Researchers have surprising news about what breeds of dogs came first and which dogs are most closely related.

The scientists found new information about the canine family tree as they were looking at genetic variations in dogs for clues to the nature of human diseases.

An extensive genetic analysis of 85 dog breeds – representing the majority of registered purebred dogs in the United States – has revealed that pooch pedigrees from the Shiba Inu to the greater Swiss mountain dog each possess a genetic signature far more distinctive than expected. The surprising discovery, researchers say, may help them pinpoint the underlying basis of a host of genetic diseases shared by dogs and humans alike.

Authors of the study, published Friday in the journal Science, said the extent of the genetic differences surprised them since most purebred lines have been separated only within the past few centuries.

“The most surprising thing was that the breeds that first split off (from the wolf) are pretty far flung geographically. They cover Africa, Asia and the Middle East. They’re extremely different in size and behavior, and yet they share a genetic signature,” said Howard Hughes Medical Institute reseasaid Howard Hughes Medical Institute researcher and co-author Leonid Kruglyak.

It has been hypothesized that dogs originated in Asia, migrating with nomadic human hunters to Africa and the Arctic. This would account for the wide distribution of subsets of that oldest group, which include the Chinese chow chow, Pekingese, Shar-Pei and Shih Tzu; the Japanese Akita and Shiba Inu; the Central African basenji; the Middle Eastern Saluki and Afghan; and the Tibetan terrier and Lhasa apso.

Also in that subset are the Nordic breeds including the Arctic Alaskan malamute, Siberian husky and Samoyed, all of which have the closest genetic relationship to the wolf and may be “the best living representative of the ancestral dog gene pool,” according to the researchers.

Surprisingly, several breeds believed to have ancient roots turn out to have been created in more recent times by combining various modern breeds.

Pharaoh hounds, Ibizan hounds and Norwegian elkhounds have long been considered continuous breeds, based on Egyptian tomb drawings and Scandinavian folk tales. But while their appearance matches ancient images, their genes don’t.

“History says these breeds have unbroken bloodlines stretching back 5,000 years to Egypt and Scandinavia. But if you look at (the genes of) those breeds, you don’t see the ancient signature at all. They look like they’re European re-creations,” Kruglyak says.

The study’s main contribution, however, may be in elucidating the genetic basis of both canine and human disease.

“The number one killer in dogs? Cancer, the same thing we care about in humans,” said Elaine Ostrander, a study co-author and a geneticist at the Fred Hutchinson Cancer Research Center in Seattle.