Though it is well accepted that dogs were the first domesticated animals, the question of where dogs came from is still a heated debate among scientists.
Over the past decade, various studies pointed to Europe, the Middle East and Southeast Asia as the likely origin for dogs, depending on what samples the researchers had and what kind of genetic analyses they were performing.
An extremely important group for studying questions about dog origins were the natural populations of free-ranging dogs (“village dogs”) found around the world. Unlike purebred dogs that have undergone extensive artificial selection and genetic bottlenecking, village dogs should retain many of the genetic signatures that can be used to disentangle the early evolutionary history of dogs.
However, little genomic investigation of these dogs had been done. So Embark co-founders Ryan Boyko and Adam Boyko, PhD traveled the world collecting DNA samples from dogs all over the globe, including over 2,000 village dogs.
In 2015, the Boykos and collaborating scientists from universities around the world published a study in the scientific journal Proceedings of the National Academy of Sciences (PNAS) showing that modern village dogs had a center of diversity in Central Asia. This suggests that dog domestication likely began somewhere in or near that region.
For this study, the scientists examined genomic data from over 5,000 dogs, including DNA from the mitochondria and the Y chromosomes. (These two types of DNA give scientists information about maternal and paternal history, respectively.) They looked at 4,676 purebred dogs and 549 village dogs from 38 countries.
This study represented the largest genomic survey of canine diversity at the time.
Embark cofounders, Adam Boyko and Ryan Boyko, traveled the world studying dog DNA to better understand the evolutionary history of our canine companions.
Key findings from dogs around the world
Through this study, the Boykos and the research team gathered three main findings.
1. Purebred dogs represent only a fraction of dog diversity
Although breed dogs are physically diverse and come in all shapes and sizes, they are not very genetically diverse. Genetically, their ancestry stems in large part from European dogs.
In contrast, village dogs are geographically widespread and genetically diverse. They make up the majority of the dog population around the world. The genetic diversity of village dogs is crucial to understanding canine evolutionary history.
2. Village dogs have varying amounts of DNA from European dogs
Depending on where in the world they are, some village dog populations have a lot of DNA from European dogs, while others have a mixture of DNA from both European and indigenous dogs.
This finding shows how geographical isolation and gene flow shaped the genetic diversity of dogs. (Gene flow, also called migration, refers to the mixing of DNA that occurs when individuals from one population interbreed with another population.)
3. Dogs may have originated in Central Asia
The scientists found strong evidence that dogs were domesticated in Central Asia, possibly near present-day Nepal and Mongolia. Dogs in nearby regions (e.g., East Asia, India, and Southwest Asia) contain high levels of genetic diversity due to their proximity to Central Asia and large population sizes.
The genetic data also show that indigenous dog populations in the Neotropics and South Pacific have been largely replaced by European dogs, whereas those in Africa show varying degrees of European vs. indigenous African ancestry.
Evidence from Central Asian village dogs
One important finding in this study is that dogs from several populations—including those in Vietnam, India, and Egypt—show minimal evidence of admixture with European dogs. (Admixture is the scientific term for when two lineages mix.) The evidence suggests that dog domestication started in Central Asia and spread to nearby regions, including Afghanistan, India, and Vietnam.
It’s important to note that, despite these findings, we cannot rule out the possibility that dogs were domesticated elsewhere and later arrived in Central Asia. It’s possible that dogs migrated there, or maybe were even domesticated independently in this region. However, recent research looking at ancient DNA samples of dogs and wolves have shown the genetic signatures in these samples is also consistent with a Central Asian origin for dogs.
While they have enjoyed working in remote corners of the world and in the lab, Adam and Ryan have always wanted to share their work and improve the lives of pet dogs everywhere.
This research powers Embark’s mission
This pioneering work not only gave us insight into the origin of the domestic dog. It also influenced the origin of Embark Veterinary.
Adam and Ryan Boyko started studying village dogs in 2007. They convinced National Geographic, the National Science Foundation, and others to send them across the world to study dogs in 40 countries for this project, resulting in this discovery. This research, as well as research in Adam’s lab at Cornell University, sparked the creation of Embark.
By testing your dog with Embark, you can contribute to more discoveries that help us understand dogs better. When you participate in our active studies or fill out Embark surveys, you’re joining millions of citizen scientists in support of canine genetics research. Together, we can help all dogs live healthier lives.
