Asali da Bunkasa
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Marhala ta Farko
Kafin bayyanar tsarin binciken ilimin kimiyya irin na zamani,
fannin Tsarin Gadon Dabi'u da Siffofin Halitta yana nan, kuma galibi mutane kan
bambance dangantakar da ke tsakanin mutane ne ta hanyar dabi'un halitta na
bayyane, watau kamar yanayin kirar jiki, da tsawo, da launin idanu, da launin
gashin kai, da dai sauransu. Amma a
kimiyyance babu wasu abubuwa da ake iya tantance ingancin tabbacin wannan
alaka. A cikin wannan marhala ta rayuwar
dan adam dai abin da aka dauka shi ne, mutane kan gaji dabi'un halitta ne daga
iyayensu, ko danginsu, gaba daya, ba tare da wani kwange ba. Ma'ana duk Uba ko Uwa, suna gadar wa 'ya'ya
dukkan dabi'un halittarsu ne baki daya, babu kwange. Wannan tsarin tunani, a binciken ilimin
dabi'un halitta na zamani, shi ake kira "The Law of Blending
Inheritance." Watau ka'idar da ke
nuna cewa dukkan halitta kan gadar wa zuriyarsu cikakken jerin dabi'ar halittar
da suke dasu ne. Ma'ana suna sajewa da
su babu wani bambanci ko kadan. To amma
da tafiya tayi nisa a karni na 19 (19th Century), sai wata sabuwar
mahanga mai dalili sama da wadda ta gabaceta ta bullo.
Marhala ta Biyu
A marhala ta biyu ne aka samu wata sabuwar mahanga dangane da abin
da ya shafi tsarin gadon dabi'un halitta.
Wannan mahanga kuwa ta samo asali ne daga wani shahararren malami mai
suna Gregor Mendel dan kasar Jamus, wanda ya gudanar da bincike kan nau'ukan
shuke-shuke da yadda ake samun gadon dabi'u a tsakaninsu sanadiyyar
"hadin-aure" da yayi a tsakaninsu, watau "Hybridization" kenan. Ya yi gwaje-gwaje cikin shekarar 1865 inda ya
fitar da sakamakon da ke nuna cewa, akan samu gabon dabi'un halitta a tsakanin
jinsi da nau'ukan shuke-shuke, amma ba wai cikakkiyar gado ake samu ba, sabanin
ra'ayin marhalar farko da ya gabata mai suna "Blending Inheritance." Wannan ra'ayi na Gregor Mendel shi ake kira
da: "Mendelian Inheritance." A
wasu lokuta kuma akan kira shi da suna: "Mendlism." A cikin wannan
marhala ne har wa yau aka fara kiran wannan fanni da suna
"Genetics." Wanda ya fara
kiran wannan fanni da wannan suna kuwa shi ne William Bateson, a cikin wata
kasidarsa da ya gabatar a wani taron duniya da aka yi a birnin Landan kan
"hadin-aure" tsakanin shuke-shuke, watau 3rd
International Conference on Plant Hybridization, cikin shekarar 1906. A
wannan marhala, abin da tsarin bincike ya tabbatar na tsarin gadon dabi'un
halitta duk a kan shuke-shuke ne, ba a gudanar da wani bincike na musamman ba
kan kwayoyin halittar dan adam, dangane da abin da ya shafi fannin. A halin yanzu wannan shi ne bangaren nau'in
ilimin gadon dabi'un halitta da ake kira; "Classical Genetics."
Marhala da Uku
A shekarar 1911 kuma sai bincike kan bangaren kwayar halittar da ke
dauke da dabi'un halitta ya kunno kai. Wanda ya fara bincike kan wannan bangare
kuwa shi ne Thomas Hunt, inda ya gano cewa lallai bangaren Ma'adanar Dabi'ar
Halitta (Chromosome) ne ke dauke da wadannan dabi'un halitta masu haddasa gadon
dabi'un halitta a tsakanin halittu masu rai.
A shekarar 1913 kuma bayan shudewar Thomas Hunt, sai wani dalibinsa mai
suna Alfred Sturtevant ya tabbatar da cewa lallai Dabi'un Halitta (Genes) suna
tsare ne, daya na bin daya, a jere a cikin wannan bangare na Ma'adanar Dabi'ar
Halitta (Chromosome), ba wai a cakude suke ba ko a hargitse. Bayan wannan hobbasa da Thomas da dalibinsa
Alfred suka yi, sai kuma wata muhawara
ta kutso kai, cewa: tunda Dabi'un Halitta (Genes) ne ke taimakawa wajen samar
da Sinadaran Kara Kuzari (Cell Protein) ga Kwayar Halitta (Cell), shin,
tsakanin wannan sinadaran karin kuzari da Ma'adanar Dabi'ar Halitta (Chromosome),
wanne ne daga cikinsu ke haddasa Gadon Dabi'un Halitta a tsakanin halittu masu
rai?
Wanda ya fara kokarin gano hakan kuwa shi ne Frederick Griffith a
cikin shekarar 1928. Sakamakon bincikensa ya gano masa wani tsarin juyin
yanayin da ke faruwa a cikin Ma'adanar Dabi'ar Halitta (Chromosome) ne. Wannan tsarin juyin yanayi, wanda Frederick
ya kira da suna: "Transformation", wani mataki ne daga cikin matakan
da ke samuwa kafin Gadon Dabi'un Halitta (Inheritance) ya samu a cikin Kwayar
Halitta (Cell). Da aka shiga shekarar
1944 kuma sai wani gungun masana su uku, wato: Oswald Theodore Avery, da Colin
McLeod, da kuma Maclyn Mc-Carthy suka gudanar da bincike don tantance hakikanin
abin da ke haddasa wannan tsarin juyin yanayi da Frederick ya kira "Transformation"
a baya. Sakamakon bincikensu dai ya nuna
cewa, Madaukan Dabi'ar Halitta (DNA) ne ke haddasa wannan yanayi, wanda mataki
ne da ke samar da Gadon Dabi'ar Halitta (Inheritance) a tsakanin halittu. Ba su kadai ba, hatta gwajin bincike na
musamman da Harshey da Chase suka gudanar a shekarar 1952 ya sake tabbatar da
hakan. A nasu bangaren kuma, masana
James D. Watson da Francis Crick sun gudanar da bincike na musamman kan wannan
Madaukan Dabi'ar Halitta (DNA), inda suka gano tsarinsa, da kuma cikakkiyar
siffarsa. Wannan bincike nasu sun
gudanar da shi ne a shekarar 1953. A
cikin shekarar 1955 kuma aka sake gudanar da wani bincike kan Madaukan Dabi'ar
Halitta (DNA), inda aka gano tasirinsa wajen samar da Sinadaran Kara Kuzari
(Protein), wanda ke taimakawa wajen gina Tambarin Dabi'ar Halitta (Genetic
Code) na kowane halitta. Wadannan su ne
al'amura muhimmai da suka faru a marhala ta uku cikin wannan fanni na ilimin
Tsarin Gadon Dabi'un Halitta (Genetics).
Marhala ta Hudu
Marhala ta hudu, wadda ke cike da ci gaba a fannin kimiyya da
kere-kere, ita ce marhala ta karshe da wannan fanni na tsarin Gadon Dabi'un
Halitta ya kutsa. Wannan marhala ta faro
ne cikin shekarar 1977, lokacin da wani masani mai suna Frederick Sanger ya gudanar
da bincike na musamman kan yadda Madaukan Dabi'ar Halitta (DNA) ke jera Dabi'un
Halitta (Genes) a kwayar halittar rayuka. Sakamakon wannan bincike, wanda
Malaman kimiyya ke kira: "DNA Sequencing," yana da muhimmanci matuka
a wannan fanni na ilimi.
Bayan sakamakon wannan bincike, a shekarar 1983 kuma sai ga Kary
Banks Mullis, wani masani ne kan wannan fanni, inda bayan tsawon lokaci yana
gudanar da bincike ya fitar da sakamako kan yadda ake iya tsame sinadarin
Madaukan Dabi'ar Halitta (DNA) daga sauran sinadaran da ke mahallin Ma'adanar
Dabi'ar Halitta (Chromosome). Wannan
wani mataki ne da ya samar da karin sanayya kan Dabi'un Halitta (Genes). Wannan
sabon tsari da Kary Banks ya hankado shi ake kira "Polymerase Chain
Reaction." Daga nan aka ci gaba da
gudanar da bincike na kwakwaf cikin wannan fanni, ta hanyar amfani da sababbin
na'urorin binciken kimiyya da fasahar sadarwa da kere-kere, wajen gano wasu
al'amura da suka buya a lokutan binciken shekarun baya. Babban hobbasa da aka
yi wajen tantance matakin da ake ganin shi ne na karshe wajen bunkasa wannan
fanni shi ne sakamakon binciken da ya tabbata a shekarar 2003, shekarar da aka
kammala bincike kan adadin Dabi'un Halitta da ke cikin kwayoyin halittar jinsin
dan adam baki daya. Wannan aikin bincike na musamman wanda aka masa suna THE
HUMAN GENOME PROJECT, hukumar Kiwon Lafiyar Kasar Amuka da Kamfanin
Binciken Dabi'un Halitta mai suna Celera Genomics ne suka dauki nauyin
aiwatar da shi. A sakamakon binciken ne
aka tantance cewa jinsin dan adam na dauke ne da adadin Dabi'un Halitta (Genes)
tsakanin 20,000 zuwa 25,000. Har wa yau
sakamakon binciken ya dada tabbatar da cewa, lallai fahimtar yadda wadannan
Dabi'un Halitta ke jituwa ko kasa jituwa a tsakaninsu ne zai taimaka wajen
samar da waraka ga cututtukar da ke addabar al'ummar duniya baki daya. Wannan hobbasa ne ya fitar da abin da na kira:
"Taswirar Tambarin Dabi'ar Halitta," wato "The Human
Genome."
Wadannan su ne shahararrun marhaloli hudu masu muhimmanci da wannan
fannin ilimi ya kutso ta cikinsu. Duk
wani abin da ya danganci wannan fannin ilimi da ba a ambace shi ba, to, z aka
samu ya samo asali ne daga gare su.
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