In this essay I point out to two processes that can potentially complement the classical view of evolution by natural selection as outlined by Darwin, which captures only part of the processes driving adaptive evolution. This classical view should be complemented with sources of order generated within the biological system itself in response to its own structure and dynamics (i.e. self-organization) and by considering the existence of a fundamental circularity in the interaction between the organism and its environment, such that the action of the organisms modify their selective environment thereby affecting their own evolution. The formalization and inclusión of these two processes (and their interaction) represent major challenges and opportunities for the expansión of evolutionary theory in the Darwinian tradition.