Directly dated starch residues document early formative maize ( Zea mays L.) in tropical Ecuador

Abstract

The study of maize (Zea mays L.) domestication has advanced from questions of its origins to the study-and debate-of its dietary role and the timing of its dispersal from Mexico. Because the investigation of maize's spread is hampered by poor preservation of macrobotanical remains in the Neotropics, research has focused on microbotanical remains whose contexts are often dated by association, leading some to question the dates assigned. Furthermore, some scholars have argued that maize was not introduced to southwestern Ecuador until Ϸ4150 -3850 calendar years before the present (cal B.P.), that it was used first and foremost as a fermented beverage in ceremonial contexts, and that it was not important in everyday subsistence, challenging previous studies based on maize starch and phytoliths. To further investigate these questions, we analyzed every-day cooking vessels, food-processing implements, and sediments for starch and phytoliths from an archaeological site in southwestern Ecuador constituting a small Early Formative village. Employing a new technique to recover starch granules from charred cooking-pot residues we show that maize was present, cultivated, and consumed here in domestic contexts by at least 5300 -4950 cal B.P. Directly dating the residues by accelerator mass spectrometry (AMS) radiocarbon measurement, our results represent the earliest direct dates for maize in Early Formative Ecuadorian sites and provide further support that, once domesticated Ϸ9000 calendar years ago, maize spread rapidly from southwestern Mexico to northwestern South America.ceramic residues ͉ microfossil analysis ͉ AMS radiocarbon measurement ͉ crop dispersals ͉ agricultural origins

The cultural and chronological context of early Holocene maize and squash domestication in the Central Balsas River Valley, Mexico

“…Furthermore, a large corpus of archaeological and paleoecological microfossil (phytolith, starch grain, and pollen) research indicates that maize had spread south out of Mexico earlier-arriving in Panama by 7600 cal B.P.-and by 6000 cal B.P. was well established in northwestern South America (e.g., 9,12,[23][24][25][26]. This time frame accords with the estimated Ϸ9000 cal B.P.…”

“…(1)(2)(3). Among the many plants that were domesticated there during the pre-Columbian era, none has received as much attention and been subject to as much debate as corn, or maize (Zea mays L.), the most important crop of the Americas (4)(5)(6)(7)(8)(9)(10)(11)(12). Once thought to be a cultivar of the arid Mexican highlands, molecular data now indicate that maize was domesticated a single time and that a subspecies of teosinte classified as Zea mays ssp.…”

Starch grains from dental calculus reveal ancient plant foodstuffs at Chenqimogou site, Gansu Province

“…Plants in our comparative collection include foxtail millet (Setaria italica), broomcorn millet (Panicum miliaceum), rice (Oryza sativa), sorghum (Sorghum bicolor), oat (Avena sativa), and maize (Zea mays). In addition, the morphology of buckwheat (Fagopyrum esculentum), whitethorn (Crataegus pinnatifida), and so on are polygonal [1][2][3][4][5][6][7][8][19][20][21][22]. However, sizes of rice, oat, buckwheat, whitethorn, and others are all smaller than Group 1.…”

“…Genera include the grasses Panicum, Setaria, Lolium, and Aegilops, tree seeds of Quercus, Castanea, Corylus, and Juglans, as well as beans like Vigna (Figure 2). For starch identification, we also used description from many other studies of starch grain morphology [1][2][3][4][5][6][7][8]18].…”

“…In the past decades, starch grain analysis has been successfully employed to study the origins and dispersals of agricultural crops, artifact function, and paleoclimate reconstruction in America, Australia, and other areas [1][2][3][4][5][6][7][8][9][10].…”