英語の two とヒンディー語の do は同じ祖先の言葉。印欧語の“ルーツ”は約8100年前？

English and Hindi look very different, but they are related. The English word "two" is "do" in Hindi, and "name" is "nām." These words come from one very old language. Many languages in Europe and India grew out of it and form one big family.

Today, almost half the people in the world speak one of them. A 2023 study says the family started to split about 8,100 years ago. Other scientists think it happened later.

Why does the English word "name" look so much like Hindi "nām" and Latin "nōmen"? These languages all belong to the Indo-European family and share a common ancestor. Experts have argued for more than 200 years about where and when that ancestor was spoken. One idea says it spread with farming from Anatolia, in what is now Turkey, about 9,000 years ago.

Another says it spread with herders who used horses on the grasslands north of the Black and Caspian Seas, about 6,000 years ago. In 2023, a team of more than 80 language experts compared basic words in 161 languages. They estimated that the family began to split about 8,100 years ago, and they placed its first home just south of the Caucasus Mountains.

About 8,100 years ago, according to a study published in Science in 2023, the ancestor of English, Hindi, Persian, and Russian began to break apart. The team, led by researchers at the Max Planck Institute for Evolutionary Anthropology, checked basic words such as "two," "water," and "black" in 161 languages, 52 of them ancient or historical.

In their family tree, five main branches had split off by about 7,000 years ago. That timing did not fit the steppe hypothesis, which places the origin among herders north of the Black and Caspian Seas about 6,000 years ago. So the team proposed a mix of both theories. In their version, the first homeland lay just south of the Caucasus, and one branch moved north onto the steppe before some of its descendants reached Europe.

A 2025 ancient DNA study points to a later date. It studied 435 ancient people and traced much of the ancestry of the steppe herders, and part of the ancestry of Hittite speakers in Anatolia, to people living between the Caucasus and the lower Volga River. The authors placed the last shared stage of the parent language among them, between 4400 and 4000 BC.