If someone makes an equation that reproduces and mutates, that's not going to be life. At this point the non-chemist is more than happy to abandon the parlor game. To be sure, life might not have started on earth, it might have dropped in from outer space. For chemists the problem is to recreate that lightning situation, and they can't do it. Biologists feel that since we have life today, we must be able to trace it back to earlier things, so they think it's the chemists' problem.
Chemists look forward and get depressed, biologists look back and are excited.
Alan and Nancy, the non-chemist finally realizes, are not trying to work their way forward from a hypothetical moment of origin. They're looking at life as it is, hoping to work backwards. A friend of ours gives a wonderful analogy. His name's Gaby Dover and he says, 'Imagine that you get life up and running like an airplane in flight. And then you have to start fixing the airplane up.