鸟类真的是恐龙进化而来的吗-.docx

鸟类真的是恐龙进化而来的吗?鸟类真的是恐龙进化而来的吗?1Newlighthasbeenthrownontheevolutionarylinkbetweenbirdsanddinosaurs.Andit'sfairtosayit'saverystronglink.That'saccordingtoDr.StephenBrusatte,apaleontologistattheUniversityofEdinburg.Heisatthestudytobuildthemostfamilytreeofcarnivorousdinosaursthat'severbeen.Anditleadsfromprehistorictimestotheday.MycolleagueDanDamonaskedhimjusthowcloselyrelatedarethebirdsweseearoundustodinosaurs.Birdsaredinosaursinthesamewaythataretypeofmammalorfrogsaretypeofamphibian.Birds,chickens,hummingbirdstheyareallliving.Howdoyoumakethatlink?Sowehavelotoffossilsnow,awholelotoffossils.Andwe'vebeenfindingmoreandmoreofthemoverthelast20yearsorso.Thisiswhatustobuildthisbigfamilytree.SomycolleaguesandItraveledaroundtheworldlookingatalotofdinosaurs,puttingtogetherthishugedataset.Thattreeshowsusthattherearesomanyoflivingbirds,thingslikefeathersandwishbones,andwingsthatdidn'tjustevolveinbirds,buttheyevolvedinthedinosaurancestorsofbirds.Ithinkalotofpeoplethinkaboutevolutionintermsoflegs.Youknow,theremustbealinkbetweenmonkeysandmenorbetweendinosaursandbirds.Butthat'snotreallyhowworks.Theevolutionofbirdswasalonggradualprocess,firstfeathersofall,thenwishbones,thenwings.Thenthesedinosaursgotsmaller.Andthentheyputitalltogether.Thebirdbodyplanwasthere.Theywereabletofly.Andthenbang!Somethingwasunlocked;birdstookoff.Andbirdssurvivedthethatkilledoffthedinosaursandtheyarestillaroundtoday,10,000ofthem.Exactly10,000species.Buttheyarebirds.Howdidtheysurvive?Imean,someofthedinosaursmusthavesurvivedwhenthat,whatwasit,somekindofcomethitFlorida.Andsothatkilledoffmostofthedinosaurs.Almosteverydinosaurdiedexpectforsomebirds.Andwhysomebirdswereabletomakeitthrough?Well,it'sprobablyduetoalotofreasons,butoneofthereasonsisbecausetheycouldfly.Maybebecausetheyweresmaller,theycouldgrowfaster.Butaswealsofoundinthisstudy,birdsevolvedfasterthanotherdinosaurs.Oncethatbirdbodyplanoffeathersandwings,andwishbonesallcametogether,itallowedbirdstosimplychangefasterthanothertypesofdinosaurs.Maybethatwasakeytotheirsuccess.第2页 共2页第 2 页 共 2 页第 2 页 共 2 页第 2 页 共 2 页第 2 页 共 2 页第 2 页 共 2 页第 2 页 共 2 页第 2 页 共 2 页第 2 页 共 2 页第 2 页 共 2 页第 2 页 共 2 页