The following report appeared in an archaeology journal.
"The discovery of distinctively shaped ceramic pots at various prehistoric sites scattered over a wide area has led archaeologists to ask how the pots were spread. Some believe the pot makers migrated to the various sites and carried the pots along with them; others believe the pots were spread by trade and their makers remained in one place. Now, analysis of the bones of prehistoric human skeletons can settle the debate: high levels of a certain metallic element contained in various foods are strongly associated with people who migrated to a new place after childhood. Many of the bones found near the pots at a few sites showed high levels of the metallic element. Therefore, it must be that the pots were spread by migration, not trade."
