However, though paleontological theory has given us good evidence to explain the how behind our ability to develop and use language it doesn't tell us why distinct languages have formed or how those languages evolved over time. For these answers we must enter other areas of scientific endeavor, components of applied linguistics. We must also step outside the box of linguistics entirely in order to understand how the physical environment has enabled or prevented the emergence and migration of particular patterns of speech through out various regions of the world. For example, we know today that many language barriers exist where geographic boundaries also exist. A cursory examination of the cultures and languages on either side of mountain ranges clearly shows patterns of linguistic separation that do not exist to the same degree between adjacent communities living say on a plain or tundra regions of the world. Geography has formed a strong factor toward the development of new languages, the separation tends to provide the isolation needed to evolve the distinct differences between languages that have only evolved in the last 2000 years following the weakened grip of the Roman civilization that brought the Latin language to previously Celtic peoples living in those regions. France exists in a relative bubble of linguistic isolation as it is separated geographically from Spain by the Pyrenees and separated from its western neighbors mostly by thick forest, rivers and the Alps. This constituted the barriers that naturally slowed the Roman expansion into Germany after conquering what was then called Gaul (pre French Celtic cultures) . The migration of language follows a pattern of being facilitated by the migration of human beings into Europe over the last 50 thousand years and then by periodic remigrations of humans from other regions to inject regional nuances into the evolved languages. Shaping the development of the languages through it all lies the relatively immobile nature of geography. Where mountains exist, differences between the language spoken by adjacent populations on either side of the range occur relatively quickly compared to their emergence across either side of a river (and also vary with the difficulty to pass those rivers) , the same is true with forested areas which when heavily forested (as is the case in many tropical rain forests) the emergence of new languages can be so varied and so rapid that within a few thousand years islands like Borneo or others in the south Pacific can develop hundreds of distinct languages from a single original migration of populations from other islands, many unique to specific villages separated only by a few tens of miles.
The preeminence of geography in shaping the development of language poses an intriguing question.
What if the reverse process can occur in some way, will languages then devolve into a common regional, continental or even global form?
We can get a strong indication that this is so by studying the history of the migration of English throughout the world in the late 19th and 20th centuries. The middle eastern trade routes and the building of a massive Navy helped England rise to power and dominance at several times in the last 500 years. The discovery of the New World opened up the hemispheres to the English navy's command of the seas and allowed them to colonize and or terrorize lands from Australia to the Falkland's. As they spread their will and culture they also spread their language, more so than any other European power the language of England is more universally known than any other on Earth. Though it is true that the total number of citizens of China and India number just over a billion each, these citizens speak dozens to hundreds of languages with much smaller global reach, English is spoken as a second or third language by speakers of any other language. The spread of the language was facilitated by the English Navy and the pressing desire to explore and colonize new lands and this explains the pervasiveness of the language today. Pervasiveness though is not sufficient to explain why English use is still growing, the answer to this is found in why the ancient roman language of Latin is NOT. Latin nears extinction because the arteries that kept Roman civilization together, that allowed the armies to march freely across Europe, the middle east and Africa are no longer with us. The local civil administrations and the marvel of the Roman road all suffered as the Empire fell. The loss of the infrastructure then inexorabaly gave rise to the loss of the common cultural identity that the infrastructure presented across a large suathe of Europe.
In the case of English , we see that the infrastructure (highly developed Naval power) that facilitated the language spread gave way to other more efficient methods of spreading culture. In the mid 19th and early 20th century the telegraph and telephone was invented, later radio and televion and today Satellite ensure that languages can be beemed or delivered to any corner of the globe nearly instantly. This allows changes to the language that would normally emerge in proportion with the previously mentioned methods of geographic isolation to be retarded or out right eliminated. Today, English is seen as the lingua franca of business and is being learned by people in foreign countries simply by watching television. The communication infrastructure that keeps the English spoken in Australia, relatively close to the English spoken in Africa and the English spoken in Great Britian or the United States works to preserve its dominance and may lead to the eventual inclusion of English into regional languages so that over time a global amalgam is developed.
The second revolution in the migration of languages was only made possible within the last 15 years with the emergence and then rapid spread of the global communication medium that is the internet. The internet is very different from telegraph, telephone and tv in that it is a medium that has both static and dynamic delivery forms. When reading a blog written in English, German or French ...the delivery form is static, the language fixed for interpretation (or even translation) however when participating in a real time chat room, the language is dynamic..nuances of conversation can be read and translated in a way that no previous medium allowed. (eg. when you read a news paper, it is not interactive, when you listen to the radio you can't rewind the conversation stream, when you watch tv you can't (normally) see the words) the simultaneous immersion into internet communications of all these forms will in the short term hasten the spread of the dominant language (English) and also accelerate the amalgamation or extinction of non dominant languages unless a way can be found to nullify the impact of a common language base for most internet communication. This has already begun with the availability of language translation software that allows paragraphs and entire web pages to be translated from one language to the next. These tools will make the preferred language of the participants irrelevant and still available to be used locally without having a pressure to be amalgamated into a dominant language. So which force will be the one to win the fight? Will the spread of a global communication medium like the internet kill non dominant languages before translation technologies have their effect to preserve them? Will there be a quiessent point reached where the internet serves as an amalgamating force across all the non dominant languages , forcing them to adopt elements of the dominant one or ones? The latter outcome is in my view the more likely but the time scale over which this will occur will be incredibly short when compared to the time scale that elapsed before Latin in Portugal became Portugese and Latin in Spain became Spanish and rather than occuring due to the existence of geographical boundaries this amalgamation of language will be the first to have a non physical source, namely the pervasive communications that allow conversations to occur simultaneously throughout the globe.
The story of human language is going to have some interesting twists and turns over the next few hundred years.