The case for the adaptivity of consciousness is not open and shut because many extant phylogenetic traits are not in fact adaptive, but rather present for a whole host of other reasons not directly relevant to the narrow constraints that most people (even many scientists) consider to be evolution.

Also, it could be an emergent non-trait that is not strongly coupled to underlying instances of selection at the genetic level, perhaps reinforced now by sexual selection, and in which case instances of disruptive selection (or perhaps artificial self-selection in the future) could alter this temporary stability significantly.

Consciousness as an ephemeron of our lineage….