Animal experts frequently attribute the loyalty of dogs to a shared history. Canis lupus familiaris and homo sapiens have evolved together. The link between the two species dates many, many years back.

Researchers first theorized that dogs as we know them today evolved from wolves after they began cohabiting with humans. However, more recent studies have found a different conclusion. Experts now believe that dogs split off from their wolf ancestors approximately 135,000 years ago — before dogs or wolves started living with humans.