My second kid is 5 is in Kindergarden, hasn't been tested yet, but reads at an advanced level and just accepted Jesus
First case: "utterly impossible?" Funny choice of words. Lets say some carbon based life form out west does something stupid like inject silicone into their breasts. Silicone leaks into the body, perhaps interacts with a bacteria or a virus and through a completely bizarre but not quite impossible set of circumstances creates a carbon/silicon life form.
Impossible? I'd say it's more likely than carbon based DNA forming on it's on.
Second case: A silicon bunny is found isolated in an environment thousands of feet undergound. No fossil record can be found, but that doesn't mean it doesn't exist, as plausible reasons are quickly developed of what might have happened to the record.
Third case: Rejected apriori, despite the acknowledgement that we might soon design such life forms ourselves.
Well intelligence is only fifty percent heritable.
Did you know that the founder of the IQ test was a Darwinist and based his work on the writings of Darwin?
Hey, that's neat! I was reading the newspaper at age 3, and I accepted Santa when I was 2 of my own free will. :-) (Probably Jesus as well, as we were Catholic.)