Archaeology of Maize

The introduction of Agriculture in Mesoamerica caused a change in the way of life for populations in that area.Cultivation of plants allowed for the shift from hunter/gatherer societies to a more sedentary lifestyle. Studies conducted in the last 50 years have shed considerable light on the origins of agriculture in Mesoamerica, especially in relation to the origins of maize cultivation.

ENVIRONMENT OF MESOAMERICA

Typically the environments of Mesoamerica fall under three classifcations, (1)extratropical drylands, (2) extratropical highlands and extratropical appendages, and (3) tropical lowlands (Modified from MacNeish 1992 using the Robert West division). The extratropical drylands classification mainly deals with the region of Tamaulipas, Mexico, and consist of ecozones that produce marginal to tropical rainfall. Raindfall is closely associated with the seasonality of the region. Ecozones variability range from coastal deserts, to rain forests in the Sirrea Madres. Extratropical highlands display great diversity, from pine and oak forest, to rain forest at higher elevations. Rainfall is heavy in the summer and fall months, and at some of the higher elevations snow may appear. The tropical lowlands generally consist of coastal lowlands and interior tropical basins. For a more detailed discussion on the environment the reader may wish to consult

STUDIES ON THE ORIGINS OF MAIZE

George Beadle, a noted botanist, believes teosinte is the direct ancestor to modern corn, originating by human selection sometime between 13,000 and 6000 B.C. Evidence for such a belief comes from the fact that teosinte can "pop" similar to todays popcorn varieties when subjected to heating. Teosinte also shares a similar life cycle with maize and is easily crossbred showing remarkable genetic simularities. (Fagan 1995; Flannery and Marcus 1996: Harlan 1995). There are some hangups with this assumtion, namely the typical or classical ear of corn. Teosinte does not possess anything resembling an ear. The teosinte ear appears in clusters and are usually enclosed in a single husk. Tassles or silks appear as in maize, but the husk on maize are numerous, enclosing a well developed ear of corn, with rows of kernals (Harlan 1995). (for a list of futher differences click here).

Knowledge related to the origins of maize is largely due to the efforts of Richard MacNeish. Working with Paul Mangelsdorf, MacNeish first selected to focused his attention in southwestern Tamaulipas. In 1949 he found some small cobs in cave deposits later dated at around 2500 B.C. The Tamaulipas cobs turned out to be approximately the same age as cobs recovered from Bat Cave in New Mexico. Later excavations in the Chihuahua and Sonora regions produced indications that the origins of maize may lie to the south of those states. This propted MacNeish to move the focus of his research to areas in Honduras and Guatemala. Since he knew that dates for maize were relatively equal between Tamaulipas and Chiapas, MacNeish turned his attention to the Tehuacan Valley an arid region that lie between Tamaulipas and Chiapas. The Tehuacan Valley is situated in the arid highlands of southern Mexico making it idealy suited for the preservation of organic materials. (Byers 1967). There in the Tehuacan Valley he found early forms of maize in Ajuereado Cave, this spured him to mount a larger more extensive excavation of the valley. Later excavations at Coxcatlan rock shelter produced cobs dated by radiocarbon to around 5000 B.C. The Coxcatlan cobs showed intermidiate features in their morphology between wild teosinte and maize and are now held as amoung the earleist specimens of maize ever recovered (Fagan 1995; MacNeish 1992).

The cobs recovered from Coxcatlan were examined by Mangelsdorf and he confirmed that they were the probable ancestor to domesticated corn. Typically remains recovered were well preserved, with many parts of the plant in excellent preservation. Wild varieties as well as domesticated varieities of maize were recovered during excavations from Tehucan Valley in later years. Based upon the evidence gathered in the Tehuacan Valley MacNeish was able to show a gradual shift from hunter/gatherer lifeways to one of cultivation and the utilization of domesticated plant foods. Excavations at Coxcatlan rock shelter proved to be particularly fruitful for understanding those changing lifeways. Occupational levels at Coxcatlan date back to ~10,000 B.C. Using the data collected MacNeish was able to demonstrate that 50-60% of the populations food came from game animals during this period (Ajuereado Phase). By 7000 B.C. this figure had reduced to 30-40% and continued to decline until by 4500 B.C. 90% of food stuffs eaten consisted of wild grasses and cacti. By 3000 B.C. populations in the Tehuacan Valley had domesticated several plant foods, beans, amaranth, gourds amd maize are but a few (Fagan 1995). (see Mesoamerican domesticates list complete listing) Maize was ground and processed into edible food using manos and matates and sometimes morters and pestals. The maize itself was still very similar to teosinte and much smaller than modern forms at this stage. Along with the use of maize there is an increase in sedentary living and large storage facilities enabling the storage of food for probable lean periods (Fagan 1995).

MacNeish clearly showed that the change from hunter/gatherer lifeways to a more sedentary lifestyle was a gradual process that had a direct relation to the use of plant foods. The archeological record documented this change and indicates how this cultural changed may have come about. While maize was not the only cultivated domesticate it soon become a very important one. The inclusion of domesticated plants allowed populations to build more permanate settlements and this proved to be an important step in the overall cultural development of later Mesoamerica.

Mesoamerican Chronology

SOUTHWEST

We may probable never know the means by which maize was introduced into the Southwestern portion of North America, but what we do know is that it provided the platform for the later emergence of Pueblo cultures. The origins of Southwestern agriculture is rooted in a subsistence strategy of foraging and seasonal transhumerence. Advantages of incorporating domesticated plants into a foraging complex are related to domesticates relative perdictability and ability to store for long periods of time, suppling food stuffs over different seasons. Maize cultivation appears to have been adopted sometime near the end of the second or early first millennium B.C. (Fagan 1995).

Since maize requires more than a casual effort to plant, grow, and process into edible food stuffs it took sometime before it was fully adopted as a serious subsistence method. It is believed that maize remained a supplement to regular foraging for a millennium or so after its initial introduction to the region. The maize to first reach the Southwest was a low yielding form called Chapalote. Dates from the San Jaun Basin in northern New Mexico seem to confirm the arrival of Chapalote into the Southwest as early as the second millennium B.C.(Fagan 1995)

Radiocarbon dates from AMS place the appearence of maize in the Tucson Basin between 800-500 B.C. Dates from Bat Cave are thought to be from 1000 B.C. and pollen grains found at Cienga Creek average around 500 B.C. The consistency of dates lead archaeologist to believe maize entered the Southwest probably between 1500-1000 B.C. Its introduction to the region coincided with a period of wetter climate over the eastern and central portions of the Southwest (Fagan 1995).

Here the picture becomes cloudy, some believe that Chapalote mixed with indigenous teosinte producing a hybrid maize that appears in the remains recovered from archaic sites such as Bat Cave. This hybridization appears to have produced a maize with a greater number of kernals per row and a larger cob size. It was the development of these hybrids that allowed maize to spread across the Southwest. This new maize is referred to as Maize de Ocho Maize de Ocho is highly adapted to arid conditions and produces higher yields than previous varieties of maize. Some archaeologist believe that Maize de Ocho arose from a indigenous Southwestern variety of maize, this assumtion is based upon radiocarbon dates obtained by MacNeish and Steadman Upham of 1225 +/- 240 B.C. from excavtions at Roller Skate and Tornillo rock shelters located in the southern portion of New Mexico (Fagan 1995). Not everyone is comfortable with this assumtion.

Maize de Ocho's success was probably due to its thick rachis that better held the kernel to the stalk. It also pocessed a larger kernel of corn, and its relative ease of grinding made it more suitable for daily consumption. With all its advatages maize had little effect on the typical Southwestern lifeways of foraging and transhumerence mobility at its onset. Early forms of maize had low productivity and probably had a yield on par with a stand of wild seed plants in those early stages of introduction. Only later as yields increase and maize adapts to a variety of environmental conditions do we see a decrease in overall population mobility. Southwestern peoples became expert maize horticulturalist and incorporated irrigation technqies to assist in raising production and yields. Only after the development of these techniques and adaptations do we see a more sedentary lifeway emerge. Over the coarse of the next 2000 years from the introduction of maize to European contact we see the establishment of maize agriculture and the abatement of hunter and gatherer patterns. With the establishment of maize agriculture we have the development of Village Life and increased population densities across the Southwest (Fagan 1995).

After maize is well established in the Southwest, sometime in the twelth century A.D. Maize de Ocho spread into the Eastern Woodlands of North America. Possibly moving across the Plains as a small cob 12 to 14 rowed ears, referred to as hard flint corn, more commonly called North American pop (Fagan 1995).

Southwestern Chronology

ANDEAN

Solid dates for the introduction of maize into the Andeas first appear around 3200 B.C., earlier dates have been reported from the Ayacucho region at around 4000 B.C. Earlier dates obtained from phytolith dating would put the appearence of maize at 5000 B.C., but this date is tenative at best (Pearsall 1990). Still, if these early dates of 5000 B.C. hold true it would match the earliest dates taken from Mesoamerica. One must remember that data on maize remains prior to 4000 B.C. is sparse at best. It isn't until the Early Horizon Period (900-200 B.C.) that maize becomes more common in the archaeological record. Dispite this fact Pearsall (1990) holds firm to her beleif that maize was introduced to South America sometime before 5000 B.C. Others are more conservative in their approach advocating an introduction closer to the more solid dates of 3000 B.C. (Bird 1984).

Whether we except the dates of 5000 B.C. or 3000 B.C. we know from the archaeological record that maize remained a rather minor food stuff until ~1000 B.C. This is based upon increased frequencies of maize remains in the archaeological record over this period (Pearsall 1990). The relative late reliance on maize as a staple may speak to the diversity of food stuffs cultivated and consumed in this equatorial region. Peanut (Archis hypogaea), beans (many varieties), potato (Solanum tuberosum), quinoa (Chenopodium quinoa ), and chili peppers (Capsicum spp.) are just a few of the more common food stuffs eaten by Andean peoples before the introduction of maize.(see Andean Domesticates for a complete list) Potato, peppers and beans show evidence that early domestication by humans may date back to 7000-8000 B.C. Incredibly we see an increase in plant food diversity during the Initial Period and Early Horizon (1500-200 B.C.) after maize is included in the complex (Harlan 1995: Pearsall 1990). After maize becomes a staple its importance to local cultures is clearly reflected in the achaeological record.

Dr. George Gumerman at the University of Northern Arizona has demonstrate the use of maize in burial rituals as a prevalent practice amoung the Moche peoples. His excavations of burial sites at Pacatnamu shows the importance the Moche placed on maize as a mortuary food. Detailed excavations found maize to be the most common plant food item contained in burials and overall plant food items within the burials were primarily agriculture products. A stricking contrast was found between burial foods and the actual items consumed in the average Moche diet. The predominant staple appeared to be marine in origin, shellfish and varieties of fish for example. Gumerman found that these items were absent from burial offerings, despite the fact they were eaten daily. Further excavation into midden piles have shown a marked difference between the maize eaten and that selected for burial offerings. The burial maize was larger and displayed a greater number of rows per kernal when compaired to the midden maize. These differences reflected in the archaeological record point to the fact that maize and other agricultural produces were the selected chioce of the Moche when chosing burial offerings (Gumerman 1994).

In the mid-1980's the question of the South American influence on the Eastern Woodlands in terms of maize introduction was addressed with interesting results. William F. Keegan (1987), speculated that maize migrated into the Eastern Woodlands via the Antillie's, the string of Caribbean islands between the Florida coast and South America. He builds a convincing case for migration over a sea route rather than thru the Southwest circa the Plains to the Woodlands. Others think the sea route is possible but do not rule out the influx of maize from the Southwest and their possible hybridization forming the maize that would later support the complex cultures that emerge from a Woodlands context (Lathrap 1987). Andean Chronology

EASTERN WOODLANDS

The Eastern Woodlands has a rich tradition of plant use, one that saw nearly every human population by 1500 B.C. relying to some extent on wild vegetable foods. Before the arrival of maize Woodland peoples had domesticated several plant species. Species of gourds and squashes were domesticated by ~1000 B.C, sunflowers and other indigenous plants were also common domesticates.(for a more complete list see Eastern Woodlands Domesticates Sunflowers presumably were domesticated as early as 2265 B.C. and were used for its oils and seeds. Other plants included march elder (Iva an nua), its use has been documented at the Koster site as early as 3880 B.C. The use of domesticated plant foods establihed the platform for the inclusion of maize into an already existing agriculture complex. Some of the earliest dates for maize in the American Bottom come from the Holding site, these dates range between 170 B.C. to A.D. 60. Maize has been well documented in the Eastern Woodlands and increased in intensity after about A.D. 700 over much of the area (Fagan 1995). The earliest documented evidence of maize in the Eastern Woodlands region comes from maize pollen recovered in southern Alabama.Zea maize pollen taken from the sediments of Lake Shelby near coastal Alabama has been positively dated at 3500 B.P. (~1550 B.C.). This make it the earliest confirmed reporting of maize in the Woodlands region. Despite this early date for maize, it remained a relatively unimportant crop for Woodlands populations until a 1000 years later. The increase of maize in the diet can be tracked by isotope studies which show the increase of maize in the dietary complex. This apparent lag between introduction and reliance as a staple is probable due to the time period needed to produce strains of maize that were adapted to the Woodlands climate and soils (Fearn and Liu 1995).

As cultivation of maize increases so to does population densities. With greater populations there is a need for storage capacityies beyond those preveiously seen. Also to some degree there are changes in the social and political structure of the native peoples. By A.D. 800 to 1000 maize agriculture is widespread, ranging from the western Appalachians, east to the Mississippi Valley. Maize itself is one of the defining charateristics used in classification of one of the best know cultures to emerge in from the Woodlands period, the Mississippian Tradition (Fagan 1995: Pauketat 1994).

Over much of the Southeast around A.D. 900 we have the Mississippian adaptation appearing more-or-less contemporaniously. The Mississippian population tended to gather in river valleys were abundant resources of game, vegetable, and aquatic resources concentrated. River valleys also provided ideal soils, rich in nutrients, for the cultivation of maize (Fagan 1995). The Mississippian Tradition shows great variety in its expression of social complexity. One of the best know examples of the upper end of social complexity can be found at the Cahokia site. Covering nearly 4,000 acres, Cahokia was first inhabited around 700 A.D. growing to a population of nearly 20,000 at its height. By A.D. 1100 Cahokia was the largest settlement in the Americas north of Mexico. Over 120 earthen mounds functioning as civic buildings, residences for the ruling elite and ceromonial centers. The entire complex was situated over five square miles. Sometime around A.D. 1200, Cahokia went into a decline, possible because of deforestation and over explotation of resources, by A.D. 1400 the site was virtually empty (Fiedel 1994: Mehrer 1995: Pauketat 1994).

Cahokia's success was due in no small part to the cultivation of corn. River valleys such as the area where Cahokia is located have been estamatied to be able to produce 22 bushels of corn per acre. Even with such production the risk of crop failure was an ever present threat. Drought, pest infestation, and nutriant depletion of the soils were just a few of the hazards faced by Mississippian farmers. Because of the increased reliance on maize any disruption of maize production might have caused wide spread famine. Since people had become accustom to living in permanent settlements they would have had difficulty moving to more productive areas in search of food. (Fagan 1995).

This page hosted by
Get your own Free Home Page