Universidad Autónoma de Madrid (UAM) Prehistory Associate Professor Luis Benitez de Lugo and other researchers were involved in the largest study to date of ancient DNA from the Iberian Peninsula
This study offers new insights into the populations that lived in this region over the last 8,000 years. The most startling discovery suggests that local Y chromosomes were almost completely replaced during the Bronze Age, around 2000 BCE. For this study, a team of researchers at Harvard Medical School and the Institute of Evolutionary Biology in Spain analyzed genomes from 403 ancient Iberians who lived between about 6000 BCE and 1600 CE.
Some of the samples used for this study, published in Science on March 15, were obtained by Benítez de Lugo from excavations he directed at the 4000 year-old burial site of Castillejo del Bonete, in Terrinches (Ciudad Real-Spain). This site is a key site for understanding the nature of the interactions between people of different biological ancestries. There, a woman and man were found buried side by side, and analyses revealed that the woman's ancestry was entirely local, while the man had very recent ancestors from central Europe.
“In Castillejo del Bonete there are no signs of violence or invasion, but of acculturation. It must. This specific gene does not imply any phenotypic features (of appearance) or a different vulnerability to diseases. The disappearance of pre-existing males in a relatively short time (something over 200 years) must be explained based on other arguments. The male carrier of genes from the eastern steppes deposited next to an Iberian woman in Tomb 4 was buried in a similar way to other deceased in this funerary monument. It can be considered that the beliefs and treatment of death in the case of that man did not differ from those of other people of the Bronze Age in La Mancha. In addition, the tomb contained the personal objects of the couple, which in both cases are characteristic of the Culture of the Motillas: two copper knives, two bowls, two buttons of ivory, a protector or armband on the forearm of the man and a copper punch inside the globular bowl ".
On the other hand, note the work, both the Tomb 1 and the Tomb 5 have recent ancestry of these populations that came to the Iberian Peninsula of Eastern Europe, as the rest of individuals of the Bronze, but not 100%. In other words, they have local and oriental ancestors and, during the Bronze Age, they develop common social practices in the Culture of Motillas de La Mancha.
"We knew that Castillejo del Bonete was a ceremonial center in which people and objects from very different places were buried inside a monument built in a sacred place in relation to the death-resurrection cycle of the sun. Now it is possible to affirm, in addition, that people with a genetic lineage from far away places were buried here together with other local and mixed, without having detected a difference in social practices until now" concludes Benítez de Lugo.
In short, Castillejo del Bonete reveals a union and genetic integration, at a time of increasing social stratification and environmental stress due to a climate crisis produced by a great drought that lasted hundreds of years.
Next summer professor Katina Lillios (The University of Iowa) will collaborate on the excavations at the site. With the help of a UI Global Research Partnership Award from International Programs, Lillios and five UI students will excavate at Castillejo del Bonete in July.
Lillios notes that “The period between 3000 and 2000 BCE in Iberia was a time of profound shifts in culture and climate. Large aDNA studies are valuable in that they generate questions and another set of variables that we need to consider in our analyses of historical change. Excavations at sites like Castillejo del Bonete provide an opportunity for us as archaeologists to investigate whether biological ancestry had a relationship to social or cultural practices in the Iberian Bronze Age.”
The genomic study, which was conducted by a 111-person international team led by researchers at Harvard Medical School and the Institute of Evolutionary Biology in Barcelona, Spain, also details genetic variation among ancient hunter-gatherers, documents intermingling of ancient Iberians with people from North Africa and the Mediterranean, and provides an additional explanation for why present-day Basques, who have such a distinctive language and culture, are also ancestrally different from other Iberians.
Referencia bibliográfica:
Iñigo Olalde et al. “The genomic history of the Iberian Peninsula over the past 8000 years”. Science. DOI: 10.1126/science.aav1444
