Ubushakashatsi bushya bugaragaza ko ubunini bw’ubwonko bw’abantu no kugenda n’amaguru abiri ari byo bishobora kuba byaratumye abantu benshi bakoresha ukuboko kw’iburyo.
Abantu benshi bariho muri iki gihe bakoresha ukuboko kw’iburyo mu bikorwa byinshi nko kwandika, gutera ibintu, kurya no koza amenyo.
Ariko se kuki bimeze bityo? Abantu ni bo bwoko bwonyine bw’inyamaswa z’inkende n’inguge (primate) bufite ubwiganze mu gukoresha ukuboko kw’iburyo, kandi abashakashatsi bamaze igihe bibaza inkomoko y’iyi miterere bashingiye Ku byo bita ubwihindurize(evolution).
Ubushakashatsi bushya bwatangajwe mu kinyamakuru PLOS Biology bwerekana ko gukoresha ukuboko kw’iburyo ku bantu bishobora kuba bifitanye isano no gukura kw’ubwonko bwabo no gutangira kugenda bahagaze ku maguru abiri.
Abashakashatsi bageze kuri uyu mwanzuro nyuma yo gukoresha uburyo bw’imibare no gusengura iby’ubwihindurize mu gusesengura imikoreshereze y’amaboko mu bwoko 41 bw’ibisabantu(primates) bitandukanye.
Basuzumye ibisobanuro bitandukanye byatanzwe ku nkomoko yo gukoresha ukuboko kw’iburyo ku bantu, harimo imirire yabo, imibereho y’imiryango, ikoreshwa ry’ibikoresho ndetse n’aho babaga.
Ibyagaragaye cyane ni ibintu bibiri: ubunini bw’ubwonko ndetse n’igereranya ry’uburebure bw’amaboko n’amaguru, bifitanye isano no kugenda ku maguru abiri.
Hashingiwe kuri ibyo byavuye mu bushakashatsi, abashakashatsi bakeka ko gukoresha ukuboko kw’iburyo ku bantu byagiye bikura buhoro buhoro uko imyaka yagiye ishira.
Mbere na mbere, abantu batangiye kugenda ku maguru abiri, bituma amaboko yabo abona uko akora indi mirimo.
Nyuma y’igihe, abantu bashoboraga gukora neza imirimo ibasaba ubuhanga bwo gukoresha ukuboko kumwe kandi ni bo bashoboraga kubaho no kororoka ibyago kurushaho.
Nyuma yaho, ubwonko bw’abantu bwagiye bwiyongera mu bunini no guhindura imikorere yabwo, bituma gukoresha ukuboko kw’iburyo birushaho gukomera.
Abashakashatsi baranditse bati: “Uburyo budasanzwe bwo kugenda bwabaye intandaro nyamukuru yo gukoresha cyane ukuboko kumwe naho ubwonko bunini bukaba bwari bufitanye isano n’icyerekezo cy’ukuboko bwagombaga gukoresha.”
Abashakashatsi banagerageje kumenya uko abakurambere bacu batakiriho bakoreshaga amaboko, kandi ibyo byashyigikiye iyi nyigisho.
Ubushakashatsi bwerekanye ko abantu ba kera barimo na Australopithecus afarensis bari bafite icyerekezo gito cyo gukoresha ukuboko kw’iburyo.
Iyo myitwarire yagiye irushaho gukomera mu moko yakurikiyeho nka Homo erectus na Homo neanderthalensis, kugeza igeze ku rwego rwo hejuru kuri Homo sapiens, ari we muntu tureba muri iki gihe.
Homo floresiensis niwe wagaragaje ko yari afite ubwo bushobozi buke muri uru ruhererekane, kuko yagaragazaga ubushobozi buke mu gukoresha ukuboko kw’iburyo.
Abashakashatsi bakeka ko ibi bishobora kuba byaraterwa n’uko yari afite ubwonko buto kandi agakoresha uburyo bwo kugenda buvanga kugenda ahagaze no kurira ibiti.
Nubwo ubu bushakashatsi butanga ibimenyetso ku nkomoko y’ubwihindurize bw’abakoresha ukuboko kw’iburyo, busiga hari ibindi byo kwibazaho.
Urugero: umuco wagize uruhe ruhare mu gutuma abantu benshi bakoresha ukuboko kw’iburyo?
Kandi niba gukoresha ukuboko kw’iburyo byarashinze imizi cyane, ni kuki hakiriho abakoresha ukuboko kw’ibumoso?
Ku isi, abantu bagera kuri 10 ku ijana bakoresha ukuboko kw’ibumoso, ibintu abashakashatsi batekereza ko bifitanye isano n’itandukaniro ry’imikorere y’ubwonko ritangira mbere y’uko umuntu avuka.
Abakoresha ukuboko kw’ibumoso akenshi bagira uruhande rw’iburyo rw’ubwonko rukora cyane mu gihe abakoresha ukuboko kw’iburyo bo bagira uruhande rw’ibumoso rw’ubwonko narwo rukora kurusha rugenzi rwarwo.
Mu mwaka wa 2024, abashakashatsi bavumbuye impinduka zidasanzwe z’akaremangingo kitwa TUBB4B kaboneka cyane ku bantu bakoresha ukuboko kw’ibumoso, bikerekana ko ‘genes’ zishobora kugira uruhare mu gutuma umuntu akoresha ukuboko kw’iburyo cyangwa kw’ibumoso.
Ariko kandi, abashakashatsi bakeka ko bamwe bashobora gukoresha ukuboko kw’ibumoso “kubera gusa impinduka zisanzwe ziba mu mikurire y’ubwonko bw’urusoro rw’umwana, bityo ko nta mpamvu yihariye ya génétique yaba ibirimo,” nk’uko umuhanga mu by’uturemangingo tw’irondakoko Clyde Francks wo muri Max Planck Institute for Psycholinguistics yabibwiye Reuters.
Abashakashatsi kandi bafite amatsiko yo kumenya niba hari isano hagati y’ukuntu abantu bagize umwihariko wo gukoresha ukuboko kw’iburyo n’uburyo bumwe bwo gukoresha amaguru cyangwa amaboko ku zindi nyamaswa.
Urugero, amoko menshi y’inyoni bita kasuku akunda gukoresha uruhande rumwe rw’umubiri kurusha urundi.
Iyo zirya, zikunda gukoresha ijisho n’ikirenge by’ibumoso cyangwa by’iburyo hamwe.
Mu buryo busa n’ubwo, amoko menshi ya kangaroo na yo agaragaza gukoresha ahanini uruhande rumwe rw’umubiri, aho kangaroo zikoresha cyane akaguru cyangwa ukuboko kw’ibumoso mu mirimo ya buri munsi nko gushaka ibiryo no kwisukura.
Nk’uko bimeze ku bantu, abashakashatsi batekereza ko ibi bishobora kuba bifitanye isano no guhagarara ku maguru abiri.
Yegor Malashichev, wari umuhanga mu binyabuzima muri Saint Petersburg State University, yabwiye ikinyamakuru Smithsonian mu 2015 ati: “Birasa nk’aho kugenda ku maguru abiri ari byo byateye iterambere ryihariye mu gukoresha ukuboko kumwe. Guhagarara ku maguru abiri bituma amaboko abohoka, ugashobora kuyakoresha icyo ushaka.”
