Phylogenetics Reveals the Importance of Biodiversity to Food Plants in Mexico

Díaz-Toribio and colleagues recently published a paper in AoB PLANTS about the evolutionary relationships and usage patterns of edible native plants in the Gulf of Mexico region. Their research gives insights into which plant groups have been preferred and selected for food over time, indicating the breadth of human diets and the use of regional flora resources.  

They found that condiment species like peppers showed phylogenetic clustering, meaning related species were repeatedly used for the same purpose over time. Plant groups with wide leaves used for wrapping tamales also showed evolutionary convergence. Wild and cultivated edible plants belonged to identical lineages, with different species swapped in and out, showing people relied on the same useful plant families. However, wild versus cultivated plants used for condiments did come from different lineages.

Understanding patterns in the traditional use of native plants gives clues to their potential nutritional value and biocultural heritage. Archaeologists believe Mesoamerica was a key centre of plant domestication, with crops like maize, beans, squash and chilli peppers originating in the region. Many wild greens and fruits there also remain important foods. 

The researchers compiled a database of around 500 edible native vascular plants from the Gulf of Mexico Province in Mexico, noting which parts were used and whether plants were wild or cultivated. They generated phylogenetic trees to analyze evolutionary relationships and clustering of edible species and usage types.

Results showed the highest diversity of lineages used as food, reflecting the breadth of human diets. Significant phylogenetic clustering occurred in certain branches for wild edible plants, condiments and wrappers. For instance, hot nodes for condiments appeared in Piperaceae peppers and Asteraceae marigolds. Despite wild versus cultivated species differences, plant families like Fabaceae legumes and Cactaceae cacti were preferred food sources either way.

Díaz-Toribio and colleagues argue their results have implications for conservation in Mexico. They write:

Research of the phylogenetics of edible plants like our study supports arguments for the conservation of incipiently cultivated species, varietal forms and wild types of already domesticated crops…. Furthermore, the estimation of PD [phylogenetic diversity] and identification of patterns of ethnobotanical convergence act to promote new research in ethnobiology…

Díaz-Toribio et al. 2023

Overall, this evolutionary ethnobotany reveals how indigenous cultures have sustainably utilized the diversity of plants available to them for millennia. The phylogenetic patterns can guide the discovery of nutrition and cultivation potential in underused species. Most importantly, this is not a process that is over, with people still using wild as well as domesticated plants. Appreciating this biocultural heritage is crucial for food security and sustainable development.

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Díaz-Toribio, M.H., de-Nova, J.A., Piedra-Malagón, E.M., Angulo, D.F. and Sosa, V. (2023) “Wild and cultivated comestible plant species in the Gulf of Mexico: phylogenetic patterns and convergence of type of use,” AoB PLANTS, 15(5), p. lad063. Available at: https://doi.org/10.1093/aobpla/plad063.