What hypothesis about the Proto-Indo-Europeans is contradicted by the hypothesis first developed in 1987 by a British archaeologist?
Anatolian hypothesis: The Anatolian hypothesis, first developed by British archaeologist Colin Renfrew in 1987, proposes that the dispersal of Proto-Indo-Europeans originated in Neolithic Anatolia. Colin Renfrew:  This hypothesis contradicted Marija Gimbutas's Kurgan hypothesis, which states that Proto-Indo-European was spread by a migration of peoples from the Pontic-Caspian steppe approximately 6,000 years ago.
Kurgan hypothesis