Re: Our rocky solar system may be rare
Sat, 11 Sep 1999 08:22:57 -0700

J. R. Molloy, <>, writes:
> But on the basis of what scientists have found necessary for life to get
> going, I tend to think life springs up more commonly than anthropic-minded
> folks would like to believe.

It's true that many of the basic building blocks of life, like amino acids, form pretty easily. But actually assembling some kind of self-replicating system or cycle is still not well understood. In particular, it is very hard to find non-biological pathways to synthesize RNA or DNA. At this point it looks unlikely that the first self-replicating systems used these chemicals, but there aren't any well accepted alternatives.

There is still a very hard step here, going from the building blocks to self-replication. Until we have come up with some convincing way to bridge this gap I don't think we can say that scientific evidence suggests that life is likely to be common.