Language and genetics | Max-Planck-Gesellschaft

Genetic methods have revolutionized research into many aspects of languages, including the tracing of their origins. Homepage Newsroom Article Languageandgenetics Languageandgenetics October01,2010 Evolution Genetics Language Geneticmethodshaverevolutionizedresearchintomanyaspectsoflanguages,includingthetracingoftheirorigins.Genevariantsunderlieindividuallanguageskills.Geneticpredispositionmightfavourtheevolutionofstructuralfeaturesoflanguages. Humanshaveauniquenaturalabilitytodevelophighlycomplexlinguisticsystems—anabilitythatliesinourgenesbutisalsoshapedbyourdifferentenvironments.Wecanlearnlanguagesfromothersandusethemtoshareourthoughts,feelingsanddesires;languagesarethefoundationofsociety,cultureandscience.Soitisperhapsnotsuprisingthatallaspectsoflanguage—includingstructure,globaldistribution,acquisition,processinginthebrain,roleinthoughtandactions,andlinkswithcultureandeducation—canbeconsideredtobeimportantsubjectsofresearch. Whatissospecialaboutourgeneticmake-upthatallowsustouselanguage?Howdoesthisabilityrelatetootherhighercognitivefunctions,likehumanmemoryandmathematicalormusicalability?Untilrecently,ithasbeenhardtoevenposethesequestions.Thepastfewyears,however,haveseentherapiddevelopmentofmethodstoanalysegenesquicklyandrelativelycheaply.Atlastwecanbegintostudythegeneticbasisofhumancognitionand,hence,language.Threeexamplesofongoingresearcharedescribedhere. Languageprocessing Fig.1 TheFOXP2gene:Thoughttobelinkedtospeechdisorder. ©RamonAndrade,SciencePhotoLibrary Fig.1 TheFOXP2gene:Thoughttobelinkedtospeechdisorder. ©RamonAndrade,SciencePhotoLibrary Thehumangenomedoesnot‘create’languages;however,itdoesdirecttheorganizationofthehumanbrainandsomeperipheralorgansthatareprerequisitesforthelanguagesystem,andisprobablyresponsibleforthesignificantdifferencesinlanguageskillsbetweenindividuals.Attheextremesarepeoplewithextraordinarygiftsforlearningmanylanguagesandundertakingsimultaneousinterpretation,andpeoplewithseverecongenitalspeechdisorders1. Excitingearlyresultshaveidentifiedageneunderlyingoneformofspeechdisorderknownasverbaldyspraxia2.Thisseriousimpairmentischaracterizedbyproblemsinarticulation,alongwithotherlinguisticsymptoms.GeneticstudiesofanEnglishfamilywithverbaldyspraxiahaveshownthattheconditionresultsfromamutationinthegene,knownasFOXP2(Fig.1)–locatedonchromosome7,whichaffectsthelanguageareasofthebrainviaseveralintermediatesteps.Althoughthisspeechdeficitisrare,itnowseemsthatthesamegeneticmechanismcouldplayaroleinother,muchmorecommoncongenitalspeechpathologies. However,FOXP2isnota‘languagegene’—thatisatermcoinedbythemedia.Thesamemutationalsoaffectstheliverforexample,andthenon-mutatedgeneisfoundinmanyotheranimals,suchasthemouse,whichdonotspeak.Rather,itisoneofmanygeneticcomponentsimportantinthedevelopmentoflanguageability3.Nevertheless,itsdiscoverywasthefirstsmallbreakthroughinunderstandingthegeneticbasisofhumanlanguage4. Languageandpopulations AnthropologistsbelievethatmodernhumansoriginatedinAfrica.Istherealinkbetweenthespreadoflanguagesandthegeneticdifferencesbetweenthepeopleswhospeakthem? Recentresearchusingmodernscientificmethodshasthrownupsomesurprises.Oneofthemostinterestingshowshowgeneticandlinguisticclassificationsofpopulationscandiverge.MostEuropeanlanguagesbelongtotheIndo-Europeangroup.TwonotableexceptionsareBasque,whichisrelativelyisolated,andtheFinno-Ugriclanguages,inparticularFinnish.ModernFinnshavebeenfoundtobegeneticallyclosetoIndo-Europeans,butgeneticallydifferentfromtheirSaamineighbourswhoselanguageisalsoFinno-Ugric5. Fig.2PhylogenetictreesareusedtostudythesophisticatedevolutionoflanguagesinMelanesia. ©AdaptedfromFig.7inDunn,M.ContactandphylogenyinIslandMelanesia.Lingua119,1664-1678(2009) Fig.2PhylogenetictreesareusedtostudythesophisticatedevolutionoflanguagesinMelanesia. ©AdaptedfromFig.7inDunn,M.ContactandphylogenyinIslandMelanesia.Lingua119,1664-1678(2009) Onestudyisexaminingtheeffectofcontactbetweenprehistoricpopulationswithdifferentsocioculturalbackgroundsindifferentlocations,particularlyAfricaandSiberia,onlanguageandgenetics.Thetypesofcontactthatoccurredareunknown,soitishardtoassesstheirconsequencesusingonlylinguisticmethods.Moleculargeneticanalysescanhelpspotabottleneck,orfoundereffect,thatmightindicateamixingofdifferentpopulations,orrevealdiscrepanciesbetweengeneticandlanguagerelationshipsindicativeofrecentlanguagedrift6. Anotherstudyisaddressingthedevelopmentandspreadoflanguagesoverlargergeographicalareas.Thetraditionalmethodsofcomparativehistoricallinguistics,basedprimarilyonsimilaritiesinvocabulary,canmakesenseoflanguageevolutionoveronlythepastfewthousandyearsatmost.Thenewprojectadaptsthewidelyusedmethodsofevolutionarygenetics—namely,theconstructionofphylogenetictrees(Fig.2)—withthephonological,morphologicalandsyntacticfeaturesoflanguageasrawdata,primarilytostudythesophisticatedlanguagesandpeoplesofMelanesia(anareacoveringmostoftheislandsnorthandnortheastofAustralia)7. Themethodsweredevelopedandtestedonasmallwell-researchedsubgroupofAustronesianlanguagesandarenowbeingappliedtothemuchmorecomplexrelationshipsbetweenthePapuanlanguagesspokeninthesamearea.TheresultssuggestthattheselanguagesderivefromacommonphylumthatismucholderthantheAustralianlanguages,whicharrivedintheareaonly3,000yearsago8. Structuraldifferences Eventhoughlanguagesarenotinborn,aspecificgeneticpredispositionwithinagroupofgeneticallysimilarindividualsmightinfluencetheevolutionofparticularstructuralfeaturesofalanguage.Tonallanguages,forexample,likeChinese,aredifferentfromnon-tonallanguages(likeGerman). ©Chinesin:GettyImages/GuangNiu;Cafe:GettyImages/NationalGeographic/JodiCobb Eventhoughlanguagesarenotinborn,aspecificgeneticpredispositionwithinagroupofgeneticallysimilarindividualsmightinfluencetheevolutionofparticularstructuralfeaturesofalanguage.Tonallanguages,forexample,likeChinese,aredifferentfromnon-tonallanguages(likeGerman). ©Chinesin:GettyImages/GuangNiu;Cafe:GettyImages/NationalGeographic/JodiCobb Languagesarenotinborn.Thereareapproximately7,000languagesintheworldtoday,andlearninganyoneofthemisalengthyprocessthattakesaroundadecade.ThereisnoreasonwhyaChinesechildgrowingupinGermanyshouldlearntospeakGermananyworsethanaGermanchildorachildofanyothernationality.Aspecificgeneticpredisposition,however,mightinfluencetheevolutionofparticularstructuralfeaturesofalanguagewithinagroupofgeneticallysimilarindividuals,forexamplewhetherthelanguageistonalornon-tonal. Chineseisperhapsthemostwell-knownofthetonallanguages,inwhichasinglesyllablecanconveydifferentmeaningsaccordingtowhetheritisspokeninaconsistenttoneorarising,rising–fallingorfallingtone.Thedistributionoftonalandnon-tonallanguagescorrespondscloselywiththedistributionoftwoalleles,orforms,oftheabnormalspindle-likemicrocephaly-associated(ASPM)andmicrocephalingenes9,10.Ofcourse,allelesbythemselvesdonotdirectlyleadtotheevolutionanduseoftonallanguages;childrenwithdifferentformsofthegeneswillstillbeabletolearntonallanguages.Aparticulargeneticpredispositioninapopulation,however,mightfavourtheemergenceoflanguageswithparticularstructuralcharacteristics.Itisnowpossibletostudywhethertheremightalsobeageneticpredispositiontootherstructuralproperties,likepovertyorrichnessofinflexion. Sciencehistoriansarefamiliarwiththepowerofnewtechnologiestorevolutionizescience.Wearestandingbeforeanadvancethatwillfeelparticularlyclosetohome.Overthenextdecadeorso,wecanexpectnewgenomicstechnologiestofurtherourunderstandingofonequintessentialaspectofbeinghuman:language. Thelanguagesoftheworld,whichformpartofandarethemainbearersofcultures,arehighlydiverse.Thecapacitytodevelop,learnandusethem,however,belongstooursharedgeneticheritage.TheseaspectsoflanguageareresearchedintensivelyattheMaxPlanckInstitutesforPsycholinguistics,EvolutionaryAnthropology,andHumanCognitiveandBrainSciences. Vernes,S.C.etal. Afunctionalgeneticlinkbetweendistinctdevelopmentallanguagedisorders. N.Engl.J.Med.359,2337–2345(2008). Source Lai,C.etal. TheSPCH1regiononhuman7q31:genomiccharacterizationofthecriticalintervalandlocalizationoftranslocationsassociatedwithspeechandlanguagedisorder. Am.J.Hum.Genet.67,357–368(2000). Source Vargha-Khadem,F.etal. FOXP2andtheneuroanatomyofspeechandlanguage. NatureRev.Neurosci.6,131–138(2005). Source Ramus,F.&Fisher,S.E. inTheCognitiveNeurosciencesIV(Gazzaniga,M.Sed.) (MITPress,Cambridge)(inpress). Pääbo,S. inWieentstehenneueQualitäteninkomplexenSystemen?50JahreMax-Planck-Gesellschaft 49–56(VandenhoeckundRuprecht,Göttingen,2000). Pakendorf,B. ContactinthePrehistoryoftheSakha(Yakuts):LinguisticandGeneticPerspectives. LOTDissertationSeries170(LandelijkeOnderzoekschoolTaalwetenschap,Utrecht,2007). Dunn,M.etal. Structuralphylogenyinhistoricallinguistics:MethodologicalexplorationsappliedinIslandMelanesia. Language84,710–759(2008). Source Dunn,M. ContactandphylogenyinIslandMelanesia. Lingua119,1664-1678(2009). Source Dediu,D.&Ladd,R. Linguistictoneisrelatedtothepopulationfrequencyoftheadaptivehaplogroupsoftwobrainsizegenes,ASPMandMicrocephalin. Proc.NatlAcad.Sci.USA10,1073(2007). Source Hunley,K.etal. GeneticandlinguisticcoevolutioninNorthernIslandMelanesia. PLoSGenet.4,e1000239(2008). Source ScienceMagazine Events ImagesofScience OnLocation Infographics PressNewsletter Contact Prof.Dr.WolfgangKlein MaxPlanckInstituteforPsycholinguistics,Nijmegen, Niederlande +31243521-453 [email protected] OtherInterestingArticles Thehemispheresarenotequal September15,2022 Brain CognitiveResearch Language Astudyanalyzesdifferencesinbrainasymmetryamongdifferentindividuals ModernhumansgeneratemorebrainneuronsthanNeandertals September08,2022 Brain Genetics Neanderthals Duetothechangeofasingleaminoacid,brainevolutionhasproceededdifferently Sweetsap,savoryants August18,2022 Evolution Woodpeckerstastesweet,butwrynecks—unusualwoodpeckersthatspecializeonants—losttheabilitytotastesugars Costsandbenefitsofgeneticmixing August04,2022 Evolution Baboonsborrowedathirdoftheirgenesfromacloselyrelatedspecies TheBantuexpansiontookarainforestroute August01,2022 Language Migration EarlyBantuspeakerscrossedthroughthedenseCentralAfricanRainforest4,000yearsago ThebrainsofNeanderthalsdevelopeddifferentlyfromthoseofmodernhumans July29,2022 Brain Evolution Genetics Neanderthals Brainstemcellsofmodernhumansmakefewermistakesinthedistributionoftheirchromosomestothedaughtercells Sheddinglightonlinguisticdiversityanditsevolution June16,2022 Evolution Language OpenAccess LinguistsandcomputerscientistscollaboratetopublishalargeglobalOpenAccesslexicaldatabase Coppermakesseedpodsexplode June07,2022 Genetics PlantResearch(B&M) Researchersidentifythegenescontrollingthemechanicalstructureofexplodingseedpods Greatwhitesharksmayhavecontributedtomegalodonextinction May31,2022 Evolution Usingzincisotopes,researchersinvestigatedthedietofmegalodon,thelargestsharktohaveeverlived Chimpanzeescombinecallstoformnumerousvocalsequences May16,2022 BehavioralBiology Language Evidenceofstructuredvocalsequencesinwildchimpanzeecommunicationprovidesinsightsintohumanlanguageevolution Spreadofblackratswaslinkedtohumanhistoricalevents May03,2022 Evolution HumanHistory NewresearchrevealshowtheblackratcolonisedEuropeintheRomanandMedievalperiods Onebird'sjoyisanotherbird'ssorrow March16,2022 Biodiversity Evolution Ageneticconflictbetweenthesexespromotesintraspecificdiversityinruffs Web-View PrintPage Openinnewwindow EstimatedDIN-A4page-width GotoEditorView NotificationSettings ReceivenotificationsforEnglishcontent ReceivenotificationsforGermancontent Save Close