EKIBUUZO 1
Ebiine Amagara Bikabaho Bita?
Obu waabaire okiri muto, okabuuzaho abazaire baawe oti: “Abaana nibaruga nkahi?” Ku kiraabe nikwo kiri, bakagarukamu bata? Kurugiirira aha ku waabaire noingana, n’emitwarize yaabo, nibabaasa kuba baayehugize ekibuuzo kyawe nari bakakugarukamu ahonaaho obundi omu muringo ogwakureeteire kuteehurira gye. Nari obundi bakakugambira ekitebyo kitahikire eki bwanyima waamanyire ngu kigwire. Kwonka omwana yaaba ari ow’okukura gye akeetebeekanisiza obushwere, naaba aine kuhitsya obwire akeega aha kuteerana n’okuzaara.
Nk’oku abazaire baingi barikugira enshoni kugaaniira aha nshonga ahu abaana barikuruga, nikwo n’abanyasaayansi barikweziringa kugaaniira aha kibuuzo kikuru eki: Ebiine amagara bikaruga nkahi? Okutunga eky’okugarukamu ekihikire eky’ekibuuzo eki nikikwata aha magara g’omuntu. Mbwenu shi ebiine amagara bikabaho bita?
Eihuri ry’omuntu eritwekirwe, barihangukize emirungi 800 kukira aha buhango bwaryo bwenyini
Abanyasaayansi baingi bo nibagamba ki? Baingi abarikwikiriza ngu ebintu bikabaho bubaho nibagira ngu obuhumbi bw’emyaka ira, ebiine amagara bikatandika kubaho omu kiyanja kihango. Nibagira ngu omu mwanya ogwo, emyoya ekatandika kwetabura kitaraariire yaakora obutafaari bugumire munonga reero bwatandika kwetaanisamu ebindi. Nibagira ngu ebiine amagara omu nsi bikabaho nka butandu kuruga omu butafaari “bworobi” obu.
Hariho abanyasaayansi abandi abarikuheebwa ekitiinisa abarikwikiriza ngu ebintu bikabaho bubaho. Nibateebereza ngu obutafaari bw’okubanza nari ebyabandize kubaho omu nsi bikaruga aheeru yaayo. Ahabw’enki? Ahakuba abanyasaayansi n’obu baakuteeraho bata, tibarikubaasa kuhamya oku obutafaari obutaine magara burikubaasa kurugamu amagara. Omu 2008, Omuhangu omuri Biology Alexandre Meinesz akagamba aha buremeezi obu. Akagira ngu omu myaka erengire 50, “tihariho buhame obuhikire oburikworeka ngu ebiine amagara omu nsi bikaruga omu katafaari kakye, kandi tihariho buhame bwona omu saayansi oburikuhamya eki.”1
Obuhame nibworeka ki? Eky’okugarukamu ky’ekibuuzo eki, abaana nibaruga nkahi? kiine obuhame kandi tikirikwehakanisa. Butoosha ekiine amagara nikiruga omu kintu ekindi ekiine amagara ekitwireho. Kwonka, waagaruka enyima, abantu nibabaasa kuba baahenzire kare ekiragiro eki. Mbwenu shi amagara nigabaasa kuruga omu katafaari akataine amagara? Mbwenu shi hariho emigisha engahi ngu ekyo nikibaasa kubaho?
Abacondooza beetegyereize ngu akatafaari kubaasa kuguma kahuriire, haine ebintu bishatu ebiine kukora hamwe nk’obutafaari bw’akarande—DNA (deoxyribonucleic acid), RNA (ribonucleic acid), na puroteini. Obunaku obu, abanyasaayansi bakye nibo barikubaasa kwikiriza ngu akatafaari akaine amagara kakaruga omu bintu ebitaine magara kitaraariire. Mbwenu shi kihikire kugira ngu RNA nari puroteini bikabaho bubaho? a
Stanley Miller, 1953
Abanyasaayansi baingi nibateekateeka ngu amagara gakabaho bubaho ahabw’okucondooza okwabandize kukorwa omuri 1953. Omu mwaka ogwo, Stanley L. Miller akabaasa kukora obutafaari bwa amino asidi, oburikubaasa kukora ekiriisa kya puroteini, arikuta amashanyarazi omu myoya emwe ey’omu mwanya ei baabaire nibateekateeka ngu neejwekyera ensi etatunguukire. Kuruga obwo, amino asidi neeshangwa n’omu nkiri z’omu mwanya. Mbwenu shi eki nikimanyisa ngu obutafaari bwona oburikukora amagara nibubaasa kukorwa bukorwa?
Robert Shapiro, omuhangu omu by’emibazi aha Yunivasite ya New York naagira ngu “abahandiiki abamwe obutafaari bw’amagara bwona nibubaasa kukorwa omu muringo gworobi kurugiirira aha kugyezesa oku baakozire aha nkiri z’omu mwanya. Kwonka eki tikihikire.”2 b
Teekateeka aha katafaari akarikwetwa RNA. Bukozirwe otutafaari tukye oturikwetwa nucleotides. Akatafaari ka nucleotide nikataana aha ka amino asidi kandi kagumire munonga kwetegyerezibwa. Shapiro naagira ngu “tihariho nucleotides ez’omuringo gwona ezirikugamba ngu zikaruga omu kugyezesa okwakozirwe aha nkiri z’omu mwanya.”3 Naagumizamu kugira ngu eky’okugira ngu obutafaari bwa RNA nibuguma nibwebaganisamu kitaraariire, “hariho akagisha kaingana busha kugira ngu ekyo nikibaasa kubaho omu bintu ebirikureebwa, kandi ekyo kyabaho niruba ruri orugisha.”4
RNA (1) neeyetengyesa kukora puroteini (2), kwonka kandi puroteini nizitwarirwa omu kukora RNA. Mbwenu shi obutafaari obu buri kamwe kakabaho kata bubaho, nari bwombi? Obutafaari oburikwetwa Ribosomes (3) nibuza kugambwaho omu kicweka 2.
Kandi shi obutafaari bwa puroteini? Nibubaasa kukorwa omu tutafaari tukye nka 50 nari enkumi n’enkumi ez’obutafaari bw’amino asidi bugaitsirwe hamwe omu muringo ogutebeekanisiibwe. Akatafaari kamwe ka puroteini karimu amino asidi ezirikwingana 200. Nangwa n’omu butafaari obwo harimu enkumi n’enkumi zitarikushushana eza puroteini. Okuteebereza ngu puroteini emwe erimu obutafaari 100 obw’amino asidi neebaasa kuruga ekintu kyona omu nsi buzima ogwo n’omugisha gumwe aha migisha akakaikuru k’obuhumbi.
Okukora obutafaari bukye omu itaburiro ry’emibazi ku kiraabe nikyetengyesa omunyasaayansi omunyabwengye, mbwenu shi otutafaari oturikukora akatafaari k’amagara two tukabaho bubaho?
Omucondooza Hubert P. Yockey, orikushagika enyegyesa ngu ebintu bikabaho bubaho, naayongyera ati: “Tikirikubaasika kugira ngu amagara gakatandika kubaho kuruga omu puroteini.”5 RNA neeba neeyetengyesa omu kukora puroteini, kwonka puroteini neetwarirwa omu kukora RNA. Mbwenu shi ku haraabe hariho akagisha kakye ngu obutafaari bwa RNA n’obwa puroteini bukabaho bubaho? Nikibaasika kita ngu nibukwatanisa kukora ekintu ky’amagara ekirikuguma nikyebaganisamu? Dr. Carol Cleland c, ow’eitendekyero rya National Aeronautics and Space Administration’s Astrobiology naagira ati: “Okugira ngu eki nikibaasa kubaho aha bwa butandu (puroteini na RNA waabijwanzya) nikireebeka ngu buzima tikirikubaasika.” Naayongyeraho ati: “Abacondooza baingi nibateekateeka ngu obutafaari bwa RNA bwaba nibubaasa kwekora bwonka, bwayegaita n’obwa puroteini nibubaasa kwekoramu ekintu ky’amaani.” Aha bikwatiraine n’okugira ngu obutafaari bw’amagara obu bukabaho bubaho, Dr. Carol Cleland naagira ati: “Tihaine na kamwe aharibwo akarikutureetera kuhamya gye oku eki kyabaireho.”6
Ku kiraabe nikyetengyesa obwengye kukora rooboti etaine magara n’okugitebeekanisa, noogira ngu nikyetengyesa ki kukora akatafaari akaine amagara, nari omuntu weena?
Ahabw’enki twine kufayo aha nshonga ezi? Teekateeka aha buremeezi obu abacondooza baine abarikuteekateeka ngu amagara gakabaho bubaho. Bashangire ngu amino asidi eri n’omu butafaari obuhuriire. Omu macondoorezo gaabo babaasize kugyezesa kandi baakora otutafaari tugumire otu. Buzima, baine amatsiko g’okukora kyona ekirikubaasika kwombeka akatafaari akoorobi eikora. Embeera yaabo neebaasa kugyeragyeranisibwa n’omunyasaayansi orikukwata ebintu ebiriho, akabihindura akaihamu emitehimbwa, purasitika, ruraba, waaya, na rooboti. Kandi akatebeekanisa rooboti kukora ezindi rooboti. Yaakora atyo, naayoreka ki? Buzima obwengye nk’obwo nibubaasa kurugamu okukora ekyoma ky’amaani munonga.
Nikyo kimwe, abanyasaayansi baakora akatafaari, nibaba baakozire ekintu ky’omuhendo. Kwonka shi obwo n’obuhame ngu akatafaari kakabaho bubaho? Eki buzima nikiba nikyoreka ekirikutaana nakyo, tikwo kiri?
Nooteekateeka ota? Abanyasaayansi boona ab’obunaku obu nibooreka ngu ebiine amagara bikaruga omu biine amagara ebyabaire biriho. Kubaasa kwikiriza ngu akatafaari k’amagara kakabaho bubaho karikuruga omu tutafaari otutaine amagara, nikyetengyesa okwikiriza kw’amaani munonga.
Waaheebwa omugisha, oyeteekateekire kugira okwikiriza nk’okwo? Otakagarukiremu ekibuuzo ekyo, yetegyereze gye oku akatafaari kakozirwe. Okukora otyo nikiija kukuhwera kumanya yaaba enyegyesa z’abanyasaayansi abamwe ezirikworeka ahu amagara gaarugire ziri ez’oburyo nari ziri nk’ebitebyo ebi abazaire abamwe barigamba kworeka ahu abaana barikuruga.
a Okutebeereza ngu DNA ekabaho bubaho nikiza kugambwaho omu kicweka kya 3, “Engyenderwaho Ekaruga Nkahi?”
b Omuhangu Shapiro tarikwikiriza ngu amagara gakahangwa. Naikiriza ngu amagara gakabaho bubaho omu muringo ogutakeetegyereziibwe. Omu 2009, obu abanyasaayansi baabaire bari aha Yunivasite ya Manchester, omuri England, nikigambwa ngu bakakora obutafaari oturikwetwa nucleotides omu eitaburiro ryabo ery’emibazi. Kwonka, Shapiro naagira ngu ebi baakoreise “buzima tibirikwikirizana n’enshoboorora erikukwata ahari RNA.”
c Dr. Cleland tarikwikiririza mu kuhanga. Naikiriza ngu amagara gakabaho bubaho omu muringo ogutaketegyereziibwe.
