Homo sapiens–Cucurbita interaction in Mesoamerica: Domestication, Dissemination, and Diversification

Abstract

Cucurbita are monoecious and creeping plants including 20 taxa and 15 species. In Mesoamerica, four species were domesticated or diversifi ed after domes- tication in other geographic areas: C. argyrosperma C. pepo , C. moschata , and C. fi cifolia . The earliest evidences of the domestication of Cucurbita date 9000 BP from Southwestern Mesoamerica and 10,000 BP from Southwestern Ecuador. The main targets of human selection were the seeds contained in larger and less bitter and toxic fruits (due to cucurbitacins), without vine detachment. C. argyrosperma ssp. sororia from México to Central America warm-humid and subhumid climates is considered the wild ancestor of the domesticated C. argyrosperma ssp. argyro- sperma . For C. pepo , the proposed ancestor of the domesticated populations of México is C. pepo ssp. fraterna from northeastern Mexico, while the putative pro- genitor of the cultivars from in North America is C. pepo ssp. texana from eastern United States. For C moschata , there are two hypotheses as to its domestication region: southern Mesoamerica, or from the lowlands of Colombia and southern Ecuador. Cultivated C. fi cifolia is found from the Mexican highlands south to Chile and Argentina, its center of domestication is either Central America or southern Mexico/Central America, as supported by linguistic evidence, or the Andes, as indi- cated by archaeological evidences from Peru dated at 3000 BC. Humans spread cultivated Cucurbita inside and out of Mesoamerica, structuring a complex agricul- tural system along with corn ( Zea mays ), and different species of beans ( Phaseolus spp.) called “milpa,” that were established in a wide range of environments.