Human populations throughout the world currently speak thousands of languages. However, if you are to go back through history, people spoke less numbers of languages. The more you go back in time, the less languages there are. This can only mean one thing. And that is the languages we have today evolved and branched out through the course of history.
In the following lesson by Alex Gendler, the evolution of language is concisely and clearly explained with the help of the animation by Igor Coric. You can find the full lesson here.
