Ngo-May 15, 1953, usokhemisi oneminyaka engu-23 ubudala wanyathelisa ephephabhukwini elithi Science imiphumela yokuhlolwa okubalulekile kwesayensi yezinto eziphilayo okwavula indlela yomkhakha omusha wolwazi lwesayensi. Le nsizwa kwakunguStanley L. Miller. Umsebenzi wakhe waphayona isiyalo samakhemikhali e-prebiotic njengoba siwazi namuhla futhi wasinikeza izinkomba zokuqala zokuthi impilo yavela kanjani eMhlabeni. I Ukuhlolwa kukaMiller Kwaziwa kakhulu emhlabeni wesayensi.
Ngakho-ke, sizonikezela lesi sihloko ukuze sikutshele konke okudingeka ukwazi mayelana nokuhlolwa kukaMiller nokuthi kuhlanganisani.
Umhlaba wokuqala
UStanley Miller wayesanda kuphothula izifundo zamakhemikhali futhi wadlulela eNyuvesi yaseChicago ngombono wethisisi yobudokotela. Ezinyangeni ezimbalwa eqashiwe, owazuza umklomelo kaNobel uHarol C. Urey waphumelela ekolishi futhi uMiller waya emhlanganweni wakhe wokufundisa ngemvelaphi yomhlaba nomkhathi wokuqala. Le nkulumo yakhanga uMiller kangangokuthi wanquma ukushintsha isihloko se-thesis futhi wethula u-Yuri ngokuhlolwa ayengakaze azame ngaphambili.
Ngaleso sikhathi, Isazi samakhemikhali ezinto eziphilayo saseRussia u-Alexander I Opalin sanyathelisa incwadi enesihloko esithi “The Origin of Life”. Kuyo, wachaza ukuthi izinqubo zamakhemikhali ezizenzakalelayo ziholela kanjani ekuveleni kwezinhlobo zokuqala zokuphila, eziye zathuthuka kancane kancane phakathi nenkathi yezigidi zeminyaka.
Cishe eminyakeni eyizigidi eziyizinkulungwane ezingu-4 edlule, ama-molecule ezinto eziphilayo zomhlaba wakudala ayengasabela ukuze akhiqize ama-molecule okuqala ezinto eziphilayo, kusukela lapha ama-molecule ayinkimbinkimbi, futhi ekugcineni izinto eziphilayo zokuqala.
U-Oparin wayenombono wezwe lasendulo elalihluke ngokuphelele ezweni lamanje, ngaphambi kokuba liguqulwe yisidalwa ngokwaso.
Imikhondo evela ekuhlolweni kukaMiller
Enye yezinkomba zokuthi lo Mhlaba wakuqala wawunjani isekelwe olwazini olukhona lwesayensi yezinkanyezi. Uma sicabanga ukuthi umhlaba kanye namanye amaplanethi esimiso sonozungezilanga avela efwini elifanayo legesi nothuli, ukwakheka komkhathi womhlaba kungafana kakhulu nalokho kwamaplanethi afana neJupiter neSaturn: ngakho-ke, cishe inothe nge-methane, i-hydrogen, ne-ammonia. Lona kuzoba umoya onciphisayo onokugcwala komoyampilo okuphansi kakhulu ngoba lona umnikelo wakamuva webhaktheriya yokuqala ye-photosynthetic.
Ubuso bomhlaba buyocwiliswa emanzini. Ulwandle lucebile ngama- molecule amakhemikhali. I-Oparin yayibheka ulwandle lwasendulo njengesobho lasendulo elicebile ngama-molecule amakhemikhali.
Lo mhlaba wakudala uzoba nesiyaluyalu kakhulu kunezwe lanamuhla, elinokuqhuma kwentaba-mlilo njalo, iziphepho zikagesi ezivamile, nemisebe yelanga enamandla (alukho ungqimba lwe-ozone lokugwema imisebe ye-ultraviolet). Lezi zinqubo Bazonikeza amandla okusabela kwamakhemikhali okwenzeka olwandle futhi ekugcineni kuzoholela ekuveleni kokuphila.
Ososayensi abaningi, kuhlanganise no-Yuri, baye babelana ngale mibono. Kodwa lokho kwakuwukuqagela okumsulwa, akekho owayekuzamile, ingasaphathwa eyokuthi ihlolwe. Kwaze kwavela uMiller.
Ukuhlolwa kukaMiller ngokujulile
UMiller ucabange ukuhlola okungahlola umbono ka-Yuri no-Opalin futhi kunxenxe u-Yuri ukuthi akwenze. Ukuhlola okuhlongozwayo kuhilela ukuxuba amagesi okukholakala ukuthi akhona emkhathini wokuqala woMhlaba - i-methane, i-ammonia, i-hydrogen, nomhwamuko wamanzi - nokuhlola ukuthi angakwazi yini ukusabelana ukuze akhiqize inhlanganisela yezinto eziphilayo. Kufanele uqinisekise ukuthi inqubo yenziwa ngaphansi kwezimo ze-anaerobic (okungukuthi, ngaphandle komoyampilo) futhi akubandakanyi izakhi eziphilayo ezingakhuthaza ukusabela.
Ngenxa yalesi sizathu, waklama idivayisi yengilazi evaliwe ene-flask neshubhu, umoya-mpilo awukwazi ukungena, futhi wavala amagciwane zonke izinto ukuze aqede zonke izinhlobo zokuphila. Wathela amanzi amancane amelela ulwandle lwakudala eflaskini. Wagcwalisa elinye iflaski nge-methane, i-hydrogen, ne-ammonia njengomkhathi wokuqala.
Ngezansi, i-capacitor ivumela izinto ezakha emkhathini ukuthi ziphole futhi zincibilike ngokuphuma okukhiqizwe ama-electrode amabili, azolingisa imiphumela yombani.
UMiller wenza isilingo ngobunye ubusuku. Lapho ngibuyela endaweni yokusebenzela ngakusasa ekuseni, amanzi efulaski ayesephuzile. Ngemva kwesonto elilodwa lokusebenza, yahlaziya amanzi ansundu futhi yathola ukuthi kwakhiqizwa izinhlanganisela eziningi ezazingekho ngaphambili, okuhlanganisa ama-amino acid amane (izinhlanganisela ezisetshenziswa yizo zonke izinto eziphilayo njengezinto zokwakha amangqamuzana) (amaprotheni).
Ukuhlola kukaMiller kubonisa ukuthi uma izimo zemvelo zilungile, ama-athomu angazenzela ngokuzenzakalelayo asuka kuma-athomu alula.
Ama-molecule aphilayo avela emkhathini
Nokho, eminyakeni embalwa kamuva, ososayensi baphetha ngokuthi izinga lokuncipha emkhathini wakuqala laliphansi kunalokho uYuri noMiller ababekucabanga, nokuthi lingahlanganisa isikhutha nenitrogen. Ukuhlola okusha kubonisa ukuthi, ngaphansi kwalezi zimo, ukwakheka kwezinhlanganisela eziphilayo akunakwa. Kunzima ukucabanga ukuthi isobho elihle kangaka linganikeza ukuphila. Kodwa-ke isixazululo sale nkinga savela, hhayi ekuhloleni okusha eMhlabeni, kodwa ... kusuka emkhathini.
Ngo-1969, i-meteorite eyakhiwe eminyakeni eyizigidi eziyizinkulungwane ezingu-4.600 edlule yawela eduze kwaseMurchison, e-Australia. Ngemva kokuhlaziywa, kwatholakala ukuthi iqukethe izinhlobonhlobo zamangqamuzana ezinto eziphilayo, okuhlanganisa ama-amino acid nezinye izinhlanganisela ezihlanganiswe uMiller elabhorethri.
Ngale ndlela, uma izimo zomhlaba wakudala zingafaneleki ukwakheka kwama- molecule ephilayo, Izinto zangaphandle kungenzeka zisebenzise amakhemikhali anele ukuze zinonge isobho le-prebiotic yomhlaba futhi ake sibone ukuphila okokuqala.
Njengamanje, ochwepheshe babonakala bethambekele futhi esimweni sokuqala sokunciphisa futhi bathambekele kakhulu emiphumeleni kaMiller. Ngakho-ke, kuyamukeleka ukuthi uma umkhathi weplanethi yethu uncipha, cishe uhlanganisa izakhi ezidingekayo ekuphileni emhlabeni, futhi uma umkhathi wethu ugqwalile, zingase zinikelwe ama-meteorite namanuclei enkanyezi enomsila.
Nokho, kungakhathaliseki ukuthi kwaqala eplanethini yethu noma ngaphandle kweplanethi yethu, inqwaba yokuhlola okuhlukahlukene kuye kwabonisa ukuthi izinhlanganisela zezinto eziphilayo zingaba umphumela wokuhlangana kwamakhemikhali okulula.
Ngithemba ukuthi ngalolu lwazi ungafunda kabanzi mayelana nokuhlolwa kukaMiller.