Richly endowed grave from the Early Bronze Age of Bohemia, in today's Czech Republic.The most far-reaching archaeogenetic study to date on 271 humans who lived between 4900 and 1600 BC in the heart of Europe has just been published in Science Advances, revealing unprecedented genetic changes and social processes.The first macro-study of its kind on such a specific regional scale, in the fertile Bohemian lowlands on the banks of the Elbe River, in the western part of today's Czech Republic.The knowledge we have of the third millennium before Christ (BC), has been built with the traces of our ancestors.Traces in the form of objects, and in the best of cases, spoils of what remains of their bodies, buried in a way and with objects that also give us clues about the rituals and culture to which they belonged.In short, to reconstruct the story of humanity, archaeologists and historians date what they find with the radiocarbon technique, or Carbon 14. In the case of this news, they also study the genomes of the bones they find with laboratory techniques of archaeogenetics, scraping bone marrow powder to extract their DNA.The analysis of this DNA and its comparison with the rest of the bone samples of bodies found in the same area, dated at different dates, will give us an idea of ​​how and when the human clans mixed or isolated, how we have come to to be who we are today, and to complete our family tree.Contributions of the study in the Bohemian Region of the Elbe River.The new foci in which samples of bones and objects that were later classified were found are represented in red.Luka Papac, first author of the research, sums up its importance by claiming that "Despite the importance of the third millennium BC, our genetic understanding is based mainly on pan-European studies, with little emphasis on regional time periods in more detail. For those there are still many gaps in time and geography, and we have limited knowledge of the processes of societies and communities, how different cultural groups interacted, or whether they influenced and originated one another.Papac and his team elucidated that individuals associated with the Corded Pottery culture spread from Eastern Europe and mixed with Central European women, burying them with the same rituals.They added them to their community.The researchers also saw that about 5,000 years ago, at the confluence of the Globular Amphorae, Rivnac, and Corded Pottery cultures, a major genetic change occurred.They found individuals with high amounts of steppe, hunter-gatherer, ancestry, along with others with little or none, but all buried according to the same customs.Dating of new and previously published samples (Top) and chronology of archaeological cultures, external influences, and degree of change in material culture (Bottom).The individuals of the Ceramica Cordada culture, once established in the region some 4,900 to 4,400 years ago, changed genetically over time.An important change was the decrease in Y-chromosome lineages (for which only males are carriers).At first, Corded Pottery individuals carried five different Y-chromosome lineages, over time, that variety became a single Y-chromosome lineage."This pattern may reflect the emergence of a new social structure or mating regulation in which only a subset of males fathered the majority of offspring," says Papac.In the next society, the Bell Beaker Culture, about 4,500 to 4,200 years ago, each man analyzed belonged to a single Y-chromosome lineage never before seen in Bohemia.This implies that a new clan arrived in the region and almost immediately replaced all pre-existing Y lineages, with not a single lineage of Corded Pottery or earlier societies being found among the men of the Bell Beaker culture.Representative grave goods from one of the first burials of the corded pottery culture of Central Europe.In the transition from the Bell Beaker culture to the Unetice culture of the Early Bronze Age, another surprise discovered in this study is that there was a genetic turnover from regions of northeastern Bohemia.To date, the Unetice culture was considered to be descended from individuals of the Bell Beaker culture, with perhaps a limited contribution from individuals from the south-east, from the Carpathian Basin.The study has provided that 80 percent of the early Y lineages of the Unetice culture are also new to Bohemia.In fact, these lineages relate to individuals from northeastern Europe, not southeastern Europe."We did not expect to see such clear patterns. Although the region has played a key role in the emerging trade in, for example, Baltic amber, it also became an important trading center during the Bronze and Iron Ages. " adds co-author and co-researcher Michal Ernée.The full investigation can be accessed here.© La Vanguardia Ediciones, SLU All rights reserved.