Ubomi eMhlabeni buye benza utshintsho olubalulekileyo kubo bonke ubukho babo, kunye nokutshabalala okukhulu kwezinto ezintlanu kugqame njengendawo ebalulekileyo yokutshintsha. Ezi ziganeko ziyintlekele, ezenzeka kwiibhiliyoni zeminyaka, ziye zayila ikhondo lendaleko zaza zamisela iindlela ezibalaseleyo zobomi bexesha ngalinye. Kwiminyaka embalwa edlulileyo, izazinzulu zizama ukusombulula ingxaki iimfihlelo ezingqongileyo ezi ziphela ngobuninzi, ukuhlola oonobangela bazo, iziphumo, kunye izidalwa ezinomdla oko kwavela emva kwabo.
I-Ordovician kade: Ulwandle loTshintsho (iminyaka eyi-443 yezigidi eyadlulayo)
Ukutshabalala kwe-Ordovician yaLate, okwenzeka kwiminyaka engama-443 yezigidi eyadlulayo, kwaphawula inguqu ebalulekileyo Imbali yomhlaba. Ngeli xesha, ubuninzi bobomi babukhona elwandle. Iimolluscs kunye ne-trilobites yayizezona ntlobo zibalaseleyo, kwaye iintlanzi zokuqala ezinemihlathi zenze ukubonakala kwazo, zimisela iqonga lezilwanyana ezinomqolo ezizayo.
Esi siganeko sokuphela, sitshabalalisa malunga nama-85% eentlobo zezilwanyana zaselwandle, kukholelwa ukuba sibangelwe luthotho lomkhenkce kuMazantsi eHemisphere yoMhlaba. Njengoko umkhenkce wawusanda, ezinye iintlobo zatshabalala, ngelixa ezinye ziqhelana neemeko ezibandayo. Noko ke, xa umkhenkce wawuthotha, aba basindileyo bajamelana nocelomngeni olutsha, njengokutshintsha kweendlela zomoya, nto leyo eyakhokelela kwilahleko engakumbi. Isizathu esichanekileyo se-glaciations sihlala sisihloko sengxoxo, njengoko ubungqina buye bufihliwe ngokuhamba kwamazwekazi kunye nokuhlaziywa kweendawo zolwandle.
Okumangalisayo kukuba, oku kutshabalala okukhulu akuzange kuzitshintshe kakhulu ezona ntlobo zibalaseleyo emhlabeni. Iifom ezininzi ezikhoyo, kubandakanywa nezinyanya zethu ze-vertebrate, ziqhubekile ngamanani amancinci kwaye ekugqibeleni zachacha kwizigidi ezimbalwa zeminyaka.
I-Devoni yasemva kwexesha: Ukuhla kancinci (izigidi ezingama-372-359 yezigidi kwiminyaka eyadlulayo)
Ukuphela kwenyambalala yeDevonia yaLate, ukusukela kwiminyaka engama-372 ukuya kuma-359 yezigidi eyadlulayo, kwaphawulwa ngokuncipha okucothayo kune isiganeko esiyintlekele ngesiquphe. Ngeli xesha, i-colonization yomhlaba ngezityalo kunye nezinambuzane yayinyuka, kunye nokuphuhliswa kwembewu kunye neenkqubo zangaphakathi ze-vascular. Nangona kunjalo, izilwanyana ezitya utyani ezisemhlabeni bezingekabizi ukhuphiswano olumandla kwizityalo ezikhulayo.
Oonobangela besi siganeko sokuphela, esaziwa njenge-Kellwasser kunye ne-Hangenberg Events, bahlala beyintsonkotha. Ezinye izazinzulu ziqikelela ukuba ukubetha kwemeteorite okanye i-supernova ekufuphi kunokubangela ukuphazamiseka emoyeni. Nangona kunjalo, abanye baxoxa ngelithi esi siganeko sokubhanga yayingeyiyo ukuphela kwenyambalala yokwenyani kodwa yayilixesha lokufa kwendalo eyongeziweyo kunye nesantya esicothayo sokuziphendukela kwemvelo.
IPermian-Triassic: Ukufa Okukhulu (iminyaka eyi-252 yezigidi eyadlulayo)
Ukuphela kobunzima bePermian-Triassic, ekwabizwa ngokuba yi "The Great Dying," yayisesona siganeko sitshabalalisayo kwimbali yoMhlaba. Yenzeka malunga nezigidi ezingama-252 kwiminyaka eyadlulayo, yakhokelela ekulahlekeni kobuninzi beentlobo zezinto eziphilayo emhlabeni. Uqikelelo lucebisa ukuba kangange-90% ukuya kwi-96% yazo zonke iintlobo zezilwanyana zaselwandle kunye ne-70% yezilwanyana eziphila emhlabeni zaphela.
Izizathu zesi siganeko siyintlekele zihlala zingaqondwa kakuhle ngenxa yokungcwatywa nzulu kunye nokusasazwa kobungqina obubangelwa yi-continental drift. Ukuphela kubonakala kufutshane, mhlawumbi kugxininiswe kwisigidi seminyaka okanye ngaphantsi. Imiba eyahlukeneyo iye yacetywa, kubandakanywa nokutshintsha kwee-isotopes zekhabhoni ye-atmospheric, ugqabhuko-dubulo olukhulu lwentaba-mlilo kwi-China yanamhlanje kunye neSiberia, iibhedi ezivuthayo zamalahle, kunye neentyantyambo ze-microbial eziguqula umoya. Ukudityaniswa kwezi zinto kusenokwenzeka ukuba kukhokelele kutshintsho olubalulekileyo lwemozulu oluphazamise inkqubo yendalo kwihlabathi liphela.
Esi siganeko sokutshabalala sitshintshe kakhulu indlela yokuphila eMhlabeni. Izidalwa ezisemhlabeni zathatha izigidi zeminyaka ukuba ziphinde ziphile, ekugqibeleni zavelisa iindlela ezintsha kwaye zavula indlela yamaxesha alandelayo.
I-Triassic-Jurassic: Ukunyuka kweeDinosaurs (iminyaka eyi-201 yezigidi eyadlulayo)
I-Triassic-Jurassic mass extinction, eyenzeka malunga ne-201 yezigidi zeminyaka eyadlulayo, yayingaphantsi kwesiganeko sePermian-Triassic kodwa yayinempembelelo ebalulekileyo kubomi eMhlabeni. Ngexesha leTriassic, ii-archosaurs, izirhubuluzi ezinkulu ezinjengengwenya, zazilawula umhlaba. Esi siganeko sokutshabalala satshayela uninzi lwee-archosaurs, sidala ithuba lokuvela kweqela elincinci eliya kuthi ekugqibeleni libe ziidinosaurs kunye neentaka, ezilawula umhlaba ngexesha leJurassic.
Ithiyori ekhokelayo yokutshabalala kweTriassic-Jurassic icebisa ukuba umsebenzi wentaba-mlilo kwiPhondo laseMbindi weAtlantiki Magmatic uphazamise ukubunjwa kweatmosfera. Njengoko i<em>magma yayisanda kuMntla Merika, uMzantsi Merika, neAfrika, ezi nxalenye zomhlaba zaqalisa ukwahlukana, zithwala iziqwenga zentsimi yantlandlolo ukunqumla oko kwakuya kuba luLwandlekazi lweAtlantiki. Ezinye iithiyori, ezifana neempembelelo zecosmic, ziye zaphelelwa kukuthanda. Kunokwenzeka ukuba akukho ntlekele inye yenzekayo, kwaye eli xesha laphawulwa nje ngesantya esikhawulezayo sokubhanga kunendaleko.
I-Cretaceous-Paleogene: Ukuphela kweeDinosaurs (iminyaka eyi-66 yezigidi edlulileyo)
I-Cretaceous-Paleogene mass extinction (eyaziwa ngokuba yi-KT Extinction), mhlawumbi eyaziwa kakhulu, ibonise ukuphela kweedinosaurs kunye nokuqala kwexesha le-Cenozoic. Malunga ne-66 yezigidi zeminyaka eyadlulayo, iintlobo ezininzi, kubandakanywa iidinosaurs ezingezizo iintaka, zatshatyalaliswa. Unobangela woku kutshabalala ngoku wamkelwa ngokubanzi ukuba sisiphumo sempembelelo enkulu yeasteroid.
Ubungqina bejoloji, obufana nobukho bamanqanaba aphezulu e-iridium kumaleko entlenga kwihlabathi liphela, ixhasa ithiyori yempembelelo yeasteroid. I-crater ye-Chicxulub yaseMexico, eyenziwe yimpembelelo, iqulethe i-iridium anomalies kunye nezinye iisignali ze-elemental ezidibanisa ngokuthe ngqo kumaleko wehlabathi we-iridium-rich. Esi siganeko saba nefuthe elimandla kwi-ikhosistim yoMhlaba, sivula indlela yokwanda kwezilwanyana ezanyisayo kunye neentlobo ezahlukeneyo zezinto eziphilayo ezihlala ngoku kwisijikelezi-langa sethu.
Iingcamango zokugqibela
Ukutshabalala kwezinto ezintlanu ezinkulu kwimbali yoMhlaba kudlale indima ebalulekileyo ekubumbeni indlela yobomi kwiplanethi yethu. Ukususela kwi-Late Ordovician ukuya kwi-Cretaceous-Paleogene yokutshatyalaliswa, isiganeko ngasinye siye sazisa utshintsho oluphawulekayo, olukhokelela ekuveleni kweentlobo ezintsha kunye nokuncipha kwabanye. Ngelixa oonobangela boku kutshabalala kusenokubamba iimfihlakalo, basebenza njengezikhumbuzo ezibalulekileyo zobuthathaka, ukomelela kunye nokuguquguquka kobomi emhlabeni.
Noko ke, ingxaki ekhoyo ngoku yeentlobo ngeentlobo zezinto eziphilayo, ephenjelelwa ubukhulu becala zizinto ezenziwa ngabantu ezinjengokugawulwa kwamahlathi, ungcoliso, nokutshintsha kwemozulu, isoyikisa ngokuphazamisa oku kulungelelana okucekethekileyo nokunokubangela isiganeko esikhulu sesithandathu sokubhangisa.
Ukuqonda izinto ezadlulayo kunokusinceda ukuba sijonge imeko yangoku kwaye senze izigqibo ezinolwazi ngekamva. Ngokufunda ezi zinto ziphela ziphela, izazinzulu zinokufumana ukuqonda kwiziphumo ezinokuthi zenzeke zezenzo zethu kwaye ziphuhlise amacebo okukhusela nokugcina izinto eziphilayo ezixabisekileyo zoMhlaba.
Le yimfuneko yexesha esiyifundayo kwiimpazamo zexesha elidlulileyo kwaye sithathe amanyathelo akhawulezileyo ukunciphisa impembelelo yethu kwindalo esingqongileyo ukuze sithintele ilahleko eyongezelelekileyo yeentlobo zezilwanyana. Ikamva lezinto eziphilayo ezahlukahlukeneyo kwisijikelezi-langa sethu kunye nokusinda kweentlobo ngeentlobo zezinto eziphilayo kuxhomekeke kwimigudu esiyenzayo.
Emva kokufunda malunga nokuphela kobunzima obu-5 kwimbali yoMhlaba, funda malunga Uluhlu lwembali edumileyo elahlekileyo: Ilahleka njani iipesenti ezingama-97 zembali yoluntu namhlanje?
