An international team of scientists claims to have uncovered answers to why certain diseases are more prevalent in different parts of Europe and why there is a height disparity between northern and southern Europeans, by examining DNA extracted from ancient teeth and bones.
The researchers identified that genetic variants initially advantageous for our ancestors in protecting against animal diseases are now associated with an increased risk of multiple sclerosis (MS).
This discovery, published across four papers in Nature journal, is described as a significant breakthrough in understanding the evolution and causes of MS, potentially influencing future treatments.
MS is characterized by the immune system attacking the brain and spinal cord, leading to symptoms like muscle stiffness and mobility issues.
The disease is twice as prevalent in north-western Europe compared to southern regions, prompting a decade-long investigation by researchers from the universities of Cambridge, Copenhagen, and Oxford.
The study traced the origins of MS-associated genes to a migration event approximately 5,000 years ago by the Yamnaya, cattle herders who moved westward from western Russia, Ukraine, and Kazakhstan into Europe.
Initially, these genetic variants provided protection against diseases in livestock. However, changes in modern lifestyles, diets, and hygiene have altered their impact, now correlating with a heightened risk of MS.
Dr. William Barrie from the University of Cambridge remarked on the surprising findings, noting that the genetic analysis of ancient DNA from museum collections and comparison with contemporary genetic data revealed critical insights.
“The genes which increase the risk of MS entered into north-western Europe about 5,000 years ago via a massive migration of cattle herders called Yamnaya,” Dr. Barrie explained.
Professor Lars Fugger, an MS specialist at the John Radcliffe Hospital in Oxford and co-author of the research, emphasized the importance of these discoveries in demystifying the disease.
He highlighted that MS is not caused by mutations but rather by normal genes originally meant to protect against pathogens.
Changes in disease space due to vaccinations, antibiotics, and improved hygiene have altered the role of these genes, potentially making modern immune systems more susceptible to autoimmune diseases like MS.
The team’s ongoing research aims to further look into ancient DNA for insights into other diseases such as autism, ADHD, bipolar disorder, and depression. Their findings also linked Yamnaya herders to the taller stature of northern Europeans compared to their southern counterparts.
Furthermore, the study revealed regional genetic predispositions to other conditions: southern Europeans are more prone to bipolar disorder, while eastern Europeans have higher risks of Alzheimer’s disease and type 2 diabetes.
Insights into human dietary adaptations were also uncovered, showing the transition from a meat-heavy diet to one including dairy products and vegetables around 6,000 years ago.
The researchers hope that continued exploration of ancient DNA will shed light on the genetic underpinnings of various diseases and conditions, providing new perspectives on human evolution and health.
