What happened at the Tower of Babel and why is it used in explaining language origins?

A:

The story of the Tower of Babel was added to Genesisduring the Babylonian Exile, and talks of a tower being built right up to heaven by the people in their arrogance, and of God punishing the people by dispersing them and making them all speak in different languages. The exiled Jews, who had never before seen a great cosmopolitan city like Babylon, were in awe of the great ziggurut, a pyramid-like tower, and at the same time surprised to meet people who spoke so many different languages. They associated the tower, which seemed to reach to heaven, and the many strange languages, and so developed the story of the Tower of Babel.

This story, in Genesis chapter 11, says that long after the time of Noah, there was only one language in the world, but that God confounded their language because the people built the great tower of Babel. Anthropologists know that languages developed quite differently, over a period of many thousands of years - even in recent centuries, new languages have developed and old languages have evolved.