The diversity of human languages reached its peak thousands of years ago before declining as a result of expanding empires, colonialism, and other historical processes that reshaped the world's cultural landscape, according to research published in Science.

According to the study, humanity may have spoken between 30,000 and more than 75,000 different languages during the same period in history. Researchers estimate that the highest level of linguistic diversity occurred between the first millennium BC and the first millennium AD, far exceeding the approximately 7,500 languages spoken around the world today.

To reach this estimate, researchers used mathematical models and combined insights from anthropology, linguistics, and demography to reconstruct the evolution of languages over the past 12,000 years, beginning at the end of the last Ice Age and the start of the Holocene.

The study states that the earliest human communities, organized into small groups of hunter-gatherers scattered across different regions of the planet, spoke between 4,500 and 6,200 languages. As the population expanded and agriculture and permanent settlements emerged, the number of linguistic communities also increased.

Researchers explain that the development of more sedentary societies encouraged the emergence of numerous local languages. Over time, different language families developed, followed by the invention of writing in civilizations such as Mesopotamia, Egypt, China, and Mesoamerica.

However, the research identifies a prolonged decline in linguistic diversity driven by the expansion of major empires and, centuries later, by European colonialism. These processes promoted the replacement of local languages with dominant ones and significantly reduced the number of languages spoken around the world.

The authors emphasize that languages serve not only as tools of communication but also as repositories of knowledge, traditions, and historical information about societies. They also note that languages make it possible to reconstruct aspects of the past, including where people lived, what they ate, and how they organized their communities.

The study recalls that many ancient languages disappeared, while others evolved into new ones. One example is Latin, which, after the fall of the Western Roman Empire, gave rise to languages such as Spanish, French, and Italian. It also points out that some Indigenous languages survived despite efforts to suppress them during the colonial period.

Today, about half of the world's languages are at risk of disappearing. Researchers warn that nearly 90% of the global population speaks just 10% of the world's existing languages, reflecting an increasing concentration of linguistic use and the growing risk of losing an important part of humanity's cultural heritage.