So if you think of it from a protocell point of view, the selfish replicators which are the best at making copies of themselves are necessarily those… - Nick Lane

[B]acteria, the simplest of cells, are... so complex that we still have almost everything to learn about their invisible organization.

s of some sort [lie between a hydrothermal vent system and a virus] in my mind. The trouble with viruses is that they do need a sophisticated environment to make copies of themselves. Same with selfish jumping genes, transposable elements and so on. They need to be in an environment where they can take advantage of something which is converting the environment into copies of themselves, and there's a rule... This is changing with the discovery of all these es, but as a rule you need some form of to convert the environment into copies of yourself.

Now CO₂ itself... doesn't really want to pick up any electrons and become reduced to an organic molecule, but if it's in a relatively ic environment where there's s available, it picks up a negative charge. It doesn't want another negative charge. It's going to try and repel that, but if there's a proton around, it picks up the proton. Now it's neutralized the charges... pick up another electron, another proton. So it's much easier to accept electrons in an acidic environment. And this is the structure of these vents and it's the structure of cells, and it's how these earliest, most ancient cells we know about actually do fix CO₂. They use the proton channel in the , which effectively locally acidifies an environment and allows this reaction to proceed. So I think that's fundamental, simple... works well, and it's testable in the lab.