What’s with this “clay”stuff anyway? Moving back to “RNA world” for a moment:
RNA is a jack-of-all trades. Like DNA it can store genetic material, but it can also catalyse chemical reactions. For this reason, many believe it was the basis of the first life. If this was the case then those early organisms must have had an enzyme created out of RNA to copy their RNA genomes. But no known RNA enzyme can copy a stretch of RNA as long as itself, without which RNA organisms couldn’t have survived for long.
Unless, the hypothesis runs, they were put on ice:
The RNA enzyme’s effectiveness at cold temperatures suggests ice was crucial to the first life. When a mix of RNA and metal ions freezes, growing ice crystals suck up the water, leaving tiny pockets of RNA and concentrated salt. RNA replication can happen in these pockets. “They’re a little bit like artificial cells,” says Holliger, and could be where evolution started.
Problem:
At cold temperatures, RNA strands often stick together, making it tricky to separate them after the RNA has been copied. Primitive life would need to warm up to separate the strands, says Jack Szostak of Harvard Medical School. “It couldn’t just live at continuously cold temperatures.”
Szostak himself is trying to construct life artificially in the lab: “You want something that can grow and divide and, most importantly, exhibit Darwinian evolution.” But genetic material is a harder problem than the cell membrane because “the chemistry is just more complicated..”
Actually, Szostak would have better luck with is project of just inventing life than expecting it to arise from Darwinian evolution. Inventing it is at least theoretically possible.
Note: Ice world has come up before, even though cold quickly reduces the speed of essential chemical reactions.