Ukuthuthukiswa Kwemfundiso Yokuziphendukela Kwemvelo
Inkolelo-mbono yokuziphendukela kwemvelo ingenye yezinkolelo-mbono zesayensi ezibaluleke kakhulu nezinethonya emlandweni wesayensi. Kusukela yethulwa nguCharles Darwin ngekhulu le-19, le nkolelo-mbono iye yathuthukiswa futhi yathuthukiswa ngezifundo ezahlukahlukene kanye nokutholwa okusha. Lesi sihloko sizohlola intuthuko yenkolelo-mbono yokuziphendukela kwemvelo, kusukela emqondweni wayo wokuqala kuya ekuhlolweni kwesimanje okusekelwa ubuchwepheshe obuthuthukisiwe.
Ukuqala Komcabango Wokuziphendukela Kwemvelo
Umqondo wokuziphendukela kwemvelo wawukhona kudala ngaphambi kokuba uDarwin ashicilele incwadi yakhe edumile, ethi On the Origin of Species, ngo-1859. Kwifilosofi yemvelo yasendulo yamaGreki, u-Anaximander wayeveze umbono wokuthi izinto eziphilayo zingashintsha ngokuhamba kwesikhathi. Kodwa-ke, lo mbono wokuqala wawunokucabangela kakhulu futhi uyifilosofi kunokuba ube wesayensi.
Kwaze kwaba ngekhulu le-18 lapho ososayensi abanjengoPierre-Louis Moreau de Maupertuis no-Erasmus Darwin (umkhulu kaCharles Darwin) baqala ukucabangela ukuthi kungenzeka kube noshintsho ezinhlotsheni eziphilayo. UJean-Baptiste Lamarck, isazi semvelo saseFrance, naye waphakamisa umbono wokuthi izinto eziphilayo zingadlulisela izici ezitholwe ngesikhathi sokuphila kwazo ezizukulwaneni zazo—umqondo manje owaziwa ngokuthi ifa lezimpawu ezitholwe. Nakuba kwafakazelwa ukuthi awulungile, imibono yakhe yasiza ekuvuleni ingxoxo yesayensi ngoshintsho lwezinhlobo.
Ushintsho Lwepharadigm nguCharles Darwin
Intuthuko enkulu kakhulu yenzeka lapho uCharles Darwin esungula umqondo wokukhethwa kwemvelo njengendlela yokuziphendukela kwemvelo. Phakathi nohambo lwakhe lweminyaka emihlanu nge-HMS Beagle, ikakhulukazi lokho akubonile eziQhingini zaseGalapagos, uDarwin waqoqa idatha eningi ngokuhlukahluka kwezinhlobo ezifanayo ezindaweni ezahlukene. Ku-On the Origin of Species, uDarwin wachaza ukuthi izinto eziphilayo azishintshi. Ziyashintsha futhi zivumelane nezimo zazo ngenqubo yokukhethwa kwemvelo—abantu abanezimfanelo ezinhle banethuba elikhulu lokusinda nokuzala.
Imibono kaDarwin yaphinde yahlanganiswa ngu-Alfred Russel Wallace, isazi semvelo saseNgilandi esasungula ngokuzimela inkolelo-mbono yokukhethwa kwemvelo. Ukuhlanganiswa kwale mibono emibili kwaphawula iphuzu elibalulekile ku-biology, kwashintsha ukugxila kusuka embonweni oqhubekayo wezinto eziphilayo kuya ekuqondeni ukuthi impilo iyashintshashintsha futhi ishintsha njalo.
Isikhathi Sangemva KukaDarwin kanye Nokwenziwa Kwanamuhla
Ngemva kokushicilelwa kwemfundiso kaDarwin, ososayensi abaningi bamukela umbono wokuziphendukela kwemvelo, kodwa izindlela zokuthola ifa zahlala zingacacile. Ukutholwa kukaGregor Mendel kwemithetho yefa ngo-1865, okwakungaqashelwa ngokugcwele kwaze kwaba sekuqaleni kwekhulu lama-20, kwadlala indima ebalulekile ekuchazeni ukuthi izici zizuzwa kanjani njengefa.
Olunye ushintsho olukhulu lwenzeka ngawo-1930 nango-1940 ngokuvela kwe-Modern Synthesis, isigaba lapho imiqondo kaDarwin nekaMendelian yahlanganiswa khona. Ososayensi abanjengoRonald Fisher, J.B.S. Haldane, noSewall Wright badlale indima ebalulekile ekuthuthukisweni kwalokhu kuhlanganiswa. I-Modern Synthesis ibonise ukuthi ukukhetha kwemvelo, kanye nokuguqulwa kwezakhi zofuzo, ukugeleza kwezakhi zofuzo, kanye nokuhlanganiswa kabusha, yizona zinto eziyinhloko eziqhuba ukuvela kwemvelo.
Intuthuko Ebhayoloji Yamamolekyuli
Intuthuko ku-biology yama-molecule, ikakhulukazi ngemva kokuthola kukaJames Watson noFrancis Crick isakhiwo se-DNA ngo-1953, yaqinisa isisekelo senkolelo-mbono yokuziphendukela kwemvelo. Ukutholakala kwe-DNA kwanikeza ubufakazi obucacile bokuthi ulwazi lwezakhi zofuzo ludluliselwa kanjani kusukela esizukulwaneni kuya kwesinye nokuthi ukuguqulwa kwezakhi zofuzo kungathonya kanjani ukuguquka kwama-molecule.
Emashumini eminyaka alandela, intuthuko yobuchwepheshe bokulandelana kwe-DNA yathuthukisa ulwazi lwethu ngokuziphendukela kwemvelo. Izifundo ze-phylogenetic zama-molecule zanikeza ukuqonda okusha ngobudlelwano bokuziphendukela kwemvelo phakathi kwezinhlobo, okwavula indlela yokuba ososayensi bakwazi ukumaka umuthi wokuphila ngokunembile.
Izindlela Zokubhekana Nezingxabano ZaseNeo-Darwin Nangale Kwazo
Enkathini yanamuhla, inkolelo-mbono yokuziphendukela kwemvelo iyaqhubeka nokuguquka ngokusetshenziswa kwemibono evela kwezinye izifundo, njenge-epigenetics kanye ne-evo-devo (i-biology yokuthuthukiswa kokuziphendukela kwemvelo). Isibonelo, i-Epigenetics ikhombisa ukuthi ukuguqulwa kwamakhemikhali ku-DNA okuthinta ukubonakaliswa kwezakhi zofuzo kungazuzwa njengefa ngaphandle kokushintsha kochungechunge lwe-DNA uqobo. Lokhu kunezela isici esisha ekuqondeni kwethu izindlela zofuzo kanye nokuziphendukela kwemvelo.
I-Evo-devo ihlola indlela izinqubo zokukhula kwezinto eziphilayo ezithonywa ngayo ukuziphendukela kwemvelo, igxile ezinguqukweni zezakhi zofuzo ezinemiphumela ebalulekile ekubunjweni komzimba. Okutholakele ku-evo-devo kusiza ukuchaza imvelaphi yokwehlukahlukana kwezinhlobo zokuphila esizibonayo emvelweni.
Indima Yobuchwepheshe Nezinselele Zesikhathi Esizayo
Ubuchwepheshe obuthuthukisiwe banamuhla, njengokuhlela izakhi zofuzo nge-CRISPR kanye nokuhlaziywa kwekhompyutha okusheshayo, kuvula amathuba amasha okuhlola ukuziphendukela kwemvelo ngokujulile. Ososayensi bangenza izivivinyo elabhorethri ukuze babone ukuthi izingcindezi ezithile zokukhetha zingaqondisa kanjani ukuziphendukela kwemvelo ngesikhathi sangempela. Amathuluzi ekhompyutha, ngakolunye uhlangothi, avumela ukwakhiwa kabusha kwamamodeli okuziphendukela kwemvelo okuyinkimbinkimbi kanye nokulingisa izinqubo zezinto eziphilayo.
Kodwa-ke, inkolelo-mbono yokuziphendukela kwemvelo iyaqhubeka nokubhekana nezinselele, kokubili ngokwesayensi nangokwenhlalo. Ngokwesayensi, ochwepheshe bayaqhubeka nokulwela ukuqonda okwengeziwe ngezinhlobo eziphelile, ukutholakala kwezinsalela ezintsha, nokuthi ukushintshashintsha kwesimo sezulu emhlabeni wonke kuyithinta kanjani inkambo yokuziphendukela kwemvelo. Okwamanje, izingxoxo mayelana nokwamukelwa komphakathi kanye nokusetshenziswa kabi kwemibono yokuziphendukela kwemvelo, njengasemongweni we-eugenics yesikhathi esidlule, ziqokomisa ukubaluleka kokufundiswa nokusatshalaliswa okufanele kwale nkolelo-mbono.
Isiphetho
Imfundiso yokuziphendukela kwemvelo isihambe ibanga elide kusukela yasungulwa. Kusukela ekuqageleni kwefilosofi kuya ensika eyinhloko yesayensi yezinto eziphilayo yanamuhla, ukuziphendukela kwemvelo kunikeza isisekelo seminye imikhakha eminingi, njengesayensi yezinto eziphilayo, izakhi zofuzo, kanye nesayensi yezinto eziphilayo. Ngokuthuthuka kwezobuchwepheshe kanye nokutholwa okusha, le mfundiso iyaqhubeka nokuhlungwa. Ukwamukelwa kabanzi kanye nokuqonda okujulile kwemfundiso yokuziphendukela kwemvelo akugcini nje ngokunikeza ukuqonda ngemvelaphi yokuphila kodwa futhi kusiqondisa ekubhekaneni nezinselele zemvelo kanye nezinto eziphilayo zesikhathi esizayo. Njengenye yemibono yesayensi enamandla kakhulu futhi ephelele, ukuziphendukela kwemvelo kusalokhu kuyindaba yokuthakazelisa kanye nokutholwa okusha.
