Capital naturalist (6)

I believe the answer is:

darwin

I believe this is a double definition.

'capital' is the first definition.
(Darwin is an example)

'naturalist' is the second definition.
(Darwin is an example)

(Other definitions for darwin that I've seen before include "Naturalist and Australian city" , "Man of note" , "I'd warn this natural scientist" , "Evolution theorist" , "Author of The Descent of Man" .)

I've seen this clue in The Telegraph.

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