A Case for an Alien Ancestry [and Discussion]

A. G. Cairns-Smith, I. R. Kaplan, P. Fellgett


Many modern biochemicals can be formed in significant yields under loosely controlled abiogenic synthetic conditions. They are, in this sense, easy to make and appear to be among the moderately common molecules of the Universe. We might expect a highly evolved life form like ours to have perfected a system that uses a kit of easily made parts. This is a sign of sophistication, but it may well be the hard won outcome of a prolonged evolution. It is by no means clear that this evolution started with anything like the system that it eventually perfected. Arguments are presented, suggesting that our original ancestors had alien biochemistries. It would seem also that synthetic (alien) life is a prospect for the fairly near future.