Im a bipc student ihad studied about darwins theory but not understood origin of life plz clarify that doubt..

Question

origin had taken place through some theories like BOTTLE NECK EFFECT etc..................

Answer 1

you question is really to broad to answer. You really need to clarify your question. DArwins theory is basicallly animals reproduce faster then resaources so that there is competition. Individuals vary and some variation is heredible. This leads to better suited individuals passing on the genes in greater numbers then les suited individuals. Eventually the allele for the advantageous trait is present in the majority of the population.

Bottleneck effect occurs when a species is reduced to low number and then start to rebound "a bottleneck". This causes less genetic variability because all new members of the population are descendants of the few surviving members of the original population. This leads to problems because the loci for an allele may be fixed and no longer have any hereditary variation.

Hope this helps a bit. I would try wikipedia or do  searches for individual topics if that doesnt help you could always ask a teacher. The origin of species is a bout 600 pages so there is alot of stuff to cover

Answer 2

You cannot learn everything but where to look for it.  You are not net already, try searching it on net and I am sure you will find satisfying answers yourself.  

As such the answer to your question is not straight forward coz there are many a theories and one of them is Darwin's theory as per which Man came into being step by step in Millions of Years and at first there was nothing but a single cell...