As I see it, there are two possibilities; either we come to a point where the moral value drops to zero, or else we decide that entities approach zero to some arbitrary limit: e.g. a c. elegans roundworm with its 300 neurons might have a 'hedonic coefficient' of 3x10^-9. I personally favor the former, the latter just seems absurd to me, but I am open to arguments or any comments/criticisms.

Less absurd than that some organism is infinitely more valuable than its sibling that differs in lacking a single mutation (in the case of the first organism of a particular species to have evolved "high" enough to have minimal moral value)?