Glottogeny is the origin of language in the human species.
Language in Animals
While some people have suggested that animals use language, this is generally not accepted among linguists. Animals, including most higher primates, are known to have semantics, that is sounds that correspond to arbitrary meanings and some animals. Additional some parrots studied are known to have dialects, where the "words" they use differ among regional groups, and new members must learn them. There is also the posibility that some species, such as prairie dogs which may form simple sentences with nouns and adjectives. However, there are no species apart from humans known to use recursion, which is therefore considered the defining feature of human language.
A theory of the linguistic origins must take into account the complexity of human language. Steven Pinker argues in his book The Language Instinct that human language is like an elephant's trunk--a very complex system in which the intermediaries have been lost, but nonetheless not a hopeless problem, if we can work out the stages of language development.