Iingcali zebhayoloji ezikholelwa kwindaleko zinikela ingxelo yokuba ziye zadibanisa iPET scans zamahobe ale mihla kunye nohlolisiso lweefosili zedayinaso ukuze zincede ekuphenduleni umbuzo ongagungqiyo webhayoloji: Bazivelela njani ingqondo yeentaka ukuze zikwazi ukubhabha?
Intaka - ifoto engumzekeliso. Umfanekiso wekhredithi: pixabay (Ilayisensi yePixabay yasimahla)
Impendulo ibonakala ikukunyuka okuguquguqukayo kubungakanani becerebellum kwezinye iifossil vertebrates. Icerebellum yingingqi engasemva kwengqondo yentaka enoxanduva lokushukuma kunye nolawulo lwemoto.
Iziphumo zophando zipapashwa kwijenali Iinkqubo zeRoyal Society B.
"Sifumanise ukuba xa iintaka zisuka ekuphumleni zisiya kubhabha, iisekethe kwi-cerebellum zisebenza ngakumbi kunayo nayiphi na enye indawo yengqondo," utshilo umbhali-mbhali. UPawulos Gignac, unjingalwazi onxulumene neYunivesithi yaseArizona Ikholeji yezoNyango-Tucson, ukufunda i-neuroanatomy kunye ne-evolution. Ukwalilungu lophando kwiMyuziyam yaseMelika yeMbali yeNdalo.
"Siye sajonga ukhakhayi oluhambelana nalo mmandla kwi-dinosaur kunye neefosili zeentaka ukulandelela xa i-cerebellum yanda," utshilo uGignac. "Isantya sokuqala sokwanda kwenzeka ngaphambi kokuba iidinosaurs zithathe iphiko, nto leyo ebonisa ukuba ukubhabha kweentaka zisebenzisa iireyilayi zemithambo-luvo zamandulo nezilondolozwe kakuhle, kodwa ngomgangatho ophakamileyo wokusebenza."
Izazinzulu kudala zicinga ukuba i-cerebellum ifanele ukuba ibalulekile ekubhabha kweentaka, kodwa babengenabungqina obuthe ngqo. Ukuphawula ixabiso lalo, uphando olutsha ludibanise idatha ye-PET scan yangoku yamahobe aqhelekileyo kunye nerekhodi yefosili, evavanya imimandla yobuchopho beentaka ngexesha lokubhabha kunye neengqondo zeedinosaurs zamandulo. I-PET scan ibonisa indlela amalungu kunye nezicubu ezisebenza ngayo.
"Ukubhabha okunamandla phakathi kwezilwanyana ezinomqolo sisiganeko esinqabileyo kwimbali yendaleko," utshilo umbhali okhokelayo uAmy Balanoff, ovela kwiJohns Hopkins University School of Medicine.
Enyanisweni, amaqela amathathu kuphela e-vertebrates, okanye izilwanyana ezinomqolo, zavela ukuba zibhabha: i-pterosaurs eziphelile - ukwesaba kwesibhakabhaka ngexesha le-Mesozoic, eliphelile kwiminyaka eyi-65 yezigidi edlulileyo - amalulwane kunye neentaka, kusho uBalanoff. La maqela mathathu abhabhayo akazalani ngokusondeleyo kumthi wendaleko, kwaye ezona nkalo ziphambili ezibangele ukubhabha kuzo zontathu zihlala zingacacanga.
Ngaphandle kolungelelwaniso lwangaphandle lokubhabha, njengemilenze emide engaphezulu, iintlobo ezithile zeentsiba, umzimba olungelelanisiweyo kunye nezinye iimpawu, eli qela lenze uphando ukuze lifumane izinto ezenze ingqondo elungele ukubhabha.
Ukwenza njalo, iqela libandakanya iinjineli ze-biomedical kwiYunivesithi yaseStony Brook eNew York ukuthelekisa umsebenzi wobuchopho wamajuba anamhlanje ngaphambi nangemva kokubhabha.
Abaphandi benza i-PET scans ukuthelekisa umsebenzi kwimimandla ye-26 yengqondo xa intaka iphumle kwaye ngokukhawuleza emva kokuba ibhabhe imizuzu eyi-10 ukusuka kwelinye i-perch ukuya kwelinye. Bahlola iintaka ezisibhozo ngeentsuku ezahlukeneyo. Izikena ze-PET zisebenzisa ikhompawundi efana neglucose enokulandelelwa apho ifunxeka khona kakhulu ziiseli zengqondo, nto leyo ebonisa ukusetyenziswa okwandileyo kwamandla kwaye ngaloo ndlela isebenze. Umkhondo wehlisa isidima kwaye ukhutshelwa ngaphandle komzimba ngosuku okanye ezimbini.
Kwimimandla engama-26, indawo enye - i-cerebellum - ibe nokunyuka okuphawulekayo kumanqanaba omsebenzi phakathi kokuphumla kunye nokubhabha kuzo zonke iintaka ezisibhozo. Ngokubanzi, inqanaba lokunyuka komsebenzi kwi-cerebellum lahluke kakhulu, xa kuthelekiswa nezinye iindawo zengqondo.
Abaphandi baye bafumanisa ukwanda komsebenzi wengqondo kwinto ebizwa ngokuba yi-optic flow pathways, inethiwekhi yeeseli zengqondo ezidibanisa i-retina kwiso kwi-cerebellum. Ezi ndlela ziqhubela phambili intshukumo kumhlaba wokubonwayo.
U-Balanoff uthe iziphumo zeqela zokunyuka komsebenzi kwi-cerebellum kunye neendlela zokuhamba kwe-optic azizange zothusa, kuba iindawo ziye zacingelwa ukuba zidlala indima ekubhabha.
Eyona nto yayintsha kuphando lwabo yayikukunxulumanisa iziphumo ze-cerebellum zobuchopho obukwazi ukubhabha kwiintaka zanamhlanje kwirekhodi yefosili eyayibonisa indlela ubuchopho beedayinaso ezinjengeentaka baqala ngayo ukuphuhlisa iimeko zengqondo zokubhabha okunamandla.
Ukwenza njalo, iqela lasebenzisa i-database egciniweyo ye-endocasts, okanye i-molds yendawo yangaphakathi ye-skulls ye-dinosaur, ethi, xa izaliswe, ifane nengqondo.
Emva koko bachonga kwaye balandelela ukonyuka okukhulu komthamo we-cerebellum kwezinye zezona ntlobo zokuqala ze-maniraptoran dinosaurs, ezandulela ukubonakala kokuqala kokubhabha okunamandla phakathi kwezalamane zamandulo zeentaka, kubandakanya. Iarcheopteryx, idayinaso enamaphiko.
Abaphandi abakhokelwa nguBalanoff baphinde bafumana ubungqina kwi-endocasts yokwanda kwezicubu ezisongayo kwi-cerebellum ye-maniraptorans yokuqala, isibonakaliso sokunyuka kobunzima bobuchopho.
Abaphandi balumkise ukuba ezi zinto zifunyenwe kwangoko, kwaye utshintsho lomsebenzi wobuchopho ngexesha lokubhabha okunamandla lunokwenzeka ngexesha lezinye iindlela zokuziphatha, ezinje ngokubhabha. Bakwaqaphela ukuba iimvavanyo zabo zibandakanya ukubhabha okuthe ngqo, ngaphandle kwemiqobo kunye nendlela elula yokubhabha, kunye neminye imimandla yobuchopho inokusebenza ngakumbi ngexesha lokuhamba ngenqwelomoya.
Iqela lophando liceba ngokulandelayo ukukhomba iindawo ezichanekileyo kwi-cerebellum eyenza ingqondo elungele ukundiza kunye nokudibanisa kwe-neural phakathi kwezi zakhiwo.
Ithiyori zenzululwazi zokuba kutheni ingqondo isiya iba nkulu kuyo yonke imbali yendaleko ibandakanya isidingo sokunqumla imihlaba emitsha neyohlukeneyo, ukubeka inqanaba lokubhabha kunye nezinye izitayile zelocomotive, utshilo umbhali-mbhali uGabriel Bever weJohns Hopkins University School of Medicine.
Abanye ababhali abafundayo baquka u-Elizabeth Ferrer we-American Museum of Natural History kunye neYunivesithi yaseSamuel Merritt; ULemise Saleh kunye noPaul Vaska weYunivesithi yaseStony Brook; M. Eugenia Gold we-American Museum of Natural History kunye neYunivesithi yaseSuffolk; uYesus Marugán-Lobón yeYunivesithi eZimeleyo yaseMadrid; uMark Norell weMyuziyam yaseMelika yeMbali yeNdalo; UDavid Ouellette waseWeill Cornell Medical College; UMichael Salerno weYunivesithi yasePennsylvania; U-Akinobu Watanabe we-American Museum of Natural History, iNew York Institute of Technology College of Osteopathic Medicine kunye neMyuziyam yeMbali yeNdalo yaseLondon; kunye noShouyi Wei weNew York Proton Centre.
Olu phando luxhaswe ngemali yiNational Science Foundation.
umthombo: Yunivesithi yaseArizona
