Early Potato Use Reveals Ancient Trade Networks and Domestication Clues

Greg Howard
23rd January, 2026

Early Potato Use Reveals Ancient Trade Networks and Domestication Clues

The Four Corners potato (Solanum jamesii) produces a flowering plant (left) and small, energy-rich tubers (right) that were ideal for the long-distance transport and ancient use by Indigenous peoples that signifies the initial stages of domestication.

Image adapted from: Louderback et al. / CC0 1.0 (Source). Photos by Tim Lee/NHMU and Alastair Lee Bítsoí, respectively.

Key Findings

  • This study examined ancient potato (Solanum jamesii) use across the Colorado Plateau, focusing on tools dating back as far as 10,900 years ago
  • Potato starch was consistently found on tools in southern Utah, southwest Colorado, and northwest New Mexico, indicating intentional transport and processing of the potato beyond its natural range
  • Genetic analysis confirms these potatoes were transported from the Mogollon region, suggesting early Indigenous cultivation and shaping of the plant through selective movement over long distances
The Four Corners potato ( Solanum jamesii Torr.) has a long history of use by Indigenous peoples in the Southwestern United States, providing both nutrition and cultural significance. However, determining the extent to which this potato was intentionally cultivated – essentially, whether it was domesticated – has remained a challenge. Domestication isn’t simply about growing a plant, but about humans actively shaping its genetics through selective breeding over generations. Evidence of intentional cultivation requires demonstrating both the transport of the potato beyond its natural range and consistent processing, indicative of purposeful use. A recent study conducted by researchers at the Univ of Utah and UC Berkeley[1] addresses this question by examining microscopic evidence of potato use on ancient tools. The researchers hypothesized that if S. jamesii tubers were intentionally cultivated, starch granules – tiny structures within the potato that act as energy storage – would be found on ground stone tools at archaeological sites outside the potato’s natural distribution area. The study focused on 401 ground stone tools from 14 archaeological sites. Ground stone tools are implements used for processing plants, and starch granules can adhere to their surfaces during use. The team recovered over 6,600 starch granules, identifying 163 as belonging to S. jamesii. Importantly, four sites – North Creek Shelter, Long House/Mesa Verde, Pueblo Bonito/Chaco Canyon, and Point of Pines – showed consistent evidence of potato use (ubiquity exceeding 18%). This means that in over 18% of the tools examined at these sites, potato starch was present. Crucially, three of these sites are located significantly north of the potato’s natural center of distribution in the Mogollon region of Arizona and New Mexico, spanning hundreds of kilometers across the Colorado Plateau. The oldest evidence of potato use at these sites dates back as far as 10,900 years ago, continuing through various periods of Puebloan occupation. This distribution pattern strongly suggests that humans were actively transporting S. jamesii tubers over long distances. This finding aligns with earlier research demonstrating the potential for Indigenous peoples to initiate plant domestication through the gathering and transport of plant propagules[2]. The movement of tubers, as identified in this study, would have resulted in the establishment of new potato populations outside their original range. Genetic studies have already shown reduced genetic diversity in archaeological potato populations compared to those in the Mogollon region[2], supporting the idea that these populations originated from a limited number of transported tubers. The genetic analysis also revealed complex patterns of movement, with populations in Utah, for example, showing connections to those on the Mogollon Rim despite being geographically distant[2]. The study further builds upon the understanding that early domestication often begins with plants evolving traits that facilitate human-mediated dispersal[3]. Plants with weak natural dispersal mechanisms are more likely to benefit from human assistance, leading to a mutualistic relationship where humans spread the plant’s seeds in exchange for a reliable food source. The researchers combined the microbotanical evidence with ethnographic interviews and nutritional data, reinforcing the idea that S. jamesii tubers were valued for their energy density and portability. Interestingly, the presence of S. jamesii at Pueblo Bonito/Chaco Canyon also connects to earlier findings regarding the use of cacao in the same site[4]. Both cacao and potatoes were likely brought to Pueblo Bonito from Mesoamerica and the Mogollon region respectively, suggesting a pattern of integrating important culinary ingredients into Chacoan ritual and culture. The cylinder jars used for cacao beverages[4] may represent a broader tradition of specialized containers used for processing and consuming valued foods, potentially including potatoes. The consistent use of S. jamesii at these sites, coupled with its presence in caches, suggests a unique cultural identity associated with this native potato.

AgriculturePlant ScienceEvolution

References

Main Study

1) Ancient use and long-distance transport of the Four Corners Potato (Solanum jamesii) across the Colorado Plateau: Implications for early stages of domestication

Published 21st January, 2026

https://doi.org/10.1371/journal.pone.0335671

Related Studies

2) Evidence for human-caused founder effect in populations of Solanum jamesii at archaeological sites: II. Genetic sequencing establishes ancient transport across the Southwest USA.

https://doi.org/10.1002/ajb2.16365

3) Anthropogenic Seed Dispersal: Rethinking the Origins of Plant Domestication.

https://doi.org/10.1016/j.tplants.2020.01.005

4) Evidence of cacao use in the Prehispanic American Southwest.

https://doi.org/10.1073/pnas.0812817106


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