Courtesy of Albano Beja-Pereira

Donkeys still perform transport duty in Africa’s Nile delta.

Did modern civilization ride out of Africa on the back of an ass? Albano Beja-Pereira, a molecular biologist from CIBIO-University of Porto, Portugal, sampled donkey DNA from 52 countries and found that the modern-day animals are descended from two lineages domesticated in northeast Africa about 5,000 years ago, making the donkey the only significant domesticated species that originated in Africa. The donkey certainly predated the camel and arrived around the same time or earlier than the horse. Interestingly, the donkey joined human society right about the time the first city-states began to band together into larger, more complex civilizations.

“I don’t think it’s wildly speculative to suggest that the use of donkeys, which were the first tamed transport animal, played an important role in the unification of distant cities,” Beja-Pereira says. “It marks the boundary between human societies concerned with survival and agriculture and stabilized people who wanted to explore and trade.” He notes that the arrival of the donkey marks the point when pharaonic kingdoms really began to flourish. All donkeys today are physically indistinguishable, which Beja-Pereira regards as a tribute to their well-traveled past: “Think of how much variation between continents—and even between regions—there is in cattle. Donkeys have been intermixing with distant relatives for so long that they’ve reached a point where there are zero regional differences no matter where you look.”