So How Did It Evolve?

If we accept that 'natural selection' and 'survival of the fittest' both exist, which they surely do - even if this actually lends precious little help to the proponents of the evolutionary hypothesis - a question (just one?) is begged.

'From whence came parenthood?' If creatures are by nature 'selfish' - how come that this is sidelined where offspring are concerned? Surely there is something 'inbuilt' which could not have evolved!
If a 'what' did not 'build it in' then maybe it was a 'who'.