Kutiphendvukela Kwemvelo—Timfundziso Temanga Kanye Nemaciniso
Phrofesa Richard Dawkins, longusosayensi lodvume ngekusekela kutiphendvukela kwemvelo utsi: “Liciniso lekuba khona kwekutiphendvukela kwemvelo angeke liphikwe njengobe kungeke kuphikwe nekushisa lokuvela elangeni.”16 Kuliciniso kutsi lucwaningo kanye neluhlolo lolucondzile luye lwafakazela kutsi lilanga liyashisa. Kodvwa lucwaningo kanye neluhlolo lolucondzile luyifakazele yini ngendlela lefananako imfundziso yekutiphendvukela kwemvelo?
Singakawuphendvuli lombuto, kunalokutsite lokufanele sikucacise. Linyenti labososayensi liye latsi ngekuhamba kwesikhatsi tintfo letiphilako tingaba nelushintjo loluncane. Nasi sibonelo: Bantfu labatsite bangahlanganisa tinja teluhlobo lolungafani kute titalane, futsi ekugcineni kube neluhlobo lwetinja lolunemilente lemifishane nobe boya lobudze kwendlula bokhokho bato. a Labanye bososayensi babita lolushintjo ngekutsi “kutiphendvukela kwemvelo lokunemiphumela lemincane.”
Nanobe kunjalo, bososayensi bekutiphendvukela kwemvelo bafundzisa kutsi lolushintjo lwandza kancane kancane eminyakeni letigidzigidzi lwase luveta lushintjo lolukhulu, lolwaludzingeka kute inhlanti ibe silwane lesiphila emhlabeni nasemantini (amphibian) nekutsi imfene ibe ngumuntfu. Lolushintjo lokukhulunywa ngalo lubitwa ngekutsi “kutiphendvukela kwemvelo lokunemiphumela lemikhulu.”
Charles Darwin kanye nencwadzi yakhe i-Origin of Species
Nasi sibonelo: Charles Darwin watsi lolushintjo loluncane lesikwati kulubona lukhombisa kutsi lushintjo lolukhulu kakhulu—lokute umuntfu lowake walubona, nalo lungaba khona.17 Abekholelwa kutsi eminyakeni leminyenti leyengcile, tintfo letivamile letiphilako tashintja kancane kancane—“ngekushintja lokuncane kakhulu kwetakhi telufuto”—taba tigidzi tetinhlobo tetintfo letiphila emhlabeni.18
Kubantfu labanyenti, loku kuvakala kunengcondvo. Bayatibuta: ‘Nangabe lushintjo loluncane lukwati kwenteka etintfweni letitsite letiphilako, kungenteka njani-ke kutsi kutiphendvukela kwemvelo kwehluleke kuveta lushintjo lolukhulu ngekuhamba kwesikhatsi?’ b Liciniso likutsi imfundziso yekutiphendvukela kwemvelo isekelwe etimfundzisweni letintsatfu letingemanga. Cabanga nganati letilandzelako.
Imfundziso lengemanga 1. Kugucuka kwetakhi telufuto kuveta tintfo letidzingekako kute kwakhiwe tinhlobo letinsha tetintfo letiphilako. Imfundziso yekutiphendvukela kwemvelo lokunemiphumela lemikhulu isekelwe embonweni wekutsi kugucuka kwetakhi telufuto etitjalweni nasetilwaneni angeke kuvete nje kuphela luhlobo lwentfo lensha kodvwa kungaveta nemacembu lamasha etitjalo netilwane.19
Njengalesitjalo lesingakavami lesinetimbali letinkhulu, kuguculwa kwetakhi telufuto kungalwenta lushintjo etitjalweni—kodvwa kube ngulolulingene
Emaciniso. Imininingwane leminyenti yetitjalo nobe yetilwane icondziswa miyaleto lesetakhini tato telufuto kanye nemibhalo letfolakala kunukliyasi yaleyo naleyo nhlayiya (cell). c Bacwaningi baye batfola kutsi kugucuka kwetakhi telufuto kungabangela lushintjo nasentalweni yetitjalo neyetilwane. Kodvwa kugucuka kwetakhi telufuto kutiveta mbamba yini tinhlobo letinsha tetintfo letiphilako? Yini levetwe luhlolo lwetifundvo tetakhi telufuto lolutsatse likhulu leminyaka?
Ngasekupheleni kwabo-1930, ngekutimisela bososayensi bemukela umbono lomusha. Besebavele bacabanga kutsi sikhatsi lapho tintfo letiphilako tihleti kahle endzaweni yato ngiso lesikahle kute titalane, futsi tingaveta tinhlobo letinsha tetitjalo ngetakhi telufuto letigucukako. Ngako-ke, bavumelana ngekutsi kuguculwa kwetakhi telufuto lokucondziswa bantfu kungenta intfo lefananako kodvwa ngendlela lephumelela kancono. Wolf-Ekkehard Lönnig, longusosayensi wase-Max Planck Institute for Plant Breeding Research eJalimane watsi: “Kwaba nenjabulo lenkhulu kubo bonkhe bososayensi, kubocwephesha etakhini telufuto, kanye nakulabo labatalisa tilwane netitjalo.” d Kungani bajabula? Lönnig, longusosayensi lobesacitse iminyaka lengaba ngu-30 acwaninga ngekugucuka kwetakhi telufuto etitjalweni watsi: “Labacwaningi bebacabanga kutsi kwase kufike sikhatsi sekutsi kushintje indlela levamile yekutalanisa titjalo netilwane. Bebacabanga kutsi ngekukhutsata nangekukhetsa kuguculwa kwetakhi telufuto lokuncono, bebatawukwati kuveta titjalo kanye netilwane letinsha naletincono.”20 Ecinisweni, labanye bebanelitsemba lekuveta tinhlobo letinsha-nsha tetintfo letiphilako.
Timphungane ema-fruit flies, letiguculwe takhi telufuto, nanobe tikhubatekile, tisengema-fruit flies
Bososayensi e-United States, e-Asia, kanye naseYurophu bacala tinhlelo tekucwaninga letatisekelwe ngemali lenyenti, futsi bebasebentisa tindlela letatetsembisa kusheshisa kutiphendvukela kwemvelo. Ngemuva kweminyaka lengu-40 yekucwaninga ngekutimisela, batfola miphi imiphumela? Umcwaningi Peter von Sengbusch utsi: “Ngetulu kwemali lenyenti leyacitfwa, imetamo yekuveta tinhlobo tetintfo letinsha letiphilako ngekusebentisa imisebe yelilanga yabonakala yehluleka ngendlela ledzabukisako.”21 Lönnig yena watsi: “Ngabo-1980, ematsemba nekujabula kwabososayensi besekunyamalele emhlabeni wonkhe. Kufundvwa kwekuguculwa kwetakhi telufuto kwayekelwa emaveni aseNshonalanga. Cishe tonkhe tintfo letatiguculwe takhi telufuto . . . tafa nobe taba butsakatsaka naticatsaniswa naleto temvelo.” e
Nanobe kunjalo, kwatiswa lesekukhona nyalo ngemuva kweminyaka lengaba likhulu yekucwaninga ngekugucula takhi telufuto, kanye neminyaka lengu-70 yekutalisa tintfo, kuye kwasita bososayensi kutsi bafinyelele esiphetfweni ngelikhono tintfo letiguculwe takhi letinalo kute tivete tinhlobo letinsha tetintfo letiphilako. Ngemuva kwekuhlola lobufakazi, Lönnig waphetsa: “Kugucula takhi telufuto akukwati kugucula luhlobo lwentfo lephilako [sitjalo nobe silwane] kutsi lube luhlobo lolwehluke ngendlela lephelele. Lesiphetfo sivumelana nako konkhe lokutfoliwe, kanye nemiphumela yelucwaningo lwangelikhulu lesi-20 leminyaka lolumayelana nekugucula takhi telufuto, futsi siphindze sivumelane nemtsetfo wekuphindzeka kwetintfo (laws of probability).”
Ngako-ke, kuguculwa kwetakhi telufuto kungayenta yini intfo lephilako kutsi ibe luhlobo lolusha lwesidalwa? Bufakazi buveta kutsi angeke! Kucwaninga kwa-Lönnig kumente waphetsa ngekutsi “tinhlobo tetintfo letiphilako letinetakhi telufuto letehlukile tinemincele lengeke isuswe nobe yoniwe ngisho nangekuguculwa kwetakhi telufuto.”22
Cabanga ngaloko lokushiwo ngulamaciniso langenhla. Nangabe bososayensi labafundze bagogodzela behluleka kuveta tintfo letiphilako letinsha ngekugucula nangekukhetsa takhi telufuto letifanele, kungenteka yini kutsi lenye inchubo lengakahlakaniphi ikwati kuveta tintfo letinsha letiphilako? Ngako-ke, nangabe kucwaninga kubonisa kutsi kugucula takhi telufuto angeke kukwati kushintja intfo lephilako kutsi ibe ngulensha, kutiphendvukela kwemvelo lokunemiphumela lemikhulu bekungenteka njani?
Imfundziso lengemanga 2. Kutihlela kanye nekutivumelanisa kwemvelo kwaholela ekwakhekeni kwetinhlobo letinsha tetintfo letiphilako. Darwin abekholelwa kutsi loko lakubita ngekutsi kutihlela nekutivumelanisa kwemvelo bekutawuzuzisa tintfo letiphilako letihambelana kahle nendzawo yonkhe, kodvwa leto letatingavumelani kahle nayo betitawugcina tifile. Tati tekutiphendvukela kwemvelo talamuhla tifundzisa kutsi njengobe tinhlobo tetintfo letiphilako betandza futsi tisakateka, imvelo beyikhetsa leto lebetinetakhi telufuto letivumelana kahle nendzawo yato lensha. Ngaleso sizatfu, tati tekutiphendvukela kwemvelo taphetsa ngekutsi lamacembu lasakatekile agcine asagucuke aba luhlobo lolusha lwetintfo letiphilako.
Emaciniso. Njengobe kuchaziwe, bufakazi lobuvela ekucwaningeni bubonisa kutsi kugucula takhi telufuto akukwati kuveta tinhlobo letinsha tetitjalo nobe tetilwane. Nobe kunjalo, ngubuphi bufakazi tati tekutiphendvukela kwemvelo letibuniketako kute tisekele umbono wekutsi imvelo ikhetsa tintfo letinetakhi telufuto letiguculiwe kute ivete tinhlobo letinsha tetintfo letiphilako? Incwajana leyashicilelwa yi-National Academy of Sciences (NAS) nga-1999 e-United States icaphuna “tinhlobo letingu-13 tetinyoni Darwin latihlola ngesikhatsi asetiChingini tase-Galápagos, nyalo lesetatiwa ngekutsi ngema-Darwin’s finches.”23
Ngabo-1970, licembu lebacwaningi lebeliholwa ngu-Peter R. kanye na-B. Rosemary Grant lase-Princeton University lacala kufundza ngaletinyoni futsi latfola kutsi ngemuva kwemnyaka wesomiso, letinyoni lebetinemilomo lemikhulu betiphila ncono kunaleto lebetinemilomo lemincane. Njengobe kubuka bukhulu kanye nekwakheka kwemlomo bekuyindlela leyinhloko yekwehlukanisa letinhlobo letingu-13 tetinyoni, lelicembu belicabanga kutsi lemiphumela ibalulekile. Lencwajana ye-NAS yachubeka yatsi: “Baka-Grant balinganisela kutsi nakungaba nesomiso njalo ngemuva kweminyaka lelishumi kuletichingi, kungavela luhlobo lolusha lwetinyoni ngemuva kweminyaka lengaba ngu-200.”24
Nanobe kunjalo, lencwajana ye-NAS ayiwanaki emaciniso ekutsi eminyakeni leyalandzela lesomiso, tinyoni letinemilomo lemincane taphindze tandza. Bacwaningi batfole kutsi njengobe emazinga ekushisa etichingi abeshintjashintja, tinyoni letinemilomo lemikhulu betigcwala umnyaka munye, kodvwa ngemuva kwaloko kugcwale leto letinemilomo lemincane. Baphindze bacaphela kutsi letinyoni lebekutsiwa “luhlobo” lolusha tiyatalana futsi tivete intalo lephilile kwengca batali bato. Baphetse ngekutsi nangabe letinyoni tiyachubeka nekutalana kutawugcina sekuhlangene “tinhlobo” letimbili, tibe luhlobo lolulodvwa.25
Lokuhle kakhulu lokubonakala etinyonini ema-Darwin’s finches kutsi tinhlobo tetintfo letiphilako tingakwati kuvumelana nesimo selitulu lesigucukako
Ngako-ke, kutivumelanisa netimo letishintjashintjako tekuphila kuluveta mbamba yini luhlobo lolusha lwetintfo letiphilako? Emashumini eminyaka leyengcile, sati sekutiphendvukela kwemvelo lesingu-George Christopher Williams saphakamisa imibuto mayelana nekutsi kutivumelanisa netimo letishintjashintjako tekuphila kunemandla yini.26 Nga-1999, umhlatiyi wemfundziso yekutiphendvukela kwemvelo longu-Jeffrey H. Schwartz wabhala ngekutsi kutivumelanisa netimo letishintjashintjako tekuphila kungenteka kutsi kuyatisita tinhlobo tetintfo letiphilako kutsi tetayelane netimo letishintjashintjako, kodvwa akutidali tintfo letinsha.27
Loku kuliciniso, ngobe ema-Darwin’s finches awabi “ngulokutsite lokusha.” Asesetinyoni. Neliciniso lekutsi tiyatalana lenta kuphakame imibuto mayelana netinchubo letisetjentiswa tati tekutiphendvukela kwemvelo kute tichaze luhlobo lolutsite lwentfo lephilako. Ngetulu kwaloko, imininingwane lemayelana naletinyoni iveta liciniso lekutsi ngisho netinhlangano letisetulu tetesayensi tiyakhetsa kutsi ngubuphi bufakazi letitabubika.
Imfundziso lengemanga 3. Tinsalela tetilwane netihlahla (fossil) letitfolakele tiniketa bufakazi bekutiphendvukela kwemvelo lokunemiphumela lemikhulu. Incwajana lokukhulunywe ngayo ye-NAS ishiya umfundzi acabanga kutsi tinsalela letitfolwa bososayensi tiniketa bufakazi lobunyenti bekutiphendvukela kwemvelo lokunemiphumela lemikhulu. Lencwajana itsi: “Kutfolakale tinhlobo letinyenti tetintfo emkhatsini wetinhlanti kanye netilwane letiphila emhlabeni nasemantini, emkhatsini wetilwane letiphila emhlabeni nasemantini kanye nemihumane (reptiles), emkhatsini wemihumane kanye naletimunyisako (mammals), kanye nasemkhatsini wetilwane letihlakaniphile (primate), futsi kumatima nekusho kutsi lolushintjo lwenteka kuphi emkhatsini wetinhlobo letitsite.”28
Emaciniso. Lenkhulumo leyashiwo yincwajana ye-NAS iyamangalisa. Kungani? Niles Eldredge, losati sekutiphendvukela kwemvelo, uyavuma kutsi tinsalela letatfolakala ativeti kutsi kunelushintjo lolunyenti lolwentekile, kodvwa tiveta kutsi esikhatsini lesidze, “kuncane nobe kute nhlobo kutiphendvukela kwemvelo lokube khona etinhlotjeni letinyenti tetintfo letiphilako.” f29
Lokuhle kakhulu lokubonakala etinyonini ema-Darwin’s finches kutsi tinhlobo tetintfo letiphilako tingakwati kuvumelana nesimo selitulu lesigucukako
Kute kube ngunyalo, bososayensi emhlabeni wonkhe batfole futsi babike ngetinsalela letinkhulu letingaba tigidzi letingu-200 kanye naletincane letingaba tigidzigidzi. Linyenti lebacwaningi liyavuma kutsi lomlandvo lomkhulu lonemininingwane uveta kutsi onkhe emacembu lamakhulu etilwane avela ngekushesha futsi ahlala anjalo angagucuki, kantsi letinye tinhlobo tona tanyamalala ngendlela letativele ngayo.
Kukholelwa Ekutiphendvukeleni Kwemvelo Kusento Lesingakahlakaniphi
Kungani tati letinyenti tekutiphendvukela kwemvelo tigcizelela kutsi kutiphendvukela kwemvelo lokunemiphumela lemikhulu kuliciniso? Richard Lewontin, losati sekutiphendvukela kwemvelo lesidvumile, wabhala kutsi bososayensi labanyenti batimisele kwemukela imibono yesayensi lete bufakazi ngobe “batinikele kusengembili, lokukutinikela embonweni wekutsi konkhe lokusendzaweni yonkhe, kuhlanganise nato tonkhe tintfo letiphilako, kwaba khona ngephandle kwekusetjentiswa kwemandla langetulu kwewemvelo.” Linyenti labososayensi liyala ngisho nekuvuma kutsi kungenteka kuneMdali lohlakaniphile, kunjengobe Lewontin abhala: “Isayensi ayivumi kutsi ukhona uMdali.”30
Akhuluma ngaloku, Rodney Stark, losati setekuhlalisana kwebantfu, wacashunwa ku-Scientific American atsi: “Sekuminyaka lengu-200 kukhutsatwa umbono wekutsi nawufuna kuba ngusosayensi kufanele ungakunaki loko lokufundziswa yinkholo.” Uphawula nekutsi kumanyuvesi ekucwaninga, “bantfu labakholwako abakhulumi nakancane ngaNkulunkulu.”31
Nangabe ufuna kwemukela imfundziso yekutiphendvukela kwemvelo njengaleliciniso, kufanele ukholelwe kutsi bososayensi labaphika kuba khona kwaNkulunkulu nobe labatsi akatiwa angeke bavumele loko labakukholwako kutsi kutsintse indlela labaluchaza ngayo lucwaningo lwabo lwesayensi. Kufanele ukholwe kutsi kuguculwa kwetakhi telufuto nekutihlela kwemvelo ngiko lokwaveta tonkhe tintfo letiphilako letisimangaliso, nanobe kucwaninga lokutsatse likhulu leminyaka kubonisa kutsi letintfo atikake tashintja, ngisho neluhlobo lolulodvwa lwaba luhlobo lolusha. Kufanele ukholwe kutsi tonkhe tintfo letiphilako tavela kancane kancane kukhokho loyedvwa, nangetulu kweliciniso lekutsi tinsalela letitfolakele tiveta kutsi tinhlobo letiyinhloko tetitjalo netilwane tavela ngekushesha futsi atizange tigucuke tibe nguletinye tinhlobo, ngisho nangemuva kweminyaka leminyenti. Kukholwa lokunjalo kuvakala kusekelwephi, ecinisweni nobe emfundzisweni lengemanga? Kutsatsa kutiphendvukela kwemvelo njengeliciniso kusento lesingakahlakaniphi.
a Lushintjo lolwentiwa ngulabo labatalisa tinja imvamisa luphumela ekonakaleni kwendlela takhi telufuto letisebenta ngayo. Nasi sibonelo: Lokwenta inja lebitwa ngekutsi yi-dachshund ibe nemtimba lomncane kwehluleka kwekwakheka kwemgumugumu (cartilage), lokuyibangela kutsi ingafanani naletinye tinja teluhlobo lwayo.
b Sehluko 1 saGenesisi sitsi titjalo tatiyawutsela titselo futsi tilwane nato tatiyawutalana “ngetinhlobo tato.” (Genesisi 1:12, 21, 24, 25) Nanobe kunjalo, ligama leliBhayibheli lelitsi “tinhlobo” alikasetjentiswa ngemcondvo wesayensi, futsi akukafaneli lihlanganiswe nendlela isayensi lelichaza ngayo.
c Kucwaninga kubonisa kutsi i-cytoplasm yenhlayiya, ludvwadvwasi, kanye naletinye tintfo letikulo tinemsebenti lobalulekile letiwentako nakwakheka intfo lephilako.
d Lönnig ukholelwa kutsi kuphila kwadalwa. Loko lakusho kulencwadzi kungumbono wakhe, akusiwo umbono we-Max Planck Institute for Plant Breeding Research.
e Sekukanyenti kuhlolwa kwekuguculwa kwetakhi telufuto kuveta kutsi tinhlobo letinsha tetintfo letiphilako betiloku tihhohloka, futsi bekuloku kuvela luhlobo lunye lwetintfo letiguculwe takhi. Ngetulu kwaloko, kwakhetfwa titjalo letingephansi kweliphesenti lelilodvwa kute kuchutjekwe nekucwaninga, futsi kwatfolakala kutsi yincenye lengephansi kweliphesenti lelilodvwa leguculwe takhi telufuto lebeyifanelekela kusetjentiswa. Ecinisweni, kute nalunye luhlobo lolusha lwentfo lephilako loluke lwakhiwa. Imiphumela yekugucula takhi telufuto etilwaneni ayiphumelelanga nakakhulu nayicatsaniswa netitjalo, futsi ekugcineni lenchubo yavele yayekelwa yonkhe.
f Ngisho netibonelo letimbalwa tetinsalela letitfolakele, leto bacwaningi labatikhomba njengebufakazi bekutiphendvukela kwemvelo kusaphikiswana ngato. Fundza emakhasi 22 kuya ku 29 encwajana letsi: “The Origin of Life—Five Questions Worth Asking,” ngesiNgisi, leshicilelwa boFakazi BaJehova.
