After participating in a study on the genetic evolution of the populations of the Iberian Peninsula, published in Science, UA researchers try to see if the Steppe-related ancestry new lineage did survive or was replaced
Alicante, 27 March 2019
What happened between 1,200 and 800 B.C.? University of Alicante researchers from the Institute for Archaeology and Heritage Research (INAPH) are trying to explain the gaps existing between 1200 and 800 B.C.
The archaeological site ‘Cabezo Redondo’ in Villena is one of the few with samples from the Bronze Age that have been provided to validate the international study The genomic history of the Iberian Peninsula over the past 8,000 years, published in the journal Science on 15 March, which analyses the genetic evolution of the populations of the Iberian Peninsula in the last 8,000 years. The research project on this site – directed by INAPH members and lecturers Mauro Hernández, Gabriel García Atiénzar and Virginia Barciela has contributed three of the 271 samples of the genomes analysed from individuals coming from sites on the peninsula with different timelines. The result is a genetic map of the peninsula. The data provided by several burial remains in the Cabezo Redondo site have allowed to genetically identify the populations of the Bronze Age (2,200-1,200 B.C.), making clear the replacement of elites and the appearance of a new population group originally from the Steppes (southern Russia and Ukraine) that settled on the Peninsula at the beginning of this period and managed to remain in power for centuries.
The samples of Cabezo Redondo analysed in the study correspond to three males, whose Y chromosome matches that of haplogroup R1b and who died between 1,700 and 1,600 B.C. They were buried inside different dwellings in the village, a ritual reserved for people of higher rank. Also, as part of grave goods, small gold and silver jewels were found in tune to this higher status.
The evidence of the arrival of groups descended from shepherds from the Eastern European steppe, the so-called Yamna culture, between 4,000 and 4,500 years ago is associated with the Beaker culture expansion in the Iberian Peninsula, a period characterised by the appearance of the first copper weapons and decorated ceramic vessels used in different social rituals associated with elites. Genetic results show how, progressively and during a stage that could last about four hundred years, the Y chromosome lineages — exclusively of male individuals — present in the Iberian Peninsula until the Copper Age were replaced by a new steppe-ancestry lineage, the R1b. This fact should not be understood as a massive migration or a violent replacement of local populations, but instead as a process that took place over several generations, during which these steppe populations were able to consolidate their power.
They arrived around the year 2,400 B.C. and were replaced by the local elites. These new settlers breed with local women. The result is that six hundred years later the local elites are their genetic heirs This is confirmed in the graves, many of them linked to the elites, documented during the following stage, the Bronze Age, in which the survival of this lineage is observed. For this reason, the UA researchers have been able to contribute the three samples for DNA analysis to the international study. According to García Atienza, the arrival of this population group to the Iberian Peninsula may have been due to the fact that at that time there was a climatic change in the Steppe that tended towards greater dryness and, probably, they were looking for new lands as they were farmers and shepherds.
The macro-study has been co-led by researchers from the Spanish National Research Council (CSIC), the Institute for Developmental Biology (IBE) and Harvard University (United States) and is based on the analysis of the genomes of 271 individuals from sites on the peninsula with different timelines, and later contrasted with data from 1,107 other ancient remains and 2,862 modern remains collected in previous studies.
The survival of the steppe lineage for so many generations must be explained by a context of strong social stratification, in which elites became not only the social and political leaders but also the genetically predominant lineages, researcher Gabriel García Atiénzar stated He also said that we should bear in mind that the archaeological record, especially for burial remains, is not always representative of the entire population of groups from the past. In this sense, only the remains of sixty individuals have been found in Cabezo Redondo, a settlement from 2,000 to 1,250 B.C. and which, in its moment of maximum splendour could have been inhabited by more than two hundred people. The researcher explained that where and how the rest of the population was buried is still to be known, and it is possibly the inheritor to the pre-existing lineages in these lands before the arrival of the elites from central Europe. He reminded us that there were local women and men who did not have the right to be buried; it was the elites who had the right to be buried in Cabezo Redondo. This is the reason why UA researchers don't know where they are. According to the directors of the excavation, genetic data alone will not reveal the entire history of the human groups that have passed through our lands. In order to understand the changes suffered throughout history, it is essential to combine them with all the nuances and richness that can be offered by the research derived from the archaeological record.
These new settlers from the Eurasian Steppe arrived on horseback and this animal had not been tamed by that time. They used copper weapons, which were more advanced technology and managed to replace the elites of the time. This lineage was perpetuated until the arrival of the Phoenicians, in the first millennium B.C. (800 - 900 B.C.). At that moment, populations from North Africa, Phoenicians, arrive and settle there and, with the passage of time, they will end up settling in within the elites.
Four hundred more years to explore
What happened between 1,200 and 800 B.C.? UA researchers are trying to explain the gaps in between. The change in the funerary ritual that exists in the Iberian Peninsula from the year 1,000 B.C. is the incineration. This leaves a blank gap. Archaeologists want to know why it happened, whether it is due to social change, or because new settlers arrive or because they copy customs from other places. Experts are trying to find samples from this period to sequence the DNA of individuals from 1,200 to 8,00 B.C. and see if there is survival or replacement of that lineage. For this purpose, the samples contributed by researcher Alberto Lorrio, who works at the Phoenician sites of La Fonteta (Guardamar del Segura) and Peña Negra (Crevillente) are vital.
Science 15 Mar 2019: Vol. 363, Issue 6432, pp. 1230-1234
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