The largest genetic database of ancient humans has provided new insights into various medical conditions and heritable traits. One significant finding is that the genes associated with multiple sclerosis (MS) may have become more common because they helped people resist infections passed on from animals. The study analyzed bone and teeth samples from nearly 5000 ancient remains found in museum collections in Europe and west Asia.
The researchers compared these individuals with genetic data from 410,000 people from the UK Biobank, focusing on those with European ancestry. They discovered that individuals with a higher genetic risk of MS in the UK also had more ancestry from the Yamnaya, a group of livestock herders from the Eurasian steppe. Some of the genetic variants linked to MS first arose in the Yamnaya and became more frequent in their descendants as they migrated west through Europe.
The researchers suggest that these genes may have helped the Yamnaya fend off infections transmitted by animals. Another finding from the research is that people with more Yamnaya ancestry tend to be taller, which may explain the height differences between people in northern and southern Europe. Furthermore, the study also shed light on how ancestry affects genetic risk for Alzheimer's disease. Individuals with more ancestry from the first hunter-gatherer populations of Europe are more likely to have a gene associated with a higher risk of developing Alzheimer's.
Overall, this research highlights the profound effects that events from thousands of years ago can have on the health and traits of modern populations.