As one might expect, ecologists study such history (7)
I believe the answer is:
natural
'as one might expect' is the definition.
(I've seen this before)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for natural that I've seen before include "Plain - lifelike" , "Innate - neither flat nor sharp" , "Inborn; unaffected" , "An ideal person" , "Reason for death when not suspicious" .)