Samuwar, Kimiyya
Great Permian nau'i nau'i na jinsin: yiwu haddasawa
Permian nau'i nau'i ya zama daya daga cikin mafi girma bala'i a lokacin da dogon tarihi na duniya. A biosphere na duniya ya rasa kusan dukkan marine dabbobi da kuma fiye da 70% na nazarin sasannin wakilan. Shin masana kimiyya fahimtar Sanadin nau'i nau'i, kuma a tantance da tasiri? Abin da ya gabatar da ka'idar da kuma ko za su iya zama amintacce?
Permian
Don kamar wakilci a jerin al'amuran yanzu, shi wajibi ne su yi amfani da ma'aunan kasa lokaci sikelin. Total Paleozoic yana 6 lokaci. Perm - a kan iyakar da ke tsakanin Paleozoic da Mesozoic. A tsawon lokaci da ma'aunan kasa lokaci sikelin na 47 shekaru miliyan (daga 298 zuwa 251 da miliyan shekaru da suka wuce). Dukansu AD kuma Paleozoic da Mesozoic, wani bangare ne na Phanerozoic eon.
Kowane lokaci na Paleozoic zamanin a yadda ban sha'awa da kuma m. A Permian lokaci zo juyin tura wajen samar da sabon siffofin rayuwa, da kuma Permian extinctions cewa halakar da mafi yawan dabbobi na duniya.
Mene ne dalilin da sunan da lokaci
"Perm" - mamaki saba sunan, kada ku tunani? Eh, za ka karanta cewa dama, shi yana da Rasha asalinsu. Hujjar cewa a 1841 da aka samu tectonic tsarin m ga lokaci na Paleozoic zamanin. A find ne dake kusa da birnin Perm. Kuma duk tectonic tsarin yanzu da aka sani da Ural foredeep.
A ra'ayi na taro extinctions
A ra'ayi na taro extinctions gabatar a cikin kimiyya wurare dabam dabam da masana kimiyya na jami'ar Chicago. A aikin da za'ayi Sepkoski D. kuma D. Raup. By ilimin kididdiga analysis shi aka kasaftawa 5 taro extinctions kuma kusan 20 karami fama. Niyya ya duba bayanai ga karshe 540 miliyan shekaru, kamar yadda na baya lokaci bai isa ba data.
The most extinctions sun hada da:
- Ordovician-Silurian.
- Devonian.
- Permian nau'i nau'i na jinsi (haddasawa wanda mu duba yiwuwar).
- Triassic.
- Cretaceous-Paleogene.
Dukkan wadannan abubuwan da suka faru ya faru a cikin Paleozoic, Mesozoic da Cenozoic zamanin. Su mita daga 26 zuwa miliyan 30, shekaru, amma sai ya tabbatar ga masana kimiyya da dama ba su yarda da ita.
A mafi girma muhalli da bala'i
Permian karewa - mafi m bala'i a cikin tarihi na duniya tamu. Marine fauna mutu daga kusan gama nazarin sasannin jinsunan tsira kawai 17% na jimlar. Mutu fiye da 80% na kwari jinsi wanda bai faru ba a cikin sau da sauran taro extinctions. Dukan waɗannan asarar da ya faru a cikin kimanin 60 dubu. Years, ko da yake wasu masana kimiyya bayar da shawarar cewa lokaci na taro annoba tsawon game da dubu 100. Years. Global asarar da cewa kawo babban Permian nau'i nau'i, aka gudanar da wani karshe line - ƙẽtare shi, da Duniya ta biosphere ne farkon juyin halitta.
Tanadi fauna bayan mafi girma muhalli bala'i dade sosai dogon. Za mu iya cewa ga tsawon yawa fiye da bayan da wasu taro extinctions. Masana kimiyya suna kokarin sake tsarin, wanda zai iya daukar sanya wani m annoba, amma har yanzu ba zai iya zo tare ko a cikin yawan kona a cikin tsari da kanta. Wasu masana kimiyya yi imani da cewa babban Permian nau'i nau'i miliyan 250 da suka wuce da wani 3 ganiya dirka, da sauran ilimi da makarantu ne karkata zuwa yi imani da cewa akwai 8.
Daya daga cikin sabon theories
Bisa ga zaton da masana kimiyya, Permian nau'i nau'i da aka riga da wani taro bala'i. Haka ya faru ga 8 shekaru miliyan kafin babban events da muhimmanci gurgunta Duniya ta yanayin kasa. The dabba duniya ya zama m, saboda haka na biyu nau'i nau'i a cikin wani lokaci ya tabbatar da mai girma bala'i. Idan muka gudanar da su tabbatar da cewa akwai biyu nau'i nau'i, cewa shakka zai zama da ra'ayi na periodicity na taro bala'i a cikin Permian lokaci. A ãdalci, mun bayyana cewa wannan ra'ayi kalubalanci daga dama matsayi, ko da ba tare da shan la'akari yiwu ƙarin nau'i nau'i. Amma wannan ra'ayi, yayin da rike kimiyya matsayi.
Yiwu haddasawa na Permian bala'i
Permian nau'i nau'i ne har yanzu haddasa wata yawa muhawara. M shawara revolves a kusa sa na muhalli bala'i. Dauke a matsayin m ga duk yiwu dalilai, ciki har da:
- ciki da kuma na waje catastrophic events.
- sauka a hankali canje-canje a cikin yanayi.
Ka yi kokarin duba wasu daga cikin gyara na biyu mukamai a more daki-daki ga fahimtar yadda m da tasiri a kan Permian nau'i nau'i. Photo support ko shanyewa da binciken samar da masana kimiyya daga da yawa jami'o'i kamar yadda muka yi nazarin batun.
Bala'i a matsayin hanyar da Permian nau'i nau'i
External da ciki catastrophic events ana daukar ta a mafi m Sanadin Mai girma Karewa:
- A wannan lokacin akwai wani gagarumin karuwa a volcanic aiki a abin da shi ne a yanzu Siberia, wanda ya jagoranci wani babban outpouring tarkuna. Wannan yana nufin cewa akwai wata babbar shigowa na basalt a cikin wani gajeren lokaci a ma'aunan kasa ra'ayi. Basalt weakly saukin kamuwa zuwa yashewa, da kewaye sedimentary kankara ana iya hallaka. A matsayin hujja da tarko magmatism masu bincike buga da misali da babbar ƙasa a cikin nau'i na lebur filayen taka a kan tushen da basalt. Babban tarko ƙasa ne Siberian Tarkuna, kafa a karshen da Permian lokaci. Its yanki ne fiye da miliyan 2 sq. Km. Masana kimiyya Nanjing Cibiyar Geology (China) ta gudanar da wani bincike na isotopic abun da ke ciki na kankara na Siberian tarkuna da kuma gano cewa, da Permian nau'i nau'i faru daidai a lokacin da samuwar. Sai da na ɗauki wani fiye da 100 shekara dubu (a baya an yi tunanin cewa da shi ya dauki tsawon lokaci - game da shekara miliyan 1 da haihuwa) .. Ayyukan eruptions iya fararwa da greenhouse sakamako, volcanic hunturu, da kuma sauran matakai ne cutarwa ga biosphere.
- A dalilai na bala'i da biosphere zai iya zama wani digo na daya ko fiye meteorites, taurari karo da manyan asteroid. Matsayin shaida na bakin dutse yanki ne fiye da kilomita 500 (Wilkes Land, Antarctica). Har ila yau, shaidar tasiri events samu a Australia (Bedout tsarin, da Arewa maso gabashin nahiyar). Mutane da yawa daga cikin samfurori da aka daga baya karyata a wani zurfi binciken.
- Daya zai yiwu dalilin ne dauke da wani tashin hankali saki na methane daga seabed, wanda zai kai ga duka lalata marine jinsunan.
- Da hatsari zai iya haifar da samun daya daga cikin yankunan na rayuwa guda-celled kwayoyin (Archaea) da ikon maimaita kwayoyin halitta, sakewa da yawa methane.
Sauka a hankali canje-canje a cikin yanayi
A wannan category akwai dalilai da dama hada maki:
- Sauka a hankali canje-canje a cikin abun da ke ciki na teku ruwa da kuma sararin sama, inda a can anoxia (rashin oxygen).
- Inganta da sauyin yanayi na Duniya rashin ruwa - fauna iya ba daidaita da canje-canje.
- A sakamakon sauyin yanayi ya keta teku igiyoyin da kuma raguwa a cikin teku matakin.
M rinjayi dukan kewayon dalilai, saboda da bala'i ya na da wani taro hali, da kuma ya faru a kan wani gajeren lokaci.
Sakamakon na Great Karewa
Great Permian nau'i nau'i, wanda yake ƙoƙarin kafa da Sanadin kimiyya duniya, tare da tsanani sakamakon. Gaba daya bace dukan kungiyoyin da azuzuwan. Mutu parareptilia mafi part (akwai kawai zamani kunkuru kakanninsa). Yana bace wata babbar lamba na jinsunan arthropod, da kuma kifi. Na canza da abun da ke ciki na kwayoyin. A gaskiya ma, cikin duniya da aka komai, aka mamaye fungi da cewa ciyar a kan mũshe.
Bayan Perm nau'i nau'i nau'in tsira maximally saba overheat, low oxygen matakan, rashin abinci da kuma wuce haddi da sulfur.
Mass biosphere cataclysm ya bude hanya ga sabon irin dabbobi. Trias, na farko lokacin da Mesozoic zamanin, wahayi zuwa duniya archosaurs (magabatan dinosaur, crocodiles da tsuntsaye). Bayan da Great Karewa a Duniya bayyana farko dabbobi masu shayarwa jinsunan. A sabuntawa na biosphere dauki tsakanin 5 da 30 da miliyan shekaru.
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