Archaeologists challenge theory of violent invasion of Iberian steppes

A study by the Autonomous University of Barcelona (UAB) and the University of Murcia (UM) questions the theory that warrior groups with a “steppe” genetic component originating from Eastern Europe violently replaced the male population of the Iberian Peninsula around 4,200 years ago and presents a different scenario, in which groups of steppe ancestry mixed with other demographically weakened local populations.

In the article published in the Journal of Archaeological Sciences: ReportsThe research team studied how society and populations changed in southeastern Spain 4,200 years ago, during the transition from the Copper Age to the Bronze Age.

To do this, they focused on one of the best-known aspects of this transition: the shift from Copper Age collective burials to the single and double tombs of the Bronze Age El Argar society. The team examined a large sample of radiocarbon dates (C-14) of human bones found in these different types of tombs.

The first result of the analysis is chronological, suggesting that the shift from collective to individual graves occurred rapidly. But it is the second result that arguably has the most important implications. Examining a large sample of radiocarbon dates of human remains in southeastern Iberia, they observed a spike in the number of buried dead between 2550 and 2400 BCE, followed by a sudden drop between 2300 and 2250 BCE.

The authors interpret these data from a demographic point of view. “It is likely that the inhabitants of the southeast of the Iberian Peninsula were already very few in number, around 4,300 or 4,200 years ago, just before the arrival of populations with new genetic components, called ‘steppe’. When individuals of steppe ancestry were found in the southeast of the Iberian Peninsula, around 2,200-2,000 BC, they simply mixed with small local groups or occupied uninhabited areas,” explains Rafael Micó, professor at the UAB and co-director of the Mediterranean Social Archaeology Research Group (ASOME-UAB), who conducted the study.

Along with these findings, the team also cites previous archaeogenetic studies that highlight the absence of a “male bias” among peninsular groups of steppe ancestry.

“This allows us to propose a different historical scenario, which does not envisage the invasion of hordes of steppe warriors who would have annihilated the local men and formed a male elite with exclusive access to local women,” explains Cristina Rihuete Herrada, also a professor at UAB and co-author of the study.

A period of abrupt change, but with a gradual genetic influence from the “steppe”

Around 4,200 years ago, between the Late Copper Age and the Early Bronze Age, major social upheavals occurred in Central and Western Europe. Archaeologists still debate their exact origins, and explanations range from drought to large-scale violent migrations to the spread of contagious diseases.

“In recent years, it has been suggested that populations with so-called ‘steppe ancestry’ migrated westward from the region around the Black Sea, aided by the horse and the wheel as new technologies, and brutally attacked Western Europe,” says Camila Oliart, a UAB researcher and co-author of the study.

“In the case of the Iberian Peninsula, it has been suggested that men arriving from the East had preferential access to women and discriminated against or eliminated local men, in what is a very impactful “invasionist” interpretation in the media, but perhaps also too hasty.”

In the now published study, the research team describes a context that could have important implications for understanding the transition between the Chalcolithic and the Bronze Age in the south of the Iberian Peninsula 4,200 years ago, and in the southeast in particular.

In the two centuries preceding this date, the social landscape was probably very different from that of a prosperous Copper Age. It was probably characterized by smaller settlements and low population densities. In this respect, the Copper Age collapse 4,200 years ago was not a rapid, massive, disruptive event affecting a densely populated and powerful society, but the culmination of two centuries of declining local dynamics.

This new scenario does not involve the mass elimination of men or the subjugation of local women after an alleged conquest, as the study points out.

“The inhabitants of the southern Iberian Peninsula were already few in number at the end of the Copper Age and mixed with groups of steppe genetic ancestry without the need for a large-scale invasion. We should start considering alternative explanations,” suggests Miguel Valério, a UAB researcher and co-author of the study. “We cannot ignore the fact that violence was an ingredient of social life in the Copper Age, but so far there is no evidence that its end was the consequence of a generalized conflict between genetically distinct populations.”

However, the team stresses that more precise radiocarbon dating and genetic analyses on human samples from late Copper Age and early Bronze Age burials (El Argar) are needed.

“Such data are absolutely crucial to better understand the nature, magnitude and pace of changes occurring in the formation of Bronze Age societies,” they concluded.

During the study, some 450 radiocarbon dates matched individuals buried in Copper Age and Early Bronze Age tombs in Almería (La Atalaya, Las Churuletas, Los Millares, El Argar, El Barranquete, Fuente Álamo, Gatas, Llano del Jautón, Loma del Campo and Loma de Belmonte), Murcia (Camino del Molino), Granada (Cerro de la Virgen, Panoría), Jaén (Marroquíes Bajos), Seville (Valencina de la Concepción) and Évora (Perdigões) were analyzed.