“Ihindagurika ni ntaseswa nka kurya nyene ubushuhe bw’izuba ari ntaseswa.” Ivyo bivugwa na Porofeseri Richard Dawkins, umunyasiyansi yemerwa cane mu bijanye n’ivy’ihindagurika.¹⁶ Mu vy’ukuri, ivyo umuntu ashobora kwibonera be n’amatohoza yagizwe biremeza ko izuba rishushe. Ubwo none, ivyo umuntu ashobora kwibonera be n’amatohoza yagizwe, vyoba bitanga ikimenyamenya ntaharirizwa c’uko ukwo ari na ko biri ku bijanye n’inyigisho y’ivy’ihindagurika?

Imbere y’uko twishura ico kibazo, hariho ikintu dukwiye kubanza gutomora neza. Abanyasiyansi benshi barabonye yuko haciye igihe ushobora gusanga ibinyabuzima bidasa neza na neza n’ivyo biba vyarakomotseko. Nk’akarorero, hariho abantu bashobora gukoresha ubuhinga bwo kubangurira imbwa kugira ngo izizobwagurwa mu nyuma zizogire amaguru magufi canke ivyoya birebire kurusha izo zikomokako. a Ukwo kuntu haba uduhinduka dutoduto tugatuma ibinyabuzima binaka bidasa neza na neza n’ivyo vyakomokako, ni vyo abanyasiyansi bamwebamwe bita ngo ni ihindagurika ribayabaye.

Ariko rero, abemera ivy’ihindagurika bigisha ko mu myaka amamiliyaridi utwo duhinduka dutoduto twagiye turongerekana buhorobuhoro maze dutuma haba amahinduka akomeye yari akenewe kugira ngo amafi ahinduke mwene vya bikoko bishobora kuba imusozi no mu mazi, ibikoko vyo mu bwoko bw’inkende na vyo bihinduke abantu. Ayo mahinduka akomeye bibaza ko yabaye, ni yo bita ihindagurika rihambaye, irishobora gutuma ubwoko bunaka  bw’ikinyabuzima buhinduka bukavamwo ubundi bwoko bushasha bw’ikinyabuzima.

Nk’akarorero, uwitwa Charles Darwin yigishije ko twa duhinduka dutoduto dushobora kwibonekeza mu binyabuzima twerekana ko n’amahinduka akomakomeye ashoboka, ayo na yo akaba ata n’umwe arayabona.¹⁷ Yabona ko mu gihe kirekire cane, ibinyabuzima bimwebimwe vy’inkomoko, ivyo yise ngo ni ibinyabuzima bisanzwe, buhorobuhoro vyagiye birahindagurika bivamwo ubwoko amamiliyoni bw’ibinyabuzima biri kw’isi, ivyo ngo bikaba vyabaye biciye ku vyo yise uduhinduka dutoduto ata co tuvuze.¹⁸

Abantu benshi babona ko ivyo yavuze bisa n’ivyumvikana. Bibaza bati: ‘Niba mu bwoko bunaka bw’ikinyabuzima hashobora kuba uduhinduka dutoduto, kubera iki none mu kiringo kirekire cane hatoba amahinduka akomeye?’ b Mu vy’ukuri rero, inyigisho y’ivy’ihindagurika ishingiye ku binyoma bitatu. Rimbura ibi bintu bikurikira.

Ikinyoma ca 1. Amahinduka aba mu tugingo ngengakamere aratuma haboneka ubwoko bushasha bw’ibinyabuzima. Ya nyigisho yerekeye ihindagurika rihambaye, usanga ishingiye ku ciyumviro c’uko amahinduka apfa kwiyadukiza mu tugingo ngengakamere tw’ibiterwa be n’ibikoko adashobora gusa gutuma habaho ubwoko bushasha bw’ibiterwa canke bw’ibikoko, ariko ko ashobora no gutuma haboneka ayandi moko y’ibiterwa canke y’ibikoko ata ho asa asana n’aya mbere.¹⁹

Ukuri kuri ico kintu. Ibintu vyinshi biranga igiterwa canke igikoko kinaka usanga bishingwa hisunzwe ubuyobozi buri mu tugingo ngengakamere twaco, ubwo na bwo bukaba ari icokwitwa umugero uri mu ntimatima y’akagingo ngengabuzima ako ari ko kose werekana ukuntu ico kinyabuzima kizomera nicakura. c Abashakashatsi basanze amahinduka aba mu tugingo ngengakamere ashobora gutuma ibiterwa canke ibikoko binaka bidasa neza na neza n’ivyo vyakomotseko. Ariko none ayo mahinduka aba mu tugingo ngengakamere yoba vy’ukuri atuma ubwoko bunaka bw’igiterwa canke bw’igikoko buhinduka bukavamwo ubundi bwoko bushasha ata ho busa busana n’ubwa mbere? None imyaka 100 abahinga bamaze bagira ubushakashatsi ku bijanye n’utugingo ngengakamere yahishuye iki?

Mu mpera z’imyaka ya 1930, abanyasiyansi barakiranye urweze iciyumviro gishasha. Bari basanzwe biyumvira yuko kuba ibinyabuzima bidakomeye bigenda birahona hagasigara ibikomeye kuruta ibindi, bishobora gutuma haboneka ubwoko bushasha bw’ibiterwa, ivyo ngo bikaba bitumwa n’amahinduka apfa kwiyadukiza mu tugingo ngengakamere. Ni co gituma ico gihe babona yuko hamwe abantu boyobora ayo mahinduka apfa kwiyadukiza, vyorushiriza gutuma haboneka ikintu ciza kuruta ico. Uwitwa Wolf-Ekkehard Lönnig, uno akaba ari umunyasiyansi wo mu Kigo co mu Budagi kijejwe kugira ubushakashatsi mu bijanye no kwomekera ibiterwa, yavuze ati: “Naho muri rusangi abahinga mu bijanye n’ibinyabuzima bagize akanyamuneza, ntibarushije abahinga mu bijanye n’utugingo ngengakamere be n’abo mu bijanye no kwomekera ibiterwa.” d Ni kubera ki none bagize ako kanyamuneza? Lönnig, uwamaze imyaka hafi 30 agira ubushakashatsi ku bijanye n’amahinduka aba mu tugingo ngengakamere tw’ibiterwa, yavuze ati: “Abo bashakashatsi biyumvira yuko hari hageze ko bagira  ivyo baryohoye mu buhinga bwahora bukoreshwa mu vyo kwomekera ibiterwa no mu vyo kubangurira ibikoko. Biyumvira ko hamwe bokabura amahinduka aba mu tugingo ngengakamere hanyuma bakarobanura ibifise utugingo ngengakamere tubereye, boshobora gutuma haboneka ibiterwa canke ibikoko birushirije kuba vyiza.”²⁰ Mu vy’ukuri, hari abari bizigiye yuko ivyo vyotumye haboneka ubwoko bushasha bw’ibiterwa canke bw’ibikoko ata ho busa busana n’ubwa mbere.

Abashakashatsi bo muri Leta Zunze Ubumwe za Amerika, muri Aziya n’i Buraya baratanguje imigambi yo kugira ubushakashatsi isaba amahera menshi cane bakoresheje ubuhinga butari bumwe bari biteze ko bwotumye ibinyabuzima bigira ihindagurika ryihuta. Uti none inyuma y’imyaka irenga 40 bamaze bagira ubwo bushakashatsi badatezura, bashitse ku ki? Umushakashatsi umwe yitwa Peter von Sengbusch avuga ati: “Naho hakoreshejwe amahera menshi cane, utwigoro twagizwe mu bijanye no guteragira ubwoko butandukanye bw’ibiterwa vyimbuka cane, hakoreshejwe ubuhinga bwo gukabura [amahinduka aba mu tugingo ngengakamere], twabaye impfagusa.”²¹ Lönnig na we yavuze ati: “Mu myaka ya 1980, ivyizigiro be n’akanyamuneza abanyasiyansi bo hirya no hino kw’isi bari bafise, vyarakamanganye. Mu bihugu vya Buraya, barahagaritse imigambi y’ubwo bushakashatsi. Ibiterwa canke ibikoko hafi nka vyose vyabayeho biciye kuri ubwo buhinga . . . vyarahonye canke na ho ntivyagira inkomezi nk’iz’ivyari bisanzwe biriho.” e

Naho ari ukwo, amakuru abanyasiyansi begeranije muri rusangi mu myaka nka 100 bamaze bagira ubushakashatsi ku vyerekeye amahinduka aba mu tugingo ngengakamere, na canecane ayo begeranije mu myaka 70 bamaze bakoresha uburyo bwo kwomekera ibiterwa canke kubangurira ibikoko, aratuma bashikiriza ivyiyumviro bitandukanye ku bijanye n’uko ayo mahinduka yoba canke atoba ashobora gutuma habaho ubundi bwoko bushasha bw’ibinyabuzima. Inyuma y’aho Lönnig asuzumiye ivyo bintu, yavuze ati: “Amahinduka aba mu tugingo ngengakamere ntashobora gutuma ubwoko bwo mu ntango [bw’igiterwa canke bw’igikoko] buhinduka bukavamwo ubundi bwoko bushasha ata ho busa busana n’ubwa mbere. Ico ciyumviro ciwe kirahuza n’ibintu vyose vyashizwe ahabona n’amatohoza be n’ubushakashatsi vyagizwe mu kinjana ca 20 ku bijanye n’amahinduka aba mu tugingo ngengakamere. Vyongeye, kirahuza n’amategeko agenga ubuhinga abantu bisunga mu kuvuga ibishobora gushika.”

Ubwo none amahinduka aba mu tugingo ngengakamere yoba ashobora gutuma ubwoko bunaka bw’ikinyabuzima buhinduka bukavamwo ubundi bwoko bw’ikinyabuzima ata ho busa busana n’ubwa mbere? Ibimenyamenya vyerekana ko ivyo bidashoboka na gato! Ubushakashatsi Lönnig yagize bwatumye ashika ku ciyumviro c’uko “ubwoko bw’ibinyabuzima vyisangije utugingo ngengakamere usanga mu vy’ukuri bifise uturimbi amahinduka apfa kwiyadukiza muri utwo tugingo adashobora kurenga canke gukuraho.”²²

Rimbura ico ivyo bishaka kuvuga. Niba abanyasiyansi karuhariwe badashobora gutuma haboneka ubwoko bushasha bw’ibinyabuzima bakoresheje ubuhinga bwo gukabura amahinduka aba mu tugingo ngengakamere no guca barobanura ibifise utubereye, wumva none hari uwokwitega ko hoboneka ubwoko bushasha bw’ibinyabuzima biciye ku kintu gipfuye kwiyadukiza, kitaranga ubwenge? Nimba ubushakashatsi bwagizwe bwerekana yuko amahinduka aba mu tugingo ngengakamere adashobora gutuma ubwoko bw’ikinyabuzima bwo mu ntango buhinduka bukavamwo ubundi bwoko bushasha bw’ikinyabuzima ata ho busa busana n’ubwa mbere, ubwo wumva koko rya hindagurika rihambaye bavuga ko ryabayeho, vy’ukuri rishoboka?

Ikinyoma ca 2. Ukuba ibinyabuzima bidakomeye bigenda birahona hagasigara ibikomeye kuruta, bituma haboneka ubundi bwoko bushasha bw’ibinyabuzima. Darwin yaremera yuko ngo ibinyabuzima bidakomeye bigenda birahona hagasigara ibikomeye kuruta. Abemera ivy’ihindagurika bo mu gihe ca none bigisha ko uko ibinyabuzima vy’ubwoko bunaka bishwiragira maze bigatandukana, ari ko usanga mu karere biba vyashwiragiriyemwo hasigaye harangwa ibikomeye kurusha ibindi, ngo kubera yuko mu tugingo ngengakamere twavyo haba harabaye amahinduka atuma bishobora kuba aho hantu. Ivyo vyatumye abemera ivy’ihindagurika biyumvira yuko ivyo binyabuzima biruhira kuvamwo ubwoko bushasha bw’ibinyabuzima ata ho busa busana n’ubwa mbere.

Ukuri kuri ico kintu. Nk’uko vyamaze kuvugwa, ibimenyamenya vyavuye mu bushakashatsi bwagizwe birerekana mu buryo bukomeye yuko amahinduka aba mu tugingo ngengakamere adashobora gutuma haboneka ubwoko bushasha bw’ibiterwa canke bw’ibikoko ata ho busa busana n’ubwa mbere. Naho biri ukwo, ni ibimenyamenya ibihe none abemera  ivy’ihindagurika batanga kugira ngo bashigikire iciyumviro c’uko ibinyabuzima bikomeye kuruta ari vyo bibandanya kubaho, ngo bivanye n’uko mu tugingo ngengakamere twavyo haba harabaye amahinduka abereye, ano akaba ngo ashobora gutuma haboneka ubwoko bushasha bw’ibinyabuzima? Agatabu kamwe kasohowe mu 1999 n’Ikigo c’ivya siyansi co muri Leta Zunze Ubumwe za Amerika karavuga ibijanye n’“ubwoko 13 bw’inyoni zo mu bwoko bw’iseke Darwin yagireyeko ubushakashatsi mu mazinga ya Galápagos, muri iki gihe izo nyoni zikaba zitirirwa Darwin.”²³

Mu myaka ya 1970, hari umugwi w’abashakashatsi wari uyobowe n’umugabo umwe yitwa Peter R. Grant be n’umukenyezi wiwe B. Rosemary bo kuri Kaminuza y’i Princeton watanguye kugira amatohoza ku bijanye n’izo nyoni zo mu bwoko bw’iseke maze nya mugwi usanga inyuma y’uruzuba rwamaze umwaka muri ayo mazinga, izari zifise iminwa yisumbuye gatoyi ari zo zashoboye kwihanganira urwo ruzuba kurusha izari zifise iminwa mitomito. Kubera ko ubunini bw’iminwa y’izo nyoni be n’ukuntu imeze ari bimwe mu bintu nyamukuru bifatirwako mu gutandukanya ubwo bwoko bwazo uko ari 13, ivyo uwo mugwi washitseko vyasa nk’aho bifise ishingiro. Nya gatabu kabandanya gati: “Grant n’umukenyezi wiwe bavuze ko hamwe muri ayo mazinga hoza haraka uruzuba incuro imwe uko imyaka 10 iheze, mu myaka nka 200 gusa hoshobora kuboneka ubundi bwoko bushasha bw’izo nyoni.”²⁴

Ariko rero, ako gatabu karirengagiza kuvuga ibijanye n’uko mu myaka yakurikiye urwo ruzuba, za nyoni z’iminwa mitomito ari zo zasubiye kuba nyinshi kuruta izindi. Abashakashatsi basanze inyoni z’iminwa yisumbuye zaza ziraba nyinshi mu mwaka umwe, mu nyuma na ho iz’iminwa mitomito zikaba ari zo ziba nyinshi, bivanye n’ukuntu ivy’ikirere vyaza birahinduka kuri iryo zinga. Barabonye kandi yuko inyoni zimwezimwe zo muri ubwo “bwoko” butandukanye zaza zirahura kugira ngo zirondoke, ivyo bigatuma izizikomotseko ziramba kuzirusha. Ni co gituma baciye bashika ku ciyumviro c’uko mu gihe ubwoko bw’izo nyoni bwoguma buhura kugira ngo burondoke, vyotumye “ubwoko” bubiri bwo muri izo nyoni bunywana bukavamwo ubwoko bumwe gusa.²⁵

None ukuba ibinyabuzima bidakomeye bigenda birahona hagasigara ibikomeye kuruta, ubwo vy’ukuri vyoba bituma haboneka ubwoko bushasha bw’ikinyabuzima ata ho busa busana n’ubwa mbere? Mu myaka mirongo iheze, uwitwa George Christopher Williams, uno akaba ari umuhinga mu vy’ibinyabuzima yemera ivy’ihindagurika, yaratanguye gukekeranya ku vy’uko ukwo kuntu ibinyabuzima bidakomeye bigenda birahona hagasigara ibikomeye kwoba mu vy’ukuri gutuma ico kintu gishoboka.²⁶ Mu 1999, Uwitwa Jeffrey H. Schwartz, uno akaba ashigikira inyigisho y’ivy’ihindagurika, yanditse yuko ukwo kuntu ibinyabuzima bidakomeye bigenda birahona hagasigara ibikomeye kwoshobora gutuma ubwoko bw’ibinyabuzima bimwebimwe bugerageza kubaho buhuza n’uko ibintu biba vyifashe, ariko ko kudashobora gutuma haboneka ubwoko na bumwe bushasha bw’ikinyabuzima.²⁷

Mu vy’ukuri, za nyoni zitirwa Darwin ntizihinduka ngo zibe inyoni z’“ubundi bwoko bushasha.”  Ziguma ari izo mu bwoko bw’iseke nyene. Vyongeye, ukuba ziza zirahura kugira ngo zirondoke bituma umuntu akekeranya ku bijanye n’uburyo butari bumwe abantu bamwebamwe bemera ivy’ihindagurika bisunga kugira ngo badondore ubwoko bunaka bw’ikinyabuzima. N’ikindi kandi, ibivugwa kuri izo nyoni birerekana yuko mbere n’inzego karuhariwe mu vya siyansi zidashobora gutanga ibimenyamenya bitagira aho bihengamiye.

Ikinyoma ca 3. Ibisigarira vy’ibinyabuzima biremeza ko rya hindagurika rihambaye ryabaye. Ibiri muri ka gatabu twavuga, bituma uwugasomye aca yiyumvira ko ibisigarira vy’ibinyabuzima vyubuwe n’abanyasiyansi ari vyo vyemeza neza yuko rya hindagurika rihambaye ryabayeho. Kavuga gati: “Barubuye ibisigarira vyinshi cane vy’ibinyabuzima bifise imero iri hagati y’amafi be n’ibinyabuzima bishobora kuba imusozi no mu mazi, ibifise imero iri hagati y’ibinyabuzima bishobora kuba imusozi no mu mazi be n’ibikwega inda hasi, ibifise imero iri hagati y’ibikwega inda hasi be n’ivyonsa, bongera basanga mu bwoko bw’inkende akenshi bitoroshe kumenya neza na neza igihe ubwoko bumwe bw’inkende bwahindutse bugacika ubundi bwoko bunaka bw’iyindi.”²⁸

Ukuri kuri ico kintu. Ivyo ako gatabu kavugana ubujijutsi ukuraho biratangaje cane. Uti kubera iki? Uwitwa Niles Eldredge, uno akaba ari karuhariwe mu kwemera ivy’ihindagurika, avuga yuko ibisigarira vy’ibinyabuzima vyubuwe vyerekana ko ata hindagurika ryabayeho intambwe ku yindi, mugabo ko mu gihe kirekire cane cahaciye, “mu bwoko bw’ibinyabuzima hafi nka bwose habayeho amahinduka make cane, canke mbere ko ata yabayeho namba.” f²⁹

Gushika ubu, abanyasiyansi bo hirya no hino kw’isi baramaze gucukura no gushira mu migwi ibisigarira nk’imiliyoni 200 vy’ibinyabuzima bininibinini be n’ibisigarira amamiliyaridi vy’ibinyabuzima bitobito. Abashakashatsi benshi baremera yuko ivyo bintu umuyoro kandi vy’ido n’ido vyerekana ko imigwi nyamukuru yose y’ibikoko yabayeho bukwi na bukwi kandi ko bisa n’ibitigeze bigira amahinduka, bikerekana kandi ko ubwoko bwinshi bw’ibinyabuzima bwahonye bukwi na bukwi nk’uko nyene bwabayeho bukwi na bukwi.

Ni kubera ki none abantu benshi bazwi cane bemera ivy’ihindagurika usanga bashimika ku vy’uko vy’ukuri mu binyabuzima habayeho ihindagurika rihambaye? Uwitwa Richard Lewontin, uno akaba ari umuntu yubahwa yemera ivy’ihindagurika, yanditse adaca ku ruhande yuko abanyasiyansi benshi usanga biteguriye kwemera ivyiyumviro bitagira ishingiro bijanye na siyansi kubera yuko “bafise iciyumviro ngenderwako c’uko ibintu vyose biriho vyishizeho.” Abanyasiyansi benshi usanga banka no kurimbura ivy’uko hashobora kuba hariho Uwabishizeho w’umunyabwenge. Uti kubera iki none? Kubera ko Lewontin avuga ati: “Ntiturota twemera ko Imana ibaho.”³⁰

Ku bijanye n’ivyo, ca kinyamakuru (Scientific American) kirasubiramwo ivyavuzwe n’uwitwa Rodney Stark, uno akaba ari umuhinga mu bijanye n’imibano, giti: “Muri iyi myaka 200 iheze, harakwiragijwe iciyumviro c’uko ngo nimba umuntu yipfuza kuba umunyasiyansi, ategerezwa kutemera ngo idini rigire akosho ku vyiyumviro vyiwe.” Uwo muhinga abandanya avuga ko mu makaminuza agira ivy’ubushakashatsi usanga “abayoboke b’amadini badakurako n’umunwa.”³¹

Mu gihe wohitamwo kwemera ko rya hindagurika rihambaye ryabayeho koko, utegerezwa kubanza kwemera yuko abanyasiyansi b’abahakanamana batarota bareka ngo ivyo basanzwe bemera bigire ico bihinduye ku nsiguro baha ibintu bubura biciye kuri siyansi. Utegerezwa kwemera yuko amahinduka aba mu tugingo ngengakamere tw’ibinyabuzima be n’iciyumviro c’uko ibinyabuzima bidakomeye bigenda birahona hagasigara ibikomeye vyatumye haboneka ubwoko bwose bw’ibinyabuzima bigoye itahura, naho ubushakashatsi bwagizwe mu myaka 100 bwerekana yuko amahinduka aba mu tugingo ngengakamere ata bwoko na bumwe bw’ibinyabuzima kandondwa bwigeze buhinduka bukavamwo ubundi bwoko bw’ibinyabuzima ata ho busa busana n’ubwa mbere. Utegerezwa kwemera ko ibinyabuzima vyose vyagiye birahindagurika intambwe ku yindi bivuye ku kinyabuzima kimwe c’inkomoko, naho ibisigarira vyacukuwe vyerekana bishimitse yuko amoko nyamukuru y’ibiterwa be n’ay’ibikoko yabonetse bukwi na bukwi kandi ko nya moko atahindaguritse ngo avemwo ayandi moko mashasha, naho hoba haraciye igihe kitagira urugero. None kwemera ivyo bintu wumva gushingiye ku bintu vy’ukuri canke gushingiye ku binyoma? Mu vy’ukuri, kwemera ivy’ihindagurika ni ugushirukanya.