Tracking the Invisible Organic Commodities of Ancient Trade

Biomolecular methods for exploring spices, aromatics, and psychoactive substances

Long-distance trade of commodities played a major role in forming political structures and transferring socio-cultural practices among the major centers of ancient civilization in the Old World. Some of the most high-value products that moved along ancient routes of dispersal and trade were not substantive, calorie-laden foods, but powders, extracts, and obscure dried plant components that nonetheless packed substantial flavor and aroma. Not only did these substances possess the ability to transform cuisines, but they also often, and sometimes even more importantly, played significant roles in economic, cultural, and ritual contexts. These so called ‘spices‘ encompassed a broad range of commodities including food flavorings, aromatics, medicines, and psychoactive products. Control over and access to these trade goods became the source of great wealth and political power in the ancient world, leading to major trade expeditions, new trade routes, imperialism, and war.

Despite their importance, however, these substances often remain difficult or impossible to study in the archaeological record, due to their past rarity and poor present-day preservation. Even more challenging, many of these substances no longer hold their natural form prior to use which makes it difficult to identify them using morphological characteristics. The research of the Department’s Biogeochemistry Group, led by Dr. Thomas Larsen, seeks to address some the limitations of studying these types of remains by developing a biomolecular approach for their analyses. To do this the group uses a wide range of chromatographic and mass spectrometric techniques such as Gas Chromatography-Mass Spectrometry (GC-MS) and Liquid Chromatography-Mass Spectrometry (LC-MS) to identify the unique biomolecular fingerprints of these ancient substances. Secondary metabolites, which constitute the bioactive compounds in various medicinal, aromatic, and spice plants, are a key component to this identification. As part of this research, several Department projects are examining the flow of these so called ‘invisible organic commodities’ across global trade routes.

One of the most prominent vectors of cultural exchange in the ancient world was the network now known as the “Silk Road” that encompassed trade routes spanning the area between China and the Mediterranean. In addition, there was widespread distribution of products between East Africa, Arabia, and Western Asia, conceptualized as the “Incense Road”. Until now, most of our knowledge of ancient trade commodities in these regions has derived from written sources, yet there is a vast but largely untapped potential in the form of biomolecules to obtain more tangible evidence from the archaeological record. Such evidence can help both to ground-truth and challenge traditional hypotheses of exchange networks.

Current Projects:

• Global Scents: Tracing Aromatics through Biomolecular Archaeology

 

This project aims to investigate the global dimensions of the dispersal of ancient aromatics throughout Asia and East Africa by implementing a biomarker approach to key artefacts that evidence aromatics. This includes not only the spread of goods, but also the transfer of socio-cultural practices associated with their use. In this perspective, the project will shed light on how humans transformed their environment and their perception of spaces with different aromatics, providing unique insight into the sensual world of the past.

 

• Biomolecular Archaeology along the Silk Road: Exploring the use of psychoactive plants and fungi in ancient Central Asia

The project seeks to uncover the use and role of psychoactive plants and fungi along the ancient Silk Routes of Central Asia and its surrounding regions, e.g. western Mongolia, the Tuva region of Russia, Xinjiang, Qinghai, and Tibet. To do this, a biomolecular approach targeting secondary metabolites will be applied to analyze residue from archaeological evidence such as preparation and delivery tools, storage vessels, archaeobotanical material, and human remains. The identification of these biomolecules combined with other forms of evidence, such as iconography, historical records, and ethnobotany, will help us to develop a greater understanding of the past behavior associated with these plants surrounding their medicinal, social, and ritual value. Ultimately, identifying these plants and their accompanying consumption practices will allow for us to determine the potential implications they may have had for global exchange networks.