Wandering Through History: The Evolution of Steppe Pastoralist Societies

The broader Caucasus area, situated between the Black and Caspian Seas, acts as a bridge among Europe, the Near East, and Asia. Today, it showcases a wide diversity in geography, ecology, economy, culture, and languages, with a northern steppe zone, central Caucasus mountains, and southern highlands encompassing modern-day Armenia, Georgia, Azerbaijan, and Iran. This historical diversity is well-documented in archaeological findings, reflecting numerous influences from adjacent regions.

“The unique interface of various eco-geographic features and archaeological traditions makes this region particularly intriguing for research,” says Dr. Wolfgang Haak, the study’s senior author and principal investigator. “By creating a timeline across multiple archaeological eras, we aimed to identify significant periods, such as when the first farmers entered the area or when advancements in areas like herd management, dairy production, and mobility allowed for a fully autonomous nomadic lifestyle suited for utilizing the vast Eurasian steppe.”

The research team identified a recurring pattern of interaction and genetic exchange between the inhabitants of the significant eco-geographic areas of the mountainous highlands and the northern steppe regions of the Caucasus. “Initially, we recognized two distinct genetic lineages among hunter-gatherer communities north and south of the Greater Caucasus,” adds lead author Ayshin Ghalichi, a PhD candidate at the Max Planck Institute for Evolutionary Anthropology in Leipzig.

This scenario evolved with the arrival of early farmers from northern Mesopotamia during the 6^th millennium BC. This led to two major mixing processes: one that combined these farmers with Caucasian and Iranian hunter-gatherers, which contributed to the main ancestry profile south of the Caucasus mountains, and a second that involved the earlier hunter-gatherer groups, forming the genetic background of the northern steppe zone. In the subsequent 5^th and 4^th millennia BC, Eneolithic cultures emerged in the river valleys of the North-Pontic steppe, evident through the construction of distinctive earthen burial mounds known as ‘kurgans’. New Eneolithic groups migrating from the south initiated a period of interaction and exchange, leading to the development of the Maykop culture during the 4^th millennia BC, noted for its significant technical and social advancements in archaeology.

Into the great wide open

“This marks a peak era for the transfer of knowledge and technology in the North Caucasus, characterized by the presence of similar cultural elements among genetically diverse groups, along with abundant signs of intermingling,” explains Dr. Sabine Reinhold, co-lead author and principal investigator at the German Archaeological Institute in Berlin. “We discover when populations began altering their lifestyles to accommodate a more mobile economy, better suited to the seemingly limitless grasslands of Eurasia.” The archaeological evidence reflects crucial innovations in herd management, dairy production, transportation methods like the use of wheels and wagons, and the onset of horse domestication, among other advancements. “Today’s global dairy industry is built on the foundation of these Bronze Age innovations,” remarks Prof. Christina Warinner, a co-author and anthropology professor at Harvard University. “They transformed what was once a niche practice into a widespread, multi-continental phenomenon.”

Storable food products like early types of cheese, along with advancements in transport, enabled permanent settlement in the Eurasian steppe and led to interconnected networks of communication across the continent. These developments set the stage for a fully nomadic pastoral lifestyle by the 3^rd millennium BC, adopted by groups associated with the Yamnaya cultural complex, which subsequently expanded throughout the western steppe zone, reaching as far as Mongolia in the east and the Carpathian Basin in the west. Interestingly, it was also a time when groups from the Caucasus moved southward, such as the Kura-Araxes culture from Georgia, which spread into areas such as eastern Anatolia, the Levant, and Iran, though with limited interactions with the northern steppe regions.

The research team also studied the social structures of prehistoric populations by analyzing biological relationships and kinship patterns, discovering differences between steppe and Caucasus groups. The more sedentary groups in the Caucasus exhibited higher levels of consanguinity and closer connections among individuals buried in nearby kurgans, while the steppe groups displayed fewer such associations, indicating a different social organization in mobile pastoral communities.

Dissolution and transformation

However, the 2^nd millennium BC marked yet another period of interaction between the steppe and Caucasus populations. This was triggered by a time of aridification, potentially coupled with an over-exploitation of the sensitive steppe ecosystems and inconsistent rainfall, leading to significant depopulation in the steppe zone. The archaeogenetic findings indicated clear evidence of the blending and assimilation of Caucasus groups, while the resulting Middle and Late Bronze Age populations retreated into the higher regions of the Caucasus, establishing a stable sedentary economy. This shift also laid the cultural and genetic foundation for the contemporary populations of the North Caucasus.

“Our integrated study exemplifies human resilience, adaptability, and innovation in response to changes in ecological, economic, and socio-political contexts,” concludes Prof. Svend Hansen, director of the Eurasia Department at the German Archaeological Institute and co-senior author of the study.