At sites in Tunisia (pictured here) and Algeria, archaeologists found evidence the adoption of agriculture wasn’t accompanied by a mass influx of new people.Giulio Lucarini

About 12,000 years ago, people in a dusty corner of Anatolia started the agricultural revolution. Their descendants soon spread west across Europe, bringing with them herds of animals, domesticated crops, and pottery—a shift in lifestyle archaeologists call the Neolithic transition. Over the course of several thousand years, these agrarian standard bearers absorbed, and then mostly replaced, the hunter-gatherers who had occupied Europe since the end of the last ice age.

New DNA results published today in Nature show hunter-gatherers in North Africa somehow flipped that script. In the long stretch of coast between modern-day Egypt and Morocco, known as the eastern Maghreb, the preexisting local hunter-gatherer ancestry remained dominant even after immigrant farmers arrived and began to marry into the population. Those farmers, the new study confirmed, first entered North Africa from what today is Spain and then later from the east, across the Sinai Peninsula.

Apparently, people in North Africa were pickier than Europeans about what parts of the farming revolution they adopted, which may have helped them hold on to their culture and traditions in the face of new arrivals. “It’s quite a difference,” says Mattias Jakobsson, a population geneticist at Uppsala University who was not involved with the work. “It’s clear European Neolithic ancestry is coming in, but not in a strong way.”

“In the broad picture of the Mediterranean transition, this is the most distinctive case we know of in terms of the local population persisting,” says David Reich, a geneticist at Harvard University who led the new research. “It’s surprising … given the turnover we’ve seen in the Neolithic transition everywhere else.”

The genetic data confirm recent archeological work showing hunter-gatherers in North Africa didn’t always adopt the so-called Neolithic package—including crop domestication, herding, and pottery—wholesale. In what is today Algeria and Tunisia, locals rejected crops and the sedentary lifestyle that comes along with growing them, but enthusiastically took to herding newly introduced domesticated cattle, sheep, and goats about 6800 years ago.

To better understand the population dynamics at play, researchers sampled DNA from skeletons at four sites in Tunisia and Algeria buried between 15,000 and 6000 years ago. They compared it with DNA from Europeans from the same and earlier time periods and from ancient individuals buried in modern-day Morocco.

The genetic results help fill in what had been a lopsided picture of Mediterranean prehistory. The North African heat—which breaks down ancient DNA faster—along with a lack of funding and a greater interest in European prehistory among European institutions has left a blank spot on the African side of the map. “This study is particularly valuable because, so far, research on ancient DNA from populations in North Africa and the Sahara remains extremely scarce,” says Barbara Barich, an archaeologist at the Sapienza University of Rome who was not part of the study.

The new data also reveal where the first farmers who intermingled with the local population originated. Their DNA is a match for that of people living in the Iberian Peninsula not long before. That’s an indication their ancestors came the long way around: not directly from Anatolia via the Levant and Egypt, but from the far west of Europe, crossing the Strait of Gibraltar and then spreading east. Only later did migrants arrive from the east, bringing with them domesticated animals.

The team also found signs that the Mediterranean was intimately interconnected long before the first farmers arrived. At a Tunisian site called Djebba, several individuals buried more than 8000 years ago had traces of ancestry connecting them to hunter-gatherers living on the other side of the sea.

Those data bolster the possibility of Stone Age seafaring, which archaeologists have long suspected based on stone tools sourced from islands in the middle of the Mediterranean Sea found in North African locales. “Ancient DNA has shown over and over again that human populations were more mobile than we initially expected,” says Rosa Fregel, a geneticist at the University of La Laguna who was not part of the research team.

There’s no clear explanation yet for why the region remained such an outlier when it comes to the spread of agriculture. Perhaps, Reich says, the hunter-gatherer population in the area was larger than that found elsewhere in North Africa at the time, and its sheer size may have helped maintain its traditions and lifestyle in the face of new arrivals.

Or maybe the shift to farming simply wasn’t as inevitable as early Europeans made it look in retrospect. Lucarini says the people of the eastern Maghreb consciously adopted the parts of the Neolithic package that worked for them. They herded goats, sheep, and cattle, for example, while continuing to hunt, gather wild plants, and collect abundant land snails, hedging their bets in an environment prone to drought and changing environmental conditions. “Perhaps this more fluid exploitation of the environment was less risky,” says Giulio Lucarini, an archaeologist at the National Research Council of Italy who co-authored the new study. “We’re thrilled to see the transition to the Neolithic in North Africa differs from the European model.”

The results are adding a fresh perspective to what had so far been a Euro-centric view of Mediterranean prehistory. “The Mediterranean is a linked world at this time period,” Reich says. “Without the genetic story of the southern Mediterranean, it’s like one hand clapping.”