Our hesitancy to think is also in our heads. And one could argue it doesn't take a lot of mindfulness to simply repeat that notion.
( I'll just drop this link here:
http://xkcd.com/610/ )
Also, by any sensible definition, microbes or fungi or cockroaches don't dominate. They persevere at best. You could say no species has full control over Earth's biosphere, but if you name one that has the most of it, it has to be Homo Sapiens.