Impilo Emhlabeni yenze izinguquko ezinkulu kukho konke ukuba khona kwayo, nokushabalala kwenqwaba yabantu emihlanu kugqame njengamaphuzu abalulekile okuguqula izinto. Lezi zenzakalo eziyinhlekelele, ezithatha izigidigidi zeminyaka, ziye zalolonga inkambo yokuziphendukela kwemvelo futhi zanquma izinhlobo zokuphila ezivelele zenkathi ngayinye. Emashumini ambalwa eminyaka adlule, ososayensi bazama ukuxazulula inkinga izimfihlakalo ezizungezile lokhu kushabalala okukhulu, ukuhlola izimbangela zako, imiphumela, kanye izidalwa ezithakazelisayo lokho kwavela ngemuva kwabo.
I-Ordovician Yakamuva: Ulwandle Loshintsho (iminyaka eyizigidi ezingama-443 edlule)
Ukushabalala kwe-Late Ordovician mass, okwenzeka eminyakeni eyizigidi ezingama-443 edlule, kwaphawula inguquko ebalulekile Umlando womhlaba. Ngalesi sikhathi, iningi lempilo lalikhona olwandle. Ama-molluscs nama-trilobite kwakuyizinhlobo ezivelele, futhi izinhlanzi kuqala ezinemihlathi zavela, zabeka inkundla yezilwane ezinomgogodla zesikhathi esizayo.
Lesi sigameko sokushabalala, esiqothula cishe amaphesenti angama-85 ezilwane zasolwandle, kukholakala ukuthi sibangelwa uchungechunge lwezinguzunga zeqhwa eNingizimu Nenkabazwe. Njengoba izinguzunga zeqhwa zanda, ezinye izinhlobo zezilwane zashabalala, kuyilapho ezinye zajwayelana nezimo ezibandayo. Nokho, lapho iqhwa libohla, laba abasinda babhekana nezinselele ezintsha, njengokushintsha ukwakheka komkhathi, okuholela ekulahlekelweni okwengeziwe. Isizathu esiqondile salokhu kuqhwa kweqhwa kuseyisihloko senkulumo-mpikiswano, njengoba ubufakazi buye bafihlwa ukuhamba kwamazwekazi kanye nokuvuselelwa kwezitezi zasolwandle.
Ngokumangalisayo, lokhu kushabalala okukhulu akuzange kuzishintshe kakhulu izinhlobo zezinto eziphilayo eMhlabeni. Amafomu amaningi akhona, okuhlanganisa namadlozi ethu ezilwane ezinomgogodla, aphikelela ngamanani amancane futhi ekugcineni alulama phakathi neminyaka eyizigidi ezimbalwa.
I-Devonian Yakamuva: Ukwehla Kancane (iminyaka eyizigidi ezingu-372-359 million edlule)
Ukushabalala kwenqwaba ye-Devonian Late, kusukela eminyakeni eyizigidi ezingama-372 kuya kwezingama-359 edlule, kwabonakala ngokuncipha kancane kunokuba isigameko esiyinhlekelele engazelelwe. Phakathi nalesi sikhathi, ukubuthwa komhlaba yizitshalo nezinambuzane kwakukhuphuka, ngokuthuthukiswa kwembewu kanye nezinhlelo zangaphakathi ze-vascular. Kodwa-ke, izilwane ezidla uhlaza ezihlala emhlabathini zazingakafaki ukuncintisana okukhulu ezitshalweni ezikhulayo.
Izimbangela zalesi sigameko sokushabalala, esaziwa ngokuthi i-Kellwasser kanye ne-Hangenberg Events, zisalokhu ziyindida. Abanye ososayensi bacabanga ukuthi ukushaya kwe-meteorite noma i-supernova eseduze bekungabangela ukuphazamiseka emkhathini. Kodwa-ke, abanye baphikisa ngokuthi lesi senzakalo sokuqothulwa kwakungelona ukushabalala kwenqwaba yeqiniso kodwa kunalokho kwakuyinkathi yokwanda kokufa kwemvelo kanye nezinga elihamba kancane lokuziphendukela kwemvelo.
I-Permian-Triassic: I-Great Dying (iminyaka eyizigidi ezingu-252 edlule)
I-Permian-Triassic mass extinction, eyaziwa nangokuthi "The Great Dying," kwakuyisenzakalo sokuqothulwa esibi kakhulu emlandweni womhlaba. Kwenzeka cishe eminyakeni eyizigidi ezingu-252 edlule, kwaholela ekulahlekelweni kwezinhlobo eziningi zezilwane emhlabeni. Izilinganiso ziphakamisa ukuthi cishe amaphesenti angama-90 kuya kwangu-96 azo zonke izinhlobo zezilwane zasolwandle kanye nama-70% ezilwane eziphila emhlabeni ashabalala.
Izimbangela zalesi sigameko esibi azikacaci kahle ngenxa yokungcwatshwa okujulile nokusatshalaliswa kobufakazi obudalwa wukukhukhuleka kwezwekazi. Ukushabalala kubonakala kufushane, ngokunokwenzeka kugxile phakathi neminyaka eyisigidi noma ngaphansi. Kuphakanyiswe izici ezihlukahlukene, okuhlanganisa ukugudluka kwe-carbon isotopes yasemkhathini, ukuqhuma okukhulu kwentaba-mlilo eChina yanamuhla naseSiberia, imibhede yamalahle evuthayo, kanye nezimbali ezincane ezishintsha umkhathi. Ukuhlanganiswa kwalezi zici kungenzeka kuholele ekushintsheni kwesimo sezulu okuphawulekayo okuphazamise imvelo emhlabeni wonke.
Lesi senzakalo sokuqothulwa sashintsha kakhulu inkambo yokuphila eMhlabeni. Izidalwa ezihlala emhlabeni kwathatha izigidi zeminyaka ukuthi zilulame, ekugcineni kwavela izinhlobo ezintsha futhi kwavula indlela yezinkathi ezalandela.
I-Triassic-Jurassic: I-Rise of Dinosaurs (eminyakeni eyizigidi ezingu-201 edlule)
Ukuqothulwa kwenqwaba ye-Triassic-Jurassic, okwenzeka cishe eminyakeni eyizigidi ezingu-201 edlule, kwakungenzima kakhulu kunomcimbi we-Permian-Triassic kodwa kwakusenomthelela omkhulu empilweni yasemhlabeni. Phakathi nenkathi ye-Triassic, ama-archosaur, izilwane ezihuquzelayo ezinkulu ezinjengengwenya, zazibusa izwe. Lesi senzakalo sokuqothulwa saqothula iningi lama-archosaur, kwadala ithuba lokuvela kweqembu elincane eliguqukile elizogcina libe ama-dinosaurs nezinyoni, elibusa umhlaba ngesikhathi se-Jurassic.
Ithiyori ehamba phambili yokushabalala kwe-Triassic-Jurassic iphakamisa ukuthi ukuqhuma kwentaba-mlilo e-Central Atlantic Magmatic Province kuphazamise ukwakheka komkhathi. Njengoba i-magma ikhula inqamula eNyakatho Melika, eNingizimu Melika, nase-Afrika, lezi zingqimba zomhlaba zaqala ukuhlukana phakathi, zithwala izingcezu zensimu yokuqala ziwela lokho okwakungase kube uLwandlekazi i-Atlantic. Eminye imibono, efana nemithelela ye-cosmic, ayisetshenziswanga kahle. Kungenzeka ukuthi akukho nhlekelele eyodwa eyenzeka, futhi lesi sikhathi samane saphawulwa ngezinga elisheshayo lokuqothulwa kunendlela yokuziphendukela kwemvelo.
I-Cretaceous-Paleogene: Ukuphela Kwe-Dinosaurs (iminyaka eyizigidi ezingu-66 edlule)
I-Cretaceous-Paleogene mass extinction (eyaziwa nangokuthi i-KT Extinction), mhlawumbe eyaziwa kakhulu, yabonisa ukuphela kwama-dinosaurs kanye nokuqala kwenkathi ye-Cenozoic. Cishe eminyakeni eyizigidi ezingu-66 edlule, izinhlobo eziningi zezilwane, kuhlanganise nezibankwakazi ezingezona izinyoni, zaqedwa. Imbangela yalokhu kushabalala manje seyamukelwa kabanzi njengomphumela womthelela omkhulu wasemkhathini.
Ubufakazi bokwakheka komhlaba, obufana nokuba khona kwamazinga aphakeme e-iridium ezingqimbeni ze-sedimentary kuwo wonke umhlaba, busekela umbono womthelela we-asteroid. I-Chicxulub crater e-Mexico, eyakhiwe umthelela, iqukethe i-iridium anomalies namanye amasignesha ayisisekelo ayixhumanisa ngqo nongqimba lomhlaba wonke olucebile nge-iridium. Lesi senzakalo sibe nomthelela omkhulu ku-ecosystem yoMhlaba, savula indlela yokwanda kwezilwane ezincelisayo kanye nezinhlobonhlobo zezinto eziphilayo ezihlala eplanethini yethu.
Imicabango yokugcina
Ukushabalala kwenqwaba enkulu okuyisihlanu emlandweni womhlaba kudlale indima ebalulekile ekulolongeni indlela yokuphila emhlabeni wethu. Kusukela ku-Late Ordovician kuya ekuqothulweni kwe-Cretaceous-Paleogene, umcimbi ngamunye ulethe izinguquko eziphawulekayo, okuholela ekuveleni kwezinhlobo ezintsha kanye nokuncipha kwezinye. Nakuba izimbangela zalokhu kushabalala zingase zibambe izimfihlakalo, zisebenza njengezikhumbuzo ezibalulekile zobuthakathaka, ukuqina kanye nokuvumelana nezimo zokuphila eMhlabeni.
Nokho, inkinga yamanje yezinhlobonhlobo zezinto eziphilayo, eqhutshwa ikakhulukazi imisebenzi yabantu njengokugawulwa kwamahlathi, ukungcola, nokushintsha kwesimo sezulu, isongela ukuphazamisa lokhu kulinganisela okuntekenteke futhi okungase kubangele isenzakalo esikhulu sesithupha sokuqothulwa.
Ukuqonda okwedlule kungasisiza ukuthi sihlole okwenzeka manje futhi senze izinqumo ezinolwazi mayelana nekusasa. Ngokutadisha lokhu kushabalala okukhulu, ososayensi bangathola ukuqonda emiphumeleni engaba khona yezenzo zethu futhi bakhe amasu okuvikela nokulondoloza imvelo eyigugu ehlukahlukene.
Lesi isidingo senkathi esifunda ngayo emaphutheni esikhathi esidlule futhi sithathe isinyathelo ngokushesha ukuze sinciphise umthelela wethu endaweni ezungezile ukuze sigweme ukulahlekelwa okunye okuyinhlekelele kwezinhlobo zezinto eziphilayo. Isiphetho sezinto ezihlukahlukene eziphilayo zeplanethi yethu nokuphila kwezinhlobo eziningi zezinto eziphilayo kuncike emizamweni yethu esiyiqoqo.
Ngemva kokufunda mayelana nokuqothulwa kwenqwaba ye-5 emlandweni womhlaba, funda mayelana Uhlu lomlando odumile olahlekile: Ulahleka kanjani umlando wabantu ongu-97% namuhla?
