Interdependence drives successful collaboration, and collaborative arrangements never survive without clear areas of interdependence.
When individual collaborators judge their actions in the context of the best outcome for the group, rather than their own short term best interests, you have a collaboration that is sufficiently robust to survive and add value.
In other words, interdependence emerges when an individuals best interests are best served by serving the best interests of the collaboration.
Inevitably, this involves some sacrifice of independence, sometimes hard to do, but usually very profitable.