Yes. (I like to say "evolution is a chemical tautology".)
> But every property of an animal could be described that way. height, weight, speed, etc. intelligence isn't singled out that way, so the description doesn't provide insight or leverage.
Ah, but that's just it: intelligence has been singled out, "only human brains are intelligent" is the prevailing dogma, eh? Are you familiar with Levin's work?
> > intelligence is ambient in living tissue
> What does this mean?
Cells think, particularly when they are organized in colonies like biofilms or organisms.
Operationally, it means things like being able to regenerate limbs and organs. In humans that is.
I can't really do a decent summary of Levin et. al.'s research this morning (I woke up hella grumpy.) But if you haven't, do check it out. (E.g. https://news.ycombinator.com/item?id=18736698 )
> A skin cell is doing something like a random walk, and thermodynamics lets it fall down energy gradients.
Only on the most physical level, same as every other chemical reaction, eh? "When you kick a rock it moves from the energy imparted by your foot. When you kick a dog it moves by it's own stored energy." I don't know if cells are little people or just robots, but their behavior isn't adequately described by thermodynamics alone, eh?
> The random walk fall down gradients theory has no explanatory power for people.
Nor for cells.
> How can the same word be useful at both levels?
It's describing the same phenomenon.
> How does a notion of cellular intelligence get aggregated/relate to/describe any notion of the emergent mind at the descriptive level of humans.
This is a fascinating question.
To be sure, Levin et. al. are going the other way, showing that what we think of as the machinery of mind is present in all cells, (and therefore IMO we should expect "mind" whatever it is to be happening in all cells too.)
Consider that every ability of a multicellular organism is an ability of its cells. Motility, digestion, homeostasis, sensory modalities, etc. This includes "mind" (if you define mind as what brains do) because "what brains do" is actually done by all cells to some degree (they all have synapses and neurotransmitters and internal computation and some kind of self-model.)
How it happens that the vision of each retina cell combines to make a subjective view, is likely how it happens that the mind of your cells creates the mind of you. In a sense they are the same thing. Dunno how it happens though.
Biofeedback research in the 60's and 70's seemed to show that you could learn to communicate with your own tissues down to individual cells.