The term Proto-World language refers to the hypothetical latest common ancestor of all the world's languages, an ancient language from which all modern languages and language families – and usually including all known dead languages – derive. The concept is thus analogous to the widely accepted Proto-Indo-European, the ancestor of all the Indo-European languages as reconstructed by historical linguistics.
Proto-World would have been spoken roughly 200,000 years ago, the time suggested by archaeogenetics for the phylogenetic separation of the ancestors of all humans alive today, mainly by analysis of mitochondrial DNA. Note that it would not necessarily be the first language spoken altogether, but only the latest common ancestor of all languages known today, and already may have looked back on a long evolution, and even may have existed alongside other languages of which no trace survived into historical times. For example, it is disputed whether or not Homo neanderthalensis had the faculty of speech. If they did, their language in all probability would not have been derived from Proto-World as defined above. Furthermore, if they had a language, this would substantiate the claim for the existence of Proto-World, without making any prediction as to its form, because it would imply that glottogony predates human phylogenetic separation.
However, due to the time depth involved, most historical linguists doubt that any available methods will ever uncover information about such a language, and proposals for attributes of Proto-World are considered to be on the fringe of linguistic studies. Many also question the underlying theory of monogenesis , the assumption that all known languages even do derive from a common ancestor, suggesting that language may have developed independently in different groups of early humans from proto-linguistic means of communication, thereby disputing the existence of Proto-World, or at least shifting focus to glottogonic issues. In addition, situations are conceivable in which a completely new language may have arisen even at later times -- for example, if deaf parents were to raise hearing children in an isolated situation (e.g. as survivors of some catastrophe), the children might develop a language among each other and later pass it on to their own children, eventually forming a full-fledged new language without any ancestor language. While this scenario isn't very likely at any one time, it is quite possible that it has occured a few times throughout the millenia of human history.
The Russian linguist Nicholas Marr expounded a monogenetic theory of language that resolves all modern languages to four primordial exclamations.
Drawing on the works of Vladislav Illich-Svitych, the American linguist Joseph Greenberg claimed that long-distance relationships can be shown by applying an approach he called "mass comparison". The languages are compared by using a limited set of words (including function words and affixes) simply by means of counting cognates. He used this method to establish a classification of African languages. His work has generated considerable interest outside the linguistic community. It is still much debated.
Traditional historical linguistics states that so far it has been impossible to show that all the world's languages are genetically related. Critics say that from a purely statistical point of view, even among any two unrelated languages, there will most likely be a number of similar-sounding words with similar meanings.
Therefore, the concept of a comparison of languages based exclusively on their respective vocabularies is widely considered flawed and on the outer fringe of linguistics, although studies based on exactly such comparisons are still frequently published.
- Hock, Hans Henrich & Joseph, Brian D. (1996). Language History, Language Change, and Language Relationship: An Introduction to Historical and Comparative Linguistics. Berlin: Mouton de Gruyter. Chapter 17.