Skyhooks and cranes

In a review of David Dennett's Consciousness Explained, Chet Raymo employs two brilliant metaphors for two ways of looking at purpose in the universe:

The big question is how we got here. Was our existence foreordained, drawn up as by a skyhook from the dreary world of matter into the realm of angels? Or are we the unforeseen accumulation of blind, chance mutations selected by interaction with the environment, matter lifting itself into ever greater domains of complexity, eventually into consciousness, as if by those cranes used by builders of skyscrapers that ratchet upward as the buildings rise?

After a thoughtful look at both world views, Raymo concludes:

This humble reader is not convinced that we yet know enough about life or mind to commit ourselves solely to cranes or skyhooks. No one who is remotely knowledgeable about science doubts that life and consciousness evolved over billions of years; what is still at issue is how complexity and consciousness arise. Is natural selection enough to drive evolution toward ever more sophisticated systems? Or is there a natural tendency toward complexity and consciousness built into creation from the very beginning, a lawful natural skyhook of sorts that might be accessible to scientific description?  In my mind, the issue is undecided.