Father sent back by himself? That's obvious (8)
I believe the answer is:
apparent
'obvious' is the definition.
('apparent' can be similar in meaning to 'obvious')
'father sent back by himself?' is the wordplay.
'father' becomes 'pa' (pa is a kind of father).
'sent back' says the letters should be written in reverse.
'by himself?' becomes 'parent' (I am not sure about this - if you are sure you should believe this answer much more).
'pa' back-to-front is 'ap'.
'ap'+'parent'='APPARENT'
'that's' is the link.
Can you help me to learn more?
(Other definitions for apparent that I've seen before include "See 1" , "Obvious; seeming real" , "Seeming to be but not necessarily so" , "Pane part may be quite obvious" , "Evident or seeming to be" .)