By some classifications, nearly 7000 languages exist worldwide, with a great amount of variation thought to have evolved through cultural differentiation. There are four factors that are thought to be the reason as to why language variation exists between cultures: founder effects, drift, hybridization and adaptation. With the vast amounts of lands available, different tribes branched out to claim territory, which would require new place names, as well as names for new activities (such as terms for new fishing techniques required in streams by a people who had previously only fished from the ocean). Groups who lived far apart had little or no communication, even if they originally spoke the same language, allowing for their languages to drift apart. Hybridization also played a significant role in the language evolution. One group would come in contact with another tribe, then the two groups would pick up words and sounds from each other, eventually leading to the formation of a new language. Finally, adaptation had an impact on language differentiation. Natural environments and cultural contexts would change over time; therefore the groups had to adapt to the environment and their language had to adapt to it as well. For example, the introduction of bronze-making in an area would prompt the introduction or creation of terms related to bronze.
