(sorry if the title seems like flame-bait - but it's a real question). I'm trying to understand what could have come before the first cell (What are the "minimum requirements" for a single cell?)
From what I've seen, the presented chemical evolution (aka abiogenesis) process centers around self-replicating RNA that gets trapped inside a lipid-based protocell and then somehow turns into a functioning cell. But it seems like a giant leap to go from that situation to the most basic cell we know about.
Instead of starting from basic molecule and trying to get more complex, what if we take a simple cell (which is actually really complicated) and try to get more simple - try to take out some of the pieces. Work our way backwards. The problem is, I don't know what pieces you can take out. It seems there are several molecular systems that need to be functioning for cell to be viable. Once you start to imagine a cell without them, it seems the cell will not be able to survive or replicate.
My question is, what would the step just before a "minimum cell" look like? Are there pieces we can take away and it would still be able to survive and replicate?
** Edit **
Based on some of the discussions in the comments, I wanted to clarify what I'm asking. This is a bit long - but hopefully it will help.
Evolution is a process in which replicating systems transfer beneficial permutations to 'offspring'. Usually the term is applied to "biological evolution) (meaning something living - from a cell to more complex organism) but I've also heard people refer to "chemical evolution" which is the process in which atoms combine to make molecules and amino acids and the amino acids combine to make RNA which can replicate. Or fatty molecules combine to make a lipid membrane, etc.
In this process to get to something more complex, you have to have gone through a simpler stage. To arrive at RNA, you had to have a system that would first produce nucleic acids. If the first life was in the oceans, you needed something that could survive in and out of water before you now have creatures on dry land. Each stage has to have a predecessor.
Generally question of the origin of life start at the raw materials and work their way towards the more complicated. Most of the discussion I've seen basically end with RNA in lipid cells + billions of years = a prokaryote. The difference between RNA in a protocell and a working basic cell is vast and I haven't seen an explanation on how to bridge that gap.
I'm approaching the question from the opposite direction. If we take the most basic, simple prokaryote cell - what came before it? Even such a simple cell is in actually very very complicated (semi-permeable membrane, nucleoid, ribosomes, cytoplasm, etc..) There are so many interconnected pieces that it seems are only valuable when working as a whole. Eg, could I have had a cell without ribosomes and then some how it mutated to have ribosomes? It seem not, because a cell without ribosomes would never have survived/replicated. The same with other components.. if I have some precursors without that piece, it would never have survived long enough to mutate to now have that component.
So my question is what could the predecessor to a basic cell have been, considering its complexity and the seeming interdependence on the pieces for the cells survival?
I hope that helps explain the question better - thanks for any insight you can provide!