ziz originagriculturemesoamerica

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R E S E A R C H A R T I C L E

Origin of agriculture and plant domestication

in West MesoamericaDaniel Zizumbo-Villarreal • Patricia Colunga-GarcıaMarın

Received: 24 April 2009 / Accepted: 14 December 2009 / Published online: 2 February 2010

Springer Science+Business Media B.V. 2010

Abstract Recent paleoecological, archaeobotanical

and genetic-molecular data are used to develop a

hypothesis on the where, when, how and whom of

plant domestication and the origin of agriculture in

west Mesoamerica, and the formation of the maize-

bean-squash multicrop milpa system and agro-food

system which formed the base for development of

ancient complex societies in this area. It is highly

likely that about 10,000 before present (BP) human

groups specializing in plant gathering and small game

hunting in the dry tropical forest of the Balsas-Jaliscobiotic morphotectonic province began the process of

plant domestication and agriculture, using fire as a

tool. Sympatric distribution of the putative wild

ancestral populations of maize, beans and squash

indicate the extreme northwest Balsas-Jalisco region

as a possible locus of domestication. Diffusion of

these domesticates to the rest of Mesoamerica would

have occurred via existing biological-cultural corri-

dors. The milpa agro-food system would have been

established between 7,000 and 4,400 calendar years

(cal) BP. The complex food technology developed inthe northwest Balsas-Jalisco region between 4,500

and 3,500 BP, much more complex than in other

areas at the time, also suggests this area as the origin

of the milpa agro-food system. Further archaeobo-

tanical research is needed to confirm this hypothesis.

Exploratory, collection and conservation efforts are

needed in these putative source populations, as well

as studies on their adaptation to climatic, edaphic and

biotic factors, before they are displaced by the

African grasses and pesticides forming part of the

region’s growing cattle industry.

Keywords Agriculture Beans Domestication

Maize

Mesoamerica

Squash

Introduction

One of the most significant events in human history

was the transformation from a hunting-gathering

economy to an agricultural economy (Smith 2005).

This change probably occurred independently in at

least six regions in the world, primarily tropical and

subtropical areas with high biological and cultural

diversity (Gepts 2008; Piperno and Pearsall 1998;Sauer 1952). Along with the Middle East and north

China, Mesoamerica is one of the world’s primary

centers of domestication (Harlan 1971, 1995). It was

here that species such as maize ( Zea mays L.), beans

(Phaseolus spp.) and squash (Cucurbita spp.) were

domesticated and integrated into a multi-crop system

known in the region today as milpa. It was this

system’s ecological and nutritional complementarity

that helped to support the development of highly

D. Zizumbo-Villarreal (&) P. Colunga-GarcıaMarın

Unidad de Recursos Naturales, Centro de Investigacion

Cientıfica de Yucatan, Calle 43 No 130. Col. Chuburna de

Hidalgo, 97200 Merida, Yucatan, Mexico

e-mail: [email protected]

1 3

Genet Resour Crop Evol (2010) 57:813–825

DOI 10.1007/s10722-009-9521-4



complex societies in Mesoamerica (Gepts 2008).

Mesoamerica is most commonly defined as the

cultural area extending from the Santiago and Panuco

river basins in Mexico, south to the Central Valley

region of Costa Rica (Kirchhoff 1943).

Plant domestication is understood as the continuous

historic evolutionary process, driven by human selec-tion, which produces fixation of a set of alleles that

provides wild populations with favorable human

consumption and cultivation phenotypes, but which

also diminishes or eliminates the capacity for survival

under natural conditions, making a domesticated

population dependent on humans (Harlan 1992). The

set of phenotypic traits determined by these alleles is

known as the domestication syndrome (Hammer

1984). Plants’ reproductive systems and genetic con-

stitution have favored and hindered domestication to

varying degrees. Plants that have responded positivelyto the selection process and agricultural management

have been completely domesticated, while in others

only certain traits of the syndrome have been fixed,

leaving them semi-domesticated or in process (Gepts

2004). In agricultural systems under limiting environ-

mental conditions, humans have managed to maintain

some species in a semi-domesticated state as part of

their productive strategy (Colunga-GarcıaMarın and

Zizumbo-Villarreal 1993).

For the purposes of this discussion, agricultural

management is to be understood as a set of deliberate,environmental modifications made by humans aimed

at increasing survival and biomass production in

selected plant species, and therefore meeting human

needs given prevailing environmental conditions.

Plant domestication and agriculture are temporally

continuous and interdependent processes. Over time,

humans have selected a group of local and introduced

species for subsistence, and developed knowledge

and techniques for their cultivation, transport, stor-

age, transformation, consumption and preservation.

This group of species and the knowledge andtechniques associated with them are known as an

agro-food system.

The present study aim was to integrate current

paleoecological, archaeobotanical and genetic-molec-

ular data to develop hypotheses on the where, when,

how and whom of plant domestication and agricul-

tural development in west Mesoamerica; by what

routes these domesticates and related knowledge and

technology were distributed; and how and where the

milpa multicrop system and associated agro-food

system came into existence. The answers to these

questions will be vital to locating the genetic

diversity nuclei so important to productivity, sustain-

ability and improvement in current agro-food sys-

tems, and to better understanding the material

foundations of complex cultures in Mesoamerica.

Initial human occupation

Human occupation of Mesoamerica began about

11,600 years before present (BP) (Dixon 1999).

These partially sedentary early arrivals survived by

fishing, hunting megafauna and collecting plants in

areas near the highland intermontane lake systems of

Chapala, Sayula-Zacoalco, Zacapu, Cuitzeo, Mexico

and Puebla-Valsequillo, (Aliphat 1980; Irish et al.2000; Lorenzo and Mirabell 1986; Niederberger

1979; Tolstoy et al. 1977). Their principal hunting

implement was initially designed like a harpoon used

for hunting marine mammals, suggesting that they

had moved inland from the Pacific coast (Fig. 1).

A following migration into the area probably

occurred around 10,600 BP (Dixon 2001) from the

west and great plains of North America. These groups

implemented an ecological strategy based on small

game hunting and plant gathering. They processed

some plant species to make them edible or extractcertain elements; for instance, ground seeds from

Panicum spp. and Setaria spp.; cooked stems and leaf

bases from Agave spp.; stems and fresh fruits from

Opuntia spp.; seeds from Quercus spp. and Pinus

spp.; and fruits from Prosopis spp. They used

sharpened scrapers and points for gathering and

hunting, and stone technology for breaking, grinding

and cooking (Doebley 1984; Poinar et al. 2001;

Willis 1995). In addition to their use of fire, they

introduced the dog (Canis familiaris L.), domesti-

cated from multiple lineages in eastern Asia (Leonardet al. 2002; Wayne et al. 2006). Use of dogs allowed

them to form small, highly mobile bands with

defensive capacity. They occupied rock shelters

along the banks of rivers communicating the inter-

montane valleys with the west coast. Technology

among these groups included thin bifaces, flint points,

river pebbles and stone blocks or platforms modified

for grinding (Flannery 1986; MacNeish 1967a; Mac-

Neish and Peterson 1962; Ranere et al. 2009).

814 Genet Resour Crop Evol (2010) 57:813–825

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Ecological conditions during initial domesticationand early agriculture

Paleoecological records for the Neovolcanic Trans-

verse Axis and the lowlands south of this axis, indicate

rises in temperature, rainfall and atmospheric CO2

concentrations between 12,000 and 9,000 BP, as well as

the presence of a long drought period before the rainy

season (Cunniff et al. 2008; Metcalfe 2006; Piperno

2006). Tropical flora began to displace the boreal

forests, and the lowland thorny bush vegetation was

taken over by tropical dry forest (TDF). The combina-tion of these transformations produced a transition from

C3 to C4 grasses, growing populations of Panicum spp.,

Setaria spp., Tripsacum spp. and Zea spp., and

expansion of certain dicotyledonea families, such as

Chenopodiaceae, Amaranthaceae, Asteraceae, Cucur-

bitaceae and Solanaceae (Cunniff et al. 2008; Piperno

et al. 2007; Sage 1995). It was during this period that

the Balsas-Jalisco (BJ) biotic morphotectonic province

(Fig. 2) took form south of the Neovolcanic Transverse

Axis (Ferrusquıa-Villafranca 1990). Its floral andfaunal distribution, structure and composition have

changed little during the last 9,000 years (Metcalfe

2006; Piperno 2006). Between 16,500 and 4,000 BP,

high eruptive activities and extensive lava flows from

the Colima Volcanic Complex (CVC) split the region

from north to south (Cortes et al. 2005; Capra and

Macıas 2002), leaving an area to the northwest rich in

grasses, including: Tripsacum dactyloides (L.) L. var.

mexicanum De Wet et Harlan L; T. lanceolatum Rupr.

ex Fourn.; T. maizar Hernandez et Randolph;

T. pilosum Scribner and Merr.; Zea diploperennis Iltis,Doebley et Guzman; Z. mays L. ssp. parviglumis Iltis et

Doebley; and Z. perennis (Hitchcock) Reeves et

Mangelsdorf (Eubanks 2001; Wilkes 2004).

Distribution of putative ancestral populations

Phylogenetic analyses using nuclear DNA have shown

that Z. mays ssp. parviglumis populations in the central

Fig. 1 Probable routes of initial human migrations into

Mesoamerica along river corridors: (1) Grande de Santiago-

Lerma, (2) Armerıa-Tuxcacuesco, (3) Balsas, (4) Amacuzac

and (5) Mexcala-Nexpa-Atoyac. Main Pleistocenic fauna

hunting sites in the Neovolcanic Transversal Axis: ( A)

Chapala-Zacoalco-Sayula, ( B) Valley of Mexico and (C )

Puebla-Valsequillo

Genet Resour Crop Evol (2010) 57:813–825 815

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and west BJ region could be the putative progenitors of

domesticated maize (Buckler et al. 2006; Fukunaga

et al. 2005; Matsuoka et al. 2002). Phylogenetic

relationships inferred from mitochondrial genes sug-

gest that wild populations of C. argyrosperma Huber

ssp. sororia Merrick et Bates in this region are the

putative source populations of domesticated varieties

(Sanjur et al. 2002). For the bean Phaseolus vulgaris

L., genetic-molecular research using nuclear DNA

suggests that wild populations of this species in the

lower Lerma-Santiago river basin and in the northwestBJ region are the ancestral populations of domesti-

cated varieties (Gepts 1988; Kwak et al. 2009,

Zizumbo-Villarreal et al. 2009a) (Fig. 3).

The origin of agriculture

A growing carbon accumulation in paleoecological

records from the BJ region to Panama’s southern

coast between 10,000 and 7,000 BP seems to indicate

systematic use of fire by humans. There is also a

simultaneous increase in the presence and accumu-

lation of Zea genus grass pollens in the central-

western BJ (Piperno 2006; Piperno et al. 2007).

Continued use of fire in the TDF of the BJ region led

to a drastic decline in diversity, the dominance of tree

species with the capacity to sprout from the root

crown or stem and the appearance of grass patches

(Miller 1999; Miller and Kauffman 1998; Sanchez-

Velazquez et al. 2002). Eventually, teocintle, beansand squash would begin to grow together in these

patches (Flannery 1986; Wilkes 2004).

The increased density of edible species promoted by

burning could have defined collecting rounds and the

location of seasonal shelters nearby. Rock shelter

distribution, their size and the archaeological remains

inside them in the central BJ region about 8,700 cal-

endar years (cal) BP indicate that they were occupied

for a number of weeks by small groups of humans.

Fig. 2 Biotic provinces (Ferrusquıa-Villafranca 1990), and archaeological sites (Flannery 1986; Kelly 1980; MacNeish 1964;

Mountjoy 2006; Ranere et al. 2009)


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These groups made use of the surrounding resources bygathering plants, hunting deer and smaller fauna, and

cultivating of maize and squash using tools such as fire,

bifacial scrapers and choppers, as well as handstones

and base stones for grinding (Ranere et al. 2009).

Plant domestication

Based on molecular clock results, the initial separa-

tion between wild and domesticated maize popula-

tions probably occurred &9,000 BP (Matsuoka et al.2002). This coincides with accelerator mass spec-

trography (AMS) results for maize and squash starch

grains domesticated about 8,700 cal BP found in

Xihuatoxtla in the central BJ region (Ranere et al.

2009). Results reported by Piperno et al. (2009)

support a scenario in which maize was domesticated

in the low, humid portions of the Balsas river

watershed, where Z. mays ssp. parviglumis is native.

The size and morphology of maize starch grains and

phytoliths is indicative of human selection for theteocintle glume architecture gene (tga1), a major

domestication gene in Zea which controls phenotypic

attributes key to efficient utilization of maize as a

grain (Doebley 2004; Piperno et al. 2009). This

selection increased starch quantity and quality, while

reducing grain glume size and hardness, leading to

naked grains with soft glumes (Wang et al. 2005). For

squash, phytolith size and morphology is indicative

of human selection pressure on the Hr gene, a major

domestication gene in Cucurbita which controls

crucial phenotypic attributes such as fruit hardnessand phytolith quantity (Piperno et al. 2002; 2009).

Leguminous starch grains found at Xihuatoxtla in

the central BJ region may correspond to beans

(P. vulgaris or P. lunatus) (Piperno et al. 2009:

supporting data) and suggest that bean may have been

domesticated in this region as early as 9,000 cal BP.

However, AMS-dated macro-remains of beans found

at Tehuacan suggest domestication by 2,285 cal BP,

while bean remains from Guila Naquitz have been

Fig. 3 Location of wild populations of putative ancestors to

plant species domesticated in Mesoamerica: (Cu) Cucurbita

argyrosperma Huber; (Pv) Phaseolus vulgaris L; ( Zm) Zea

mays L. (Fukunaga et al. 2005; Gepts 1988; Kwak et al. 2009;

Matsuoka et al. 2002; Sanjur et al. 2002; Zizumbo-Villarreal

et al. 2009a)


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dated to 2,098 cal BP (Kaplan and Lynch 1999). In

beans, the domestication syndrome includes traits

that limit natural dispersion, such as loss of fruit

dehiscence, seed latency and photoperiod sensitivity

(Koinange et al. 1996).

Diffusion of domesticated species

In the early Holocene, the distribution of human

shelters in Mesoamerica and the similar technological

development of human groups in the area (MacNeish

1967a; MacNeish and Peterson 1962; Flannery 1986;

Ranere et al. 2009) suggest that rivers, which would

have been regular water sources during the long dry

season, functioned as biological and cultural disper-

sion corridors (Fig. 4). Diffusion of domesticated

plant species throughout Mesoamerica along these

river corridors can be inferred from the earliest dates

for the presence of maize. Paleoecological maize

pollen and phytolith records from the Gulf of Mexico

coast date from ca. 7,300 BP (Pohl et al. 2007),

suggesting diffusion along the Tehuantepec, Coatza-

coalcos and Grijalva rivers. Records for maize in theTehuacan and Oaxaca intermontane valleys dating to

about 6,300 BP imply diffusion along the Tepalcate-

pec-Balsas-Mexcala and Atoyac-Salado systems. The

presence of maize pollen in Belize by about 5,400 BP

(Pohl et al. 1996) suggests another route along the

Grijalva and Motagua rivers, while records from

Veracruz state dating to ca. 5,000 BP (Sluyter and

Domınguez 2006) indicate the Salado and Papaloapan

rivers also functioned as diffusion corridors (Fig. 5).

Of these different routes in Mesoamerica, the

Fig. 4 Distribution of human populations in Mesoamerica

during the Archaic period: (a) Sayula (Irish et al. 2000; Benz

2002); (b) Matanchen (Mountjoy et al. 1972); (c) Tlapacoya

(Tolstoy et al. 1977); (d ) Valsequillo (MacNeish 1967b); (e)

Xihuatoxtla (Ranere et al. 2009); ( f ) Puerto Marques (Brush

1965); (g) Tehuacan (MacNeish 1964); (h) Oaxaca (Flannery

1986); (i) Ocozocuautla (MacNeish and Peterson 1962); and ( j)

Chanuto (Voorhies et al. 2002). Biocultural corridors during

the Archaic: ( A) Chapala-Santiago-Matanchen; ( B) Sayula-

Tuxcacuesco-Armerı a-Tuxpan-Coahuayana; (C ) Chapala-Cuit-

zeo-Lerma; ( D) Chapala-Tepacatepec-Infiernillo, (E ) Valley of

Mexico-Cuautla-Amacuzac-Mezcala-Atoyac; (F ) Valsequillo-

Salado-Atoyac-Tehuantepec-Grijalva-Coastal Chiapas


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Tepalcatepec-Balsas-Mexcala corridor was probably

a major route for human movement beginning in the

early Holocene (Benz 1999).

Domesticated maize also moved quickly into

Central and South America, as shown by its presence

in Panama by about 7,800–7,000 BP (Dickau et al.

2007), suggesting diffusion routes along the Grijalva,

Motagua and Chamelecon rivers and along the south

coast of Central America. Paleoecological data for

the presence of maize pollen, starch grains and

phytoliths in the Cauca and Ponce valleys of Colombia by about 7,500 BP (Aceituno and Castillo

2005), and on the southwest coast of Ecuador around

the 6,200 cal. BP (Zarrillo et al. 2008) imply another

route along the western and central mountain ranges

of Colombia. Finally, maize and chili phytoliths and

starch grain records from grinding artifacts in the

Andean region by 6,000 BP indicate these two

domesticated species were probably diffused simul-

taneously (Perry et al. 2007).

Agricultural intensification

Paleoecological records for the BJ region between

7,000 and 5,550 BP contain evidence of increased

levels of Asteraceae family weed species (typical of

short fallow systems), greater maize pollen accumu-

lation and decreases in carbon deposits (Piperno

2006; Piperno et al. 2007), suggesting agricultural

intensification. Between 7,000 and 6,000 cal BP, a

new tool kit begins to appear in the archaeological

record, including large, open stone ovens, woodentools such as levers, contracting stems and traps,

bifacial knives, plano-convex scrapers, bifacial stone

choppers, mortars, pestles and grinding handstones

and bases. Human shelter and camp distribution, size

and occupation show that macrobands (15–20 per-

sons) began to form during the rainy season to

cultivate and harvest plants (Flannery 1986; MacNe-

ish 1964), further suggesting agricultural intensifica-

tion. Cultivation areas were in the piedmont, on

Fig. 5 Possible routes for early diffusion of plant species

domesticated in Mesoamerica: ( A) Santiago-Lerma; ( B) Tepal-

catepec-Balsas; (C ) Mexcala-Amacuzac; ( D) Atoyac1-Salado-

Atoyac2; (E ) Mixteco-Verde-Atoyac2; (F ) Tehuantepec;

(G) Grijalva; ( H ) South coast; ( I ) Motagua; ( J ) Caribbean;

(K ) Chamalecon; ( L ) Belize; ( M ) Coatzacoalcos; ( N ) Papaluapan;

and (O) Maya lowland


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terraces close to valleys and plains near lakes

(MacNeish 1964; Ranere et al. 2009).

Morphological analyses of maize cobs dating to

6,300 BP indicate the presence of cobs with two to

four rows of grains, grains with reduced glumes and

total retention of seeds, meaning this crop had

become completely reliant on humans as a replace-ment seed dispersal mechanism (Benz 2001; Piperno

and Flannery 2001). Molecular analyses using

archaic DNA show fixing of Teocintle branched 1

(Tb1), a gene that largely controls short branches

tipped with ears in domesticated maize (Jaenicke-

Despres et al. 2003; Jaenicke-Despres and Smith

2006).

Milpa multicropping

Between 6,000 and 5,000 BP in Mesoamerica,

semi-sedentary macrobands lived on valley terraces

in small circular or oval units, with small ovens for

cooking food, and common storage of agricultural

surplus (MacNeish 1964; Flannery 1986). Stone

bases are replaced by manos and metates for

grinding, and stone cups and pots appear in the

record (Flannery 1986; MacNeish 1964, 1967b).

These tools broadened the ability to transform

foods, involving their human users in the applica-

tion of new selection pressures on grain species.During this period, cultivated plots may have been

established near habitation units by transport of

domesticated perennials such as red mombin and

agaves and the spontaneous arrival of weed species

like chilies, tomatoes (Physalis spp.), amaranth

( Amaranthus spp.) and cotton (Gossypium hirsutum

L.). Dogs were raised as food, and archaeological

and molecular studies suggest it was at this time

that the Xoloitzcuintle dog breed arose and was

raised as a food resource in the BJ region (Wayne

et al. 2006).By 5,500 BP, the alleles for four rows of grains on

maize cobs had fixed; archaeobotanical remains

indicate the presence of cobs with 8–12 rows,

although the alleles for this trait had not yet fixed.

In-field selection for higher numbers of rows sub-

stantially increased maize’s genetic productivity

(Jaenicke-Despres et al. 2003; Jaenicke-Despres and

Smith 2006).

Development of the agro-food system

The traits involved in the compact architecture of the

maize plant had fixed by about 4,400 BP, including

apical dominance, fewer stalks, one to two cobs on

the central axis and cobs with 12–16 rows (Jaenicke-

Despres et al. 2003; Jaenicke-Despres and Smith2006). Ceramics appear in the archaeological record

in the form of comals, cups and simple pots (Brush

1965; Mac Neish 1976b; Flannery 1994), which

would further open the possibilities for food trans-

formation and introduce new selection pressures. It is

during this period that human selection begins to

change the alleles determining protein and starch

quality ( pbf and SuI ) (Jaenicke-Despres et al. 2003;

Jaenicke-Despres and Smith 2006), suggesting a

focus on cooking traits. By 4,000 BP, inhabitants of

the intermontane valleys cultivated crops in agrohab-itats including piedmont terraces, valley terraces,

plains along lakes and rivers and house gardens

(Flannery 1986; MacNeish 1964). A utilitarian

ceramic tradition developed and diversified between

4,500 and 3,500 BP that was related to food harvest,

transport, storage, transformation and consumption.

By 3,500 BP, the Capacha culture had developed in

Colima state and Mascota in southern Jalisco, with a

ceramic corpus that included food processing tools

for soaking, cooking and steaming, as well as

fermentation and possibly distillation of alcoholicbeverages (Kelly 1980; Mountjoy 2006; Zizumbo-

Villarreal et al. 2009b) (Fig. 2). This ceramic diver-

sification reflects greater complexity in the methods

used for food transformation and in the selection

pressures on domesticated species. Between 3,000

and 2,000 BP, maize with a high frequency of the suI-

M2 allele, implied in the amount and quality of floury

starch, appears in the archaeological record (Jae-

nicke-Despres and Smith 2006), suggesting selection

linked to tortilla production.

Discussion

Archaeological evidence suggests that agriculture and

plant domestication in west Mesoamerica were

probably initiated by small, highly mobile groups of

humans from a Clovis cultural tradition who gathered

plants, hunted small animals and seasonally inhabited


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small rock shelters near rivers between inland lake

systems and the Pacific coast (Flannery 1986; Mac-

Neish 1967a; MacNeish and Peterson 1962; Ranere

et al. 2009). These archaeological data do not support

the hypothesis of Sauer (1952) and Harlan (1995) that

domestication was initiated by semi-sedentary fish-

erfolk living near lake systems who initiated agricul-ture and domestication by transporting weedy

ancestral populations of domesticated maize, squash

and beans to plots near habitation sites, where they

would care for and harvest them. Evidence for more

permanent settlements with homegardens in the BJ

region, Oaxaca and Tehuacan appear rather later than

domestication and agriculture (Flannery 1986; Rane-

re et al. 2009).

Paleoecological, ecophysiological and molecular

genetic data suggest that plant domestication and

agriculture began in the TDF of the BJ region underconditions of warm temperatures and annual rainfall

near 1,000 mm, and from selection and management

of the tropical grass Zea mays ssp. parviglumis. It is

unlikely that domestication and agriculture arose in

the intermontane valleys under temperate, semi-dry

conditions in xerophytic bush vegetation through

cultivation of the hybrid Zea diploperennis 9

Tripsacum dactyloides, as suggested by MacNeish

and Eubanks (2000) and Eubanks (2001, 2002).

The autoecological traits and altitude distribution

of putative wild ancestral populations for maize andbeans suggest that agriculture could have begun at

intermediate elevations (600–1,600 masl), including

at the oak forest ecotone (Buckler et al. 2006; Kwak

et al. 2009). This would have enabled human groups

to cultivate plants, while making relatively short

excursions to the coast or intermontane lakes (&40–

80 km), thus reinforcing the biocultural corridors

developed during the early Holocene.

The sympatric geographic distribution of the

putative ancestral populations of maize, beans and

squash in the northwest BJ region suggest that theircultivation and domestication could have begun in

that area. Early dates for maize and squash place the

beginning of this process around 10,000 BP, making

it roughly contemporaneous with the beginning of

domestication in the Old World (Piperno et al. 2009).

The presence of starch grains from domesticated

maize and squash, as well as the presumed presence

of beans, in grinding stones by 9,000 BP (Piperno

et al. 2009) indicates that these species were

simultaneously harvested and consumed and may

have been contemporaneously domesticated. This

possibility is reinforced by records of early and

simultaneous diffusion of maize and chili to South

America (Perry et al. 2007), although a number of

authors have suggested that maize, beans and squash

were domesticated in different regions and periods(Harlan 1995; Kwak et al. 2009).

According to paleoecological data, clearing and

fire were commonly used between 10,000 and

7,000 cal BP. Initially, fire was probably a tool for

hunting, but probably also became the main strategy

to produce harvests and a strong selective force for

plant species that would become domesticated, a

scenario suggested for other regions in the world

(Lewis 1972; Zong et al. 2007). During the Archaic

period, at least 220 hunter-gatherer groups in what is

today west Mexico and the United Stated used fire toestablish grasslands, guide and enclose animals and

augment forage and grain species production (Parker

2002; Stewart et al. 2002; Williams 2003). Zea,

Phaseolus and Cucurbita species are preadapted to

fire. This element favors colonization and establish-

ment in Zea species, and cyclical fire disturbance

helps them maintain populations (Sanchez-Velazquez

et al. 2002). Fire also helps Phaseolus, Cucurbita and

Capsicum species to recolonize fire-disturbed areas

since their seeds exit latency when exposed to

temperatures greater than 60C (Rolston 1978;Degreef et al. 2002). Arboreal species such as

Leucaena spp.; Psidium spp., Prosopis spp. and

Spondias purpurea L. are also preadapted to fire

because of their ability to sprout from the stem base

and root crown. The same holds true for agaves with

the capacity for vegetative propagation because they

can emit root-shoots. Under these circumstances,

humans may have taken advantage of partial removal

of vegetation by fire to cultivate desired grains and

seeds, while the sprouting ability of wild bush species

and humans’ technological inability to eliminateperennial plant roots dictated use of an agricultural

system with a long fallow period in which both fire-

resistant annuals and perennials were domesticated

and incorporated.

Changes in the maize tga 1 gene were initially

focused on the cob and grain, in an effort to produce

naked, detachable grains (Piperno et al. 2009).

Selection for infructescences that retain ripe grains

increased the likelihood of harvest in the field, while


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selection for naked grains facilitated processing by

grinding. Archaeological dates for maize from

Xihuatoxtla (Piperno et al. 2009) do not support the

hypothesis of Harlan (1995), Iltis (2000) or Smalley

and Blake (2003) that initial selection of maize was

linked to use of the stalk and unripe cobs as greens

and as a sugar source in alcoholic beverage produc-tion. Archaeological records also indicate frequent

use of cooked agave leaf bases and Spondias fruit

about 9,000 BP (Callen 1967; Flannery 1986; Smith

1986), suggesting selection for high sugar content

variants in both plants. These sugar sources became

extremely important in alcoholic beverage production

in the BJ region (Bruman 2000; Colunga-Gar-

cıaMarın and Zizumbo-Villarreal 2007).

Initial domestication of grasses was therefore

linked to ease of harvest and processing. Given that

technological development was similar among humangroups at the time, domestication could have

occurred over a wide area, both in the intermontane

valleys where Setaria parviflora (Poiert) Kerguelen

could have been domesticated (Austin 2006; Callen

1967), and in the lowlands where Z. parviglumis was

domesticated (Ranere et al. 2009). Fixation of

maize’s Tb1 and tga1 genes by about 6,400 BP

suggests that selection continued to be linked to ease

of harvest (e.g. total retention of seeds on the cob,

rachis with two spikelets with two rows of grains) and

processing (e.g. naked grains with short glumes)(Doebley 2006; Dorweiler et al. 1993; Wang et al.

2005). Simultaneously, the high eruptive activities in

CVC between 7,300 and 6,300 BP might have caused

environmental changes related to the metal content of

local soils that may have been important in maize

domestication (Cortes et al. 2005; Ville-Calzada et al.

2009).

Diffusion of the maize-beans-squash domesticates

suite most likely occurred via existing biocultural

corridors, i.e. rivers, since these would have been

dependable year round food and water sources forhumans and animals, particularly during the long dry

season. The diffusion of domesticated maize and

squash began when they still exhibited low genetic

differentiation with wild varieties. As a result, their

transport to areas lacking wild populations could have

accelerated the fixation of domestic traits and the

disappearance of wild traits. Environmental and

cultural conditions in each region would have

promoted initial diversification.

Agricultural intensification began to occur

between 7,000 and 5,000 BP as humans actively

worked soils using wooden tools such as levers,

which helped to remove perennial plants, and extract

and arrange rocks to improve soil conditions. This

technique produces a heterogeneous land surface in

which maize, squash and bean seeds are sowntogether simulating their natural growth after fire

disturbance in the BJ region. The structuring of the

milpa multi-crop agricultural system occurred

through joint sowing of one or various seeds of these

three species in the same ‘‘microsite’’ within a burned

area, which would have been previously prepared by

removal of roots and rocks using wooden levers.

Additional structuring would have been accom-

plished through individual care and harvest of each

plant. Under these circumstances, these three species

would have been subject to concurrent natural andhuman selection pressures that could have led them to

a state of ecological adaptation and complementarity.

This does not coincide with the scenarios proposed

for other regions such as the Middle East, where

preparation of homogeneous planting areas using

draft animals and crop rows allowed use of broadcast

sowing and harvest without human selection of

individual plants. Fixing of the alleles involved in

maize plant architecture by 4,400 cal. BP suggests

that this multicrop system was established by this

time.Grinding of maize, squash and possibly beans

under domestic conditions suggest the presence of a

selective process that could have produced food

complementarity. Fixation of the alleles involved in

maize protein and starch quality by 4,400 BP may

indicate that this complementarity had been attained

by this time. In the BJ region, agro-food technology

had become highly complex between 4,500 and 3,500

BP, as reflected in the use of pots for steaming, and

probably also distilling, not found in other regions of

Mesoamerica at this time (Zizumbo-Villarreal et al.2009b). In other words, in this region at this time, the

agro-food system was complete, suggesting that the

milpa system originated here.

Despite the highly complex cultural development

in the BJ region during the rise of plant domestication

and agriculture in Mesoamerica, very few archaeo-

botanical studies have been done there (Benz 2002,

Ranere et al. 2009). New research will be vital to

better understanding the initial development of


1 3



human societies in Mesoamerica. Study of the TDF in

the BJ region is particularly urgent since almost 80%

of this vegetation type has disappeared to date, and,

of the TDF zones in Mesoamerica, it suffers the

highest deforestation rate and is at the highest risk of

disappearing (Janzen 1988; Kauffman et al. 2003;

Trejo and Dirzo 2000). Native grasses in the regionhave experienced strong selective pressure since the

introduction of cattle in the 16th Century. This has

accelerated during the last 30 years as cattle ranching

has grown rapidly and African grasses have been

introduced and managed with pesticides, putting

many of the putative wild source populations,

particularly those of Z. parviglumis, at serious risk

(Houghton et al. 1991; Wilkes 2007). In situ conser-

vation programs at reserves such as Manantlan-Cerro

Grande and Zicuiran-Infiernillo need to be reinforced

and broadened to include nearby areas and humancommunities, collection programs need to be stepped

up and adaptive studies of climatic, edaphic and

biotic factors done before these wild ancestral of

domesticated species disappear.

Acknowledgments The authors thank the CONACYT and

CICY for sabbatical scholarships and P. Gepts for his

hospitality at UC-Davis.

References

Aceituno FJ, Castillo EN (2005) Mobility strategies in

Colombia’s middle mountain range between the early and

middle Holocene. Before farming 2005/2, Article 2.

Available at www.waspress.co.uk/journals/beforefarming/

journal_20052/abstracts/index.php

Aliphat FM (1980) La cuenca Zacoalco-Sayula: Ocupacion

humana durante el pleistoceno final en el occidente de

Mexico. In: Gonzalez-Jacome A (ed) Orıgenes del hom-

bre americano. SEP, Mexico, pp 145–176

Austin DF (2006) Fox-tail millets (Setaria:Poaceae). Aban-

doned food in two hemispheres. Econ Bot 60(2):143–158

Benz B (1999) On origin, evolution and dispersal of maize. In:

Blake M (ed) Pacific Latin America in prehistory: the

evolution of Archaic and Formative cultures. Washington

State University Press, Pullman, pp 25–38

Benz B (2001) Archaeological evidence of teocintle domesti-

cation from Guila Naquitz, Oaxaca. Proc Nat Acad Sci

USA 98:2104–2106

Benz B (2002) The origins of Mesoamerican agriculture: recon-

naissance and testing in the Sayula-Zacoalco lake basin.

www.famsi.org/reports/99074/section11.htm. Accessed 10

Nov 2009

Bruman HJ (2000) Alcohol in ancient Mexico. Univ of Utah

Press, Salt Lake City

Brush CF (1965) Pox pottery: earliest identified Mexican

ceramic. Science 149:194–195

Buckler ES, Goodman MM, Holstford TP, Doebley JF, San-

chez GJ (2006) Phylogeography of the wild subspecies of

Zea mays. Maydica 51:123–134

Callen EO (1967) Food habits of some Pre-Columbian Mexi-

can Indians. Econ Bot 19(4):335–343

Capra L, Macıas JL (2002) The cohesive Naranjo debris-flow

deposit (10 km3): a dam breakout floor derived from the

Pleistocene debris-avalanche deposit of Nevado de Coli-

ma Volcano (Mexico). J Volcan Geotherm Res 117:

213–235

Colunga-GarcıaMarın P, Zizumbo-Villarreal D (1993) La

evolucion de las plantas bajo seleccion artificial y manejo

agrıcola. In: Leff E, Carabias J (eds) Cultura y manejo

sustentable de los recursos naturales. CIIH-UNAM-

Miguel Angel Porrua, Mexico, pp 123–163

Colunga-GarcıaMarın P, Zizumbo-Villarreal D (2007) Tequila

and other Agave spirits from west-central Mexico: current

germplasm diversity, conservation and origin. Biodivers

and Conserv 16:1653–1667

Cortes A, Garduno-Monroy VH, Navarro-Ochoa C, Komo-rowski JC, Saucedo R, Macıas JL, Gavilanes JC (2005)

Geologıa del complejo volcanico Colima. Carta Geolog-

ica y Minera No. 10. Instituto de Geologıa UNAM.

Mexico

Cunniff J, Osborne CP, Ripley BS, Charles M, Jones G (2008)

Response of wild C4 crop progenitors to subambient CO2

highlights a possible role in the origin of agriculture.

Global Change Biol 14:576–587

Degreef J, Rocha OJ, Vanderborght T, Baudoin JP (2002) Soil

seed bank and seed dormancy in wild populations of lima

bean (Fabaceae): considerations for in situ and ex situ

conservation. Am J Bot 89(10):1644–1650

Dickau R, Ranere AJ, Cooke RG (2007) Starch grain evidence

for the preceramic dispersals of maize and root crops intotropical dry and humid forest of Panama. Proc Nat Acad

Sci USA 104:3651–3656

Dixon EJ (1999) Bones, boats and bison. Archaeology and the

first colonization of western North America. Univ of Utah

Press, Salt Lake City

Dixon EJ (2001) Human colonization of the Americas: timing,

technology and process. Quarter Sci Rev 20:277–299

Doebley JF (1984) ‘‘Seeds’’ of wild grasses: a major food for

Southwestern Indians. Econ Bot 38(1):52–64

Doebley JF (2004) The genetics of maize evolution. Ann Rev

Genet 38:37–59

Doebley JF (2006) Unfallen grains: how ancient farmers turned

weeds into crops. Science 312:1318–1319

Dorweiler J, Stec A, Kermicle J, Doebley JF (1993) Teocintle

glume architecture 1: a genetic locus controlling a key

step in maize evolution. Science 262:233–235

Eubanks M (2001) The origin of maize: evidence for Tripsa-

cum ancestry. Plant Breed Rev 20:15–66

Eubanks M (2002) An interdisciplinary perspective on the

origin of maize. Latin Am Antiquity 12:91–98

Ferrusquıa-Villafranca I (1990) Provincias biogeograficas con

base en rasgos morfotectonicos. Mapa IV8.10. Atlas

Nacional de Mexico, vol III. Instituto de Geografıa,

UNAM, Mexico

Flannery KV (1986) Guila Naquitz. Academic Press, Orlando


1 3

http://www.waspress.co.uk/journals/beforefarming/journal_20052/abstracts/index.php


http://www.famsi.org/reports/99074/section11.htm

http://www.famsi.org/reports/99074/section11.htm





Flannery KV (1994) Early formative pottery of the Valley of

Oaxaca, Mexico. Memoir No. 27. Museum of Anthro-

pology, University of Michigan, Ann Arbor

Fukunaga K, Hill J, Vigouroux Y, Matsuoka Y, Sanchez J, Liu

K, Buckler ES, Doebley J (2005) Genetic diversity and

population structure of teocintle. Genetics 169:2241–2254

Gepts P (1988) Phaseolin as an evolutionary marker. In: Gepts

P (ed) Genetic resources of Phaseolus beans. Kluwer,

Dordrecht, pp 215–241

Gepts P (2004) Crop domestication as a long-term selection

experiment. Plant Breed Rev 24(Part 2):1–44

Gepts P (2008) Tropical environments, biodiversity, and the

origin of crops. In: Moore P, Ming R (eds) Genomics of

tropical crop plants. Springer, New York, pp 1–20

Hammer K (1984) Das Domestikationssyndrom. Kulturpflanze

32:11–34

Harlan JR (1971) Agricultural origins: centers and non centers.

Science 174:468–474

Harlan JR (1992) Crops and man, 2nd edn. American Society

of Agronomy and Crop Science Society, Madison

Harlan JR (1995) The living fields. Cambridge Univ Press,

CambridgeHoughton RA, Lefkowitz DS, Skole DL (1991) Changes in the

landscape of Latin America between 1850–1985. I. Pro-

gressive loss of forest. For Ecol Manag 38:173–199

Iltis HH (2000) Homeotic sexual translocations and the origin

of maize ( Zea mays, Poaceae): a new look at an old

problem. Econ Bot 54:7–42

Irish DJ, Davis SD, Lobdell JE, Solorzano FA (2000) Prehis-

toric human remains from Jalisco, Mexico. Curr Res in

the Pleistocene 17:95–96

Jaenicke-Despres V, Smith BD (2006) Ancient DNA and

integration of archaeological and genetic approaches to

study of maize domestication. In: Staller J, Tykot R, Benz

B (eds) Histories of maize. Academic Press, San Diego,

pp 83–95Jaenicke-Despres V, Buckler ES, Smith BD, Gilbert TM,

Cooper A, Doebley J, Paabo S (2003) Early allelic

selection in maize as revealed by ancient DNA. Science

302:1206–1208

Janzen DH (1988) Tropical dry forest. The most endangered

major tropical ecosystem. In: Wilson EO (ed) Biodiver-

sity. National Academy Press, Washington, pp 130–137

Kaplan L, Lynch TE (1999) Phaseolus (Fabaceae) in archae-

ology: AMS radiocarbon dates and their significance for

pre-Colombian agriculture. Econ Bot 53:261–272

Kauffman JB, Steele MD, Cummings DL, Jaramillo VJ (2003)

Biomass dynamic associated with deforestation, fire, and

conversion to cattle pasture in Mexican tropical dry forest.

For Ecol Manag 176:1–12

Kelly I (1980) Ceramic sequence in Colima: capacha, an early

phase. Anthropological papers No 37. Univ of Arizona

Press, Tucson

Kirchhoff P (1943) Mesoamerica. Acta Americana. Revista de

la Sociedad de Antropologıa y Geografıa 1:92–107

Koinange EMK, Singh SP, Gepts P (1996) Genetic control of

the domestication syndrome in common bean. Crop Sci

36:1037–1045

Kwak M, Kami J, Gepts P (2009) The putative Mesoamerican

center of domestication of Phaseolus vulgaris L. is

located in the Rio Lerma-Santiago basin of Mexico. Crop

Sci 49:554–563

Leonard JA, Wayne RK, Wheeler J, Valadez R, Gullen S, Vila

C (2002) Ancient DNA evidence for Old World origin of

New World dogs. Science 298:1613–1616

Lewis HT (1972) The role of fire in the domestication of plants

and animals in Southwest Asia: a hypothesis. Man (Lond)

7:195–222

Lorenzo JL, Mirabell L (1986) Tlapacoya: 35, 000 anos de

historia en el Lago de Chalco, Coleccion Cientıfica, Serie

Prehistoria. Instituto Nacional de Antropologıa e Historia,

Mexico

MacNeish RS (1964) Ancient Mesoamerica civilization. Sci-

ence 143:531–537

MacNeish RS (1967a) A summary of the subsistence. In: Byers

S (ed) Environment and subsistence, Vol. 1: the prehistory

of the Tehuacan Valley. Univ Texas Press, Austin, pp

290–309

MacNeish RS (1967b) Mesoamerican archaeology. Bienn Rev

Anthropol 5:306–331

MacNeish RS, Eubanks EM (2000) Comparative analysis of

the Rio Balsas and Tehuacan models for the origin of maize. Latin Am Antiq 11(1):3–20

MacNeish RS, Peterson FA (1962) The Santa Marta Rock

Shelter, Ocozocoautla, Chiapas, Mexico. Papers of the

New World Archaeological Foundation 14. Brigham

Young Univ, Provo

Matsuoka Y, Vigouroux Y, Goodman MM, Sanchez GJ,

Buckler E, Doebley J (2002) A single domestication for

maize shown by multilocus microsatellite genotyping.

Proc Nat Acad Sci USA 99:6080–6084

Metcalfe SE (2006) Late quaternary environments of the

northern deserts and central transvolcanic belt of Mexico.

Ann Missouri Bot Gar 93:258–273

Miller PM (1999) Effects of deforestation on seed banks in a

tropical deciduous forest of western Mexico. J Trop Ecol15:179–188

Miller PM, Kauffman JB (1998) Seedling and sprout response

to slash and burn agriculture in tropical deciduous forest.

Biotropica 30:538–546

Mountjoy JM (2006) Excavation of two middle formative

cemeteries in the Mascota Valley of Jalisco, Mexico.

Available at www.famsi.org/reports/03009/index.html.

Accessed 12 Nov 2009

Mountjoy JB, Taylor RE, Feldman LH (1972) Matanchen

complex: new radiocarbon dates on early coastal adapta-

tion in west Mexico. Science 175:1242–1243

Niederberger C (1979) Early sedentary economy in the basin of

Mexico. Science 203:131–142

Parker C (2002) Fire in Pre-European lowlands of the Ameri-

can Southwest. In: Vale TR (ed) Western wilderness: fire,

native peoples, and the natural landscape. Island Press,

Washington, pp 101–141

Perry L, Dickau R, Zarrillo S, Holst I, Persall DM, Piperno D,

Berman JM, Cooke GR, Rademaker K et al (2007) Starch

fossils and the domestication and dispersal of chili peppers

(Capsicum spp. L.) in the Americas. Science 315:986–988

Piperno DR (2006) Quaternary environmental history and

agricultural impact on vegetation in Central America. Ann

Missouri Bot Gar 93:274–296


1 3

http://www.famsi.org/reports/03009/index.html

http://www.famsi.org/reports/03009/index.html



Piperno DR, Flannery KV (2001) The earliest archaeological

maize ( Zea mays L.) from highland Mexico: new accel-

erator mass spectrometry dates and their implications.

Proc Nat Acad Sci USA 98:2101–2103

Piperno DR, Pearsall DM (1998) The origins of agriculture in

the lowland neotropics. Academic Press, San Diego

Piperno DR, Holst I, Wessel-Beaver L, Andres TC (2002)

Evidence for the control of phytolith formation in Cu-

curbita fruits by the hard rind ( Hr ) genetic locus:

archaeological and ecological implications. Proc Nat

Acad Sci USA 99:10923–10928

Piperno DR, Moreno JE, Iriarte J, Holst I, Lachniet M, Jones G,

Ranere AJ, Castazo R (2007) Late pleistocene and holo-

cene environmental history of the Iguala Valley, central

Balsas watershed of Mexico. Proc Nat Acad Sci USA

104:11874–11881

Piperno DR, Ranere AJ, Holst I, Dickau R, Iriarte J (2009)

Starch grain and phytolith evidence for early ninth mil-

lennium B.P. maize in the central Balsas River valley,

Mexico. Proc Nat Acad Sci USA 106:5019–5024

Pohl ME, Pope KO, Jones JG, Jacob JS, Piperno DR, France

SD, Lentz DL, Gifford JA, Danford ME, Josserand JK (1996) Early agriculture in the Maya Lowlands. Lat Am

Antiq 7:355–372

Pohl ME, Piperno DR, Pope KO, Jones JG (2007) Microfossil

evidence for pre-Columbian maize dispersal in the Neo-

tropics from San Andres, Tabasco, Mexico. Proc Nat

Acad Sci USA 104:6870–6875

Poinar HK, Kuch M, Sobolik DK, Barnes I, Stankiewicz AB,

Kuder T, Spaulding WG, Bryent VM, Cooper A, Paabo S

(2001) A molecular analysis of dietary diversity for three

archaic Native Americans. Proc Nat Acad Sci USA

98:4317–4322

Ranere AJ, Piperno DR, Holst I, Dickau R, Iriarte J (2009) The

cultural and chronological context of early Holocene

maize and squash domestication in the central Balsas RiverValley, Mexico. Proc Nat Acad Sci USA 106:5014–5018

Rolston P (1978) Water impermeable seed dormancy. The Bot

Rev 44(3):365–396

Sage SR (1995) Was low atmospheric CO2 during the Pleis-

tocene a limiting factor for the origin of agriculture? Glob

Change Biol 1:93–106

Sanchez-Velazquez LR, Ezcurra E, Martınez-Ramos M,

Alvarez Buylla E, Lorente R (2002) Population dynamics

of Zea diploperennis, an endangered perennial herb: effect

of slash and burn practice. J Ecol 90:684–692

Sanjur OI, Piperno DR, Andres TC, Wessel-Beaver (2002)

Phylogenetic relationships among domesticated and wild

species of Cucurbita (Cucurbitaceae) inferred from a

mitochondrial gene: implications for crop plant evolution

and areas of origin. Proc Natl Acad Sci USA 99:535–540

Sauer CO (1952) Agricultural origins and dispersal. American

Geographical Society, New York

Sluyter A, Domınguez G (2006) Early maize ( Zea mays L.) cul-

tivation in Mexico: dating sedimentary pollen records and its

implications. Proc Nat Acad Sci USA 103:1147–1151

Smalley S, Blake M (2003) Sweet beginnings: stalk sugar and

domestication of maize. Curr Antropol 44:675–703

Smith CE (1986) Preceramic plant remains from Guila Na-

quitz. In: Flannery KV (ed) Guila Naquitz. Academic

Press, Orlando, pp 265–274

Smith BD (2005) Reassessing Coxcatlan cave and the early

history of domesticated plants in Mesoamerica. Proc Nat

Acad Sci USA 102:9438–9445

Stewart OC, Lewis TH, Anderson MK (2002) Forgotten fires:

Native Americans and the transient wilderness. Univ of

Oklahoma Press, Norman

Tolstoy P, Fish SK, Boksenbaum MW, Vaughan KB, Smith

EC (1977) Early sedentary communities of the Basin of

Mexico. J Field Archaeol 4:91–106

Trejo I, Dirzo R (2000) Deforestation of seasonally dry tropical

forest: a national and local analysis in Mexico. Biol

Conserv 94:133–142

Ville-Calzada JP, Martınez de la Vega O, Hernandez-Guzman

G, Ibarra-Laclette E, Alvarez-Mejıa C, Vega-Arreguın JC,

Jimenez-Moraila B, Fernandez Cortes A, Corona-Ara-

menta G, Herrera-Estrella L, Herrera-Estrella A (2009)

The palomero genome suggests metal effects on domes-

tication. Science 326:1078

Voorhies B, Kennet DJ, Jones GJ, Wake TA (2002) A middle

archaic archaeological site on the west coast of Mexico.

Latin Am Antiq 13:179–200

Wang H, Nussbaum-Waller B, Li Q, Zhao Q, Vigouroux Y,Faller M, Bomblies K, Lunkens L, Doebley J (2005) The

origin of the naked grains of maize. Nature 436:714–719

Wayne R, Leonard JA, Vila C (2006) Genetic analysis of dog

domestication. In: Zeder MA et al (eds) Documenting

domestication: new genetic and archaeological paradigms.

Univ of California Press, Berkley, pp 279–293

Wilkes G (2004) Maize, strange and marvelous: but is a defin-

itive origin known? In: Smith C (ed) Maize: origin, history,

technology and production. Willey, New York, pp 3–63

Wilkes G (2007) Urgent notice to all maize researchers: dis-

appearance and extinction of the last wild teocintle pop-

ulation is more than half completed. A modest proposal

for teocintle evolution and conservation in situ: The

Balsas, Guerrero, Mexico. Maydica 52:49–58Williams GW (2003) References on the American Indian use

of fire in ecosystems. USDA Forest Service. Washington,

DC. Available at www.wildlandfire.com/docs/biblio_

indianfire.htm Accessed 12 Nov 2009

Willis WH (1995) Archaic foraging and the beginning of food

production in the American Southwest. In: Price TD,

Gebauer AB (eds) Last hunters, first farmers. School of

American Research, Santa Fe, pp 215–242

Zarrillo S, Pearsall DM, Raymond JS, Tisdale MA, Quon DJ

(2008) Directly dated starch residues document early

formative maize ( Zea mays L.) in tropical Ecuador. Proc

Nat Acad Sci USA 105:5006–5011

Zizumbo-Villarreal D, Papa R, Hufford M, Repinski S, Gepts P

(2009a) Identification of a new wild population of

Phaseolus vulgaris L. in western Jalisco, Mexico, near the

Mesoamerican domestication center of common bean.

BIC 52:24-25. (Bean Improvement Cooperative USA)

Zizumbo-Villarreal D, Gonzalez-Zozaya F, Olay-Barrientos A,

Almendros-Lopez L, Colunga-GarcıaMarın P (2009b)

Distillation in western Mesoamerica before European

contact. Econ Bot 63(4):413–426

Zong Y, Chen Z, Innes JB, Chen C, Wang Z, Wang H (2007)

Fire and flood management of coastal swamps enabled

first rice paddy cultivation in east China. Nature 449:

459–462


1 3

http://www.wildlandfire.com/docs/biblio_indianfire.htm




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