Sometimes they become less useful to themselves.

Animal remains also allow archaeologists to reconstruct choices.

A population under pressure may slaughter younger animals earlier, reduce the number of cattle it keeps, rely more heavily on sheep, or increase its use of wild resources.

Such patterns are not merely dietary curiosities.

They are economic decisions preserved in bone.

When combined with soil evidence and settlement chronology, they can reveal a society gradually changing its priorities.

The Greenland Norse appear to have done exactly this.