The Hypersea. theory suggests that we - along with all multicellular plants and animals on land - share a vital identity with the ocean itself. In essence, it says that we're all 'encapsulated' pieces of marine ecosystem; moving about separately but maintaining necessary connections through the exchange of fluids.
Lots of very interesting conclusions have been drawn from looking at the world in that way. An article in Discover magazine offers the best available online overview of the subject, with references to the original presentation of the theory.