Two related languages are found on opposite sides of the globe.

Have you heard the story of the Tower of Babel? According to the Bible, all of humanity lived together in harmony, until God decided to confuse the languages and spread the people across the Earth.

This story points to one of the great mysteries of human culture: why do we all speak different languages? Our ancestors probably began using language between 200,000 to 50,000 years ago.

As language evolved and moved across the globe, it changed.

In the same way that geneticists trace how genes are inherited over generations, linguists follow how specific elements of language flow into other languages. Just as you inherit brown eyes from your parents, you learn that a table is called a table and that an adjective precedes the noun it modifies. By tracing languages this way, historical linguists map how languages relate to each other.

Some languages, though, lie outside of these trends and relationships. Basque, a language spoken in Spain, is unrelated to the Indo-European languages spoken around it. Languages that cannot be tied to others are called language isolates. One language isolate, Ket, astounds linguists around the world.

Ket is spoken in Siberia, a remote part of Russia north of Mongolia. However, linguists have been unable to discover how it related to the languages spoken nearby, the language family known as Sino-Tibetan. Ket is not a tonal language like Han Chinese, the most widely spoken language in the Sino-Tibetan family, and its structure differs as well.

In 2008, Edward Vajda, a historical linguist, proposed that Ket was related to languages in the Na-Dene family. This shocked the world of linguistics. Why? The Na-Dene language family is spoken by Native American peoples in North America, thousands of miles from Siberia. However, in his analysis, Vadja traced their similarities and has convinced many other linguists that these two disparate languages are in fact siblings.

What do you think of tracing languages like genes? Do you believe that languages can migrate like people?