Why a new conception involves support for the distant past (3,4,4)

'distant past' is the definition.

'why a new conception involves support for the' is the wordplay.
I cannot quite understand how this works, but
'why' could be 'y' and 'y' is present in the answer.
'a' is found in the answer.
'new' could be 'n' and 'n' is located in the answer.
'support' could be 'back' (back is a kind of support) and 'back' is located in the answer.
This may be the basis of clue (or it may be nonsense).