Dogs may be man’s best friend, but new research on ancient canine remains shows that the relationship didn’t develop overnight. For long periods of time, humans lived in tension with their canine companions, often eating them and skinning them for pelts. Theirs was a relationship of necessity and convenience.

But they also took the analysis a step further. They reasoned that domestic dogs would share a similar diet to the humans they lived alongside, but different from their wild cousins. Through an examination of collagen from the bone fragments, the team found that the domestic dogs had higher levels of nitrogen and carbon isotopes, an indication that they were eating more seafood and certain grasses associated with human agriculture. Wolves, on the other hand, would show a varied but more strictly carnivorous diet.