Analyses of African wild ass MtDNA have confirmed the identity of one of the ancestors of the domestic donkey.
The ancestor of the other genetically distinct group is unknown, but it has been confirmed that the mostly solitary Somali wild ass is the ancestor of neither of these two groups. The exact identity of this other group is still up for speculation, including some “wild ass” guesses. (If you don’t like these jokes, then you probably think I’m an ass after reading this post.)
These studies confirm that the first domestication of the donkey occurred somewhere in North Africa around 5,000 years ago. This finding is pretty interesting, because no other large African mammal has been domesticated.
What’s more is that the researchers found that domestication was an ongoing process. The Nubian wild ass was domesticated several times, and there was always a gene flow between the wild and domestic populations. This finding is not entirely different from what we’ve found out about dog and wolf populations.
Now, the identity of the other ancestor of the domestic donkey is still a mystery. This is not actually all that unusual. We still do not know which population of wild mouflon is the ancestor of the domestic sheep and the feral European mouflon. In fact, it has only been recently that the European mouflon has been recognized as a feral sheep and is not part of Europe’s native fauna. The exact ancestral wild sheep is probably extinct.
And in this way, donkeys and sheep share a history. The Nubian wild ass is often thought of as extinct in the wild. No one has seen one since late the 1990′s.
But because it went extinct only recently, we can make comparisons using DNA extracted from recently deceased specimens.
It is certainly interesting that the MtDNA studies found this relationship. I am very curious about the identity of the non-Nubian wild ass-derived donkeys. I have not seen the study, and I am wondering whether Asian wild asses might be that ancestor.
I honestly don’t know whether onagers and kiangs can hybridize with domestic donkeys or whether these hybrids are fertile. I also don’t know whether all the different species of ass were included in that study or if all the different subspecies of African wild ass were included. I have not seen the study, but if one of my very well-connected readers could find it and send it to me, it would be very nice.
Of course, one must be careful with reading too much into MtDNA studies. MtDNA may be least prone to mutation, and it is very useful in tracing matrilinear inheritance. However, it is only one part of the genome, and there are no genome-wide analyses of the donkey. MtDNA is but one part of the genome. It’s useful for its purpose, but one must be careful in reading too much into it.
Remember, the MtDNA studies in domestic dogs strongly suggested that they were derived from East Asian wolves, specifically a South Chinese population. The genome-wide studies found that this simply was not the case. Using SNP-chip technology, it was found that Middle Eastern wolves were much more similar to domestic dogs than an East Asian population of Canis lupus.
So these are interesting findings, but we need to be cautious about accepting this finding as the final proof.
Still, it shows how important donkeys were in the founding of civilization. We Americans like to think our civilization was built on the back of a horse. It is true. However, world civilization has mostly been built on the back of the donkey.
Where I live donkeys are kept for one purpose: livestock guardians.
One can drive down any rural road in West Virginia and come across small herds of beef cattle. Usually standing in the midst of those cows is a donkey. The donkey’s job is to keep the coyotes and stray dogs out of the pasture– a job they would take seriously even if there were no cows there.
As a general rule, donkeys hate anything that looks like a dog.
The next time I see one of these guard donkeys, I’m going to think of their wild North African ancestors– one extinct and the other unknown. I’m going to think of the ancient civilizations that relied upon these animals to build their marvels and to grow the grain that fed their populations.
I’m going to salute the donkey. I’m going to look at it with wonder.
We would probably be nothing without them.
And now that we no longer need them in my part of the world, it is good to know that they are being put to some use. Guarding livestock from canine predators is really not that hard compared to being a beast of burden, as they are in so many parts of the world.
Compared to their counterparts in poorer countries, most American donkeys have it good.
And that’s no wild ass speculation.