Scientific monogenesis: The Mother Tongue theory. Theories of monogenesis do not necessarily derive from religious belief. Many modern scholars believe in a theory of monogenesis that has come to be called the Mother Tongue Theory. This theory holds that one original language spoken by a single group of Homo sapiens perhaps as early as 150 thousand years ago gave rise to all human languages spoken on the Earth today. As humans colonized various continents, this original mother tongue diverged through time to form the numerous languages spoken today. Since many scientists believe that the first fully modern humans appeared in Africa, the mother tongue theory is connected with a more general theory of human origin known as the Out of Africa theory. Currently, the theory of evolutionary monogenesis tends to be favored by a group of linguists working in the United States. Regardless of the origin of language, the fact remains that there are over 5,000 mutually unintelligible forms of human speech used on Earth today. And, although many are radically different from one another in structure--the differences are superficial since each and every one of these languages can be used creatively. Languages do not differ in terms of their creative potential but rather in terms of the level upon which particular distinctions are realized in each particular language. What is expressed concisely in one language requires a phrase in another language. (Examples of aspect and evidentiality; also words like Swahilimumagamagama "a person who habitually loses things" and Russian zajchik "the rainbow reflection from glass." Linguists study how each particular language structures the expression of concepts. Such cross-language comparisons fall under a branch of linguistics called language typology. If the structural diversity of human languages is superficial,