So we can go from inorganic molecules to organic molecules under primordial conditions. Let’s even say we can go from organic molecules to things like nucleic acids. The next step always gave me a sense of unease, however: a popular assumption is that cells somehow arose from this mixture – that after DNA formed, all of the cellular machinery that makes life’s (and DNA’s) self replication possible somehow sprung into existence, inconsequentially.

This doesn’t seem right to me. Cells are pretty complex. There are a lot of things that they do – that they have always been doing, as far as we know – that weren’t likely to spontaneously arise without some prior means of evolution (and thus something that reproduces).

I think something like a prion or a virus is a more probable step. Prions in particular, since modern viruses need to hijack cells in order to reproduce, while prions just need to come in contact with the right proteins. That means if viruses were the first “living” organisms, they would have required a capability that they somehow lost over the interceding time. Among viruses, I think something akin to retroviruses in particular would be good candidates, since direct RNA replication would cut out a great deal of complexity associated with DNA transcription and still result in a semi-viable means of genetic propagation. Of course, modern retroviruses reverse-transcribe their RNA into DNA prior to replication, but that’s because that’s what the cell uses.

Those are just some of my thoughts for today. The question of life’s origin fascinates me, and it irks me a bit that we have no way to simulate processes that took great spans of geological time to find some answers.

I often wonder whether it would be possible to simulate these sorts of things on a computer… but I wouldn’t even know where to begin.