Wyatt Earp, perhaps, following in darkness to stop urge evolving (10)

'wyatt earp' is the definition.
The definition suggests a singular noun which matches the answer.

'following in darkness to stop urge evolving' is the wordplay.
I cannot really understand how this works, but
'following' could be 'f' (used when citing page numbers etc) and 'f' is found in the answer.
'darkness' could be 'night' (night is a period of darkness) and 'night' is found in the leftover letters.
an anagram of 'urge' is 'guer' which is located in the left over letters.
No letters remain.
This explanation may well be incorrect...

'perhaps' acts as a link.

Can you help me to learn more?