http://www.digitaljournal.com/tech-and-science/science/secret-history-of-dogs-revealed-in-new-research/article/491134

New insight into the family tree of canines

Posted Apr 25, 2017 by Tim Sandle
A new insight into the family tree of dogs reveals a previously unknown dimension to the history of canines. This has come about through the largest family tree of dogs ever assembled.
Jake the dog
The dogs world
File photo
The aim of the canine family tree project was to reveal the evolutionary history of the 150 or so modern breeds of dog. What is additionally interesting about the study is the finding that The study also unearths evidence that some dogs are descended from an ancient breed of dog. It is thought this so-called 'new world dog' travelled with the ancestors of Native Americans into the Americas, at a time when the American and Asian continents were adjoined by a land bridge. The idea of the 'land bridge' remains a theory. The concept is that people migrated from Siberia to Alaska across a land bridge that spanned the current day Bering Strait. With this, the first people to populate the Americas were believed to have migrated across the Bering Land Bridge while tracking large game animal herds. This diaspora appears to have included an ancestor to the modern dog.
From this 'new word dog' it is likely that many of the modern breeds descended. The breeds arouse through humans selectively breeding dogs in order to bias towards certain traits (putting genetics into action). This began with selecting dogs to breed based on their ability to perform tasks such as herding goats or cattle. Later on, physical traits like size and color were selected for. As to which dogs today most closely resemble the 'new world dog', these are likely to be the Peruvian hairless dog and the Mexican hairless dog.
The lead researcher, Dr. Heidi Parker of the U.S. National Institutes of Health explains: "We think there is still some signature of New World dog hiding in the genome of some of these American breeds."
The findings are based on a genetic study of 161 modern dog breeds together with their wild relatives: the wolf and the golden jackal. From this, the researchers traced 23 clusters of dog breeds that are all similar to each other. This produced interesting findings, such as pointers, the setters and the retrievers being very closely related.
The full findings are detailed in the journal Cell, in a research paper titled "Genomic Analyses Reveal the Influence of Geographic Origin, Migration, and Hybridization on Modern Dog Breed Development."