Tsarin yanayi na canji. Dalilin da muhimmancin

Yaya za a iya tsira da wasu nau'in raunana a yanayin yanayi masu wuyar gaske? Don rayuwarsu, wani tsari na daidaitawa an haɗa su a cikin kwayoyin halittarsu, wato, canje-canjen halayensu a ƙarƙashin rinjayar halayen yanayi, irin su iska, iska, da rana.

Tsarin kwayoyin halitta ya ƙayyade samuwar malam buɗe ido daga red da ci gaba da girma babba daga ƙananan kwai. A wannan dogon cigaban duk na ciki da kuma exogenous dalilai za su shafi phenotype daga cikin mutum.

Wannan shi ne jigilar mahalli. Misalai a cikin yanayin rayuwa basu da iyaka. Yana da kyau a fahimci yadda daidaitawa ke aiki.

Bambanci a ilmin halitta. Nau'in canji

A cikin ilimin kimiyya akwai irin wannan abu a matsayin canzawa. Ya ƙayyade yadda tsarin kwayar halitta zai ci gaba da kuma abin da zai samo a cikin hanyar ci gabanta. Bambanci gaba ɗaya shi ne ikon da za'a samu don samun sabon kaddarorin.

Akwai kwayoyin da ba marasa jinsi ba. Ba kwayoyin halitta ba zai tasiri tsarin tsarin jinsi ba. Canje-canje na faruwa ne kawai a cikin yanayin al'ada na dauki. Watau, siffar phenotype ta canza kamar yadda kwayar halittar ta ba shi damar. Ƙunan kwayoyin halitta ba a canzawa ba ne. A wata hanya dabam, ana kiran wannan kuma epigenetic canji.

Tsarin yanayi na canji

An kafa kwayoyin mutum a matakai. A lokacin kowane mataki, abubuwa daban-daban na muhalli suna shafar shi. Bayan haka, duk wani mai rai ba zai iya cigaba da rabu da shi ba. Kuma sakamakon sakamakon wasu dalilai, jiki yana samun sababbin alamu.

Tsarin yanayi ya kasance a tsaka-tsakin jigilar kwayoyin halitta da kuma marasa jinsi. A wani hanya, an kira shi epigenetic canji. Me ya sa yake haka? Irin wannan bambancin ya bambanta da wasu a cikin sababbin alamun sun fito ne saboda sakamakon tsarin jinsin saukarwa, kuma a lokaci guda saboda halaye na waje. Ba tare da irin waɗannan shirye-shiryen ba, yanayin zai halaka yawancin halittu masu rai zuwa ƙarewa.

Ma'anar ontogeny

Mene ne uwagen? Wannan ra'ayi yana daya daga cikin manyan a cikin ilimin halitta. Don ƙarin fahimtar abin da ke tattare da jigon zumunci, dole ne mutum ya san game da tsarin uwagen. A gaskiya ma, masana kimiyya sun gano irin wannan canji dangane da wannan tsari.

Tsarin ciki shine tsarin ci gaba daga zane zuwa haihuwa. Yana da sauƙi a bi wannan tsari tare da misali na ci gaba da malam buɗe ido. Da farko, an haife maciji (hoto na 1), an kafa red a jikinta (Figures 2, 3), wanda shine maimaita rayuwa. Kuma daga chrysalis wani mutum mai girma, wani malam buɗe ido, ya tashi. Ontogeny kuma halayyar tsire-tsire.

Duk abin da ke faruwa tare da zygote (kwai kwai) har sai an samu dabba ko mutum ya kammala za a iya nazarin da nazari.

Misalan yanayi

Sanadin abubuwan da ke tattare da jigilar kwayoyin halitta, bisa ga abin da aka gabatar, su ne yanayin muhalli da halaye na kwayar. Kayan ginin yana kamar tsarin da yake tsara dukkan canje-canje.

Ta yaya kwayar halittar ta tsara canji? Kwancen mutum na mutum yana sarrafa aikin wasu kwayoyin, wanda dole ne "kunna" a wani lokaci na ci gaba. Kasancewa da wani kwayar halitta ba shine alamar kanta kanta ba, amma nauyin amsawa ga wasu tasirin mazaunin. Wannan shine ka'idar yanayi, wanda ke riƙe da mahimmanci don fahimtar irin wannan tsari kamar yadda ake iya canzawa cikin uwa. Misali irin wannan canji za a samu a kasashe daban-daban da kuma a dukkanin cibiyoyin. Irin wannan canji shine halayyar dabbobi, kwari, da kuma kayan lambu.

Bari mu gano canji a cikin launi da siffar fata na Andean toad zaune a Ecuador. Canjin sa a cikin lokaci na uwagenesis shine "tsari" na al'ada a cikin yanayin.

Ƙananan yatsa ba shi da tubercles tare da jiki, balagar misali, kamar yadda muka gani, yana da accretions a tarnaƙi. Yawan fata na toad ya canza zuwa jan karfe-launin ruwan kasa; Kuma launi na iris na ido daga haske mai haske ya zama jan-orange.

Darajar yawan canji

Mahimmancin canzawar jigon jigilar halittu ga yanayin rayuwa shine, na farko, daidaitawar kowane mutum. Mafi mahimmanci shi ne mafi girma ga yiwuwar jinsunan a yanayin muhalli. Wani darajar bambancin shine bambancin samfurori. Kowane mutum yana da, saboda bambancinsa, da nasarorin kansa.

Godiya ga ingantaccen gyare-gyaren, dukkanin jinsunan suna canzawa. Kodayake, ba shakka, waɗannan canje-canje suna da jinkiri.