Oh lord. This post took me a while because I was trying to find what book I read that made me want to write it. The book I was reading (maybe John Ralston Saul’s A Fair Country) was talking about globalization and how we’re losing endangered languages. Anyways, in it, the person talked about how it can be hard to define a language, due to dialect continuums (I’m not sure if the book said that word exactly, but in my frantic attempt to find this concept, this was the word that seems to be closest to what I want to convey). This in turn, reminded me of Richard Dawkins writings on the definition of species and how it can be muddled by things such as ring species (another word I had to frantically find; however, I know which book that comes from: The Ancestor’s Tale).
Two distinct languages can usually be defined if they are mutually unintelligible. Or, as the book I was reading defined it, as requiring a translator in order for both parties to understand each other. So Icelandic and Finland-Swedish are different languages because if a Icelandic-only speaking person met a Finland-Swedish-only speaking person, they wouldn’t be able to understand each other. Dialects, on the other hand, are forms of languages in which the speakers can understand each other, even if it’s a little rough. So Icelandic-speaking people and Faroese (the Faroe islands, between Norway and Iceland)-speaking people can understand each other, as well as Finland-Swedish-speaking people and Swedish-speaking people can understand each other.
The really interesting thing though, is as you travel from Iceland to Finland (Hammarland for example), the places in between would be able to understand each other, since they speak dialects. That is: Iceland to Faroe Islands, Faroe Islands to Norway, Norway to Sweden, and finally Sweden to Hammarland (Finland). Thus you could connect Icelandic to Finland-Swedish through the dialects that connect them. This is essentially how many languages evolve: as groups of people become geographically separated (and so do not communicate with each other), their languages mutate until eventually they are two new languages (they cannot communicate with each other).
A similar thing happens with species. A species is defined as a group of organisms that are capable of interbreeding and producing viable offspring. So a gorilla and a pig are of different species because they cannot interbreed. When one group of organisms gets geographically separated (and so they don’t have the opportunity to interbreed), over time, mutations will make it so that they become two distinct species (even if they had the opportunity, they could not interbreed).
In The Ancestor’s Tale, Dawkins describes the case of the Ensatina salamanders, where you can see the divergence of species spatially (like Iceland to Hammarland), instead of the usual temporal (birds from reptiles). From wikipedia:
The Ensatina salamanders in the Central Valley in California form a continuous ring (actually a horseshoe shape) around the valley. Any two neighboring population of Ensatina around the horseshoe can interbreed, but the plain Ensatina eschscholtzii on the western end of the horseshoe cannot interbreed with the large blotched Ensatina klauberi on the eastern end.
Thus, from the picture above, pink can breed with light-purple, light-purple can breed with blue, blue can breed with cyan, and cyan can breed with green, but green and pink cannot breed. So green and pink are different species, but they are connected through mutually interbreeding incipient species (a word I honest to god just found when I randomly opened The Origin of Species).
So yeah, languages and species…neat.


another definition you could have used:
http://en.wikipedia.org/wiki/A_language_is_a_dialect_with_an_army_and_navy