We present macrobotanical, starch, and phytolith data from artifacts and sediments from Middle Formative La Blanca (1000–600 cal BC) and Late Formative El Ujuxte (600 cal BC–cal AD 115 ) in the Soconusco region in Guatemala. Potential economic plants identified included palm (cf. Arecaceae), two varieties of maize (Zea mays), guava (Psidium guajava), bean (Phaseolus), chili peppers (Capsicum), squash (Cucurbitaceae), custard apple (Annonaceae), coco plum (Chrysobalanaceae), lerén (Calathea), arrowroot (Maranta), and bird-of-paradise (Heliconia). The results suggest that control of food production and consumption was critical for the transition from complex chiefdoms during the Middle Formative to the archaic state in the Late Formative. The arrival of a more productive South American variety of maize at El Ujuxte (about 2549 BP) allowed elites to exploit an already existing broad-based economic system and to use the maize-based religious system to increase control over maize agricultural practices and maintain power through ideology and disciplinary power. These data suggest that the arrival of fully domesticated South American maize likely influenced the overall development of Mesoamerican state-level societies.

We investigated foodways at Real Alto, an early Formative (4400–1800 BC) Valdivia site in coastal Ecuador, using starch and phytoliths recovered from 50 stone tools from three residential and two ceremonial structures, as well as 46 human dental calculus samples, to explore how food reflects the social relationships and economy of the community. Maize was important in daily meals and ceremonial foods by the Middle Valdivia (2800–2400 BC), but it was only one component of an agricultural system that included yuca, arrowroot, llerén, canna, yam, jackbean, squash, gourd, chili, and cotton. Ceremonial and everyday foods at Real Alto did not differ: actions surrounding food were both domestic and ceremonial, depending on context. Households had equal access to annual crops and to root-tubers with longer growing seasons. Gelatinized starch was commonly recovered on tools, indicating the processing of cooked foods. Dental calculus residues confirmed common consumption of cooked foods, fruits, and root-tubers. Cultivating crops with different water and growing season requirements necessitated diverse practices, potentially including selection of short-season varieties, hand watering, and growing crops over multiple rainy seasons. The latter two practices required increased labor inputs: access to labor was likely a key element supporting the nascent social hierarchy that emerged by the Middle Valdivia.

Core MAN015 from Pacific coastal Guatemala contains sediments accumulated in a mangrove setting over the past 6500 yr. Chemical, pollen, and phytolith data, which indicate conditions of estuarine deposition and terrigenous inputs from adjacent dry land, document Holocene climate variability that parallels the Maya lowlands and other New World tropical locations. Human population history in this region may be driven partly by climate variation: sedentary human populations spread rapidly through the estuarine zone of the lower coast during a dry and variable 4th millennium B.P. Population growth and cultural florescence during a long, relatively moist period (2800–1200 B.P.) ended around 1200 B.P., a drying event that coincided with the Classic Maya collapse.

Scholars attribute the growth and decline of Classic period (AD 200–900) settlements in the semi-arid northern frontier zone of Mesoamerica to rainfall cycles that controlled the extent of arable land. However, there is little empirical evidence to support this claim. We present phytolith, organic carbon, and magnetic susceptibility analyses of a 4000-yr alluvial record of climate and human land use from the Malpaso Valley, the site of one such Classic frontier community. The earliest farming occupation is detected around 500 BC and appears related to a slight increase of aridity, similar to the level of the modern day valley. By AD 500, the valley's Classic period Mesoamerican settlements were founded under these same dry conditions, which continued into the Postclassic period. This indicates that the La Quemada occupation did not develop during a period of increased rainfall, but rather an arid phase. The most dramatic changes detected in the valley resulted from the erosion associated with Spanish Colonial grazing and deforestation that began in the 16th century. The landscape of the modern Malpaso Valley is thus primarily the product of a series of intense and rapid transformations that were concentrated within the last 400 yr.

The discovery of the fully developed Formative sites of Cotocallao (ca. 3750-2350 cal. B.P.) in the Quito Basin and La Chimba (ca. 2650-1700 cal. B.P.) in the northern highlands of Ecuador has raised questions about their cultural antecedents, which have not been resolved despite decades of archaeological work in the region. Paleoenvironmental coring investigations were conducted at Lake San Pablo in northern highland Ecuador to determine the date for the onset of prehistoric maize farming in the temperate highland valleys of this region. The investigations included analysis of lake sediments for pollen, phytoliths, diatoms, and tephra. Maize pollen was identified as early as 4900 cal. B.P., while maize phytoliths dated even earlier, to 6200 or 6600 cal. B.P. These results demonstrate a long history of maize farming in valleys around Lake San Pablo, but in the context of a punctuated record of major and minor volcanic eruptions. It is concluded that early horticultural sites predating Cotocallao and La Chimba must exist, but to find such sites, archaeologists will have to locate and study deeply buried A-horizon soils.

Since the Formative times, maize is and has been a highly valued social commodity in the Andes, particularly in the form of a traditional beer called chicha. While chicha production is well attested in the archaeology and ethnohistory of Andean states, the emergence of maize symbolism in earlier societies has not been systematically addressed. In this study phytolith and starch grain analyses are used to trace production, processing, and consumption of maize at sites on the Taraco Peninsula of Bolivia and thus the entrance of maize into the region. We systematically examine the role of maize by addressing its rarity, use contexts, and preparation. The pattern of plant part representation and use suggest that maize was being consumed in the form of chicha at its earliest introduction to the Titicaca Basin (800–250 B.C.). Drinking of alcohol in ceremonial spaces embodies the process of commensality of public ceremony and the establishment of reciprocal relationships during the Formative period. These results demonstrate that contextual analysis of microbotanical remains has great potential to answer anthropological questions surrounding food, ritual, and identity.

Starch and phytolith analyses of an assemblage of chert microliths from the Three Dog site, an early Lucayan settlement on San Salvador, Bahamas, yielded Zea mays, Capsicum, and possible manioc indicating that these domesticates were present by at least A.D. 800 or earlier in Cuba or Hispaniola and brought to the central Bahamas during its early peopling. The presence of corn at this site contradicts previously held ideas that it did not appear in the Bahamas until the A.D. 1200s. Starch granules tentatively identified as root/tuber starch were also found on the microliths, although we were unable to discern if these represent wild species and/or culturally transported wild or domesticated species. The presence of more than one species on the microliths, initially believed to have been manioc grater chips similar to those documented ethnographically, demonstrates multifunctional use. A broad-based plant diet that included maize and root/tuber crops was in place at least by the Archaic age in parts of the Greater Antilles and brought to the Bahamas, along with chilis, during its colonization by Ceramic age peoples.

We summarize what is known about Archaic period occupation of southeastern Mesoamerica and Central America as background for presenting new paleoenvironmental evidence of pre-Early Formative human impacts on the landscape of Pacific coastal Guatemala. Our evidence comes from sediment cores in three locations, all of which are in the mangrove-estuary zone of the lower coast. Pollen and phytoliths from the cores document increased burning, decreased forest cover, the appearance of domesticates, and increased disturbance indicators at various times during the Archaic period, the earliest being around 3500 cal B.C. The available evidence demonstrates that shifting horticulture was an early and widespread adaptation to the southeastern Mesoamerican deciduous tropical forest and constituted the base from which later adaptations, including that of early Maya farmers, differentiated. Early Formative adaptive innovations may have been favored by shifts in return rates from various estuarine and terrestrial resources during a dry and variable interval 2000 and 1500 cal B.C.

Paleoethnobotanical remains from the Three Dog site (SS-21), an early Lucayan site located on San Salvador, Bahamas, are presented and compared to data from other prehistoric Caribbean sites. Flotation, in situ, and screen recovery (1/16", 1.58 mm) revealed six taxa of fuelwood and charred Sapotaceae seed fragments. Preliminary SEM analysis of six chert microliths revealed possible evidence of the Caribbean aroid, Xanthosoma sp. (cocoyam, malanga, yautía) or Zamia sp. The presence of Sapotaceae and possibly Xanthosoma sp. or Zamia sp. in the archaeobotanical record can be attributed to a number of alternative explanations. The site"s inhabitants may have transported these plants from their homelands and transplanted them to home gardens. An alternative view is that they exploited or managed wild representatives or created disturbed habitats that encouraged the spread of wild or cultivated forms. The pollen data from two Bahama cores, one from Andros, the other from San Salvador, reflect anthropogenic disturbance during the prehistoric occupational sequence. The increasing frequency of Sapotaceae pollen in the San Salvador sequence is consistent with the occurrence of Sapotaceae at the Three Dog site. Finally, preservation- and recovery-related issues are discussed. The study suggests that multiple means of data recovery must be employed to gain a more representative picture of prehistoric Caribbean plant use and floristic environment.

La Identification of maize phytoliths from the Preceramic Vegas and Formative period Real Alto sites, Guayas Province, Ecuador, has raised the issue of the antiquity of maize in Ecuador. This paper reviews how maize is identified using phytoliths and addresses criticisms of this technique. Our reexamination of the original Vegas and Real Alto samples using Piperno's three-dimensional variant method confirms the presence of maize in western Ecuador by at least 5000 B.C. Remains of charred maize from other sites suggest that more than one race was being utilized by the Formative period.