The Silk Road term was introduced in mankind’s thesaurus by a German anthropologist Baron von Richthofen, who was inspired by Marco Polo’s travel reports.  Since the times of the both, the scientific community have collected sufficient information about the Silk Road, but nobody answered the question about how the most geopolitically important trade system of the vast land-locked territories of the Eurasian Continent came into existence.

A cadre of international scientists has crafted what is termed a «flow accumulation model.» This model suggests that nearly 75% of the most ancient segments of the Great Silk Road, those traversing the continental interior, coincide with or are connected to the enduring pathways carved by the nomads of Central Asia. These were the routes along which they drove their herds to summer pastures as far back as 5,000 years ago. That is to say, long before Marco Polo embarked upon his storied journey.

Michael Frachetti, Anthropology Professor of the Washington University and the leader of the Silk Road Research Team reports:

«Our model demonstrates that the long-term mobility strategy developed by nomadic herders resulted in the establishment of a viable structure for seasonal migration routes to summer pastures. This structure significantly correlates with the evolution of the Silk Road’s construction and the interactions it encountered while crossing the mountainous terrain of continental Asia”.

The findings of the study have been published in the journal ‘Nature.’ The modeling process utilized data from satellite analysis, human settlement geography, archaeology, and GIS systems. A preliminary conclusion of the study was the existence of alternative routes leading to many trade centers and caravanserais of the Silk Road, previously unknown to science. In support of this conclusion, a high-resolution map was created, highlighting the network of these ancient, unexplored routes.

On the illustration above, the most probable main routes used by the nomads to drive their livestock from the high-mountain pastures (shaded areas on the map) to the summer pastures in the valleys (marked in grey) are indicated by red lines.

«The locations of ancient cities, settlements, and caravanserais have long served as illustrations of how interaction developed across the entire Silk Road network involving all the parties. Accurately determining these multiple routes has been an unattainable task for a long time. Therefore, we know extremely little about the details of the routes that were used by traders, monks, and missionaries for thousands of years to explore and engage with the local populations of the mountain regions of inner Asia.»

In the past, scientists determined the passage of routes and roads by constructing models of what they deemed the most pragmatically economical and viable routes between key nodes of the Silk Road. However, Michael Frachetti counters:

«Such an approach—a straight line between two points—makes sense for modeling routes on a plain, where trade between cities is facilitated. But the ‘straight line from point to point’ is not the method by which ancient nomads moved through complex and rugged mountainous terrain. The routes of the Silk Road and the interaction of different parties along it were never static processes. While trade caravans were skilled in navigating open spaces, in the mountains, trade routes evolved from ancient nomadic paths. After all, nomads possessed extensive knowledge and strategies for organizing mobility in mountainous conditions.»

Oasis societies, which developed in the hot and arid conditions, were separated from one another by mountain ranges. Mountain nomads, in contrast, were united in the face of nature—the hot Central Asian summer scorches and dehydrates the plains. This means that over many centuries of existence, the nomads had to develop a method of salvation. Such was the retreat into the mountains from the summer sun that scorched the grass on the plains.

To prove this, the research group developed a simulation model that depicted the movements of the nomads (to whom they assigned the term «flows») based on the condition and readiness of pastures. In doing so, the researchers deliberately detached the network of mountain paths they created from the Silk Road itself, but the final model showed an alignment of the Silk Road and its infrastructural elements with this network.

Proving this assumption poses a very serious challenge even for a team equipped with the latest technology because the central thoroughfare of the Great Silk Road extends through the most inaccessible and remote mountain ranges of Eurasia—Hindu Kush in Northern Afghanistan, Pamir in Tajikistan, the Jungar Alatau in Kazakhstan, Tien Shan, and Altai.

The tools used included the aforementioned GIS system and a database of satellite sensors. Typically, such tools are widely used by hydrogeologists and ecologists around the world to create simulation models of water behavior – in rivers, lakes, and seasonal moisture accumulators. The simulation models of water behavior are based on the properties of water to move under the influence of Earth’s gravity from mountain tops downwards. Thus, hydrogeologists can more or less accurately calculate the number of small streams that further merge into large rivers or accumulate in large lakes.

The Frachetti group replaced the initial data — instead of the force of gravity, they considered the density of vegetation cover in order to calculate how the lushness of pastures attracted numerous flows of livestock periodically driven by nomads – from bottom to top, that is, actually against the force of Earth’s gravity. The method is original and incrementally pragmatic – to adapt the ready-made to the new and to move on. It should be noted that the mountain ranges of inner Eurasia stretch for more than 4000 kilometers.

The territory under study was divided into a grid, each cell of which was one kilometer long on each side. Each cell was assigned a rating code depending on the density and richness of the grass cover, which was determined based on multispectral satellite imagery. Something similar is used by countries that can afford to deploy satellites to fight drug cartels. The same cell division is used, but instead of Earth’s gravity or the density of pasture grass cover, the density of the presence of a specific narcotic plant in the vegetation is introduced – leaves of coca, plantations of opium poppy, and marijuana, which are often camouflaged among other types of plant life.

GIS software was used to calculate the routes by which nomadic herders moved downhill towards their settlements on the plains. That is, when they switched to forage at the foot of the mountains and, consequently, followed the scouts who were looking for any suitable places to obtain this forage. It is gratifying to realize that someone has penetrated so deeply into the mindset of our ancestors. It is also flattering that the prominent scholar Michael Frachetti has made one very correct conclusion, which is the following:

– Nomads, in achieving their exclusively practical goals and objectives under harsh climate conditions and a warlike life, did not just ride their horses in the random order. They simply could not afford such a luxury – the nomads moved purposefully in ways that would help them achieve their goals. Knowledge of the terrain and the ecological features of these 4,000 kilometers in the mountains allowed our ancestors to track the seasonal productivity of grass in pastures and act accordingly. Gradually, the most well-trodden routes by the nomadic cavalry from century to century began to appear on the map. Thus, a model of the «accumulation of streams» of nomadic cavalry was compiled.

The mentioned model offers options such as the density of pasture coverage in a dynamic retrospective. Nature itself sided with Michael Frachetti – the pastures stretching along these 4,000 kilometers in the mountains have not changed much over the past several thousand years. Especially the routes by which the nomads descended from the mountains back to the plains – they were trodden over many, many generations.

Given the above, the conclusion is the following – the early evolution of the Great Silk Road was shaped under the influence of nomads and their seasonal migrations, based on the knowledge of the locality and its behavioral characteristics – when, where, and which pastures would be the most attractive. It turns out that the Great Silk Road, which gave birth to a large number of civilizational processes in the form of developed infrastructure, inclusive of cities, settlements, and trading posts, has its roots in harmonious coexistence with nature. It appears that in Eurasia it used to be like this: bold and adventurous nomads – people organically existing in nature, blazed the most calculated routes, and following them came the technocratic sedentary civilization which gradually absorbed nomadism, as the great waters swallowed the great and legendary civilization of Atlantis, the keeper of the most sacred knowledge about nature and the cosmos.