Genetic data show mainly men migrated from the Pontic steppe to Europe 5,000 years ago
A new study, looking at the sex-specifically inherited X chromosome of prehistoric human remains, shows that hardly any women took part in the extensive migration from the Pontic-Caspian Steppe approximately 5,000 years ago. The great migration that brought farming practices to Europe 4,000 years earlier, on the other hand, consisted of both women and men. The difference in sex bias suggests that different social and cultural processes drove the two migrations. Ref. Source 7t.
This is fascinating to me. What drove a predominantly male migration to Europe? I would guess this was more of an invasion rather than a migration.