Yes, www.goanimal.com is a good link. There is a lot of thought and learning gone into it. (Wish I lived in their area!) See especially the discussion at http://www.goanimal.com/panorama/what_is_fitness/what_is.htm which distinguishes clearly between "fitness" as we use the term loosely in terms of exercise and physical well-being and the meaning of "fitness" in the much narrower Darwinian sense. VERY helpful. Keith Thomas