How donkeys changed the course of human history

They are best known for their remarkable ability to carry heavy loads and their tenacious – almost stoic – demeanor towards work.

In some parts of the world (including Brazil), the donkey has been unfairly associated with expressions of insult or mockery.

However, in a French village about 280 km east of Paris, archaeologists have made a discovery that is helping to rewrite much of what we know about these despised beasts of burden.

At the site of a Roman villa in the French village of Boinville-en-Woëvre, a team unearthed the remains of several donkeys that would have dwarfed most of the species we know today.

“They were giant donkeys”, says Ludovic Orlando, director of the Toulouse Center for Anthropobiology and Genomics, at the Purpan Faculty of Medicine, in France. “These specimens, genetically linked to donkeys from Africa, were larger than some horses.”

Orlando leads a project that sequenced the DNA of donkey skeletons. It was part of a much larger study to trace the origin of donkey domestication and its subsequent expansion to other parts of the world. His research provides startling insights into the history of our own species through its relationship to these versatile animals.

According to Orlando, the donkeys that were bred in the Roman villa at Boinville-en-Woëvre measured 1.55 meters (or 15 hands, following the horse’s height measurement unit) from the ground to the withers – a protruding part between the shoulder blades of the animals.

The average height of today’s donkeys is 1.30 meters (12 hands). The only modern donkeys that can come close to this height are the American mammoth asses, which are exceptionally large male donkeys often used for breeding.

Giant donkeys like those found at Boinville-en-Woëvre may have played an important, but overlooked, role in the expansion of the Roman Empire and in its later attempts to maintain territory, according to Orlando.

“Between the 2nd and 5th centuries, the Romans bred them for the production of mules [pelo cruzamento dos burros com cavalos]which played an important role in transporting goods and military equipment,” he explains. “Although they were in Europe, they were bred and mixed with donkeys from West Africa.”

But the changing fortunes of the Roman Empire probably caused this species of giant donkey to disappear as well.

“If you don’t have an empire thousands of kilometers long, you don’t need an animal that carries goods over enormous distances,” says Orlando. “There was no economic incentive to keep producing mules.”

ADAPTATION TO CLIMATE CHANGE

To find out how donkeys played their role in human history, an international team of 49 scientists from 37 laboratories sequenced the genomes of 31 ancient and 207 modern donkeys from around the world. Using genetic modeling techniques, they were able to track changes in the donkey population over time.

They found that donkeys were most likely first domesticated from wild asses – probably by pastoralists – around 7,000 years ago in Kenya and the Horn of Africa. It’s a little earlier than previously believed, but perhaps most surprising is that the researchers also concluded that all modern donkeys living today apparently descended from that same domestication event.

Previous studies have indicated that there may have been other attempts at donkey domestication in Yemen.

And it’s interesting to note that the first domestication of donkeys in East Africa coincided with the desertification of the Sahara, which was once a green area.

The sudden weakening of the monsoons around 8,200 years ago, combined with increased human activity with grazing and burning, led to falling rainfall and the gradual rise of the desert and Sahel region. Domesticated donkeys may have been instrumental in helping humans adapt to this increasingly hostile environment.

“We believe that due to climate change, populations [humanas] locals have had to adapt”, says Orlando. “On donkeys, they could provide an essential service for transporting large amounts of cargo over long distances and in difficult scenarios.”

They noted that, apparently, the donkey population also declined dramatically after their initial domestication, only to undergo another strong increase.

“This is typical of domestication and observed at some point in almost all domesticated species,” says Evelyn Todd, a population geneticist at the Center for Anthropobiology and Genomics in Toulouse, who also participated in the study.

The reduction is the result of selecting a specific set of donkeys for domestication, while their further breeding contributes to their strong increase.

Analyzes indicate that donkeys apparently spread from East Africa, having been traded to Sudan and, from there, to Egypt, where remains of donkeys have been found in archaeological sites dating back to 6,500 years ago. And over the next 2,500 years, this new domesticated species spread across Europe and Asia, developing into the lineages we find today.

‘LOAD BURS’

According to archaeologist Laerke Recht, from the University of Graz, Austria, donkeys made a huge difference in the human ability to transport goods over long distances by land, due to the resistance of these animals and their ability to carry large volumes.

“Although rivers such as the Tigris and Euphrates, in Mesopotamia, and the Nile, in Egypt, could be used to transport heavy and/or bulky goods, donkeys meant a huge increase and intensification of land contacts”, she explains. .

Recht claims that this coincided with the increased use of bronze during the third millennium BC.

“Donkeys were able to carry the weight of copper over long distances and into regions where [o metal] could not be found naturally (or only in very small amounts), including Mesopotamia,” she says.

But donkeys and other equines also changed warlike equipment in the same period.

“We began to see them at the head of wheeled vehicles participating in battles, as well as providing the transport of necessary provisions for an invading army,” says Recht.

Donkeys were so important that they were even featured in important rituals.

“In Egypt and Mesopotamia, donkeys were considered so important that they were buried with humans – in some cases, even with kings or rulers,” says Recht.

“There are also cases of donkeys buried alone.”

She adds that, in the second millennium BC, donkeys were also sacrificed for so-called building deposits or foundations and as part of rituals associated with signing treaties.

The oldest specimens studied by Orlando and his colleagues were three Bronze Age donkeys found in Turkey.

“They are radiocarbon dated to 4,500 years old and have similar genetic makeup to modern Asian subpopulations,” says Todd. This indicates that the domesticated donkey subpopulation of Asia broke off from other lineages at about this time.

Research also confirms that donkeys have been much more constant companions to humans than their equine relatives, the horse.

“Modern domestic horses, which were domesticated around 4,200 years ago, had a very big impact on human history”, says Orlando. “Now, our study reveals that the impact of donkeys is even earlier.”

The endless usefulness of donkeys somewhat belies the amount of attention they have received compared to dogs and horses. Donkeys are now quite despised in many parts of the world. But, in some places, they still maintain the same importance as ever.

“The donkey is an important animal in the daily lives of millions of people around the world,” says Todd. “Its population increases by 1% every year.”

“In developing countries, donkeys are not used in daily life, but in many developing communities in regions that include Africa and the Arabian Peninsula, donkeys are still relied on to move people and goods,” she explains. .

Todd adds that understanding the genetic makeup of donkeys could also help improve their breeding and management in the future.

One important question researchers hope to answer in future studies is finding a close wild relative of the domesticated donkey. Orlando, Todd and their colleagues were able to identify three candidates.

“We know that the donkey is descended from the African wild ass,” says Todd. “There are three known subspecies. One of them became extinct in Roman times in 200 AD, the second is probably extinct in the wild, and the third is critically endangered.”

More study is needed to determine whether or not other unidentified subspecies of the African wild ass existed or still exist, which may help to increase our understanding of the genetic history of donkeys. Perhaps they reveal more about the important role played by donkeys in our own history.

read the original version of this report (in English) here.