Origin of "It is the long history of humankind that those who learned to collaborate and improvise most effectively have prevailed”? [closed]

According to Darwin Correspondence Project (Cambridge University) it is not a quote from Darwin:

In the long history of humankind (and animal kind, too) those who learned to collaborate and improvise most effectively have prevailed.

Supposedly from Descent of Man . So far no one has found where it really comes from – but it definitely isn't Darwin.