Archaeological bone fragments show risk genes for contemporary diseases
A major international research group has simultaneously published four articles in a single issue of the highly regarded scientific journal Nature. The articles shed new light on everything from population migrations and our prehistoric relatives to genetic predispositions to developing various types of brain disorders.
Kristian Kristiansen, Professor of Archaeology at the University of Gothenburg, is co-author of all four articles and led the research study that reveals who our Scandinavian forefathers were.
Although these articles relate to such different discoveries, they all converge into a single greater narrative: a narrative that describes how the interplay between different factors such as migration patterns, environment, diet and lifestyle during the Palaeolithic Era (early Stone Age) and beyond have left their mark in contemporary genetic material.
By comparing the prehistoric DNA profiles with analyses of contemporary DNA profiles, and combining archaeology with research in a long list of other fields such as medicine, epidemiology and historical migration research, the research group has succeeded in creating a precision tool that can generate entirely new scientific knowledge.
MS origin traced back in time
For example, one question that has occupied researchers for many years is the origins of multiple sclerosis (MS), a chronic neurological disease of the central nervous system in which the body’s own immune cells attack the insulation surrounding the nerve fibres in the brain and spinal cord. Why is the risk of being affected by MS approximately twice as high in Scandinavia as in Southern Europe?
Several theories have been advanced over the years, but none have been able to present a comprehensive answer until now. One reason has been the difficulty of finding the origins of MS.
With the aid of the prehistoric DNA profiles and the interdisciplinary research model, the research group has now been able to track the genetic traces of the risk gene for MS backwards in time and find its geographical origin around 5,000 years ago.
More specifically, to when the Yamnaya culture migrated across the Pontic Steppe (modern-day Ukraine, south-western Russia and western Kazakhstan) and mixed with groups of Eastern European farmers, before spreading across Europe in the form of Corded Ware groups (read more in the article New study unearths our Scandinavian forefathers).
Zoonoses theory
The study also indicates that it could have been a distinct advantage for Corded Ware groups to retain the risk gene, despite this gene increasing the risk of developing MS.
Although the article does not present any evidence that the risk gene could have constituted an advantage, the research group has a hypothesis.
Like previous farmer groups, the people of the Yamnaya culture had domesticated and bred cattle and sheep, and thus were exposed to zoonoses – in other words, diseases that can be transmitted from animals to humans. The Yamnaya people may have succeeded in transforming and augmenting their immune response through the evolutionary process to acquire better protection against zoonoses and infections – but with the disadvantage that this increased protection also came with a greater risk of developing MS.
“Thus far, we cannot establish this with certainty, but the zoonoses hypothesis is probable,” says Kristian Kristiansen, archaeologist at the University of Gothenburg.
Contact:
Kristian Kristiansen, Phone: +46(0)704-18 57 67, e-mail: kristian.kristiansen@archaeology.gu.se
Four articles in Nature
Population Genomics of Postglacial Western Eurasia (Allentoft et al.)
The Selection Landscape and Genetic Legacy of Ancient Eurasians (Irving-Pease et al.)
100 Ancient Genomes Show Repeated Population Turnovers in Neolithic Age Denmark (Allentoft et al.)
Two of the articles in Nature are related to the RISE II research project, which is financed by the Bank of Sweden Tercentenary Foundation (RJ) and is a collaboration between the Department of Historical Studies at the University of Gothenburg, the University of Copenhagen, and the Lundbeck Foundation GeoGenetics Centre. The other two articles in Nature on the Stone Age use material from the long-standing collaboration between the University of Gothenburg and the University of Copenhagen in the research projects RISE I and RISE II – a collaboration that began in 2011.
