Genetics

This article explores how the genetic risk for multiple sclerosis (MS) emerged through ancient human evolution, particularly during the Bronze Age migrations of steppe pastoralists into Europe. Drawing on large-scale ancient DNA and modern genomic data, it reveals that key immune-related variants—now associated with MS—were positively selected for their protective roles against infectious diseases. These findings highlight a fundamental evolutionary trade-off, where adaptations that once enhanced survival now contribute to autoimmune disease susceptibility in modern environments.