vilupti
| sanrakshan sthiti |
|---|
| vilupt hone ka jokhim |
| vilupt |
| sankatagrast |
| kam jokhim |
| yeh bhi dekhein |
|
prakruti sanrakshan hetu antararaashtreeya sangh 
|
jeev vigyaan mein vilupti (extinction) us ghatna ko kehte hain jab kisi jeev jaati ka antim sadasya mar jaata hai aur fir vishv mein us jaati ka koi bhi jeevit jeev astitv mein naheen hota. aksar aisa isliye hota hai kyonki kisi jeev ka praakrutik vaataavaran badal jaata hai aur usamein in badli paristhitiyon mein panapane aur jeevit rahane ki kshamata naheen hoti. antim sadasya ki mrutyu ke saath hi us jaati mein prajanan dvaara vansh vruddhi ki sanbhaavanaaeain samaapt ho jaati hain. paaristhitiki mein kabhi kabhi vilupti shabd ka prayog kshetreeya star par kisi jeev prajaati ki vilupti se bhi liya jaata hai.
adhyayan se pata chala hai ki apni utpatti ke ausatan 1 karod varsh baad jaati vilupt ho jaati hai, haalaanki kuchh jaatiyaaain dasiyon karodon varshon tak jaari rahati hain. pruthvi par maanav ke viksit hone se pehle viluptiyaaain praakrutik vajahon se hua karti theen. maana jaata hai ki poore itihaas mein jitni bhi jaatiyaaain pruthvi par utpann hui hain unamein se lagbhag 99.9% vilupt ho chuki hain.[1] maanavon ke aagaman ke baad usane bahut si jaatiyon ko shikaar ya anya gatividhiyon se vilupt kar diya hai aur bahut si jaatiyon ko vilupti ki kaagaar par la khada kiya hai.
inhein bhi dekhein
sandarbh
- ↑ Inheritance and Evolution, Denise Walker, Evans Brothers, 2006,
ISBN 978-0-237-53010-5 , ... When a whole species dies out, we say that it has become extinct. Extinction is usually a natural process and it is estimated that 99.9 per cent of all species that have ever lived are now extinct ... - ↑ Mass Extinctions and Their Aftermath, A. Hallam, P. B. Wignall, Oxford University Press, 1997,
ISBN 978-0-19-854916-1 , ... He defines mass extinction as any substantial increase in the amount of extinction (that is, lineage termination) suffered by more than one geographically widespread higher taxon during a relatively short interval of geological time, resulting in at least temporary decline in their standing diversity ... more concise one offered here is that a mass extinction is an extinction of a significant proportion of the world's biota in a geologically insignificant period of time ... - ↑ Encyclopedia of Time: Science, Philosophy, Theology, & Culture, Edited by H. James Birx, SAGE, 2009,
ISBN 978-1-4129-4164-8 , ... There have been five mass extinctions in geological time. It is believed that a sixth mass extinction is currently in progress, theguda first since the advent of humankind ...