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Tatsuniyar rikidar halittun Ruwa zuwa na kasa

Abba BashirApril 10, 2007

Bayani game da tatsuniyar rikidar halittun Ruwa zuwa na kasa

https://p.dw.com/p/BvUs
Charles Darwin
Charles DarwinHoto: AP Graphics

Jama’a masu sauraronmu assalamu alaikum, barkammu da wannan lokaci, barkammu kuma da sake saduwa da ku a cikin wani sabon shirin na amsoshin takardunku,shirin da yake amsa tambayoyin da ku masu sauraro kukan aikomana.

Tambaya:Fatawarmu ta wannan makon, ta fitone daga hannun Malam Akilu Alhaji Gwadabe, daga Jihar Yobe a Tarayyar Najeriya, Malamin cewa yayi;Don Allah ina so ku binciko min, Shin da gaskene wai duk halittun da suke a doron kasa, asalinsu halittun cikin ruwa ne, suka rikida suka koma halittun dake takawa akan kasa?kuma ku gayamin mutanen da suka fara gano wannan ilimi, tare da hujjojin da suka dogara da su.

Amsa: Masana juyin halitta, sun yarda da cewa, halittun ruwa sun rikide sun koma halittun dake tafiya a doron kasa tun shekaru miliyan 500 da suka wuce, zamanin da ake kira da suna, zamanin cambrian a turance,a cewarsu wannan wani zamani ne da babu wasu halittu daga duwatsu sai halittun dake cikin ruwa.ma’ana halittu a wancan lokaci,sun fara wanzuwa ne a sifar kifi.To amma gaskiyar batu shine cewar, kamar yadda ya kasance halittu a zamanin cambrian basu da magabata, haka ma babu wata alaka da take nuna rikidarsu, lokaci bayan lokaci, tsakanin halittun kasa da kifi.Yana da kyau a fahimta cewa, babu wasu sifofi da suka dangantasu.Dabbobi masu kafafuwa suna da tsarin halittar jiki, haka kifi yana da nasa.In da ace wannan Da’awa ta rikidar halittun ruwa zuwa halittun doron kasa gaskiya ce,Yakamata ace "juyin halitta" ya dauki biliyoyin matakai wanda zai cika, kuma ya kamata aga biliyoyin tsaka-tsakin halittun dake nuna haka.

Masanan sun yi shekaru 140 suna yin haka, don tono burbushin halittar dake nuna wadannan ka’ida tasu.Sun gano miliyoyin kasusuwan burbushin halittun kasa da kifaye; amma har yanzu basu samu ko daya, da yake nuna tsaka-tsaki halittaba,(wato wata halitta da zata kasance rabi kifi-rabi dabba).har yau basu samo hakan ba.

Masanin binciken burbushin halittu, Gerald T. Todd ya amsa wannan batu a cikin littafinsa mai taken "Evolution of the Lung and the origin of Bony fishes."

Masana ilimin juyin halitta, sun bayar da misalan kifaye guda uku, a lokacin da halittar kifin take kokarin rikida zuwa halittar dake taka doron kasa.To amma Dukkanin bangarori uku na kifaye da aka samu a daftarin burbushin halittu, sun bayyana a kusan lokaci daya. Sun sha bamban ta kowace fuska, kuma gashi suna da girman jiki. Ta ina suka fara wanzuwa? Kuma ta kaka suka samo manyan gabbai? Kuma menene yasa ba'a gano asalinsu, ko tsaka-tsakin siffarsu ba?

Tatsuniyar juyin halitta tana da’awar cewa dai, kifi ya faro ne daga kwaro mai kasusuwa izuwa dabba mai kafafuwa.Amma babu gamsashshiyar hujja akan haka.Babu ma koda burbushin halittar data taba wanzuwa.

Dangane da halittar da ka iya kasancewa tsaka-tsaki, wato rabi kifi rabi dabba, kafin ta zama dabba gabaki daya? To anan ma dai, masana ilimin juyin halitta basu da ta cewa, domin sun ba da kai bori ya hau. wani shahararren masanin juyin halitta mai fada aji, Robert L. Carrol,ya gaskata batun cewa basu da wannan amsa, kuma mawallafin littafin Vertebrate Paleontology and Evolution, inda yake cewa: "Bamu da tsaka-tsakin burbushin halitta tsakanin magabacin kifi da kuma farkon halittar dabba mai kafafuwa."

Babu wata hujja akan daya daga halittun ruwa wadanda za'a yi zatonsu a wata magabaciyar halitta guda.

Ko dadai akwai wani nau’i na kifi da ake kira coelacanth,wanda bayan kimanin shekaru hamsin da suka shude ne, masanan suka yi zaton cewa wannan halitta ta wanzu.Wannan kifi da ake kira coelacanth, wanda aka yi kiyasin shekarunsa miliyan 410, an gabatar da burbushinsa a matsayin tsaka-tsakin sifa da ke dauke da kasusuwa irin na da, da kwakwalwa irin ta yanzu, da kuma kayan hanji da jijiyoyi wanda zasu iya aiki aban kasa, har da kuma gabobin da ka iya taimakawa wajen yin tafiya. Wadannan bayanai sun samu karbuwa a matsayin wata hujja wadda ba za'a iya juyar da ita ba a tsakanin masana kimiyya, har izuwa 1930. An gabatar da kifi coelacanth a matsayin tsaka-tsakin sifa ta gaskiya wadda ta tabbatar da hujjar rikidar halittun ruwa zuwa halittun doron kasa.

To amma Bayan shekaru 8 da samuwar waccan hujjar, a ranar 22 ga watan Disamba, 1938, bincike mai ban sha’awa ya gano dangin kifi coelacanth a tekun Indiya, wanda da, aka gabatar da shi a matsayin tsaka-tsakin sifa wadanda suka gushe shekaru miliyan saba’in da suka shude. Gano rayayyiyar wannan halitta da aka yi ya jefa masana cikin damuwa, cike da mamaki. Masanin burbushin halitta J.L.B. Smith yace ba zai zama yayi mamaki ba idan da zai ga rayayyen halittar dinosaur. A shekarun da suka wuce, an kama kifi coelacanth guda 200 a wurare daban-daban a fadin duniya.

Rayayyun coelacanth sun nuna karara irin nisan dam asana juyin halitta suka yi wajen kirkirar tatsuniyoyinsu, sabanin da’awarsu, coelacanth ya tabbata bashi da huhun da ballantana babbar kwakwalwa. Gabar da masanan suka gabatar a matsayin huhun da, an gano cewar ba komai bane illa kunzumin yawu ne. bayan haka, an gabatar da coelacanth ne a matsayin” dabba mai kokarin yin rarrafe ta fito daga ruwa zuwa ban kasa”, a hakikani kuwa kifi ne dake zaune can karkashin teku kuma bai taba saman ruwa da akalla mita 180 ba.

Dalilan da suka sa, masa ilimin kimiyya na wannan zamani (wadanda basa tare da ka’idar juyin halitta) suka bayar, game da dalilan da suka sa,rikidar halittun ruwa zuwa halittun doron kasa ba zata yiwu ba, sune;

1. Nauyin jikinsu: halittun dake rayuwa a cikin ruwa basu da matsalar daukar nauyin jikinsu.Haka kuma, halittun dake rayuwa aban kasa yawancinsu suna daukar kashi(40%) arba'in cikin dari na kuzarin daka iya daukar jikin nasu zuwa ko'ina, saboda haka kaga halittun dake neman rikida zuwa kasa sai sun samo sababbin gabobi da kasusuwan da (!) zasu iya daukar nauyin kuzarin da zai sa rayuwarsu ta daidai ta, wanda kuma mawuyaci ne maye gurbi dake tattare dasu ya samar da hakan.

2. Jure zafi: a kasa, hucin zafi ko sanyi na saurin canzawa da bazuwa mai fadi.Halittun kasa na dauke da kwayoyi a jikinsu da zasu iya jure karfin yanayin.haka kuma, a ruwa,hucin zafi ko sanyi baya saurin canzawa kuma baya fadada. Saboda haka halittar dake rayuwar a irin wannan yanayi na cikin ruwa suna bukatar sunadarai na kariya daga yanayin dake canzawa aban kasa,dai-dai gwargwado.Abu ne daya sabawa hankali ayi da'awar kifi na dauke da wadannan sunadarai ta hanyar bazuwar maye gurbi a yayin da suka hau doron kasa.

3. Amfani da ruwa: Ruwa har da jikakkiyar iska abubuwa ne da halittun dake rayuwa a doron kasa , suke amfani dasu da riritawa saboda karancin hanyar samun ruwa akan kasa.Misali, sai an halicci fata yadda zata rika fitar da ruwa zuwa wani mikidari tare da kiyayewa daga fitarsa.Saboda haka, halittun kasa zasu samu gabar jin kishirwa, wadda halittun ruwa basu da ita.Bayan haka, fitar jikin dabbobin ruwa ba daidai yake da dabbobin da ba'a ruwa suke ba.

4. K'oda: halittun ruwa na da sassaukar hanyar fitar da datti daga jikinsu, musamman sunadarin ammonia, ta hanyar tace su tunda mazaunisu cike yake da ruwa.A kasa kuwa, sai an takaita amfani da ruwa.Wannan shine yasa wadannan halittu suke da tsarin koda.Madallah da samuwar koda, sunadarin ammonia na taruwa ne anan kuma ya canza zuwa sunadarin urea(fitsari) da kuma karancin ruwan da take amfani dashi yayin fitarwa.kari akan haka, ana bukatar sababbin gabban da zasu samarwa da koda ta rika aiki sosai.A takaice idan anan son rikidar halittar ruwa zuwa ta kasa ta yiwu daidai da minti guda a wajen ruwa ba.Idan ana son rayuwarsu aban kasa, to sai sun samu kyakkywan huhu shima a ganshi kwatsam.

Abu ne mawuyaci ace dukkan wadannan canje-canje zasu afku a tsarin halittarsu a lokaci guda kuma kwatsam.

5. Tsarin Numfashi: Kifi yana “Numfashi” yayin da ya shekar iskar oxygen wadda ke narkewa a cikin ruwa, Hanyar ta itace gefen kayoyin dake daf da fuskarsu. Ba zasu taba iya rayuwa dai dai da wasu ‘yan mintina ba a wajen ruwa. Idan ana son su rayu a ban kasa, dole sai sun samu ingataccen huhun da zai iya rike su shima kwatsam.

Saboda haka abu ne mawuyaci dukkanin wadannan ace sun kawo canji a wadannan gabbai a lokaci guda kuma kwatsam

Magana ta karshe dai itace,Dukkanin wata halitta dake fadin duniya da abinda yake cikinta, Allah mahaliccin kowa da komai ne ya halicce ta, shine kuma yake da iko akan komai,idan yayi nufin halittar wani abu, sai yace da shi kasance, kuma ya kasance.