About 20,000 to 40,000 years ago, some people decided to make friends with some wolves. Or maybe some wolves decided to make friends with some people. We’ll never know. What we do know is that dogs have evolved to communicate with us, live in our homes with us, and work with us. There’s no stronger bond between two species than the one between humans and dogs. Purchase this dog skull necklace to celebrate that friendship. It also makes an excellent gift for dog lovers, evolutionary biologists, veterinarians, and starry-eyed pre-vet students.