The excellent 3quarksdaily salutes John Maynard Smith, who died earlier this year. Writing there, Abbas Raza gives links to three obituaries, including this one, by Richard Dawkins, and a fine and heartfelt piece in The Guardian by David Harper, but it is the interview with the evolutionist that caught my attention most of all — it's wide-ranging, if brief. This clip shows what pains Maynard Smith took to communicate complex ideas clearly and conveys something of his philosophical disposition:
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the evolutionist: Well let’s start at the beginning. What is life?
JMS: I think that life has two characteristics. Imagine you get out of a spaceship on the surface of Mars and something walks up towards you on legs. On the front of it there are two disc-like objects, two antennae and a large hole with sharp serrations around the edge of it and so on. I think you’d guess that either this thing is alive or that it was made by something intelligent and alive. Let’s forget about the artefact possibility. Living things have parts which are clearly functional; they are there for something. In fact they are there for the survival and reproduction of the object they’re part of. So one aspect of life is that it’s not only complicated, but it’s complicated in an adaptive way. Hands and kidneys and livers and noses and eyes and ears and so on -- everything’s adapted for something. That’s the first feature of life.
The other way you can define it is to say that life is any population of entities which have the properties necessary to evolve this complexity. And those qualities are: they must reproduce; they must vary; and they must have heredity, that is to say like must beget like. If they have those properties then the rest follows. They will evolve complex adaptations.
Very early life was just the replication of molecules that could copy their structure, but didn’t code for anything. The idea is that the first life -- what is called RNA world -- was just RNA molecules. The same molecule was the replicator, the thing that got copied, and the thing that did something, i.e. was an enzyme. So there was no division of labour between genes on the one hand and proteins on the other, as there is today. A modern gene codes for something. But think I recognize it as life before genes coded for anything. I think I would recognize life when you have complex replicators, whether they’re coding for anything or not. Coding comes later.
the evolutionist: Are you happy that biology has got rid of any notion of an "essence", the idea that life is some magic spark?
JMS: I think it was Laplace who remarked, "I have no need of that hypothesis". He said it to Napoleon I think.
