DNA. Contains all the instructions which essentially defines the behavior of each structure aka organelle, and as the narrator explained, it's possible that each component was originally its own solitary entity that eventually combined though symbiosis to become the larger organelle we refer to as a cell, much like the amoeba. Eventually these symbiotically formed a larger organism, that evolved over millions of years into humans. Perhaps our solar system is a cell within the galaxy, which is a conscious being that simply revolves, much like a huge starfish in the sea of space... I won't say I know for sure, but I'm quite certain that it wasn't because some magic dude with a beard and a nasty disposition sat down and "designed it". I believe it's actually much simpler than that. It's called probability combined with the various forces of attraction that build from the quantum to the galactic; cast across the expanse of space/time over billions of years from the heart of infinity.
