Re: Cambrian
No, the Cambrian does not disprove evolution. Yes, it presents some particular problems of interpretation. And if the Cambrian period was the only place we had fossils from, then proof of evolution would be more problematic.
But you have to look at the totality of evidence, and not fixate on the one place that presents problems. That's the fundamental difference in approach between scientists and nuts. Post Cambrian, the evidence of change in form over time is beyond massive.
Why the explosion? Possibly since life was relatively new, the evolutionary forms were more flexible. (Once you are an elephant, it's really hard to become a spider.) And as life became sufficiently populous, the competitive pressures became fiercer, producing the explosion of innovation. Those are top of the head speculations, but as MidGe states, we are a long way from needing supernatural explanations, and the more Cambrian is studied, the more it makes sense in natural terms.
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