a recent study of ancient and modern elephants has come up高考阅读答案

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1、Arecentstudyofancientandmodernelephantshascomeup高考阅读答案　　ArecentstudyofancientandmodernelephantshascomeupwiththeunexpectedconclusionthattheAfricanelephantisdividedintotwodistinct(不同的)species.　　ThediscoverywasmadebyresearchersatYorkandHarvarduniversitieswhentheywereexaminingthegen

2、eticrelationshipbetweentheancientwoollymammothandmastodontomodernelephants—theAsianelephant,AfricanforestelephantandAfricansavannaelephant.　　OncetheyobtainedDNAsequences(序列)fromtwofossils(化石)，mammothsandmastodons,theteamcomparedthemwithDNAfrommodernelephants.Theyfoundtotheiramaz

3、ementthatmodernforestandsavannaelephantsareasdistinctfromeachotherasAsianelephantsandmammoths.　　ThescientistsuseddetailedgeneticanalysistoprovethattheAfricansavannaelephantsandtheAfricanforestelephantshavebeendistinctspeciesforseveralmillionyears.Thedivergenceofthetwospeciestook

4、placearoundthetimeofthedivergenceofAsianelephantsandwoollymammoths.Thisresultamazedallthescientists.　　Therehaslongbeendebateinthescientificcommunitythatthetwomightbeseparatespeciesbutthisisthemostconvincingscientificevidencesofarthattheyareindeeddifferentspecies.　　Previously,man

5、ynaturalistsbelievedthatAfricansavannaelephantsandAfricanforestelephantsweretwopopulationsofthesamespeciesdespitetheelephants’significantsizedifferences.ThesavannaelephanthasanaverageshoulderheightofwhiletheforestelephanthasanaverageshoulderheightofThesavannaelephantweighsbetwee

6、nsixandseventons,roughlydoubletheweightoftheforestelephant.Butthefactthattheylooksodifferentdoesnotnecessarilymeantheyaredifferentspecies.However,theprooflayintheanalysisoftheDNA.　　AlfredRoca,assistantprofessorinthedepartmentofAnimalSciencesattheUniversityofMinois,said,“Wenowhav

7、etotreattheforestandsavannaelephantsastwodifferentunitsforconservationpurpose.Since1950allAfricanelephantshavebeenconservedasonespecies.Nowthatweknowtheforestandsavannaelephantsaretwoverydistinctanimals,theforestelephantshouldbecomeabiggerpriority(优先)forconservationpurpose.”　　66

8、.Oneofthefossilsstudiedbytheresearchersisthatof