The Origin and Evolution of Languages – II: Bio-informatic Apparoach

From a linguist’s perspective, there is no reason to assume that the words would behave the same way that the organism would do. Legendary linguist Prof Noam Chomsky of the Massachusetts Institute of Technology believes that (a) the evolution of spoken language does not follow biological evolution because spoken language was not present in apes and originated in humans suddenly due to a mutation, (b) the genetic clues unravel events that are much older than those mapped by the linguistics, and (c) invasions and political revolutions in certain regions, could have completely wiped out or modified the languages of those regions.

Psychologist David Premack, emeritus professor of psychology at the University of Pennsylvania is famous for having taught language to chimpanzees. Premack has shown that the chimpanzees can understand the language but cannot produce it. The epigraph at the head of the webpage for the ‘Third Conference on Evolution of Languages’ carried this provocative statement by Premack:

“HUMAN LANGUAGE IS AN EMBARRASSMENT FOR THE EVOLUTIONARY THEORY”

The above statement neatly sums up the mood of the linguists.  But look at the map of human migration generated by the molecular biologist and compare it with the presence of various language families in the world.

A map of early human migration (from the Wikimedia Commons). Figure shows number of years from present.

 

HumanLanguage Families Map (from the Wikimedia Commons)

Linguists believe that the original language of humans has become extinct. It is difficult to establish relationships across major families and that any grand evolutionary trees of languages cannot be formed. Languages totally un-related to each are spoken in geographically adjacent zones. From a biologist’s point of view, I have reasons to believe that all human beings should have carried a common mother tongue from their centre of origin in Africa. During the transmission of words from one generation to another, the words would have replicated/ reproduced. Mutations in words would have occurred in much the same way as in genes. Replacement of a wrong letter in place of the original one would have given rise to phonetic variation (a la biological variations) in vocabulary giving rise to synonyms. As branches and sub-branches of the original populations settled in different geological territories along the path of human migration, geographic isolation would have cut off the chances of communications leading to speciation of new language forms. However, some aspects of evolution of language are difficult to be explained by invoking either the classical theories of biological speciation or by theories of Chomskian linguistics. The 144-member strong Indo-European language family has a vast geographic reach. Cutting cross all sorts of geographical barriers, there is much less difference in various languages of the Indo-European family, say between Bengali and Spanish. On the other hand there are no such great equivalent barriers between territories occupied by speakers of Iranian, an Indo-European language and Arabic, an Afro-Asian language, or between Dravidian Tamil and Indo-European Oriya.  We have to find a satisfactory explanation for the abrupt discontinuities of the Afro-Asiatic and Dravid language families with the Indo-European language family. There is no historical evidence for the alleged Aryan conquest of a Dravidian India that replaced speakers of Dravidian languages in the North India with the Indo-Europeans. In the last few years, researches in molecular genetics have completely and convincingly demolished the Aryan Invasion Theory (AIT) proposed by the German linguist Max Muller in the 19^th century. A complete understanding of the factors affecting the linguistic history of the world continues to elude as well as excite the investigators and the public alike.  Christiansen, M. H. and S. Kirby, editors of the book ‘Language Evolution’ (2003) have termed the subject as “the hardest problem in science”.

In the year 2002, I was supervising the work of a student for her M.Phil. thesis on bioinformatics. We were performing genome analysis of a plant Arabidopsis by employing Basic Local Alignment Search Tool, or BLAST (it is an algorithm for comparing primary biological sequences like amino acids in proteins and bases in DNA and RNA. While editing the thesis I felt that it is time that we applied Basic Local Alignment Search Tool (BLAST) for matching the sequence of letters in synonyms. I found that although linguists have been doing matching of words indifferent languages, they were obsessed with their known theories of origin of new words. I had no such binding. I was doing for fun. I did not know theories of linguistics and I still don’t know anything. I started doing the BLAST for words manually, as a hobby and as a serious hobby by February 2004. By the end of 2010, I had the matched the sequences of about 14,000 words (and it is growing). I was playing with words all these years. During this play, the words started to unravel the rules of the game. Which letter will mutate to which one, in a manner similar to the game of bases in the genetic code. The multiple gene code for amino acids was like synonyms. The letters in words wobbled like bases in genetic code. I found that just like the bases in DNA, the letters in words never disobey those rules. But after seven years the words demanded my full time attention. I quit my job to play with them full time. I invite you to join me in this game! We shall play with the words and also discuss their behavior and evolution.

Welcome aboard to the “DNA of Words!”