ABSTRACT
The aim of this chapter is to chart a number of options for the evolution of consciousness (in a broad sense of that term) with particular attention to how consciousness fits into the genealogical relations between animals represented in the “tree of life.” The evolution of consciousness has been an area of rampant speculation. That speculative quality will remain for some time, but progress in various parts of biology is beginning to give us a more constrained sense of the likely shape of the history, or at least a range of possible shapes. The treatment in this chapter is preliminary and exploratory, though, and often written in a conditional mode: if biological feature X matters to consciousness, then the history of consciousness may have gone like this …
