The Serer people include the "Seex" (Serer or Serer-Sine), Serer-Noon (sometimes spelt "Serer-None", "Serer-Non" or just "Noon"), Serer-Ndut (also spelt "N’doute"), Serer-Njeghene (sometimes spelt "Serer-Dyegueme" or "Serer-Gyegem" or "Serer-N'Diéghem"), Serer-Safene, Serer-Niominka, Serer-Palor (also known as "Falor", "Palar", "Siili", "Siili-Mantine", "Siili-Siili", "Waro" or just "Serer"), and the Serer-Laalaa (sometimes known as "Laa", "La" or "Lâ" or just "Serer"). Each group speaks Serer or a Cangin language. "Serer" is the standard English spelling. "Seereer" or "Sereer" reflects the Serer pronunciation of the name and are mostly used by Senegalese Serer historians or scholars. The meaning of the word "Serer" is uncertain. Issa Laye Thiaw views it as possibly pre-Islamic and suggests four possible derivations:  1. From the Serer Wolof word "reer" meaning 'misplaced', i.e. doubting the truth of Islam. From the Serer Wolof expression "seer reer" meaning "to find something hidden or lost." From "the Arabic word seereer meaning sahir magician or one who practices magic (an allusion to the traditional religion)". From a Pulaar word meaning separation, divorce, or break, again referring to rejecting Islam. Professor Cheikh Anta Diop citing the work of the 19th-century French archeologist and Egyptologist, Paul Pierret, states that the word "Serer" means "he who traces the temple." Diop went on to write: "That would be consistent with their present religious position: they are one of the rare Senegalese populations who still reject Islam. Their route is marked by the upright stones found at about the same latitude from Ethiopia all the way to the Sine-Salum, their present habitat." Professor Dennis Galvan writes that "The oral historical record, written accounts by early Arab and European explorers, and physical anthropological evidence suggest that the various Serer peoples migrated south from the Fuuta Tooro region (Senegal River valley) beginning around the eleventh century when Islam first came across the Sahara."