The Origin of Life?

I think this description of life is much better than the definition of life. All living cells have all of these things going on in them, and pretty much they all seem to be necessary. So if you can find some environment where all those things just happen naturally then you're at least pointing in the right direction. And there's one other point as well, which is that we very strongly believe, based on the evidence, that there was a single origin of life. Everything that's ever existed on this planet for the last 4 billion years comes from a single origin.