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9 Corpses Reveal That Iberian Immigrants Brought Agriculture To Africa 7,400 Years Ago
DNA analysis uncovers unknown migration across the Strait of Gibraltar a millennium earlier than previously thought
Youssef Bokbot, from the National Institute of Archaeology of Morocco, and Cristina Valdiosera, from the University of Burgos, hold two skulls from the Moroccan site of Ifri Ouberrid.
07 JUN 2023 - 17:00 CEST
Some specialists believe that what happened in Europe some 7,400 years ago was like encountering an alien civilization. For thousands of centuries, Europeans had been nomadic hunters, the only known way of life on a vast and virtually unpopulated continent. Until they encountered immigrants from Anatolia, in present-day Turkey, who brought with them agriculture, animal husbandry and a sedentary lifestyle. Their advance across the northern Mediterranean was so rapid - it lasted barely a century - that it is believed they traveled in small boats along the coast. It was a time of conflict and coexistence. Farmers interbred with the locals until they were absorbed; although there were isolated clans of hunters faithful to their way of life for another 1,000 years. This 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 arrived in Africa. One hypothesis is that it appeared spontaneously, with a second invention of crops, and another that it arrived some 5,000 years ago, at the hands 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) demonstrates that the Neolithic reached this area in the same chronology as Europe, about 7,400 years ago. Their conclusions, published in the journal Nature, are based on the analysis of teeth and bones unearthed in four sites in Morocco, and their comparison with other existing sites.
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 found on the Peninsula.
Cave of Kaf Taht el-Ghar, from the early Neolithic.
One way or the other?
In the 1950s, when Morocco was still a Spanish protectorate, the Catalan archaeologist Miquel Tarradell was the first to excavate this site. It was speculated that the decorated ceramics from the Peninsula had been brought by immigrants from North Africa across the Strait of Gibraltar, Martínez explains. But upon seeing the ceramics, Tarradell changed his mind and postulated that it was the other way around: the Iberians brought them to Africa, although he died in 1995 without being able to prove it.
DNA analysis of four individuals from this site has now cleared up the mystery. The genetic profile of these farmers is 75% the same as those from the Peninsula. And approximately 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 who had been assimilated earlier.
The conclusion of the work is that a group of farmers from the Iberian Peninsula arrived in North Africa, interbred with the local populations and settled, bringing agriculture to the continent for the first time, some 1,000 years earlier than previously thought. They probably passed the Strait in wooden boats, without sails, using only oars, Martínez points out, although no remains of these vessels are known.
This is 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 some 15,000 years ago, 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 life, although they did not mix with immigrants arriving from Europe, as if there was a well-defined boundary similar to what existed 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 paper. "In Europe, hunters and gatherers never assumed the Neolithic way of life by themselves, it was always by absorption," she stresses.
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 genetics specialist estimates that the first groups of immigrants that crossed the Strait were of dozens of individuals and that there had to have been several waves along the same route.
Researcher Juan Carlos Vera in the Early Neolithic Ifri n'Amr o'Moussa cave.
Before the arrival of the first farmers, the populations of North Africa were on the verge of extinction. If during the last glaciation in Europe the population collapsed to barely 5,000 people, in North Africa there were only 1,400 left, according to the paper. The arrival of immigrants was a salvation for them, Valdiosera argues, as it increased genetic diversity and avoided the evils of inbreeding.
The study confirms that about 1,000 years after the first Neolithic migratory wave, a second wave arrived from the Near East that followed the southern Mediterranean coast until it reached present-day Morocco. The DNA of 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. The same mark is present 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 interbreeding
The most recent site analyzed is that of Kehf el Baroud, some 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 indigenous populations of North Africa and pastoralist immigrants from the Middle East. A total crossbreeding.
Ron Pinhasi, an expert in evolutionary anthropology at the University of Vienna, believes 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 of these things 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 stresses.
Carles Lalueza Fox, a geneticist at the CSIC, believes that "with this there is no longer any example left that the Neolithic could be transmitted in a cultural way". "Although it was the dominant thought a few decades ago, I think it is clear that agriculture is not something that can be explained or copied without further explanation. Like any trade, it requires people who know it, that is, migrants, at least at the beginning," he explains.
https://elpais.com/ciencia/2023-06-0...SuGjQOYrOeolHI
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Originally Posted by Jgab602
" what is from africa and what's not, how could they say this "The genetic profile of these farmers is 75% the same as those from the Peninsula. And approximately another third is North African"
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