QONUNI BIOGENETIKI

Tamomi organizmhoi serhujayra az hisobi tukhmi bordor yo bordornashuda inkishof meyoband. Inkishofi janin dar hayvonoti mansubi yak tip monand ast. Dar hamai jonvaroni khordador dar davrai janini kamonaki skeleti paydo meshavad, masalan, khorda, naychai asab, javfi galsama.

Dar zinahoi avvali inkishofi janini hayvonoti muhrador ba ham bisyor monandand (rasmi 7.10). In dalelho durust budani qonuni monandii janinro, ki K.Ber peshnihod karda bud, tasdiq mekunand. Dar janin az ibtido baze alomathoi ba hamon tipi jonvaron khos mushohida meshavand.

Ba ham monandii janini guruhhoi gunoguni hayvonot nishonai asosii paydoishi umumii onhost. Dar oyanda dar sokhti janin alomathoi sinf, avlod, namud va dar okhir alomathoi khudi fard zohir meshavand.

Durshavii alomathoi janiniro dar rafti inkishof divergensiyai janin menomand. On tarikhi inkishofi hamon namud buda, dar on tahavvuloti (evolyutsiyai) in yo on gu-ruhi hayvonot inikos yoftaast. Monandi dar davrai avvali inkishofi janin va paydo shudani farqiyatho dar davrai okhir sabab dorad. Tagyirpaziri dar hamai zinahoi inkishof ba amal meoyad. Ravandi mutatsionii genho ba amal meoyad, ki on khosiyat, sokht va mubodilai moddahoro dar janin nazorat mekunad.

Vale strukturahoe, ki dar davrai avvali inkishofi janin (alomathoi qadima, ki ba peshguzashtagon khosand) paydo meshavand, baroi inkishofi oyandai onho ahamiyati kalon dorand. CHunone ki qayd shuda bud, az hujayrahoi ibtidoi khorda va naychai asab paydo meshavand. Dar surati nest shudani onho inkishof qat megardad. Misolhoi muhim budani in sokhtorhoi funksionali dar davrahoi avvali inkishof khele bisyorand.

Az in jost, ki tagyiroti dar zinahoi avval paydoshavanda, dar bisyor mavridho ba nomukammali yo marg ovarda merasonad. Baraks, tagyirote, ki dar zinahoi okhir paydo meshavand, qismi kami alomathoro dar bar girifta, baroi organizm (fard) musoid meboshand va dar in holatho zeri tasiri intikhobi tabii memonand.

Zuhuroti alomathoi jonvaron dar davrai inkishofi janin, ki ba peshguzashtagoni onho khosand, isboti digargunii evolyutsionii sokhti uzvho meboshad. Organizmho davrai inkishofi yakhujayragi (davrai zigota)-ro az sar meguzaronand, ki on takroryobii zinai filogenezi nom dorad.

In davrai ba amyoba monandro ba khotir meorad. Dar hamai muhradoron, az jumla, namoyandagoni olii onho, ibtidoi khordaro didan mumkin ast, ki dar rafti inkishof ba muhraho tabdil meyobad. Vale dar ajdodi onho, agar neshtarshaklhoro ba nazar girem, khorda dar tamomi hayot boqi memonad. Dar rafti inkishofi janini parrandagon va shirkhuron, az jumla odam, dar gulu surokhihoi galsama paydo shuda, ba khonachaho judo shudaand.

Paydo shudani dastgohi galsama dar muhradoroni khushkigard shoyad daleli az mohishakloni qadima ba vujud omadani onho boshad. Sokhti dili janini odamizod dar davrai avvali tashakkul ba sokhti dili mohi monand ast, yane az yak

peshdil va yak medachai dil iborat meboshad. Dar nahanghoi bedandon, dar davrai janini nishonahoi dandon mavjud ast, vale on nabaromada nest shuda meravad. Hamai in isbot mekunad, ki dar bayni inkishofi fardi va tarikhii organizmho aloqai zich vujud dorad. In aloqamandi dar qo-nuni biogenetiki, ki az jonibi F.Myuller va E.Gekkel dar asri HIH peshnihod shuda bud, inikos yoftaast. Ontogenezi (inkishofi fardi) har fard takroryobii kutoh va tezi filogenezi (inkishofi tarikhi) namud meboshad. Dar peshrafti minbadai qonuni biogenetiki olimi rus A.N.Seversov sakhmi kalon guzoshtaast. Vay muayyan namud, ki dar inkishofi hayvonot dar davrai janini na alomathoi fardhoi boligi ajdod, balki alomathoi janini onho takror meshavad.

Savolho baroi sanjish:

1. Misolhoe ored, ki monandii khususiyathoi sokhtro dar janini hayvonoti gunoguni muhrador nishon dihand.
2. Diveregensiyai janin chist?
3. CHaro dar janini hayvonoti hozira alomathoi sokhti ajdodi onho paydo meshavand? Onro sharh dihed.