Did we? It's not obvious to me that evolution actually programmed us to care about consciousness in particular rather than just (a subsection of?) current culture conditioning us that way. I'm dubious that all cultures that assigned a particular group of humans a moral status similar to that of animals did this this by way of convincing themselves that that group was not "conscious", or had to overcome strong evolutionary programming. Also consider the moral weight that is assigned to clearly unconscious embryos by many people, or the moral weight apparently assigned to fictional characters by some.