My comment on Gaia was meant as a critique of applying the theory. The theory is indeed more than I described from what little I know of it and consistent with your comments. The implication I was talking about probably comes from the strong version.

I agree about prerequisites as well. Advanced intelligence would obviously have more chance of arising in primates than insectivores, but they were thought to have a common ancestor prior to the DNA based tree of life. I'm not sure where that puts them.

My comments were based on a warm blooded vertibrate as a the basic template needed to be preadapted to take advantage of any potential path to intelligence in a matter of tens of millions of years. I think there is little chance of evolving advanced intelligence without widespread distribution of the metabolism needed to support large brains. Such metabolism may take a different form elsewhere, but it evolved on Earth in that form around 200 to 250 million years ago if I recall correctly.

Regards,
Mark