句中“...just how important conservation practices can be”(to preserve good DNA)。“be hammered”之中hammer一词的意思是不断重复强调。

13.D 面信息。需要理解文章各处关于Geigl和她的同事所作的研究。

答案解析：

暂无解析

上一题下一题

-----Whataboutthepenyouboughtyesterday?

-----It____________well.Ilikeitverymuch.

Thelocalgovernmentwill_____morecollegesformorestudentstoreceivehighereducation.

-----Whataboutthepenyouboughtyesterday? -----It____________well.Ilikeitverymuch.

Thelocalgovernmentwill_____morecollegesformorestudentstoreceivehighereducation.

-----Whataboutthepenyouboughtyesterday?

-----It____________well.Ilikeitverymuch.