A yau zamu tattauna game da Ediacara fauna. Aungiyoyin halittu ne waɗanda ke wakiltar dukkan nau'ikan da suka mamaye Duniya yayin wani lokacin ilimin ƙasa wanda aka fi sani da Ediacara. Wannan lokacin ya faru kimanin shekaru miliyan 600 da suka gabata. Ana tunanin cewa wannan fauna na iya haɗuwa da haɓakar da ta faru a wancan lokacin a matakan duniya na oxygen da ke cikin sararin samaniya.
A cikin wannan sakon zamuyi bincike sosai akan yadda za'a gano Ediacara don gano dukkan sirrinsa.
Tushen
Masana kimiyya suna tunanin cewa fauna Ediacaran ya samo asali ne daga ƙaruwar iskar oxygen wanda ya faru shekaru miliyan 600 da suka gabata. Wannan gaskiyar ta fifita ci gaban wasu nau'ikan metazoans waɗanda ke da halaye iri ɗaya: jiki tare da laushi mai taushi da sifofi iri-iri. An gano wannan fauna a cikin tarihin binciken tarihin da aka samo a cikin tsaunukan Ediacara, Ostiraliya.
Ana adana bayanan burbushin wannan dabbobin a yankuna daban-daban na duniya. Wannan fauna wakilcin wani muhimmin ci gaba ne a cikin kwayoyin halittu masu yawa da yawa kafin fashewar Cambrian. Yana daya daga cikin sifofin farko na rayuwa da suke bukatar iskar oxygen a sararin samaniya don ya bunkasa. Kari akan haka, masana kimiyya suna tunanin cewa share fage ne ga kwayoyin halittar da suke da kwarangwal.
Duk da cewa Duniya ta kafa shekaru biliyan 4550, har sai da Proterozoic ya kasance akwai yanayi ko miƙa mulki zuwa wani yanayi mai dauke da iskar oxygen mai yawa. A baya can, kwayoyin halittar methanogenic ne kawai suka kasance, tun da kasancewar kwayar methane a cikin sararin samaniya tana da girma sosai kuma wadannan kwayoyin sun dace da yanayin anaerobic.
Mataki na ƙarshe na zamanin Neoproterozoic shine abin da aka sani da lokacin Ediacaran. A farkon wannan lokacin ilimin kasa shine lokacin da tsoffin kwayoyin halittu da yawa suka fara bunkasa. Wadannan kwayoyin har yanzu suna nan kuma sune mafi dadaddiyar yanayin da muka sani. Waɗannan sune farkon soso da anemones. Wannan lokacin ilimin ƙasa ya fara shekaru miliyan 635 da suka gabata kuma ya ƙare shekaru miliyan 542 da suka gabata.
Babu burbushin tarihi kafin fauna na Ediacara
Ofaya daga cikin bayanin da za'a iya bayarwa akan cewa babu burbushin duk wani nau'in fauna da aka gabatar kafin wannan zamanin shine cewa halittun da suka gabata basu da haɗin. Collagen shine furotin wanda yake taimakawa jikin jikin dabba kuma ya bashi damar kiyaye shi cikin lokaci.
Wannan mahadi kawai yana faruwa ne lokacin da matakin oxygen a cikin sararin sama yafi 3%. Saboda haka, collagen bai wanzu ba a cikin yanayi na anaerobic.
Akwai wasu ra'ayoyi game da kamanceceniya tsakanin Ediacara fauna da nau'ikan fauna na yanzu. Hypotaya ra'ayi shine cewa yawancin waɗannan dabbobin sune kakannin kakannin jinsunan da muka sani a yau. A gefe guda, akwai wani zato wanda ya bayyana cewa fawan Ediacara yana da bambancin juyin halitta daban. Wannan yana nufin cewa bashi da alaƙa da rayayyun halittun da muka sani a yau. Wannan shine dalilin da yasa aka kasafta shi a wata kwayar halittar daban wacce aka sani da dadadden kwayar halittar Vendozoa.
Idan anyi kimantawa daga burbushin da aka samo, zamu iya ganin cewa wasu nau'ikan dabbobin Ediacaran suna kama da waɗanda suka rayu a cikin Cambrian. Wannan gaskiyar tana nufin cewa, a wata hanya, suna iya kasancewa da alaƙa da ƙwayoyin halitta na yanzu. Daya daga cikin misalan da aka fi amfani dasu shine na Kimbelerra Cuadrata. Jinsi ne wanda ya rayu a cikin zamanin Ediacaran kuma yana da kamanni ɗaya da na mollusks na yanzu.
Kuma, kodayake akwai wasu hanyoyin da suke da sabani sosai, kasancewar samuwar Ediacaran zai iya zama bayanin halittar yawancin nau'ikan zamani da muke dasu a yau.
Babban fasali
Burbushin da aka samo a cikin abubuwan da aka samo su ta hanyar rufe tekun da laka da yashi mai kyau. Wannan shine yadda aka halicci wasu matsalolin cikin jikin da ke ƙarƙashin rairayi. Kamar yadda yake da ruwa mai ɗumbin yawa, ya ragu a kauri, yana ba burbushin daɗaɗe da zagaye.
Wadannan dabbobin ana tsammanin sun rayu kusa da abubuwan da aka samo a kan zurfin zurfin nahiyar. Wannan ya ba su damar kasancewa cikin zurfin iyakokin ƙasashen da ke wanzu a wannan lokacin.
De rubutattun burbushin halittun Ediacaran sun sami kwayoyin halittar dake da laushin jiki. Wannan ana tsammanin lamarin haka ne, tunda akwai sifofin diski da aka kirkira ta sifofin ribbed masu haɗi. Hakanan ana iya kiyaye radial na ciki ko ta haɗuwa duka.
Wani bangare na burbushin shine cewa an sami wasu tare da marasa tsari da kuma amorphous talakawa wadanda zasu iya kasancewa cikin sifofin da suka gabata na sporophytes.
Extarshen fauna Ediacara
An ce wannan fauna ya ɓace gaba ɗaya a ƙarshen Precambrian. Dalilin shine saboda tsananin kiwo na wadannan dabbobi na zamanin da da bambancin da tekun ke da shi. Yin kiwo ya haifar da shuke-shuke da yawa waɗanda suka zama abincin dabbobi.
Koyaya, duk da tsohuwar imani, an san shi daga sababbin binciken kwanan nan cewa wasu nau'in Ediacaran sun rayu a lokacin zamanin Cambrian.
Wasu daga cikin dalilan da yasa dukkan jinsunan suka bace sune:
- Glaciations: Lokaci ne mai tsananin sanyi wanda ke haifar da cikas ga kwayoyin halitta don faɗaɗawa da haɓakawa.
- Kaddara: Dukkanin kwayoyin a zamanin Cambrian sun kasance masu cin karensu babu babbaka. Idan wannan tsinkayen ya fara yayin faduwar fauna na Ediacara, mai yiwuwa shine babban dalilin lalacewar yawancin jinsunan.
- Canjin yanayi. Babban canjin yanayin kasa, ilimin halitta da canjin yanayi wanda ya faru a karshen Precambrian da farkon Cambrian ya sanya yawancin jinsunan sun kasa jituwa da sabon yanayin muhalli.
Ina fatan cewa tare da wannan bayanin zaku iya koyo game da Ediacara fauna.