They are best known for their remarkable ability to carry heavy loads and a tenacious – almost stoic approach to toil. In some parts of the world, the donkey has become associated, perhaps unfairly, with terms of insult or mockery. But in a French village around 174 miles (280km) east of Paris, archaeologists have made a discovery that is helping to rewrite much of what we know about these under-appreciated beasts of burden. How donkeys changed the course of human history?
At the site of a Roman villa in the village of Boinville-en-Woëvre, a team unearthed the remains of several donkeys that would have dwarfed most of the species we are familiar with today. “These were gigantic donkeys,” says Ludovic Orlando, director of the Centre for Anthropobiology and Genomics of Toulouse, at the Purpan Medical School in Toulouse, France. “These specimens, which were genetically linked to donkeys in Africa, were bigger than some of the horses.”
Orlando has been leading a project that sequenced the DNA from the donkey skeletons. It was part of a much larger study to trace the origin of the domestication of donkeys and their subsequent spread to other parts of the world. The research is providing surprising insights into the history of our own species through our relationship with these versatile animals.
According to Orlando, the donkeys bred at the Roman villa in Boinville-en-Woëvre measured 155cm (61in, or 15 hands – a unit for measuring horse height) from the ground to the withers (a ridge between the shoulder blades). The average height of donkeys today is 130cm (51 inches/12 hands). The only modern donkeys that might have come close are the American Mammoth Jacks – male donkeys that are unusually large and often used for breeding stock.
Giant donkeys like those found at Boinville-en-Woëvre may have had an important but under-appreciated role in expanding the Roman Empire and its later attempts to hang onto its territory, says Orlando.
“Between the 2nd and 5th Century, the Romans bred them for producing mules [by cross-breeding them with horses] which played a key role in transporting military equipment and goods,” he says. “Though they were in Europe, they were bred and mixed with donkeys coming from western Africa.”
But changes in the fortunes of the Roman Empire probably were instrumental in this giant breed of donkey disappearing too. “If you don’t have an empire thousands of kilometers wide, you don’t need an animal that carries goods over huge distances,” says Orlando. “There was no economic incentive to continue producing mules.”
To trace how donkeys have played their part throughout human history, an international team of 49 scientists from 37 laboratories sequenced the genomes of 31 ancient and 207 modern donkeys from all over the world. Using genetic modeling techniques, they were able to trace 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, East Africa. While this is slightly earlier than previously believed, perhaps more surprisingly, the researchers also concluded that all modern donkeys living today appear to be descended from this single domestication event. How donkeys changed the course of human history?
Previous studies have suggested, however, that there may have been other attempts at domesticating donkeys in Yemen. Interestingly, this first domestication of donkeys in eastern Africa coincided with the aridification of a once-green Sahara. An abrupt weakening of the monsoon from around 8,200 years ago combined with increased human activity in the form of grazing and burning, led to a decrease in rainfall and the gradual spread of the desert and the Sahel region. Domesticated donkeys may have been crucial for adapting to this increasingly harsh environment.
