According to several linguists, Japonic was present on large parts of the southern Korean peninsula. These "Peninsular Japonic languages" were replaced by Koreanic-speakers (possibly belonging to the Han-branch) likely causing the Yayoi migration. Similarly Whitman (2012) suggests that the Yayoi are not related to the proto-Koreans but that they were present on the Korean peninsula during the Mumun pottery period. According to him, Japonic arrived in the Korean peninsula around 1500 BC and was brought to the Japanese archipelago by the Yayoi at around 950 BC. The language family associated with both Mumun and Yayoi culture is Japonic. Koreanic arrived later from Manchuria to the Korean peninsula at around 300 BC and coexist with the descendants of the Japonic Mumun cultivators (or assimilated them). Both had influence on each other and a later founder effect diminished the internal variety of both language families.