Some specialists believe that what happened in Europe about 7,400 years ago was like encountering an alien civilization. For tens of thousands of years, Europeans had been nomadic hunters, the only known lifestyle on an immense and virtually unpopulated continent. Until they met immigrants from Anatolia, in present-day Turkey, who brought with them agriculture, livestock and sedentary lifestyle. Their advance through the northern Mediterranean was so rapid—barely a century—that it is believed that they traveled in small boats along the coast. It was a time of conflict and coexistence. The farmers interbred with the locals until they absorbed them; although there were isolated clans of hunters faithful to their lifestyle for 1,000 more years. It is what is known as the Neolithic revolution, which laid the foundations of civilization.
One of the greatest enigmas of this era is how this revolution came to Africa. One hypothesis is that it appeared spontaneously, with a second invention of crops, and another that arrived about 5,000 years ago, by the hand of shepherds and farmers from the Near East.
Now, a team led by scientists from the University of Burgos and the University of Uppsala (Sweden) shows that the Neolithic arrived in this area in the same chronology as in Europe, about 7,400 years ago. Their conclusions, published in Nature, are based on the analysis of teeth and bones unearthed at four sites in Morocco, and their comparison with existing ones.
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The key is in the cave of Kaf Taht el-Ghar, on the northern coast of the Strait on the Moroccan side, where human remains, seeds and pieces of pottery decorated with mollusk shells were found. They were practically identical to those that had been found in the Peninsula.
Cave of Kaf Taht el-Ghar, from the early Neolithic.
"It was like finding a baroque cathedral in the middle of Aztec Mexico," explains Rafael Martínez Sánchez, an archaeologist at the University of Córdoba and co-author of the study.
Going or returning?
In the 50s of the last century, when Morocco was still a Spanish protectorate, the Catalan archaeologist Miquel Tarradell was the first to excavate this place. It was speculated that the decorated pottery of the Peninsula had been brought by immigrants from North Africa crossing the Strait, explains Martínez. But when he saw the ceramics, Tarradell changed his mind and postulated that it was the other way around: the Iberians took them to Africa, although he died in 1995 without being able to prove it.
Analysis of the DNA of four individuals from this site has now cleared up the mystery. The genetic profile of these farmers is 75% the same as that of those of the Peninsula. And about another third is North African. The conclusive proof of the origin of these immigrants is that they also carry a pinch of DNA from European hunter-gatherers that had been assimilated before.
The conclusion of the work is that a group of farmers from the Iberian Peninsula arrived in North Africa, interbred with local populations and settled bringing agriculture to the continent for the first time, about 1,000 years earlier than previously thought. Probably, they passed the Strait in wooden boats, without sails, using only oars, says Martínez, although no remains of these boats are known.
"It's something never seen before. In Europe hunters and gatherers never assumed the Neolithic way of life by themselves, it was always by absorption.
Cristina Valdiosera, University of Burgos
The enigmatic thing is that in Ifri n'Amr o'Moussa, about 300 kilometers to the south, there is another site at least a century later where remains of seeds, pottery and livestock have been found, but its inhabitants have turned out to be 100% autochthonous. Their DNA is no different from the nomadic hunter-gatherer populations that inhabited this area for about 15,000 years, including their tradition of pulling out the two incisor teeth of the upper jaw to differentiate themselves, as Louise Humphrey and Abdeljalil Bouzouggar explain in a companion article.
A few centuries later, local populations had embraced sedentary living, although they did not mix with immigrants from Europe, as if there were a well-defined border similar to that in parts of Europe between farmers and the last hunters.
"It's something never seen before," says Cristina Valdiosera, a molecular biologist at the University of Burgos and co-author of the work. "In Europe hunters and gatherers never assumed the Neolithic way of life by themselves, it was always by absorption," he says.
On the brink of collapse
In 2018, Valdiosera led a similar study on the peninsula that demonstrated the presence of farmers in times very similar to those seen now in Morocco. The genetic specialist estimates that the first groups of immigrants who crossed the Strait were dozens of individuals and
Researcher Juan Carlos Vera in the cave Ifri n'Amr o'Moussa, from the early Neolithic.
that there had to be several waves along the same route.
Before the arrival of the first farmers, North African populations were on the verge of extinction. If during the last glaciation in Europe the population collapsed to just 5,000 people, in North Africa only 1,400 remained, according to the work. The arrival of immigrants was a salvation for them, argues Valdiosera, because it increased genetic diversity and avoided the evils of inbreeding.
The study confirms that about 1,000 years after the first Neolithic migratory wave came a second one from the Near East that followed, now, the coast of the southern Mediterranean until reaching the current Morocco. DNA from three people who lived 6,400 years ago found in Skhirat-Rouazi, on the west coast of the country, shows the genetic mark of this new wave of immigrants. That same mark is in the current populations of the Maghreb and also in the Guanches of the Canary Islands, whose origin is in immigrants from North Africa.
Total miscegenation
The most recent deposit analyzed is that of Kehf el Baroud, about 50 kilometers south of the previous one. In this case, its inhabitants already show DNA from the first Iberian farmers, as well as from the native populations of North Africa and pastoralist immigrants from the Middle East. A total miscegenation.
Ron Pinhasi, an expert in evolutionary anthropology at the University of Vienna, says this is "an exciting and important study." "There was a lot of debate about whether the Neolithic had arisen spontaneously or whether it came from Europe or the Middle East. Surprisingly, we see that all that happened, although not at the same time. The first to initiate this period were the Iberian farmers. And here the most interesting thing is that they mixed with the locals, while some locals did not mix with them, "he points out.
Carles Lalueza Fox, geneticist at the CSIC, believes that "with this there is no example that the Neolithic could be transmitted culturally." "Although it was the dominant thinking a few decades ago, I think it is evident that agriculture is not something that can simply be explained or copied. Like any trade, it requires people who know it, that is, immigrants, at least in the first moment," he explains.
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