[keats5]

If a species is successful as is in its environment, it will remain as is.

Then why do both humans and primates still exist? Aren't the primates sussessful in their environments today?

[NonZeroSum]

Then why do both humans and primates still exist? Aren't the primates sussessful in their environments today?

Humans are primates. In fact, they are the most successful primates--the others are under extreme environmental pressures as result, and may go extinct as a result of the success of humanity.