A byte, the standard unit of data storage, is made of 8 binary bits.
There are approximately 7 billion people on Earth, (mostly) all of which have 8 fingers, not counting thumbs.
Those fingers can be seen as having two states, lowered or raised, which means we can treat them as bits.
Given: 1 human = 8 fingers
1 finger = 1 bit, therefore 8 fingers = 8 bits
8 bits = 1 byte
Q.E.D. 1 human = 1 byte
1 Earth = 7 billion humans
7 billion humans = 7 billion bytes
7 billion bytes = 7 million kilobytes
7 million kilobytes = 7,000 megabytes
7,000 megabytes = 7 gigabytes
Q.E.D. I Earth = approximately 7 gigabytes in the form of human hands, given some sort of processor.
Food for thought.