Dog Domestication Dogs are one of humanity's most frequent companions, but when and how this relationship first began are still open questions. There is considerable evidence for fully domesticated and cohabiting dogs by around 15,000 years ago, but genetic studies and some fossils suggest that the relationship began much earlier, perhaps as long as 40,000 years ago or more. Identifying the first evidence of wolves becoming dogs is challenging, because early domesticating individuals are likely to have looked like wild wolves. Prassack et al . studied fossil canid teeth from a Paleolithic site in the Czech Republic from 28,500 years before the present. Using microwear analysis, they found distinct differences between individuals previously classified as “protodogs” or “wolves” based on their jaw structure. They argue that these differences reflect true differences in diet, specifically an increase in bone consumption in the protodogs that could have been due to a shift by early domesticated animals to a diet of human scraps. J. Archaeol. Sci. 115 , 105092 (2020).