One striking discovery related to MS, a chronic disease of the brain and spinal cord that is considered an autoimmune disorder in which the body mistakenly attacks itself.

The researchers identified a pivotal migration event about 5,000 years ago at the start of the Bronze Age when livestock herders called the Yamnaya people moved into Western Europe from an area that includes modern Ukraine and southern Russia.

They carried genetic traits that at the time were beneficial, protective against infections that could arise from their sheep and cattle. As sanitary conditions improved over the millennia, these same variants increased MS risk.

links:

• archive of reuters piece: https://archive.ph/aXcpn
• more depth: https://phys.org/news/2024-01-ancient-human-dna-hints-multiple.html
• 50+ page paper: https://www.biorxiv.org/content/10.1101/2022.09.23.509097v1.full