Your dog may be more wolf than you think. Research from scientists at the Smithsonian and the American Museum of Natural History shows that most dogs living today still carry traces of wolf DNA.

Dogs are believed to have diverged from wolves about 20,000 years ago, and that ancient connection remains visible in some breeds. Purpose-bred wolfdogs, such as the Czechoslovakian Wolfdog and Saarloos Wolfdog, have the highest levels of wolf ancestry, with 23 to 40 percent of their genomes linked to wolves.

Wolf DNA is more common in larger and working breeds, such as sled and hunting dogs, but size alone does not tell the whole story. Large guardian breeds, think Neapolitan Mastiff and Bullmastiff, show no detectable wolf ancestry, while even the tiny Chihuahua carries about 0.2 percent.

Terriers, gundogs, and scent hounds tend to have the lowest levels of wolf ancestry on average.

So whether big or small, many dogs seems to carry a little echo of the wild.