5,000 years ago, the Yamnaya culture migrated into Europe from the Caspian steppe. In addition to innovations such as the wagon and dairy production, they brought a new language — Indo-European — that replaced most local languages the following millennia. But local cultures also influenced the new language, particularly in southern Scandinavia, where Neolithic farmers made lasting contributions to Indo-European vocabulary before their own language went extinct, new research shows.