Although initially thought to have originated as a manmade variant of an extant canid species (variously supposed as being the dhole, golden jackal, or gray wolf), extensive genetic studies undertaken during the 2010s indicate that dogs diverged from an extinct wolf-like canid in Eurasia 40,000 years ago. Being the oldest domesticated animal, their long association with people has allowed dogs to be uniquely attuned to human behavior, as well as thrive on a starch-rich diet which would be inadequate for other canid species.