Maybe I was a little over enthusiastic citing "current science" as a researcher might. I'm a chef instructor at one of the best culinary schools in the US, and work with a body of 30+ highly trained food professionals of various backgrounds, some of whom have degrees in nutrition. I guess that Joe is correct in saying that there is no definitive "dietary science", as opinions and the science behind them are constantly evolving, but I'm inclined to side with the trained professionals in my field. But in terms of digestibility and common sense based upon design by evolution, I'm fairly convinced about the animal fats. We've been consuming them for our entire development as a species. Canola oil not so much.
The "healthiest" cultural diets in the world, such as the Mediterranean diet you cite all share one thing in common, a particular ratio of Omega-3 to Omega-6 fatty acids, with a higher than average level of Omega-3's from a diet high in fatty fish. Keep in mind though, Japanese, West African, French, and Inuit diets are also cited as some of the *healthiest*. Many of the studies of these cultural diets also reflect on how the American diet is way out of proportion because we've changed the fat content of our livestock by feeding our cattle, pigs, and chicken, which were normally higher in Omega-3's, a corn based diet that's disproportionally high in Omega-6's. Grass-fed cattle for instance retain their normal high levels of Omega-3's where the grain fed ones do not and develop fat disproportionately higher in Omega-6. So it's all very convoluted and I still firmly believe that the less we mess with it, the better it is for us.
I also believe that's why refined sugar is so bad for us, we were never designed to eat the pure sugars out of a plant without any of the other macro/micro nutrients, fiber, and roughage that were a part of the original plant.