I spent some of last week at a fascinating and lively symposium on the origins of life and the search for life in the universe, held at the Earth-Life Science Institute (ELSI) at the Tokyo Institute of Technology. To say that the science under discussion was broad in scope would be the understatement of the century. We went from planet formation to proto-life, digital organisms to artificial organisms in a lab, to the deeper nuances of that complex, emergent thing we label evolution, and to the means by which we look for life elsewhere.
Here are snippets of some of the things I learned, and some of the thoughts they prompted:
Planets really are extraordinarily diverse, and there doesn't seem to be any equivalent to the classic stellar Hertzsprung-Russell diagram classification system - or at least we've not chosen the right parameters yet.
Stochasticity rules planets, and probably much of what we call life too. There is no guarantee that a world, or an organism, is repeated precisely anywhere across the observable universe.
The inner workings of a planet like the Earth, especially throughout its history, are critically important yet largely unknown. How much water is 'built in' to the Earth - hydrated material from the earliest epoch of planet formation? How does the ratio of elements like magnesium and silicon alter the fundamental structure and evolution of a planetary mantle?
Chemistry is really, really, really mind-numbingly complicated. Just see what happens when we work out the isomeric possibilities for even relatively 'simple' molecular formulae.
Progress may be happening in spotting the kind of molecular structures that could have pre-dated RNA - chemistry in the lab is generating chains of 'supramolecular polymers' (rings of nucleobase-like molecules that stack together) from very plausible natural conditions.
Repeated hydration and de-hydration can drive very interesting molecular chemistry - the kind of cycles arising from day/night cycles, changing weather, or tidal variations.
Understanding life's origins will involve understanding life's dynamic nature. Swarming things are intriguing.
We can go and do experiments on life at hydrothermal systems, and we should do a lot more of this.
Buzzphrase: Open ended evolution
We still have no single definition of life. Perhaps it's not even a good question to ask?
We should stop talking about life's 'primordial soup' on Earth 4 billion years ago and instead talk about life's 'dishwater' - because whatever organics there were, they must have been extremely diluted.
The Late Heavy Bombardment need not have made the young Earth 'uninhabitable' while it was going on.
The primordial Earth 'healed' to something akin to its present geochemical/climate state, but perhaps Venus didn't - it never came out of its super-greenhouse state.
The chemical and environmental state of a young Earth is something we should probably spend a lot more time and effort on figuring out.
The bottom line: finding life in the universe and learning about its origins is one of the true scientific frontiers.