Nobody knows who invented the wheel, or when it was first used. Most historians suspect it was invented in many places at different times around the world. What is known is that it was widely in use around the world as early as 3,000 BC.

In this new study, the researchers suggest the invention and use of the wheel may have originated in an Eastern European copper mine. Such a site, they note, makes sense because of the greatly improved efficiencies that would have resulted as heavy ore was extracted from a mine and carried down a mountainside.

A likely precursor might have been a roller, essentially a tree trunk with limbs removed. It is likely people discovered that things could be moved downhill more easily when they were tossed on rollers thousands of years before the wheel was invented, including ore products moved down mountainsides in Eastern European copper mines.