Ifyouincreaseyourinitialorderto30,000,Isupposewecouldconsiderreducingthepriceto300,080$perunit.
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.
-----AheavysnowhitmostofthepartsofChinainJanuary,2008.
-----____________terriblenews!
FelicityLawrence
ThursdayDecember28,2006
TheGuardian
1.ConsumersaretobepresentedwithtworivalnewyearadvertisingcampaignsastheFoodStandardsAgencygoespublicinitsbattlewiththeindustryoverthelabellingofunhealthyfoods.
2.TheGuardianhaslearnedthattheFSAwilllaunchaseriesof10-secondtelevisionadvertsinJanuarytellingshoppershowtofollowared,amberandgreentrafficlightlabellingsystemonthefrontoffoodpacks,whichisdesignedtotackleBritain’sobesityepidemic.
3.Thecampaignisadirectresponsetoaconcertedattemptbyleadingfoodmanufacturersandretailers,includingKellogg’sandTesco,toderailthesystem.Theindustryfearsthattrafficlightswoulddemoniseentirecategoriesoffoodsandcouldseriouslydamagethemarketforthosethatarefatty,saltyorhighinsugar.
4.TheUKmarketforbreakfastcerealsisworth￡1.27bnayearandthemanufacturersfearitwillbeseverelydentedifredlightlabelsareputonpackagingdrawingattentiontothefactthatthemajorityarehighinsaltand/orsugar.
5.Theindustryisplanningamajormarketingcampaignforacompetinglabellingsystemwhichavoidscolour-codinginfavourofinformationaboutthepercentageof"guidelinedailyamounts"(GDAs)offat,saltandsugarcontainedintheirproducts.
6.Thebattleforthenation’sdietcomesasnewrulesontelevisionadvertisingcomeintoforceinJanuarywhichwillbaradvertsforunhealthyfoodsfromcommercialbreaksduringprogrammesaimedatchildren.SourcesattheTVregulatorsarebracedforalegalchallengefromtheindustryandhavedescribedthelobbyingeffortstoblockanynewadbanorcolour-codedlabellingas"themostferociouswe’veeverexperienced".
7.Ofcom’schiefexecutive,EdRichards,said:"Wearepreparedtofaceuptoanylegalactionfromtheindustry,butweverymuchhopeitwillnotbenecessary."TheFSAsaiditwasexpectinganonslaughtfromtheindustryinJanuary.SeniorFSAofficialssaidthemanufacturers’effortstoundermineitsproposalsonlabellingcouldthreatentheagency’scredibility.
8.TerrenceCollis,FSAdirectorofcommunications,dismissedclaimsthattheproposalswerenotbasedonscience."WehavesomeofthemostrespectedscientistsinEurope,bothwithintheFSAandinourindependentadvisorycommittees.ItisunjustifiedandnonsensicaltoattacktheFSA’sscientificreputationandtotrytoundermineitscredibility."
9.TheFSAisunderstoodtohavebriefeditsadagency,United,beforeChristmas,andwillaimtoairadsthatare"non-confrontational,humorousandfactual"asacounterweighttoindustry’seffortsaboutthesametime.Theagency,however,willhaveatinyfractionofthebudgetavailabletotheindustry.
10.GavinNeath,chairmanofUnileverUKandpresidentoftheFoodandDrinkFederation,hassaidthattheindustryhasmadeenormousprogressbutcouldnotacceptred"stop"signsonitsfood.
11.AlastairSykes,chiefexecutiveofNestléUK,saidthatundertheFSAproposalsallhiscompany’sconfectioneryandmostofitscerealswouldscoreared."Arewesayingpeopleshouldn’teatconfectionery?We’redrivenbyconsumersandwhattheywant,andmuchofwhatwedohasbeentomakeourproductshealthier,"hesaid.
12.ChrisWermann,directorofcommunicationsatKellogg’s,said:"Inprinciplewecouldneveraccepttrafficlightlabelling."
13.TherivallabellingschemeintroducedbyKellogg’s,Danone,Unilever,Nestlé,KraftandTescoandnowfavouredby21manufacturers,usesanindustry-devisedsystembasedonidentifyingGDAsofkeynutrients.TescosaysithastestedbothtrafficlightsandGDAlabelsinitsstoresandthatthelatterincreasedsalesofhealthierfoods.
14.ButtheFSAsaiditcouldnotlivewiththisGDAsystemalonebecauseitwas"notscientific"oreasyforshopperstounderstandataglance.
Questions1-6
AnswerthequestionsbelowusingNOMORETHANTHREEWORDSfromthepassageforeachanswer.
1.Whenwillinstructionsbegivenonreadingthecolor-codedlabels?
2.Wherecancustomersfindtheredlightlabels?
3.WhatproblemistheFSAtryingtohandlewiththelabelingsystem?
4.Whichproductsellswellbutmaynotbehealthy?
5.Whatinformation,accordingtothemanufacturers,canbelabeledonproducts?
6.Whatcannotbeadvertisedduringchildren’sprogrammes?
Questions7-13
Usetheinformationinthetexttomatchthepeople(listedA-E)withtheopinions(listed7-13)below.Writetheappropriateletter(A-E)forquestions1-7.
NBYoumayuseanylettermorethanonce.
AEdRichard
BTerrenceCollis
CGavinNeath
DAlastairSykes
EChrisWermann
7.Generallywewillnotagreetousetheredlightlabels.
8.ItisunreasonabletodoubtifFSAistrustworthy.
9.Wearetryingtomeetourconsumers’needs.
10.Thefoodindustryhasbeenimprovinggreatly.
11.Thecolor-codedlabelingsystemisscientific.
12.OurproductswillbelabeledunhealthybytheFSA.
13.Wearereadytoconfrontthemanufacturers.