praakrutik varan

jeev vigyaan shruङakhala ka ek bhaag
kram-vikaas
tantr aur prakriyaaeain

anukoolan
aanuvanshik bahaav
jeen pravaah
utparivrtan
praakrutik chayan
prajaateekaran

anusandhaan evam itihaas

parichay
pramaan
jeevan-vikaas ka itihaas
itihaas
samarthan ka star
aadhunik sanshleshan
aapatti / vivaad
saamaajik prabhaav
siddhaant aur tathya

vikaasavaadi jeev vigyaan kshetr

saamoohikeekaran
paaristhitik aanuvanshiki
vikaasavaadi vikaas
vikaasavaadi manovijnyaaan
aanavik vikaas
jaateeya aanuvanshiki
janasankhya aanuvanshiki
vargeekaran

jeevavijnyaaan portal ·

jis prakriya dvaara kisi janasankhya mein koi jaivik gun kam ya adhik ho jaata hai use praakrutik varan ya 'praakrutik chayan' (Natural selection) kehte hain. yeh ek dheemi gati se kramash: hone waali anayaadruchhik (naun-raindam) prakriya hai. praakrutik varan hi jaivavikaas (ivolushan) ki pramukh kaaryavidhi hai. Charles daarvin ne iski neenv rakhi aur iska prachaar-prasar kiya.

yeh tantr vishesh roop se isliye mahatvapoorn hai kyonki yeh ek prajaati ko paryaavaran ke liye anukool banane me sahaayata karta hai. praakrutik chayan ka siddhaant iski vyaakhya kar sakta hai ki paryaavaran kis prakaar prajaatiyon aur janasankhya ke vikaas ko prabhaavit karta hai taaki vo sabse upayukt lakshanon ka chayan kar sakein. yahi vikaas ke siddhaant ka moolabhoot pahaloo hai.

praakrutik chayan ka arth un gunon se hai jo kisi prajaati ko bache rahane aur prajanan me sahaayata karte hain aur iski aavrutti peedhi dar peedhi badhti rahati hai. yeh is tathya ko aur tarkasangat banaata hai ki in lakshanon ke dhaarakon ki santaane adhik hoti hain aur ve yeh gun vanshaanugat roop se bhi le sakte hain.

anukram

udaaharan

praakrutik varan ke siddhaant ko samajhaane ke liye jirraaf ka udaaharan diya jaata hai.

praakrutik varan ke prakaar

praakrutik varan teen prakaar ka hota hai-

  • dishik varan (daairekshanal selekshan)
  • sthaaikaarak varan (staiblaaijing selekshan)
  • vividhkaarak varan (daaivarsifaaing selekshan)

yaun varan

praakrutik varan ka udaaharan : nar mor maada ko aakarshit karne ke liye sundar roop mein nrutya karta hai

inhein bhi dekhein

baahari kadiyaaain