so i was thinking about planarians. And they are the only animal it seems that can regenerate it's entire body from a single cell. I think this is because planarians are superorganisms, except they are ones that move around like worms. So basically planarians, almost like sponges or corals, are actually just a mesh of single celled organisms stuck together in a worm like body that happens to be able to move around. Their biology is extremely simple, they have no organs but do have a very simple "nervous" system which I think aren't living nerve cells but rather non-living electrical wiring that the cells produce to help them coordinate decision making with each other. I think perhaps the "eyes" of the planarian are not really living organs either, rather they are just like the "nervous" networking the planarian has, except external and is receptive to certain wavelengths of light. Again it's like a sponge, just one that squirms around.
A new type of organism? THE PLANARIAN!
Contrast this to an earthworm, which is actually smaller on average than the planarian (are they?). They have very very complex organs and systems, this is because the earthworm is not a superorganism, rather a single individual. And because an earthworm is so much larger than a single planaria cell, he needs cell differentiation, which in turn requires more complex biology to support all the different types of cells and those cells' different metabolic rates within the earthworm.
What do you think?