Ungena kwipaseji ekhanyiswe luzizi, apho udibana nemiphefumlo esweleyo engcungcuthekiswa yintlungu nokubandezeleka. Kodwa abayi kuba noxolo apha, kuba emva kwengcango nganye balindele ukuthuthunjiswa ngakumbi kunye noloyiko, ukugcwalisa zonke iiseli zomzimba kunye nokuzalisa zonke iingcamango. Usondela kwenye yeengcango, emva kwayo uve isihogo sokusila kunye nokuncwina okukuqhaqhazela emathanjeni. Ukuqokelela isibindi sakho esiseleyo kwinqindi, wolula isandla sakho, ubanda ngokukrakra, kwisibambo somnyango, xa ngequbuliso umntu echukumisa igxalaba lakho ngasemva, kwaye wena, wothuka ngokumangala, ujike. βUgqirha uzakukhululeka kwimizuzu embalwa. Hlala phantsi okwangoku, sizakukubiza,β ilizwi elithambileyo likamongikazi likuxelela. Ngokucacileyo, le yindlela kanye abanye abantu abacinga ngayo ukuya kugqirha wamazinyo kwaye banesimo sengqondo esibi kakhulu malunga naba "sadists" kwiidyasi ezimhlophe. Kodwa namhlanje asiyi kuthetha nge-dentophobia, siza kuthetha ngeengwenya. Ewe, ewe, malunga nabo, okanye ngokuchanekileyo malunga namazinyo abo, angadingi unyango lwamazinyo.
Izazinzulu ezivela kwiYunivesithi yaseMissouri (USA) zenze uphando lwamazinyo eengwenya, ezibonisa iimpawu ezinomdla ze-enamel yalaba bazizingeli abangenakulinganiswa, bathembele ngokuchanekileyo emihlathini yabo. Yintoni eye yafunyaniswa zizazinzulu, amazinyo eengwenya zanamhlanje ahluke njani kwizalamane zazo zangaphambili, yaye luyintoni uncedo olu phando? Sifunda malunga noku kwingxelo yeqela lophando.
Isiseko sophando
Kuninzi lwezilwanyana ezinomqolo, amazinyo luphawu olubalulekileyo lokufumana nokutya ukutya (izilwanyana ezifuywayo azibali). Ezinye izilwanyana zixhomekeke kwisantya xa zizingela (iingwenkala), ezinye kwiqela (iingonyama), kwaye kwezinye, amandla okuluma kwazo adlala indima enkulu. Oku kusebenza nakwiingwenya, ezichwechwela amaxhoba azo emanzini kwaye ziwabambe ngemihlathi yazo enamandla. Ukuthintela ixhoba ukuba libaleke, ukubamba kufuneka kube namandla, kwaye oku kubangela imithwalo enzima kwisakhiwo samathambo. Ukunciphisa isiphumo esibi sokulunywa kwabo okunamandla, iingwenya zinenkalakahla yamathambo yesibini, edityaniswe ngokuthe ngqo kukhakhayi.
Umboniso obonakalayo wokuvala nokuvulwa komhlathi wengwenya.
Olunye uphawu oluphambili lwamazinyo engwenya kukutshintshwa kwawo rhoqo kufakwe amatsha xa amadala egugile. Inyaniso kukuba amazinyo eengwenya afana nonodoli ozalela, apho amazinyo amatsha akhula ngaphakathi. Malunga kanye emva kweminyaka emi-2, izinyo ngalinye emhlathini litshintshwa ngamatsha.
Qaphela ukuba lo "mgibe wamazinyo" uvale ngokuqinileyo kangakanani.
Amazinyo Crocodile 'zahlulwe ngokweendidi eziliqela ngokusekelwe imilo kunye nokusebenza ehambelanayo. Ekuqaleni komhlathi kukho ii-fangs ezinkulu ezi-4, ezifunekayo ukuze kubanjwe ngokufanelekileyo amaxhoba. Embindini kukho amazinyo angqingqwa, ayanda ngasemhlathini. Le nxalenye iyadingeka ukusika amaxhoba. Kwisiseko, amazinyo aba banzi kwaye abe flat, nto leyo evumela iingwenya ukuba zilume ngamaqokobhe e-mollusk kunye namaqokobhe e-turtle njengembewu.
Womelele kangakanani umhlathi wengwenya? Ngokwemvelo, oku kuxhomekeke kubukhulu bayo kunye nohlobo. Ngokomzekelo, ngo-2003 kwafunyaniswa ukuba i-alligator ye-272 kilogram ye-Mississippi iluma ngamandla ο½9500 N (N - Newton, 1 N = 1 kg m / s2). Kodwa ingwenya ye-1308 yeekhilogram zamanzi etyuwa yabonisa ukuvuthuza kwengqondo ο½34500 N. Ngendlela, amandla okuluma ngokupheleleyo ebantwini malunga ne-1498 N.
Amandla okuluma akuxhomekanga kakhulu kumazinyo, kodwa kwimisipha yomhlathi. Kwiingwenya ezi zihlunu zixinene kakhulu kwaye zininzi. Noko ke, kukho umahluko omkhulu phakathi kwezihlunu eziphuhle kakhulu ezinoxanduva lokuvala umlomo (nto leyo enika amandla okuluma ngolo hlobo) kunye nezihlunu ezibuthathaka ezinoxanduva lokuvula umlomo. Oku kuchaza ukuba kutheni umlomo wengwenya ungabanjwa ngeteyiphu elula.
Yiza, undibonise ukuba ngubani owakubize ngebrat encinci.
Kodwa iingwenya zifuna umhlathi kungekuphela nje ekubulaweni ngokungenalusini ukuze kutyiwe, kodwa nokukhathalela inzala yazo. Iingwenya zeemazi zihlala zithwala amantshontsho azo emihlathini (kunzima ukufumana indawo ekhuselekileyo kuzo, kuba ngubani ofuna ukunyuka apho). Umlomo weengwenya uxhotyiswe ngee-receptors ezibukhali kakhulu, ngenxa yokuba banokulawula amandla okuluma kwabo, okubavumela ukuba babambe kakuhle amaxhoba okanye baphathe abantwana ngononophelo.
Amazinyo omntu, ngelishwa, awakhuli emva kokuba amadala ewa, kodwa anento efana neengwenya - i-enamel.
Umfanekiso #1: Izinyo le-Caudal ye-Alligator mississippiensis.
I-enamel liqokobhe langaphandle lesithsaba sezinyo. Lelona lungu linamandla lomzimba womntu, kunye nezinye izilwanyana ezininzi ezinethambo lomqolo. Nangona kunjalo, njengoko sisazi, amazinyo ethu awatshintshi amatsha, ngoko ke i-enamel yethu kufuneka ibe nkulu. Kodwa kwiingwenya, amazinyo aphelileyo atshintshwa ngamatsha, ngoko akukho mfuneko ye-enamel enzima. Ivakala isengqiqweni, kodwa ngaba kunjalo ngokwenene?
Iingcali zenzululwazi zithi ukuqonda utshintsho kwi-enamel ngaphakathi kwerhafu enye kuya kusivumela ukuba sikhumbule kangcono kwixesha elizayo indlela isakhiwo se-enamel sitshintsha ngayo ngokuxhomekeke kwi-biomechanics kunye nokutya kwesilwanyana.
Iingwenya, ezizezi i-alligator mississippiensis, zilunge kakhulu kolu phononongo ngenxa yezizathu ezininzi. Okokuqala, amazinyo abo, amandla okuluma kunye nesakhiwo se-enamel sitshintsha ngokuxhomekeke kwiminyaka kunye nobukhulu bomntu, okubangelwa utshintsho kwindlela yokutya. Okwesibini, amazinyo engwenya anee-morphology ezahlukeneyo ngokuxhomekeke kwindawo yawo emhlathini.
Umfanekiso No. 2: a kunye b ukubonisa umahluko amazinyo phakathi kwabantu abakhulu nabancinane, c-f ibonisa amazinyo izinyanya iifosili yeengwenya mihla.
Amazinyo e-rostral mancinci kwaye asetyenziselwa ukubamba amaxhoba, ngelixa amazinyo e-caudal abuthuntu kwaye asetyenziselwa ukutyumza ngamandla aphezulu okuluma. Ngamanye amazwi, umthwalo kwizinyo uxhomekeke kwindawo elikuyo emhlathini nakubungakanani bomnini walo mhlathi.
Olu pho nonongo lubonisa iziphumo zokuhlalutya kunye nemilinganiselo yobukhulu obupheleleyo be-enamel (AET) kunye nobukhulu-standard (relative) ubukhulu be-enamel (RET) yamazinyo engwenya.
I-AET iqikelelo lomgama ophakathi ukusuka kwi-enamel-dentin junction ukuya kumphezulu we-enamel yangaphandle kwaye ngumlinganiselo womgca. Kwaye i-RET lixabiso elingenamda elikuvumela ukuba uthelekise ubukhulu be-enamel kwizikali ezahlukeneyo.
Iingcali zenzululwazi zivavanye i-AET kunye ne-RET ye-rostral ("empumlweni" yomhlathi), phakathi (phakathi komqolo) kunye ne-caudal (ezantsi komhlathi) amazinyo kubantu abasixhenxe bohlobo. i-alligator mississippiensis.
Kwakhona kubalulekile ukuba uqaphele ukuba isakhiwo se-enamel sinokuxhomekeke ekutyeni komntu kunye neentlobo ngokubanzi. Iingwenya zinokutya okubanzi kakhulu (into eziyibambisayo koko zikutyayo), kodwa kwahlukile koko kwezalamane zazo, ekudala zatshabalala. Ukuvavanya oku kumbono we-enamel, izazinzulu zahlalutya iifosili ze-AET kunye ne-RET Protosuchidae (UCMP 97638), Iharkutosuchus (MTM VER 2018.837) kunye I-Allognathosuchus (YPM-PU 16989). Protosuchidae ngummeli wexesha leJurassic, Iharkutosuchus - Ixesha leCretaceous, kunye I-Allognathosuchus ukusuka kwi-Eocene.
Phambi kokuba baqale imilinganiselo yokwenyani, abaphandi baxubushe kwaye bacebise iingqikelelo ezininzi zethiyori:
- I-Hypothesis 1a-Ngenxa yokuba i-AET iyimilinganiselo yomgca kwaye kufuneka ixhomekeke kubukhulu, ukuhluka kwe-AET kulindeleke ukuba kuchazwe kakuhle ngobukhulu bekhanda;
- I-hypothesis 1b-Ngenxa yokuba i-RET ilinganiswe ngobungakanani, ukuhluka kwe-RET kulindeleke ukuba kuchazwe kakuhle ngokuma kwezinyo;
- I-Hypothesis 2a-Ngenxa yokuba i-AET kunye nobude be-skull yimilinganiselo yomgca yobukhulu, kufuneka balinganise nge-slope ye-isometric;
- I-Hypothesis 2b-Ngenxa yokuba amazinyo e-caudal afumana amandla amakhulu okuluma kwi-arch, ngoko ke i-RET iya kuba phezulu kumazinyo e-caudal.
Ezi theyibhile zingezantsi zibonisa idatha yesampula (iintloko zeengwenya i-alligator mississippiensis, ithathwe kwiRockefeller Reserve eGrand Chenier, eLouisiana, kunye neefosili).
Itheyibhile ye-1: idatha yokukhangela amazinyo engwenya (i-rostral, ephakathi kunye ne-caudal).
Itheyibhile ye-2: idatha yamazinyo (i-LSkull - ubude be-skull, i-hCrown - ukuphakama kwesithsaba, i-VE - ivolumu ye-enamel, i-VD - ivolumu ye-dentin, i-SAEDJ - indawo ye-enamel-dentin interface, i-AET - ubukhulu obupheleleyo be-enamel, i-RET - ubukhulu be-enamel).
Iziphumo zophando
Ngokutsho kwedatha yamazinyo eboniswe kwiThebhile 2, izazinzulu zagqiba ukuba ubukhulu be-enamel bulinganisa i-isometrically kunye nobude bekhanda, kungakhathaliseki ukuba yiphi indawo yezinyo.
Itheyibhile ye-3: Amanani e-AET kunye ne-RET ngokuxhomekeke kwizinto eziguquguqukayo.
Umfanekiso #3: I-AET/RET yokulinganisa ngokumalunga nobude bokhakhayi.
Ngelo xesha, ubukhulu be-enamel kumazinyo e-caudal bukhulu kakhulu kunabanye, kodwa oku akuxhomekeke kubude bekhanda.
Itheyibhile yesi-4: amaxabiso aphakathi kobukhulu be-enamel kwi-vertebrates ephezulu (iCrocodyliform - iqela leengwenya ezongezelelweyo, iDinosaur - iidinosaurs, i-Artiodactyl - i-artiodactyls, i-Odontocete - i-suborder ye-cetaceans, i-Perissodactyl - i-odd-toed ungulates, i-primate-primate Iimpuku - iimpuku).
Umfanekiso #4: Ubukhulu be-enamel yamazinyo e-caudal bukhulu kunobo bamanye amazinyo.
Idatha malunga nokulinganisa (Itheyibhile ye-3) iqinisekisile i-hypothesis ye-1a, ichaza ukuxhomekeka kwexabiso le-AET kubude bekhanda, kwaye kungekhona kwindawo yezinyo. Kodwa ixabiso le-RET, ngokuchaseneyo, lixhomekeke kwindawo yezinyo emgceni, kwaye kungekhona ubude bekhanda, eliqinisekisa i-hypothesis 1b.
I-hypotheses eseleyo (2a kunye ne-2b) nayo yaqinisekiswa, ngolu hlobo lulandelayo kuhlalutyo lobunzima obuphakathi kwe-enamel yamazinyo anezikhundla ezahlukeneyo kumqolo.
Ukuthelekiswa kobunzima be-enamel yengwenya yaseMississippi yanamhlanje kunye nookhokho bayo bakudala babonisa ukufana okuninzi, kodwa bekukho umahluko. Ngaloo ndlela, kwi-Allonnathosuchus ubukhulu be-enamel bumalunga ne-33% enkulu kuneengwenya zanamhlanje (umfanekiso ongezantsi).
Umfanekiso #5: Ukuthelekiswa kobukhulu obuqhelekileyo be-enamel kwi-alligator kunye ne-fossil crocodylians ngokusekelwe kumphakamo wesithsaba sezinyo.
Ukushwankathela yonke idatha engentla, izazinzulu zafikelela kwisigqibo sokuba ubukhulu be-enamel buxhomekeke ngokuthe ngqo, ngoko kuthetha, indima yamazinyo. Ukuba la mazinyo ayafuneka ukuze atyunyuzwe, i-enamel yawo iya kuba nzima kakhulu. Ngaphambili kwafunyaniswa ukuba uxinzelelo (i-compressive force) lwamazinyo e-caudal luphezulu kunelo lwamazinyo e-rostral. Oku kubangelwa ngokuchanekileyo indima yabo - ukubamba amaxhoba kunye nokutyumza amathambo. Ke, i-enamel etyebileyo ikhusela umonakalo kumazinyo, aphantsi koxinzelelo olukhulu ngexesha lesondlo. Enyanisweni, ubungqina bubonisa ukuba amazinyo e-caudal kwiingwenya aphuka kancinci, nangona uxinzelelo olunzima.
Ukongeza, kwafunyaniswa ukuba amazinyo I-Allognathosuchus i-enamel ijiyile kakhulu kunezinye iicrocodylians ezifundiweyo. Kukholelwa ukuba olu hlobo lwefosili lukhetha ukutya kwiimfudo, kwaye ukutyumza amaqokobhe abo kufuna amazinyo aqinileyo kunye ne-enamel engqindilili.
Izazinzulu zikwathelekisa ubukhulu be-enamel yeengwenya kunye nezinye iidinosaur, ubunzima obuqikelelwayo kunye nobukhulu obuhambelanayo. Olu hlalutyo lubonise ukuba ii-crocodylians zine-enamel engqindilili (umzobo ongezantsi).
Umfanekiso #6: Ukuthelekiswa kobunzima be-enamel yeengwenya kunye needinosaurs.
Kuyathakazelisa ukuba i-enamel ye-tyrannosaurid yayiphantse yalingana nobukhulu obufana ne-Allognathosuchus encinci kunye neengwenya zanamhlanje. Kunengqiqo ukuba isakhiwo sezinyo seengwenya sichazwa yimikhwa yabo malunga nokuzingela kunye nokutya.
Noko ke, phezu kwazo nje iirekhodi zazo, i-enamel yee<em>archosaurs (iingwenya, ii<em>dinosaur, ii<em>pterosaurs, njl. njl.) incinane kuneyezilwanyana ezanyisayo.
Umfanekiso #7: Ukuthelekiswa kobunzima be-enamel (AET) yeengwenya kunye nezinye iintlobo zezilwanyana ezincancisayo.
Kutheni le nto i-enamel yabazingeli, abathembele kakhulu emihlathini yabo, ibhityile kunezilwanyana ezanyisayo? Impendulo yalo mbuzo yayisele isekuqaleni - ukutshintsha amazinyo agugileyo kunye namatsha. Nangona iingwenya zinamazinyo aqinileyo, azidingi, ngoko kuthetha, amazinyo anamandla kakhulu, ngenxa yokuba izinyo elitsha liya kuhlala lithatha indawo eyaphukileyo. Izilwanyana ezanyisayo (ubukhulu becala) azinayo le talente.
Umfanekiso #8: Ukuthelekiswa kobukhulu be-enamel (RET) yeengwenya kunye neentlobo ezithile zezilwanyana ezincancisayo.
Ngokuchanekileyo, ubukhulu be-enamel kwi-archosaurs buhluka ukusuka kwi-0.01 ukuya kwi-0.314 mm, kunye nezilwanyana ezincelisayo ukusuka kwi-0.08 ukuya kwi-2.3 mm. Umahluko, njengoko besithi, uyabonakala.
Ukujonga ngakumbi kwii-nuances zophononongo, ndincoma ukuba ujonge
Ipilo
Amazinyo, nokuba angavakala engaqhelekanga kangakanani na, asisixhobo esibaluleke kakhulu ekufumaneni ukutya. Ewe, umntu wanamhlanje unokuhlala elungisa nasiphi na isiphene esihambelana namazinyo, kodwa phakathi kwabameli basendle akukho bamazinyo. Kwanabantu babengasoloko besazi ukuba yintoni unyango lwamazinyo. Ngoko ke, ezinye iintlobo zikhetha amazinyo anamandla kwaye ahlala ixesha elide, ngelixa ezinye zikhetha ukuzitshintsha, njengeiglavu. Iingwenya kunye nezalamane zabo ezikude zingahlelwa ngokwamaqela omabini. I-enamel emazinyweni, ayimfuneko ekubambeni ngokufanelekileyo ixhoba kunye namathambo atyumkileyo, iqinile kwiingwenya, kodwa ngenxa yoxinzelelo olunzima, amazinyo abo aphelile kwaye ngamanye amaxesha aphuka. Kwiimeko ezinjalo, izinyo elitsha lithatha indawo yezinyo elidala.
Ngomntu, enye yeempawu ezihlukeneyo yisithupha esichasayo, esiye sasinceda kakhulu kwiinzame ezininzi, ukusuka "kuthatha intonga kwaye udibanise ummelwane ocaphukisayo kwisebe" kwaye uphele ngokuthi "thatha ipeni kwaye ubhale i-sonnet. β Kwiingwenya, isixhobo esinjalo yimihlathi, ngakumbi amazinyo. Lilungu lomzimba elenza iingwenya zibe ngabazingeli abayingozi nababulalayo ekufuneka ziphetshwe.
NgoLwesihlanu ukusuka phezulu:
Ikhathuni emfutshane enomdla kakhulu kwaye intle kakhulu apho ingwenya ingeyongwenya.
Ikhathuni malunga nendlela ongenakuthembela ngayo "izigodo" ezikrokrelayo emanzini, ngakumbi ukuba uyinkonkoni.
Enkosi ngokufunda, hlala unomdla kwaye ube nempelaveki emnandi bafana! π
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