[Enginerrrd]

I think the only necessary ingredient for life is sloppy self-replication. I'd have to look at von Neumann's proof but the theoretical assumptions may not all be valid.

On that note, I'm curious about quasi crystals or crystals prone to substitutions in the lattice. I envision a crystallization process that occurs right on the edge between crystallizing/dissolving. Then any small unit block with some particular contaminant that is slightly more stable becomes favored by evolutionary processes and entropic ones.

If such a thing is possible, and has a sufficiently high upperbound on possible variations, I think you can get a lot of interesting behavior. Over a long period of time, perhaps a crystal unit block could develop that encourages more of its own creation.

It's a fine line though, because usually crystallization doesn't have sufficient complexity to keep evolving, and it's usually driven more by external conditions than by local conditions in the lattice, but nevertheless, it's the most plausible bridge to life I've ever come up with.

[AstralStorm]

Hence why the guess is that it was clays not crystals. Clays are more complex mechanically, somewhat porous, kind of work as a prototype cell wall. Consensus is more on the side of biofilms than crystals at that point. There are relatively simple multiphase processes that can create such lipid and biological bubbles. Just check how micelles form from random hydrocarbons in water with additives. The more stable micelles would allow biofilms to form inside, and so it goes.

Generally cell wall first hypothesis over RNA/peptides first.

Through such a biofilm micelle only certain chemicals can get in or out. This favors particular molecules "crystallizing" (or rather polymerizing) inside such micelles.

[Enginerrrd]

>Generally cell wall first hypothesis over RNA/peptides first.

I've always felt that RNA was probably a very late addition to the game of life.

[pfdietz]

> I think the only necessary ingredient for life is sloppy self-replication.

But self-replication has to be very good to be useful. If it makes a mistake 10% of the time, the longest piece of information that be retained is about 10 bits.

[fastaguy88]

It only has to be very good if the things being replicated are very fragile. If you only need 50% accuracy, replication can be very sloppy. And remember, thanks to selection, we can start off sloppy and improve.

[pfdietz]

How could it only need 50% accuracy? That gives you a genome of 1 bit. That's completely useless and doesn't explain how this process is going to lead to anything with higher accuracy.

[fastaguy88]

There are thousands of examples of proteins that are less than 50% identical, yet fold into exactly the same shapes and catalyze exactly the same chemical reaction. Biological systems are extremely robust to change. And remember, self replicating systems do not only produce one output, they may produce millions. If only one of those million preserves the critical features, things can continue to evolve.

[pfdietz]

There's vastly more than 1 bit of information in those proteins. If there was just 1 bit, then that would mean that any randomly generated protein would have a 50% chance of having those properties (which is false.)

[fastaguy88]

The question was, how accurate does replication need to be, in a replicating system with selection. My argument is that if you do not need perfect copies, and if you can make large numbers of copies, replication does not need to be very accurate to produce offspring that can continue exhibiting some property that can be selected for.

It seems like your perspective is more information theoretic, and does not include selection.