ABSTRACT
This chapter is about how consciousness might have evolved, and why. It discusses phenomenal consciousness—the ways subjective experiences feel. The chapter points out that there are several ways that a biological trait such as phenomenal consciousness might have arisen during evolution: it might have been selected for because it performs an adaptive function, it might have arisen as a byproduct of some other trait, or it might be the result of random genetic drift. It considers what consciousness might be an adaptation for but adds that identifying the function of phenomenal consciousness is harder than it seems. The chapter also considers how phenomenal consciousness might have originated during evolution if it has no function. Finding a place for phenomenal consciousness within evolutionary history faces two additional challenges: there is little consensus on what the physical basis of consciousness is, and there is no consensus on how phenomenal consciousness relates to its physical basis.
