[判断题]WhenLadyGagareleasesanewsingle,itquicklygoesaroundtheworld.Nowscientistshavediscoveredthesamethinghappenswiththesongsofanotherunusualandinterestingcreature–thehumpbackwhale.Themammalsbecomeinterestedinnewtunesjustlikepeopledo,andthemostpopularoriginalwhalesongsspreadgloballylikehitsingles.Thediscoveryhasastonishedexpertswhosayitisthefirsttimesuchalarge,“population-wideculturalexchange”hasbeenseenintheanimalkingdom.Malehumpbackwhalesarewell-knownfortheloud,longandcomplexsongstheymakeduringthematingseason.Scientistsareunsurewhythemalessing.Somebelieveitisawayofadvertisingthemselvestofemales,othersholdthatitallowsmigratingwhalestostayincontact.Eachsonglastsfor10to20minutesandthemalescansingcontinuouslyfor24hours.Atanyperiodoftime,allthemalesinapopulationsingthesamesong.Butastudy,publishedinthejournalCurrentBiology,showsthatthissongchangesovertimeandspreadsaroundtheoceans.Dr.EllenGarland,ofQueenslandUniversity,said:“Ourfindingsshowculturalexchangeonavastscale.Songsmovelikeculturalripplesfromonepopulationtoanother,causingallmalestochangetheirsongtoanewversion.”ResearchersrecordedsongsfromsixneighboringpopulationsofwhalesinthePacificoveradecade.Theyfoundthatnewversionsofthesongsappearovertimeandalwaysspreadfromwesttoeast.IttakesaroundtwoyearsforsongsthatappearinthewatersoffAustraliatobeheardinFrenchPolynesia.Dr.Garlandbelievesthatasmallnumberofwhalesmaymigratetootherpopulationscarryingthenewsongswiththem,orthattheyareheardbypassingwhales.Dr.Garlandsaid,“Wethinkthismalesearchforsongnoveltyisinthehopeofbeingthatlittlebitdifferentandperhapsmoreattractivetotheoppositesex.”5.ItusuallytakestwoyearsforsongsthatappearinthewatersoffAustraliatobeheardinFrenchPolynesia.
