[fullstackchris]

But isn't there a major flaw here? If you require all 3 components (proteins, RNA, and lipid bilayers) as what classifies "life", then what necessarily created _those_ components? Aren't only basic compounds and elements the only thing naturally occuring in the universe? So where did the amino acids and fats come from? It's back to the chicken or the egg problem.

[jonathankoren]

All of these components can form through nonbiological means. For example, amino acids[0] and nucleobases[2] can be found in interstellar gas clouds.[0] Lipid membranes form simply because of their polar properties.[1]

[0] https://physicsworld.com/a/amino-acid-detected-in-space/

[1] https://www.ncbi.nlm.nih.gov/books/NBK9928/

[2] https://www.nature.com/articles/s41467-019-12404-1

[fullstackchris]

oh wow, i didn't realize this. i had figured that these structures would be forbidden on an energy based standing. clearly not the case!

[est31]

The common theory is of the RNA world. In theory, if the entire organism is just a long RNA strand, there is no need for proteins or lipid bilayers. How such an organism emerged in the first place is already quite hard to know.

Actually lipid bilayers are extremely complicated as they have to filter what gets into the cell and what doesn't, as well as what might leave it. Earlier systems might have done without them and instead attached everything onto long chain like structures... You know like a keychain. Both RNA and Proteins are long chains so maybe that's how they evolved.

[BlueTemplar]

The article points out that it's not clear whether RNA-only can work, and that all 3 components might have been required.