Interdisciplinary insights into the cultural and chronological context of chili pepper (<i>Capsicum annuum</i> var. <i>annuum</i> L.) domestication in Mexico.

Abstract

This study investigates the temporal and spatial factors driving the domestication of <i>Capsicum annuum</i> var. <i>annuum</i> L. in Mexico. This species exhibits the greatest morphological diversity in fruit among <i>Capsicum</i> species-a characteristic that is even more pronounced in contemporary landraces cultivated by indigenous communities. Despite the chili pepper's integral role in regional culinary traditions, its domestication history in this region remains poorly understood, often subject to scholarly interpretations that marginalize or oversimplify archaeological evidence. To address this gap, our interdisciplinary team of archaeologists, botanists, and ecologists combine modern and archaeological <i>Capsicum</i> seed data, diachronic archaeological site locations, and ecological niche modeling to identify potential regions where early human populations and the closest wild ancestors may have coexisted. Our results show spatial correlations between early <i>Capsicum</i> distribution and archaeological site prevalence, suggesting that the beginning of the domestication process occurred in ecologically suitable areas for both wild <i>Capsicum</i> and human settlement. These findings challenge previous hypotheses regarding highland/dry cave domestication regions, as our data indicate that lowland regions-specifically the Yucatán Peninsula and southern coastal Guerrero-were more conducive to early encounters between wild <i>Capsicum</i> and humans. We propose a geographically diffuse and protracted model of chili pepper domestication-driven by a ruderal pathway-which involved at least two asynchronous events across Mexico.