>>It doesn't matter at all how few these first known vertebrates
>>were (if they really were few, in number of species or of individuals). Nor
>>does it matter in the least that they were small, or that they were fish.
>
>oh, but it does. The most highly relevant word in my paragraph above is
>"only." All the cordata present were ONLY fish.
You seem to think the origin of the chordata was a trivial event compared
to the evolution of tetrapods etc from fish.
>In the history of life, complexity sort of peaked early. I don't really see
>how this helps the creationist case.
I can't speak for the creationists, but I can't help noticing that their model
involves a sudden origin of complexity followed by a stable level of
complexity, so I guess they might be encouraged by your admission.
The Cambrian boom will not be puzzled out, as long as anyone who mentions
it is labeled a creationist. It's really more fun to think scientifically about
this mystery than to worry about helping the creationist case.
--Cliff Lundberg ~ San Francisco ~ cliff@noe.com