Nobody knows when dibs started. It's likely a global natural phenomenom first seen when Adam called dibs on that apple and Eve had to share some with him.
Due to the powerful nature of Dibs, you can't just call dibs all willy-nilly. There are rules, motherfucker.
Same Room Dibs:
You must be in the same room, or able to see with your eyes, the item you want to place dibs upon.
Multi-day Dibs:
You can't call multi-day dibs. Don't be lazy.
Dibs by Proxy:
It is not permissible to have a proxy call dibs for you.
Thievery:
If you steal something, you cannot call dibs on it post-theft. This automatically nullifies your dibs.
Spouses:
It is wise to be careful when using dibs with a spouse. You have to live with this person for the rest of your life, dumbass.