Re: Another problem for the Cambrian Explosion

Tim Ikeda (
Sat, 16 Oct 1999 21:11:47 -0400

>Although this work has long been known in molecular biology, it is
>worth noting that all of the details of the "postal service" of the
>eukaryotic cell were already present in the first metazoan organism,
>since the progenitor of both plant and animal cells was already
>equipped with the complete postal delivery system (as well as all
>of the other complexitites of molecular biology). This means whatever
>molecular biological evolution that has occurred would have to have
>occurred prior to the Cambrian, where there is no physical evidence
>for its occurrence. Just a thought.

Given that the protein targeting machinery in cells doesn't
fossilize, I'm not surprised of the lack of physical evidence.
However, comparative biochemistry of today's organisms might
provide some clues.

It's been suspected for some time that the metazoan diversification
was not driven by substantial biochemical/metabolic "innovation".

Art, I know you've posted this matter before, and I still don't see
the connection to this thread's title.

Tim Ikeda (despam address before use)