Teleodynamics-updated evolutionary theory?

Also, the Cheese Shop sketch!

I’m not sure I agree, but the author makes some interesting points.

1 Like

I think they are unreasonably pessimistic about humans creating life from scratch - we don’t know how to design life from scratch, but I think that assembling life from abiotic materials is achievable in the foreseeable future.

1 Like

This may be far more difficult than you imagine.

Could you tell me what some of them are? My eyes glazed over about three paragraphs in.

2 Likes

When two statistically independent “self-organizing” systems found in chromatin14 become coupled across the extracellular space such that the constraints — understood as the thermodynamic boundary conditions that allow energy to be released as work [15] — required by each system are generated by the others, the multicellular individual emerges. And it does so as an intrinsic (with respect to the whole cell population), higher-order constraint on lower-order cellular dynamics.

This is interesting, even if I dont entirely understand what he means.

Do you partially understand what he means? What does he mean? Do you in fact have any cheese at all?

2 Likes

Happy New Year, John! :slight_smile:

1 Like

Possibly that development in multicellular organisms involves cell differentiation mediated by intercellular interactions. (But in organisms with deterministic development cell fate could conceivably be mediated solely by the initial configuration of the zygote, or even the oral-oboral and dorsal-ventral axes could be randomly produced by spontaneous symmetry breaking.)

The “statistically independent” is throwing me - in a multicellular organism the genomes are not independent, and even with epigenetics I’d expect a lot of correlation in the structure of the chromatin (I could be wrong on that point - evo-devo is not a field about which I have much knowledge). And I don’t see how it distinguishes a multicellular organism from a biofilm. In fact, doesn’t it fit a biofilm better - biofilms don’t have organised tissues of similarly differentiation cells.

1 Like

I have not deciphered the specific quoted paragraph. However, I would hazard to guess that overall the author is trying to find a concise way to articulate the differences in what drives the dynamics of chemical systems and biological systems. They are trying to do so in terms of teleology, but I think the same point can be made in different terms.

For example, the transition from chemistry to biology might be thought of as a transition from calculation to computation. The dynamics of a molecule in chemistry can be handled arithmetically, that is by sums and products of forces. The arithmetic may get complicated and perhaps even infeasible, but it is still in principle arithmetic. The dynamics of a cell by contrast may needed to be handled algorithmically, that is to say we may need to add some if-then-else conditionals to our sums and products. Two water molecules exposed to the same conditions should react the same way, but two E. coli may not.

But what could the if-then-else conditionals be conditioned on if not the external present conditions? The internal conditions of the cell represent the most obvious candidate. In other words, we have transitioned from stateless entities to stateful entities.

Because state (or alternatively, history) now matters, individual entities can have varied responses to a given stimulus, which we can interpret as making a choice. This explains the inclination to use teleological language, which is held in tension with the recognition that we don’t usually ascribe agency or rationality to individual cells. Perhaps then stateless/stateful language, or related concepts of history, contingency and memory, can be used more fruitfully than teleology.

(All of the above should be read with the understanding that I could have completely misunderstood the author’s point, only understood the basics but missed key subtleties, and/or oversimplified chemistry.)

2 Likes

Humans have already constructed an artificial genome which gave rise to the first artificial species:

We could construct an entire genome from scratch. However, it has to be injected into a cell that has all of the ribosomes and accessory proteins needed to get things started. At this point, it is more a question of if we want to put all of the massive effort into building all the proteins and ribosomes from scratch, or use the much simpler method of borrowing them from already living organisms. It’s a bit like creating iron in a particle accelerator or digging it up from the ground.

As to the main thesis, I really don’t see why teleology is being used. Personally, I would describe biology as an emergent process of more basic chemical interactions. The complexity of the emergent organism is due to the feedback process of reproduction.

That’s seems analogous to a surrogate mother - or is there more to it than that?

That’s a reasonable analogy. The genome is removed from a bacterial cell and a new one put in. The initial transcription and translation from that new genome will be performed by the tRNA, ribosomes, and proteins left over from the surrogate bacterial cell. Over time and after many replications, all of those molecules will be replaced by the gene products from the human made genome. So maybe something more akin to David Cronenberg’s “The Fly” if you want a different analogy.

1 Like