The connection between human and dog runs deep. Early signs of domestication date back to 33,000 years ago and unambiguously domesticated dogs are common in the archaeological record beginning 15,000 years ago. The pairing makes for a striking case in coevolution — no other species has been so thoroughly integrated into human society. Dogs are our sentinels and shepherds, hunting partners and cancer detectors. And more importantly, to those of us who have had dogs in our lives, they are our dearest friends.
More likely, domestication happened slowly, in fits and starts. “This symbiotic or commensal relationship,” says Robert Quinlan, professor of anthropology at Washington State University, “probably initially happened accidentally.”
Wolves more likely became acclimated to humans while scavenging the remains of their kills — they essentially kicked off the domestication process themselves. “Wolves on their way to becoming dogs were a great alarm system,” Quinlan says. Domestic dogs are in fact more vigilant than wolves. The off-spring of these more-tolerant wolves were likely then selected for other useful skills, such as hunting.