“At the interior of our cells, driving them, providing the oxidative energy that sends us out for the improvement of each shining day, are the mitochondria, and in a strict sense they are not ours. They turn out to be a little separate creatures, the colonial posterity of migrant prokaryotes, probably primitive bacteria that swam into ancestral precursors of our eukaryotic cells and stayed there.”
-Lewis Thomas
The Lives of a Cell
