It seems more and more to me like this hierarchy goes all the way up (to the single superorganism that is the universe) and all the way down (to the presence or absence of fermions in particular states, inducing a duality and thus a basis of computation via the Pauli exclusion principle). If this hierarchy is consistent across all scales, then we can conclude that if consciousness exists at one level then it exists at all levels. Sentience/awareness is a different question, mind you, and "memories" are associated with awareness of past events.
I'm also starting to believe that "consciousness" in terms of directed will doesn't truly exist, and that only "experience" exists. The rest (wants, desires, opinions, will) are electrochemical reactions which respond to local changes in the environment, although we experience them as much more than that for ultimately self- (and macrosystem-)serving reasons. These electrochemical reactions are present because they have over time become more important in the processes necessary for the propagation of whatever they're supporting. This is all very vague and hand-wavy but this article on the thermodynamic theory of life might be clearer [1].
In the discussion yesterday about this topic on HN I brought up the example of ant colonies [2] in an attempt to spur discussion in this direction.
[1] https://www.quantamagazine.org/a-new-thermodynamics-theory-o...