Note: This post is written in Urdu (Roman Script) and
English. Unless you understand Urdu/Hindi, you will not be able to read
or understand it. I will translate these later, though, since I have
quite a few American visitors I noticed.
Also if you haven't read the first two parts you can read them here: Part 1 and Part 2.
Pechli blog posts mai main nay sub say pehlay scientific theory ka mutlub clear kiya tha aur yeh show kiya tha k scientific theory ka meaning 'theory' k aam meaning say mukhtalif hota hai. Us k bad evolution k 3 basic concepts diye k evolution basically 'descent with modifications' hai aur yeh k evolution kayi levels pur hoti hai. Ek hi species ki population ki gene frequency main bi tabdeeli ati (microevolution). Aur common ancestors say new species k nikalnay ka process bi hota hai (macroevolution). Lastly yeh k tamam jan-daron ka ek hi common ancestor hai jis ko explain kurnay k liye main nay brief history of life (ya evolution) explain ki thi primitive prokaryotes say lay k insan tuk. Aj main yeh explain karun ga k evolution hoti kaisay hai.
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Pechli post main main nay evolution ko 'descent with modification' bayan kiya tha. Laikin is descent (ya new generations) main modify ya tabdeel hota kya hai? Ager kaha jaye k 'gene frequency' to ghalat nahi hoga. Evolution sirf tub hoti hai jub kisi bi biological population ki gene frequency main tabdeeli ati hai.
Biological population ki gene frequency us ki species main maujood kisi bi kisam k genes ka tanasub hai. Misal k taur pur hum furz kurtay hain matar k pauday (pea plant) k DNA main ek khas jagah (locus) pur 2 tarah k genes ho suktay hain. Ya to yellow color k mataron ka ya green color k mataron ka. Ab hum yeh bi furz kur letay hain jo population hum consider kur rahay hain us main 70% pea plants main green mataron wala gene hai. Jub k baki 30% main yellow mataron wala gene hai. To us population main yellow mataron ki gene frequency 30% hui. Aur jub yeh gene frequency change hogi, in the long run, evolution hogi.
Ab atay hain evolution ki taraf. Evolution k 4 basic mechanisms hain, mutlub evolution 4 mukhtalif tareekon say ho sukti hai. Aur woh hain mutation, gene flow ya migration, genetic drift aur sub say mashoor, natural selection. Yeh sub k sub population main gene frequencies change kur suktay hain aur descent with modification ka subub bun suktay hain.
1. Mutation: Mutation sada zuban main DNA sequence main change ko kehtay hain. Mutation ki mukhtalif wajoohat hoti hain jaisay k new cell bunnay k dauran DNA ka sahi say copy na hona ya mukhtalif radiation jaisay k x-rays, nuclear radiations waghera aur chemicals ki waja say DNA ka damage ho jana aur phir sahi say repair na ho sukna. Is tarah ki mutation zaruri nahi hai k unnatural ho kayi bar DNA thek environment main bi break down kur jata hai.
Mutation bilkul be-tarteeb hoti hai mutlub aisa nahi hota k mutation ka koi khas muqsud hota hai na hi yeh k us ka muqsud oraganism ko aisi qualities dena hota hai jo us k liye faida mund hon. Bilkul random hoti hai aur zyada tur (ek research k mutabik takreeban 70%) mutations jan-daron k liye nuksan-deh hi hoti hain. Baki bi zyada tur neutral hoti hain mutlub un ka na koi faida hota hai aur na hi nuksan. Bohat kum aisi hoti hai jo faida deti hai aur wohi gene frequency change kurti hain aur in the long run evolution ka sabab bunti hain. Ek aur bat bi kabil zikar hai k tamam mutations evolution say connected nahi hotin. Sirf woh mutations jo kabil-e-virasat (heritable) genes main hon wohi evolutionary process main contribute kurti hain. Mutation kaisay evolution main contribute kurti hai yeh samajhnay k liye nechay 'natural selection' k sath maujood image kafi faida-mund rahay ga.
2. Gene Flow ya Migration: Genes ka ek biological population say dusri population main move kurna ya migrate kurna gene flow kehlata hai. Species different populations main divided hoti hai. Misal k taur Multan k choohon (rats) ki bi ek population hai aur Beijing k choohon (rats) ki bi ek population hai. Hum yeh furz kur rahay hain woh ek hi species k choohay hain. Ab chance yeh hai k dono populations k choohon nay kabi apas main mate nahi kiya hoga aur woh kuch na kuch genetically mukhtalif hon gay. Mazeed hum yeh furz kurtay hain k ek Multani chooha kisi bi waja say Beijing pohanch jata hai. Wahin mate kurta hai aur us k bachay paida hotay hain. Jis ka nateeja yeh hoga k Beijing ki us population main kuch new genes shamil ho gay aur yehi gene flow ya migration hai. Insanon ka ek mulk say dusray mulk jana, pollen ka udr k ek population say dusri population main pohanch jana. Yeh dono bi gene flow ki hi misalain hain.
3. Genetic Drift: Gene frequency main koi bi aisa change jo be-tarteeb aur by chance ho woh genetic drift kehlata hai. Mutlub koi bi aisa change jo baki 3 mechanisms, mutation, gene flow ya natural selection ki waja say na ho woh genetic drift kehlaye ga. Muslan hum furz kurtay hain k ek choohon ki population main 5 black choohay thay aur 5 hi white. Mutlub us wuqt white aur black gene frequency brabar thi. Laikin un white choohon main say 3 nay kisi insan ki dali choohay mar dawai (rodenticide) kha li aur mar gaye. Population main gene frequency tabdeel ho gayi. Agli generation main black choohay white choohon say kafi zyada hon gay. Yeh genetic drift k zumray main aye gi. Is ka khas asar choti populations pur hota hai jahan genetic diversity nisbatan kum hoti hai. Mutlub jahan thay hi ek gene walay total 5 choohay un main say adhay say zyada mur gaye. Jub k is ki nisbat budri population main ager 3 mur bi jatay to koi itna furq nahi pudrta.
4. Natural Selection:
Source: wikipedia.org
Jub mutation aur natural selection ek sath hoti hain
Aj main sirf ek misal day kur natural selection pur bat khatam kurta hun. Next post main is ko detail main cover karun ga. Furz kurtay hain k white choohay (rats) bilion (cats) ko zyada asani say nazar atay hain ba-nisbat black choohon k. Jis ka nateeja yeh hoga k billian white choohon ko zyada pakdrain gi aur woh zyada maray jayen gay. Mutlub black choohon ka bachnay ka chance (chance of survival) zyada hoga aur woh zyada offsprings (aulad) paida kur sukain gay jin ko woh apnay black color k genes agay transfer karain gay. Mutlub yeh k agli generation main black choohay nisbatan zyada hon gay. Yeh hai chund alfaz main natural selection.
Aj ki bat yahin khatam. Next post mai main natural selection mazeed explain karun ga aur evolution pur mazeed bi likhun ga. Meri koshish to thi k juld uz juld khatam karun pur main chahta hun k jo explain karun woh sahi say explain karun aur evolution samajhna asan nahi, shayad isi liye itni controversial hai. Kher, yeh jannay k liye k main next post kub kurta hun, you can subscribe by email (option can be found on the right) or follow the blog's page on facebook or my google+.
Also if you haven't read the first two parts you can read them here: Part 1 and Part 2.
Pechli blog posts mai main nay sub say pehlay scientific theory ka mutlub clear kiya tha aur yeh show kiya tha k scientific theory ka meaning 'theory' k aam meaning say mukhtalif hota hai. Us k bad evolution k 3 basic concepts diye k evolution basically 'descent with modifications' hai aur yeh k evolution kayi levels pur hoti hai. Ek hi species ki population ki gene frequency main bi tabdeeli ati (microevolution). Aur common ancestors say new species k nikalnay ka process bi hota hai (macroevolution). Lastly yeh k tamam jan-daron ka ek hi common ancestor hai jis ko explain kurnay k liye main nay brief history of life (ya evolution) explain ki thi primitive prokaryotes say lay k insan tuk. Aj main yeh explain karun ga k evolution hoti kaisay hai.
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Pechli post main main nay evolution ko 'descent with modification' bayan kiya tha. Laikin is descent (ya new generations) main modify ya tabdeel hota kya hai? Ager kaha jaye k 'gene frequency' to ghalat nahi hoga. Evolution sirf tub hoti hai jub kisi bi biological population ki gene frequency main tabdeeli ati hai.
Biological population ki gene frequency us ki species main maujood kisi bi kisam k genes ka tanasub hai. Misal k taur pur hum furz kurtay hain matar k pauday (pea plant) k DNA main ek khas jagah (locus) pur 2 tarah k genes ho suktay hain. Ya to yellow color k mataron ka ya green color k mataron ka. Ab hum yeh bi furz kur letay hain jo population hum consider kur rahay hain us main 70% pea plants main green mataron wala gene hai. Jub k baki 30% main yellow mataron wala gene hai. To us population main yellow mataron ki gene frequency 30% hui. Aur jub yeh gene frequency change hogi, in the long run, evolution hogi.
Ab atay hain evolution ki taraf. Evolution k 4 basic mechanisms hain, mutlub evolution 4 mukhtalif tareekon say ho sukti hai. Aur woh hain mutation, gene flow ya migration, genetic drift aur sub say mashoor, natural selection. Yeh sub k sub population main gene frequencies change kur suktay hain aur descent with modification ka subub bun suktay hain.
1. Mutation: Mutation sada zuban main DNA sequence main change ko kehtay hain. Mutation ki mukhtalif wajoohat hoti hain jaisay k new cell bunnay k dauran DNA ka sahi say copy na hona ya mukhtalif radiation jaisay k x-rays, nuclear radiations waghera aur chemicals ki waja say DNA ka damage ho jana aur phir sahi say repair na ho sukna. Is tarah ki mutation zaruri nahi hai k unnatural ho kayi bar DNA thek environment main bi break down kur jata hai.
Mutation bilkul be-tarteeb hoti hai mutlub aisa nahi hota k mutation ka koi khas muqsud hota hai na hi yeh k us ka muqsud oraganism ko aisi qualities dena hota hai jo us k liye faida mund hon. Bilkul random hoti hai aur zyada tur (ek research k mutabik takreeban 70%) mutations jan-daron k liye nuksan-deh hi hoti hain. Baki bi zyada tur neutral hoti hain mutlub un ka na koi faida hota hai aur na hi nuksan. Bohat kum aisi hoti hai jo faida deti hai aur wohi gene frequency change kurti hain aur in the long run evolution ka sabab bunti hain. Ek aur bat bi kabil zikar hai k tamam mutations evolution say connected nahi hotin. Sirf woh mutations jo kabil-e-virasat (heritable) genes main hon wohi evolutionary process main contribute kurti hain. Mutation kaisay evolution main contribute kurti hai yeh samajhnay k liye nechay 'natural selection' k sath maujood image kafi faida-mund rahay ga.
2. Gene Flow ya Migration: Genes ka ek biological population say dusri population main move kurna ya migrate kurna gene flow kehlata hai. Species different populations main divided hoti hai. Misal k taur Multan k choohon (rats) ki bi ek population hai aur Beijing k choohon (rats) ki bi ek population hai. Hum yeh furz kur rahay hain woh ek hi species k choohay hain. Ab chance yeh hai k dono populations k choohon nay kabi apas main mate nahi kiya hoga aur woh kuch na kuch genetically mukhtalif hon gay. Mazeed hum yeh furz kurtay hain k ek Multani chooha kisi bi waja say Beijing pohanch jata hai. Wahin mate kurta hai aur us k bachay paida hotay hain. Jis ka nateeja yeh hoga k Beijing ki us population main kuch new genes shamil ho gay aur yehi gene flow ya migration hai. Insanon ka ek mulk say dusray mulk jana, pollen ka udr k ek population say dusri population main pohanch jana. Yeh dono bi gene flow ki hi misalain hain.
3. Genetic Drift: Gene frequency main koi bi aisa change jo be-tarteeb aur by chance ho woh genetic drift kehlata hai. Mutlub koi bi aisa change jo baki 3 mechanisms, mutation, gene flow ya natural selection ki waja say na ho woh genetic drift kehlaye ga. Muslan hum furz kurtay hain k ek choohon ki population main 5 black choohay thay aur 5 hi white. Mutlub us wuqt white aur black gene frequency brabar thi. Laikin un white choohon main say 3 nay kisi insan ki dali choohay mar dawai (rodenticide) kha li aur mar gaye. Population main gene frequency tabdeel ho gayi. Agli generation main black choohay white choohon say kafi zyada hon gay. Yeh genetic drift k zumray main aye gi. Is ka khas asar choti populations pur hota hai jahan genetic diversity nisbatan kum hoti hai. Mutlub jahan thay hi ek gene walay total 5 choohay un main say adhay say zyada mur gaye. Jub k is ki nisbat budri population main ager 3 mur bi jatay to koi itna furq nahi pudrta.
4. Natural Selection:
Jub mutation aur natural selection ek sath hoti hain
Aj main sirf ek misal day kur natural selection pur bat khatam kurta hun. Next post main is ko detail main cover karun ga. Furz kurtay hain k white choohay (rats) bilion (cats) ko zyada asani say nazar atay hain ba-nisbat black choohon k. Jis ka nateeja yeh hoga k billian white choohon ko zyada pakdrain gi aur woh zyada maray jayen gay. Mutlub black choohon ka bachnay ka chance (chance of survival) zyada hoga aur woh zyada offsprings (aulad) paida kur sukain gay jin ko woh apnay black color k genes agay transfer karain gay. Mutlub yeh k agli generation main black choohay nisbatan zyada hon gay. Yeh hai chund alfaz main natural selection.
Aj ki bat yahin khatam. Next post mai main natural selection mazeed explain karun ga aur evolution pur mazeed bi likhun ga. Meri koshish to thi k juld uz juld khatam karun pur main chahta hun k jo explain karun woh sahi say explain karun aur evolution samajhna asan nahi, shayad isi liye itni controversial hai. Kher, yeh jannay k liye k main next post kub kurta hun, you can subscribe by email (option can be found on the right) or follow the blog's page on facebook or my google+.
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