Here's how it works:
* Isolation: When groups of speakers of a language are geographically separated, they have limited contact with each other.
* Independent Evolution: Over time, each isolated group will experience changes in their language, including:
* Sound changes: Pronunciation shifts.
* Vocabulary changes: New words are coined or borrowed, while others become obsolete.
* Grammatical changes: Syntactic structures evolve independently.
* Divergence: The accumulated changes in each group lead to distinct dialects. These dialects may become so different that they are considered separate languages.
Examples of Dialectal Divergence due to Isolation:
* The Romance languages: Latin evolved into different languages (Spanish, French, Italian, etc.) after the fall of the Roman Empire, when speakers were geographically isolated.
* The dialects of English: Differences in American English, British English, Australian English, etc. are partially due to geographical isolation and different historical influences.
Important Note: Other factors besides isolation can also contribute to language variation, such as:
* Social factors: Differences in class, ethnicity, or profession can lead to language variation.
* Linguistic contact: Contact with other languages can introduce new words, sounds, and grammatical structures.