Where are domestic dogs from? Some researchers say Central Asia. Others say East Asia. Others the Middle East. And others Europe. In contrast, we know that human ancestry is "Out of Africa." We don’t know where, whether it be in the east or south of Africa, but we know the basics: that 50,000 years ago a massive human population expansion occurred from the African continent that swept the world. So why are we less certain as to the origin of our best friend? There are several differences between dogs and humans, in case you hadn't noticed.
Humans are the ones who fund research, and it turns out that there is more money put into understanding the origin of our species (perhaps Embark can push the needle on this?). There are many more samples of humans, and human genetic research has proceeded for many more years than that into the origin of dogs. In short, there's a lot more data for humans. For humans we have samples from every population you can think of (and many you probably can't), and, lots of genes surveyed. Additionally, we now have whole genome sequences galore, and, ancient DNA. This brings into greater focus human origins. The story of the dog is not quite as polished yet.
Then there is the issue that the demographic and evolutionary history of the dog may simply be somewhat more complicated than our own. There is only one human lineage still surviving today (us!). However, several human lineages (including Neanderthals) descends from the many which flourished 100,000 years ago. In contrast, wolves, the ancestors of the dog, persist today - the two can even mate and produce viable and fertile hybrids! Stick with me here...because dogs and wolves can mate, it may in fact be that the dog has had multiple partial points of origin, where early dogs mated with wolves in their local area after they left the original site of domestication. Not only may dogs have emerged at different places, but they may have emerged at different times. At this point we don't have much final resolution with the data we have on hand, though there are general pointers to somewhere in Eurasia, particularly Central Asia. Embark's scientists have traveled the globe to understand this history better than anyone else - so stay tuned for some updates to this story!
Finally, unlike humans, dogs go where we want them to go (especially if you have a pig ear) and have long been traded across human populations like salt, spices, and other valuable goods. This means that the genetic patterns of dog migrations have as much to do with human cultural patterns as they do with the natural expansion of the species. In fact, Embark's scientists have found that village dog populations can often be traced to specific European colonizing powers; the dogs in Brazil descend from Portugese dogs while those in Peru come from Spain. Apparently Europeans loved their dogs so much they brought them with them wherever they went!
Because dogs are impacted by human culture, and because culture changes fast, unraveling the layers of dog history may actually be more difficult than the deep history of humanity. Our genetic tools are getting better and better, but the task is a very hard one.
That is why Embark is committed to a scientific mission, as we aim to assemble the largest dog genetic database. Our ambition is not to survey only 10,000 dogs, but millions. With such sample sizes we may finally be able to lift the veil and unravel the mystery of the origin of our best friends.