ukushabalala okukhulu

Iplanethi esiphila kuyo Umhlaba uneminyaka engaphezu kwezigidi eziyizinkulungwane ezingu-4500 ubudala futhi ngemva kwayo yonke le minyaka akumangazi ukuthi izidalwa eziphilayo kuye kwadingeka zihlupheke ngezigigaba lapho ukuphila kwazo kwase kuseduze nokushabalala.

imvelo iyikho konke uma kuqhathaniswa nathi futhi yilokhu ukuthi, ngemicimbi ehlukahlukene, usuvele ungaphakathi eMhlabeni njengoba ngezimo zezinkanyezi ezonakalisayo, kungukuthi okubangela ezinye zokuqothulwa kwabantu abaningi esikwaziyo namuhla.

Lokhu kushabalala esizokhuluma ngakho kulolu shicilelo, yi imbangela yokufa nokunyamalala kwenani elikhulu lezinhlobo zezinto eziphilayo, baze bafinyelele ukuphila okucishe kube sekupheleni kweplanethi.

Kulesi sihloko, siya qala uhambo ngomlando ukuthola ukuthi ziyini, izimbangela kanye nemiphumela yokunyamalala kwenqwaba okukhunjulwa kakhulu namuhla.

Kuyini ukushabalala okukhulu?

Ukuze siqale ukuqonda yonke into ezungeze lezi zenzakalo, into yokuqala okufanele siyazi kuyini ukushabalala okukhulu

Lesi sigameko esikhuluma ngaso kwenzeka ngokwemvelo futhi kuphetha ngokufa nokunyamalala kwenani elikhulu lezinhlobo zezilwane. Ukushabalala kubhekwa njengokukhulu lapho okungenani u-10% wezinhlobo zezilwane zinyamalala phakathi nonyaka noma lapho ezingaphezu kuka-50% zinyamalala phakathi nenkathi ephakathi kwesigidi esisodwa nezintathu zonyaka.

Baningi ongoti kulo mkhakha abaxwayisa ngokuthi singase sisonqenqemeni lokushabalala okusha njengoba yithina esidala umonakalo ekusindeni kwezinye izinto eziphilayo.

Siyawubona lomonakalo esikhuluma ngawo ku umthelela kwezemvelo esiwudalayo, ezisabekayo. Kodwa kudingeka amandla emvelo abhubhisa kakhulu ukuze kufinyelelwe ezingeni lokuqothulwa kwabantu abaningi.

Ngokwezifundo eziningi zokuphila eMhlabeni, iye yadlula ezinkathini okungenani ezinhlanu zokuqothulwa kwabantu abaningi kuwo wonke ama-eon amane okuhlukaniswa kuwo ukuphila emhlabeni, i-Phanerozoic Eon.

Ngayinye yalokhu kuqothulwa okukhulu okuhlanu, kwenzeka ngesikhathi esithile emlandweni woMhlaba. Izimbangela zazihlukile kuzo zonke, kanye nezinga lokucekelwa phansi kanye nemiphumela eyalandela.

Yiziphi izinhlobo ezinhlanu zokuqothulwa okukhulu?

Uma sesicacile ngokuthi ukuqothulwa kwezilwane kuhlanganisani, sizodingida ukuthi bekuyini ukushabalala okukhulu okuye kwenzeka kuwo wonke umlando.

Ordovician - Silurian

Sikhuluma nge ukushabalala okukhulu okwaziwayo okokuqala, kumele sibuyele emuva esigabeni seNkathi ye-Ordovician eminyakeni engaphezu kwezigidi ezingu-480 edlule.

Kulesi sigaba somlando eplanethini enguMhlaba, impilo yayikhona olwandle kuphela, zonke izinto eziphilayo eziyinkimbinkimbi zazihlala kuleyo ndawo. Lokhu kuphila kwakunqunyelwe ezintweni ezifana ne-bivalve molluscs, cephalopods, graptolites, brachiopods, bryozoans, phakathi kwabanye.

Akwaziwa kahle ukuthi yini imbangela yalokhu kushabalala kwenqwaba., kodwa inkolelo-mbono eyamukelwa kakhulu iwukuthi i-gamma ray yashaya ungqimba lwasemkhathini woMhlaba, yawucekela phansi, okwabangela ukuba imisebe ye-ultraviolet ingene ngaphandle kwesithiyo.

Lokhu kubangele ukunyamalala kwe-plankton, i-phytoplankton nezinye zezinto eziphilayo ababehlala kuzo ngenxa yokuswelakala kokudla. Futhi, kufanele sengeze ukufa kwamaqanda nezibungu ngemisebe ye-ultraviolet nokushisa. Konke lokhu kudale ukuthi imisinga ukuze imisoco ingasatshalaliswa wulwandle futhi ingafinyeleli kwezinye izidalwa.

Ngemva kwakho konke lokhu, kwaba neqhwa elikhulu. Lokhu kushabalala kokuqala kwavela ngenxa yethonya lemisebe ye-gamma ekuqaleni kwenkathi yeqhwa. Kwathinta izindawo eziningi eziphilayo ezishiwo ngenhla ezazihlala kuzo.

iqhwa, kuvela ekunyakazeni kwepuleti le-tectonic okubangela ukuthi i-supercontinent ye-Gondwana inyukele eSouth Pole. Lokhu kwaholela ekwakhekeni kwezinguzunga zeqhwa ezingapheli emhlabeni, ukuze amazinga olwandle ehle njengoba amanzi amaningi eqina.

Izinguquko ku imigubho yolwandle ibe nezinguquko ezibalulekile, okwathinta ukugeleza komoya-mpilo ezilwandle kanye nokusakazwa kokudla. Lokhu kwaholela ekutheni izinhlobo eziningi zezilwane ziqale ukunyamalala ngokushesha okukhulu.

Abambalwa izinhlobo ezakwazi ukusinda, kwadingeka zivumelane nezimo ezimweni ezintsha, kodwa kamuva, babhekana nokuqothulwa kwenqwaba yesibili ekupheleni kwenkathi yeqhwa esikhuluma ngayo.

I-supercontinent yaphinde yathuthela eningizimu, okwabangela ukuncibilika kwezinguzunga zeqhwa kanye nokukhuphuka kwezinga lolwandle. Lezi zinguquko olwandle zabangela ukufa nokunyamalala kwezinhlobo ezingama-85%.

I-Devonian-Carboniferous

Ngemva kokushabalala okukhulu kwesigaba sangaphambilini, ukuphila kwakwazi ukululama futhi kuzalwe kabusha, izitshalo zaqala ukuvela futhi kamuva ama-arthropods. Lesi sikhathi Iqala cishe eminyakeni eyizigidi ezingama-419 edlule, ngemuva kwesikhathi seSilurian.

Lokhu kuqedwa okukhulu kwesibili, ezithintekayo ikakhulukazi izilwane zasolwandle, izixhobo zezixhobo zokusebenza nezinye izinto eziphilayo ukuhlala endaweni ehlala emanzini njengezinhlanzi, ama-cephalopod, izipontshi, njll.

La i-global cooling theory, iyona eyamukelwa kakhulu ochwepheshe ukuchaza izimbangela yalokhu kushabalala. Amanzi olwandle ahlushwa ukupholisa okubangela, eminyakeni eyizigidi ezi-3, ukunyamalala kwezinhlobo ezingaba ngu-82% ezazikhona ngalesi sikhathi.

I-Permian-Triassic

Cishe eminyakeni eyizigidi ezingu-250 edlule, izimo ezinobutha zenzeka eMhlabeni ezaholela ekuqothulweni okubi kakhulu okwaziwayo kuze kube manje. Ochwepheshe balinganisela lokho cishe amaphesenti angama-95 ezilwane zasolwandle kanye nama-75% ezinto eziphilayo zasemhlabeni zashabalala.

Ngalesi sikhathi, izindawo zomhlaba zaqala ukukhula, zanda futhi zahlukahluka. Izazi zokuma komhlaba zisola ukuthi lokhu kuqothulwa kwabantu abaningi kwaba okubangelwa ukuqhuma okukhulu kwentaba-mlilo kanye nokukhishwa okulandelayo kwe-methane olwandle.

Ngokuhamba kweminyaka nangosizo lwezinsalela zezinsalela, iqembu labacwaningi liye lakha kabusha izenzakalo futhi ngokusobala kwakungewona ukukhishwa kwe-methane okubangele le nhlekelele, kodwa ukukhishwa okukhulu kwe-magma. Lokhu kwaholela ekufudumaleni kwembulunga yonke, nochungechunge lwezinhlekelele ezashintsha le planethi yaba indawo ewugwadule.

Lokhu kulandelana kwezehlakalo ezenzeka eminyakeni eyisigidi kuyachaza ukuthi kungani cishe amaphesenti angama-95 ezinhlobo ezihlala eMhlabeni zanyamalala.

Triassic - Jurassic

Njengoba kwenzekile ngemva kokushabalala okukhulu, ukuphila kuyabambelela futhi kululama ngaphakathi kwamathuba. Lokhu kushabalala kwesine kwenzeka eminyakeni eyizigidi ezingama-200 edlule ekupheleni kwesigaba se-Triassic Period futhi kuphawula ukuqala kweNkathi yeJurassic.

Kulesi sikhathi, izilwane ezincelisayo ezahlukene kanye izibankwakazi ziyachuma futhi zizimise njengezilwane ezihamba phambili yeplanethi ngaleso sikhathi.

Impilo yalezi zidalwa ezimangalisayo yayizophela ngokushabalala kwenqwaba yesine. I-Pangea kakade yayiyizwekazi elilodwa elikhulu, kodwa iqala ukuhlukana futhi ihlukaniselane amazwekazi esiwaziyo namuhla.

Le nqubo ibangela izinguquko zesimo sezulu ezihambisana nokusebenza okushubile kwezintaba-mlilo kanye nomthelela wama-meteorite, kwaholela ekushabalaleni kwezinhlobo eziningi zezinto eziphilayo. Kunemibono eminingana ehlukene mayelana nokuthi yini ngempela ebangele lokhu kushabalala, futhi bonke bagcina bekholelwa ukuthi kwakuwukulandelana kwezenzakalo.

bafika zinyamalala cishe u-76% wezinhlobo zezilwane wezidalwa eziphilayo ezahlala emhlabeni phakathi neminyaka eyisigidi.

Cretaceous - Phezulu

Yaziwa nangokuthi iCretaceous-Paleogene futhi kwakuyinkathi yokushabalala kwezinhlobo zezilwane okwenzeka cishe eminyakeni eyizigidi ezingama-66 edlule. Kulesi sigaba sempilo yoMhlaba, izinhlobo zama-dinosaurs amakhulu ziyavela, ababa abanikazi abangenakuphikiswa beplanethi.

Njengoba sesishilo, cishe eminyakeni eyizigidi ezingama-66 edlule, i-meteorite enkulu ishaya umhlaba futhi kusukela lapho kuqala ukushabalala okusha emlandweni.

Lokhu kushabalala okubangela ukunyamalala kwezinhlobo ezihlukahlukene emhlabeni kanye nawo wonke ama-dinosaurs. Isikhathi esiqondile salokhu kushabalala akwaziwa, kodwa ibiyini imiphumela edabukisayo yomthelela we-meteorite.

Enye yezimbangela ezimbi kakhulu ukuthi lo mthelela udale a ifu lothuli elahlala ongqimbeni lomkhathi. Lokhu okwabangela, ukuthi ukukhanya kwelanga akuzange kungene ngakho izitshalo azikwazanga ukukhula uma zingakwazi ukwenza i-photosynthesis. Ngaphezu kwalokhu, amanani e-CO2 nomoya-mpilo aphazamisekile.

Konke lokhu, kutholwe ku-a uchungechunge lwemiphumela emibi yezinhlobo ezikwazile ukusinda. Izilwane ezidla uhlaza zazingenazo izitshalo ezidla kuzo futhi izilwane ezidla inyama nazo zazingenakho ukudla. Ngakho cishe asikho isidalwa esasihlala endaweni ewumhlaba esikwaziyo ukuphila.

Njengoba sikwazile ukuqinisekisa kuleyo naleyo zikhathi ezi-5 zokuqothulwa kwabantu abaningi, izidalwa eziphilayo ezazihlala emhlabeni zazintekenteke kakhulu. Kodwa ukuphila kwakwazi ukuzivuselela futhi isikhathi ngemva kwesikhathi savela entweni futhi yakwazi ukudala izinhlobo ezintsha zezilwane.