Alva Review-Courier -

WASHINGTON (AP) — Ancient DNA helps explain why northern Europeans have a higher risk of multiple sclerosis than other ancestries: It's a genetic legacy of horseback-riding cattle herders who swept into the region about 5,000 years ago.

The findings come from a huge project to compare modern DNA with that culled from ancient humans' teeth and bones — allowing scientists to trace both prehistoric migration and disease-linked genes that tagged along.

When a Bronze Age people called the Yamnaya moved from the steppes of what are now Ukraine and Russia into northwestern Europe, they carried gene v...