The widening East African Rift valley is flooded by the Red Sea, causing a new ocean basin to divide the continent of Africa and the African Plate into the newly formed Nubian Plate and the Somali Plate. Estimated time for full recovery of biodiversity after a potential Holocene extinction, if it were on the scale of the five previous major extinction events. Even without a mass extinction, by this time most current species will have disappeared through the background extinction rate, with many clades gradually evolving into new forms.