The question of abiogenesis has never properly been resolved – we know that at some point a set of non-self-replicating molecules became a self-replicating molecule, from which all further life on earth evolved (at least all the evidence points to life having only arisen once on the planet, though it’s possible this happened multiple times). One of the neatest hypotheses that I’ve heard was one from the chemist Graham Cairns-Smith. He pointed out that clay has two interesting properties. The first is that it’s made of crystals – which grow in consistent shapes. If you break a crystal, but allow it to continue growing, you get two crystals with the same basic pattern.Part 1, 2, 3, 4, 5, 6, 7, 8.
The second is that silica – which clay is made of – is a catalyst for all sorts of interesting chemical reactions.
Now, the first of these things means that natural selection, of a sort, will act on clay – different shaped crystals will be more or less likely to be destroyed by weather conditions, and the ones less likely to be destroyed will be able to reproduce. Some of these shapes will also be conducive to the creation of some molecules than others. But those molecules cold, in turn, make it easier for clay to form the shapes which make it most likely for them to appear. Suddenly, those molecules are helping the clay ‘reproduce’, and so the clay which produces those molecules is being selected for. And the molecules themselves are being selected for – increasingly complex molecules that can produce increasingly stable clay formations, and play an increasingly important part in reproduction.
Until one day one of those molecules becomes so complex, and plays such an important part in the reproductive process, that it breaks away from the clay and carries on reproducing itself without any clay at all. The clay gets left behind, as organic matter goes on to become ever-better at reproducing itself, and the clay just stays clay. The pattern has moved from one substrate to another, and transcended its origins.
2. How to make a hedge maze area rug. Via.
3. Amazon is giving away $2 in music credit. (Here's my recent music recommendations.)
