Is life a form of computation?

Articles like this indicate we should lock down the definition of "computation" that meaningfully distinguishes computing machines from other physical phenomena - a computation is a process that maps symbols (or strings of symbols) to other symbols, obeying certain simple rules[1]. A computer is a machine that does computations.

In that sense life is obviously not a computation: it makes some sense to view DNA as symbolic but it is misleading to do the same for the proteins they encode. These proteins are solving physical problems, not expressing symbolic solutions to symbolic problems - a wrench is not a symbolic solution to the problem of a symbolic lug nut. From this POV the analogy of DNA to computer program is just wrong: they are both analogous to blueprints, but not particularly analogous to each other. We should insist that DNA is no more "computational" than the rules that dictate how elements are formed from subatomic particles.

[1] Turing computability, lambda definability, primitive recursion, whatever.

I love thinking about life as computation. Cells are computers, enzymes are functions, ribosomes are compilers, nucleic acids are source code...

Enzymes in particular are a lot like unix pipelines. An enzyme catalyzes its substrate's conversion into its product which is the substrate of another enzyme. When cells ingest glucose, it flows through the glycolysis metabolic pathway until it becomes pyruvate, and may be reduced even further depending on available resources. It's a huge pipeline of enzymes. They just kinda float around within the cell and randomly perform their tasks when their substrates chemically interact with them. No explicit program exists, it emerges from the system within the cell.

  Cell              - Computer
  Enzyme            - Function / Process / Filter
  Substrate         - Data
  Product           - Data
  Metabolic pathway - Program / Script

I'm not too impressed with this article since it doesn't really give a definition for computing, just picks a few similarities between what we see as computing (in the practical sense) and what cells do.

It's a shame because there *has* been a lot of deep work done on what kind of computer life is. People often use the Chomsky Hierarchy (https://en.wikipedia.org/wiki/Chomsky_hierarchy) to define the different types of computer vs automata. Importantly, a classical Turing machine is Type-0 on the Chomsky Hierarchy. Depending on what parts you include from a biological system, you could argue it's anywhere from Type-0 to Type-4.

Interestingly, the PhD thesis of well-known geneticist Aviv Regev was to show that certain combinations of enzymes with chemical concentration states are enough to emulate pi-calculus, and therefore are Turing machines! https://psb.stanford.edu/psb-online/proceedings/psb01/regev....

Surprised the article didn't mention the most fitting sense in which life is computation, which is at the biosphere level. Life can be characterized as a (recursive) search function executing continuously over billions of years. It seeks out new environments, reacts to changes in the environment at all scales between molecules and mountains. Life is a vast, distributed visitor pattern whose payload is itself.

This feels like the kind of popsci that's written for people who already agree with the author - there's nothing resembling an argument, or even a definition of "computation." There are nods to Church-Turing, but the leap from "every effectively calculable function is computable" to "life is a computation" is larger than anything you could fit in a book.

I like the idea instead that some biological components have deterministic optimizations because they’re closer to a molecular form, like DNA, RNA, some protein machinery, etc. because essentially these are driven by some kind of chemistry and physics. Whereas higher level, emergent biological forms are more stochastic in their function, like organelles, an organism, or populations, etc. In that sense, there’s no computation to life, more that life is constrained by the physics of the world in which it develops.

It’s likely if different life forms on another planet, it will have a different “computation” model because its defined by different physics that it experiences during evolution. Though I suppose there will some similarities depending on some fundamental rules of the universe. Will propagation molecules like RNA or DNA always look like helixes, or will the radiation or physics of another planet create another form of propagation molecule we haven’t yet observed. Might make for an interesting experiment to simulate.

I don't see the point of asking this question. Like, sure, all physical systems follow certain rules, so any such process will develop in a way that it look like a computation of an algorithm. Also, evolution itself is constantly optimizing organisms to best adapt to their environment, just like a computation.

So asking if life is a computation seems mostly like a semantic musing. Define "life" and define "computation", then see if they're the same.

Reminds me of Wolfram's 'A New Kind of Science'. Specifically his principle of computation equivalence: https://en.wikipedia.org/wiki/A_New_Kind_of_Science#Principl...

The basic parameters of affective neuroscience make it difficult to conflate actions with computations. Because there isn't a content to thought, thoughts aren't about things, brains/CNS/bodies lack any units that could be computed, there's only an arbitrary sleight of hand linking life and computation.

Classic John Von Neumann, inventing both the Von Neumann architecture and non-Von Neumann architectures.

I think Federico Faggin has a much better (imo, coherent and well-considered) take on this [1].

[1] https://www.youtube.com/watch?v=0FUFewGHLLg

No, obviously not. This is just clickbait and self-congratulation for the tech industry. Computation is not the end-all of every process or entropy flow. Please get better philosophy.