[I]t's interesting to me that the bacteriophages, the viruses that you find in bacteria, are not remotely similar to the ones that you find infecting… - Nick Lane

It could be any of those <nowiki>[</nowiki>sodium, or other ion gradients]. The fact of life on earth is that it tends to use proton gradients, and we know particular environments that do use proton gradients, and the reason I think protons is because , which is to say the proton concentration, can modulate the reactivity of both and . Now sodium concentrations wouldn't do that, but protons, if you've got gas in alkaline fluids, hydrothermal fluids... what you've got coming out of these s, hydrogen is more reactive in alkaline conditions. It really doesn't want to push its electrons onto something else, but if it's in alkaline conditions it pushes its electrons onto something else, and the protons are left behind and they will react immediately with the hydroxide ions to form water, which is thermodynamically very favored, and so it's far more likely to push its electrons onto CO₂ if it's in alkaline solution.

I do like this quote from Simon Conway Morris that if the aliens call then don't pick up the phone. I'm not sure I'd really like to meet any of them very much. Perhaps... meeting bacteria would be the least scary... [T]he chances of meeting aliens is so remote that I haven't really troubled myself very much about it. It would be nice to think that if we did, somehow they would be a superior intelligence... they would have solved a lot of the problems of aggression and whatever else that humans have, but I fear not. I fear that it would be the opposite, that... natural selection has a knack of producing nastiness in intelligence.

<nowiki>[</nowiki>Martin Rees] may be right. If we were to go back 5 million years, as intelligent apes, and ask ourselves "What is postbiological life?" I think the answer is it's not a concept that would possibly mean anything. So we've had... 4 billion years of life on earth, and it's come up with an enormous wealth and variation, but it's all organic and... the chances of it coming up with humans? I can't put a number on that. ...I don't think there's an inevitability that life, once it's started will give rise to a human-like intelligence or beyond that. I think there's nothing inevitable about it, and if we just go back a few million years on earth, there was nothing inevitable about it. So I, personally would still look for organic life, but... I'm not sure that would be the easiest thing to find. It may be that it's easier to find, yes, nano aliens or something.