I agree that the use of a symbolic substitute for blood necessarily entails some degree of belief in semiotics. Does it necessarily mean a literal belief in a continuation of existence beyond death? Presuming that the basic idea of semiotics was grasped by our ancient ancestors, it follows that they understood that symbols, objects and concepts could have a non-literal meaning. This creates at least the possibility that they could believe in a non-literal form of continued existence. They need not believe that the dead would literally survive death and actually continue in some other realm. They could be acting in memorium, as the idea of a memorial is rooted more in the symbolic continuation of existence than in a literal rebirth; and memorial ceremonies, even when divorced from specific belief in an after life, do provide value in soothing and comforting the survivors.
While I think this idea is at least defensible, I am not certain it undermines the implicit connection between semiotic conceptualization and religious belief.
