>>I'm not sure about there being no "complexification drive".
>>Brain sizes have
>>increased markedly over time, and land animals
>>with the intelligence of most
>>dinosaurs probably wouldn't be viable today.
>>Certainly there aren't any.
>Maximum brain size has been increasing, just as maximum body >size has been
increasing. But I don't think there is any more >evidence for a local
tendency in brains than there is in bodies.
In land animals, body size hasn't been increasing for quite a while.
Elephants are quite a bit smaller than many dinosaurs, and even smaller than
several of the biggest mammals of the past. Whales are indeed bigger than
anything before, but that's only at sea. But the smartest dino
(Nanotyrannosaurus, I think) had an encephalization quotient about that of an
ostrich, which is about as dumb a large land animal you can find today.
I did miss something. What exactly do you mean by a local tendency?