ARCH 1870 Environmental Archaeology, Fall 2015

ARCH 1870 Environmental Archaeology, Fall 2015
Tuesday and Thursday 1:00-2:20 pm, Location: Rhode Island Hall 108
Instructor: Brett Kaufman
[email protected]
ARCH 1870
Environmental Archaeology
Brett Kaufman
Office Hours: Tuesday, 2:30-4:30 pm
Rhode Island Hall 007
This presentation and the images within are for educational purposes
only, and are not to be distributed.
Paleoenvironment and the Rise and Fall of Complex
Society in Mesoamerica
Cultural Background and Review of Adams 2000
Origins of Agriculture in Mesoamerica
Paleoenvironmental Data
Maya Collapse and Review of Dunning, Beach, and
Luzzadder-Beach 2012
Postclassic Political Restructuring
Cultural Background and Review of Adams 2000
Adams summarizes archaeology by saying that “most human behavior is
patterned and that the patterns are culturally determined…any given culture is
made up of such patterned behavior, functionally integrated, and driven by a
core of beliefs about the nature of the universe and humanity’s place in it.”
What he means by “patterned behavior” here is cultural history, or the specific
behaviors associated with specific cultures.
When discussing the use of ethnographic documents that communicate
behaviors of living communities which are then used to reconstruct ancient
behaviors, Adams relays that there is a dispute between which data to use –
Maya texts that may be biased? other ethnographic cultures that have nothing
to do with Mesoamerica? early Spanish colonial accounts, and perhaps even
these colonial accounts reflect a period of societal restructuring and are
therefore inadequate? Spanish traveler/clergy/soldier accounts and codices
written by both pre-Columbian and colonial populations are the main sources
of historical data.
Food planting
depicted in
the Maya
Adams says that cultural institutions exist within ecological and biological
(natural world) and cultural contexts, together comprising the field of cultural
ecology. The major “natural” categories being:
Climate and climatic cycles
Human demography
Health and disease parameters
Topographic and ecological characteristics
Major landscape modification
Plant and animal inventories (availability)
He goes on to state that most New World archaeologists reject
postprocessualism, which is rather an overstatement, but certainly
environmentally driven cultural change is a widespread theme.
Mesoamerica is considered a
“culture area” because during
various chronological stages of
prehistory and history, there
were commonalities throughout
the entire region in terms of
economy and cultural
institutions. Mesoamerica is
comprised of around two-thirds
of present-day Mexico, all of
Guatemala and Belize, a segment
of western Honduras, and
around four-fifths of El Salvador.
Diamond 2011
Map of Mesoamerica (Adams 2000)
Paleoindian, 10,000-7000 BC
The earliest humans in
Mesoamerica, undertaking
big game hunting with
evidence coming from small
campsites. The Iztapan
mammoth killed in the Basin
of Mexico is a prime example
of the hunting subsistence
mode, but by around 9000
BC 32 genera of animals
went extinct from the region.
Archaic, 8000 or 7000-1500 BC
Drastic loss of animal populations concomitant with transition to agriculture.
Village settlement began around 5000 BC with mixed agriculture and huntinggathering. Maize cultivation seems to have begun 2500-1400 BC as recorded
through pollen analysis. By 1500 BC agricultural villages were prevalent all
over the region with evidence for deforestation practices. Paleoindian and
Archaic periods have the least amount of recovered data compared to other
Mesoamerican periods.
Preclassic (Formative), 1500 BC-150 AD
This period witnessed the beginning of complex society, with the Olmec culture
emerging around 1350 BC. In the Maya lowlands, a sudden shift from mixed
forest species to grasses in 1200 BC is evidence of extensive slashing and
burning to create agricultural zones. By 600 BC several polities built up large
regional centers.
Olmec head
After 600 BC, writing, art, conquest monuments, and monumental architecture
began to become more common. Huge temples were built at Rio Azul and
Calakmul around 500 BC, and fortifications at Tikal and other sites. In Belize,
intensive wetland agriculture also dates to the Late Preclassic. The eruption of
the Ilopango volcano in around 150 BC drove local populations into the
Guatemalan highlands (acute environmental response versus protracted
environmental responses).
Olmec maize gods with projecting corn cobs (Taube 1996)
Classic, 150/300-650/900 AD
Widespread population growth
accompanied social and ideological
developments leading to a
fluorescence in urban culture.
Maya cities had up to 60,000 to
80,000 inhabitants based on
population estimates from
Guatemala. Hieroglyphic and
phonetic writing was performed by
Maya scribes, with the texts usually
recounting history, myth, or
propaganda. The polity of
Teotihuacan expanded to engage in
mining and trade ventures that
extended as far as the American
Southwest. These latter
populations traded turquoise for
Mesoamerican cacao to make
caffeinated drinks (Washburn et al.
Maya and Aztec glyphs (Taube 1996)
Early Postclassic, 650/900-1250 AD
Collapse of the Classic periods was in part accelerated by climate change, with
warfare being a hallmark of the period.
Late Postclassic, 1250-1519 AD
This can be seen generally as a rebound or reformation stage, which is wellinformed from historical and narrative colonial accounts. New centers of power
began to form to fill the power vacuum left by the Maya such as the Aztecs.
Origins of Agriculture in Mesoamerica
Between the end of the Pleistocene and the 5th millennium BC, people in the
semi-arid basins of Mexico, Puebla, Oaxaca, Morelos, Guerrero, and Hidalgo
pioneered the food processing of available edible resources. They roasted
Agave to make it edible, used wooden tongs to pick cactus fruit, extracted
syrup from mesquite pods, leached tannic acid from acorns, gathered wild
bean and onion, and learned about the seasonality of harvesting (Flannery
Mesquite pods
By around 5000 BC, selective cultivation and planting marked the transition in
subsistence from hunting-gathering to agriculture: beans, squashes, pumpkins,
amaranths, chiles, tomatoes, avocadoes (maybe prickly pear, maguey, and other
fruits), and the most important to be domesticated by Mesoamerican
populations – corn (maize). Maize (Zea mays)was so heavily genetically
engineered that determining its wild progenitor (maybe teosinte, its nearest
genetic relative) is one of the most mysterious and hotly contested issues in the
field of archaeology. ChMIy-G1tfn3yAIVhFQ-Ch0_FghL#tbm=isch&tbs=rimg%3ACfkoegRisRkPIjinavO-hXKJ2ONSgBgI4UUcYJuKYBVnsqTcCWTpqjn3sjc7WG01we4MvSfh1lKXxy99gjKM6aXSyoSCadq8776FconEX-gyjTTbOnLKhIJY41KAGAjhRQRDmFp2yXXMG4qEglxgm4pgFWeyhHFT10SFOXa6yoSCZNwJZOmqOfeEUS-GuDamP3_1KhIJyNztYbTXB7gRiPGL0SzssosqEgky9JHWUpfHBHI0HDkph3_1qCoSCb32CMozppdLEVlNfrGe6wAx&q=teosinte&imgrc=jW0Q0GY5Vles0M%3A
Why was maize cultivated? The recorded population densities are low prior to
5000 BC in Mesoamerica, so it does not seem that it was to feed a burgeoning
populace. Still, there are great contrasts in precipitation patterns across
highland Mesoamerica, meaning that cultivation may have been an attempt to
increase the prevalence of weedy Zea as an emergency ration. The low yield
and high labor requirements of teosinte may have prompted people to let it
grown in the highlands where it was home, and keep growing mesquite in the
Gradual genetic change led to
larger cob sizes and the minimum
yield crossed a threshold which
made it worthwhile to clear away
other crops like mesquite and
focus on maize. This occurred
sometime between 3000-1500 BC,
and by 1300 BC permanent
villages sprang up on the main
river floodplains from Puebla near
Mexico City to Guatemala. Maize
has continued to be the major crop
throughout much of the Americas.
Early pollen
grains of A) Small
Zea (4200 BC) B)
Maize (1500 BC),
and C) Manioc
(4600 BC)
(Pope et al. 2001)
Paleoenvironmental Data
The collapse of the Classic Maya is taken to be one of the major examples of
environmental impact on a group. Drought during the Late and Terminal
Classic in the Maya regions was characterized by fluctuations between moist
and drought conditions that exceeded the resilience of the ecological system, as
opposed to one protracted drought episode. Gypsum accretions are measured
by density and are a proxy for drought episodes, in this case in the northern
Four sediment cores
from Lake
showing black layers
of organic-rich strata
representing moister
periods and white
layers of gypsum
associated with drier
periods. Arrow
shows gypsum from
780-1100 CE (Hodell,
Brenner, Curtis 2005)
The so-called Terminal Classic Drought saw drought conditions from around
770-870 CE, a return to moister conditions 870-920 CE, and a final drought from
920-1100 CE (Hodell, Brenner, Curtis 2005). Other research in laminated marine
sediments and isotopic analysis have shown similar trends.
Until recently evidence for severe drought in the Maya heartland of the Petén
in Guatemala are to date more equivocal. An article came out this year that
showed that the southern Lowlands Maya heartland actually had somewhat
more severe drought than the northern Lowlands, which is further consistent
with the other paleoenvironmental data as well as archaeological evidence for
violence and collapse. Hydrogen and carbon isotopes were recorded in plant
wax lipids from lake core settlements to measure precipitation and vegetation
respectively (Douglas et al. 2015).
drought episodes
with archaeological
Balkanization of
polities and warfare
following peak
humidity during
Classic Maya before
severe drought
(Kennett et al. 2012)
Review of Dunning, Beach, and Luzzadder-Beach 2012
Two episodes of societal collapse, one in the Terminal Preclassic immediately
preceding the Maya, and the other the collapse of the Maya (Terminal Classic),
are examined in light of the paleoenvironment in the Yucatán Peninsula,
specifically drought. In light of the general absence of abrupt abandonment,
but rather evidence for more gradual decline, the authors define collapse as “a
fundamental and pronounced decline in sociopolitical complexity taking place
within two or three generations.”,_Chichen_Itza#/media/File:Chichen_Itza_3.jpg
Yucatán Postclassic pyramid of Chichen Itza
The study focused on the elevated interior region of the Yucatán Peninsula,
which was the home to two of the most dramatic collapses in the Maya region:
the Mirador Basin in the 2nd century CE (Late Preclassic) and the Puuc Hills in
the 10th century CE (Terminal Classic). “Based on underlying ecosystems,
adaptive cycles operate at multiple scales, including the scale of the individual
community. In this conceptualization, each community passes through cycles
consisting of four phases: exploitation, conservation, release, and
reorganization.” Release is the collapse phase. “The degree to which the
system experiences profound collapse or recovers and its rate of recovery
depends in large part on three system properties: (i) the range of options
available for change, (ii) the rigidity of the system (degree of
interconnectedness), and (iii) the resilient capacity (vulnerability to unexpected
Without perennial water supply,
the elevated interior region (EIR)
was more susceptible to disruption
in their subsistence base than
populations in the lowlands, and
even many of these experienced
collapse and abandonment. For
this reason, the fact that
environmental factors would have
been more stressful for the elevated
interior region populations, the
authors contend that modeling
human interaction with the
environment there may show clear
trends in the data.
Maya lowlands
(Dunning, Beach, Luzzadder-Beach 2012)
Diverse ecological zones in the region created a differential access to water and
other natural resources. The maize-based agriculture of the Maya was suited to
the region, although population increase may have exceeded the carrying
capacity for this subsistence type. Most of the available water would be
drained internally, meaning water could only be accessed through a few above
ground sources such as springs. This stands in contrast to the lower areas
which had access to year-round springs and streams.
Hypothetical cross-section from the Caribbean Sea to the EIR with associated
natural hazards (Dunning, Beach, Lozzadder-Beach 2012)
For the Maya, subjugating the forest realm and transforming them into
agricultural fields was brining order to chaos (kol and kax). Although the
ancient Maya practiced timber management by leaving stands in tact, and by
leaving individual important trees in fields, this system was taxed by growing
population demands. Deforestation to open up agricultural lands may have
led to a decrease in precipitation and soil fertility, and an increase in erosion.
Declining fertility and reduction in spacing between agricultural fields made
maize more susceptible to disease (maize mosaic virus).
Corn afflicted by a type of maize mosaic virus
The sociopolitical system also
suffered from the environmental
degradation, not only because
productivity was low but because
the Maya elites “thrived on growth
and expansion that funneled wealth
to a small ruling elite topped by
hereditary divine kings. Notably,
‘divine kingship is a double-edged
sword: it carries great privilege and
unlimited power but also demands
that a ruler deliver munificence to
their people as would a god. A string
of military defeats or seasonal
drought can do much to damage the
credibility of a divine ruler’”
(MacAnany and Négron 2010).
Furthermore, sparring princes and
forced allegiances of commoners
calcified the system which became
too rigid to adapt to a severely
changing environment.
Maya King from Calakmul, 731 AD
In the Terminal Preclassic, the 2nd century CE show a significant increase in
drought, which along with deforestation and soil erosion caused the
abandonment of the major site of El Mirador. In the Three Rivers region, two
Maya cities just 8 km apart adopted different strategies to combat climate
change. San Bartolo was abandoned around 150 CE and only reoccupied in 700
CE, but Xultun invested in a large-scale reservoir system and became a major
Classic Maya center. New rulers in the Classic period built reservoirs and
destroyed older buildings associated with apparently now-defunct dynasties.
Water control came to be associated with dynastic kingship.
El Mirador
The Classic Maya polities were largely autonomous kingdoms and each one
developed different strategies. Some areas fought erosion through terraced
fields, whereas others did not. Beginning around 760 CE, the drought began to
affect large areas, disrupting well-watered sites in the Maya Lowlands which
may mean that polities depending on rain-fed agriculture became increasingly
more susceptible. Violence between Maya states became endemic as
competition for limited resources and labor intensified. In the elevated interior
region, by 900 CE most of it was depopulated and the forest rapidly recovered
its ground within a couple of centuries. This pattern largely repeated itself
across Mesoamerica, but with varying degrees of similarity.
Postclassic Political Restructuring
We now move on to look at the
post-collapse period of
Mesoamerica which saw the
restructuring of society and the
eventual rise of the Aztec, from
the perspective of a site of
Xaltocan in the northern Basin
of Mexico. During the Early
Postclassic (900-1150 AD)
Xaltocan was settled and was a
small regional center with
around 4,200 people. The site is
an artificial island surrounded
by brackish water (De Lucia
and Morehart 2015).
Map of Xaltocan in Basin of Mexico (De Lucia and Morehart 2015)
During its development as an
independent polity, Xaltocan’s
residents built chinampas or a
large system of elevated
agricultural fields and canals.
The canals brought fresh water
into the brackish water from
distant springs. Maize was the
major staple grown, but beans,
squash, amaranth, and
chenopodium were also
recovered from excavations in
the chinampa system. The
residents also participated in
market exchange via canoe
transport, selling goods
obtained from lake resources
such as fish, waterfowl, salt,
insect larvae, and reed mats.
Map of chinampas (De Lucia and Morehart 2015)
The production of goods was not imposed on the people of Xaltocan by a
political elite, but seems to have been a household based endeavor. Surplus
goods were generated in order for the household to participate in market
exchange. Excavations in households show craft differentiation, with one
household making ceramics and bone tools, while another household made
mats, tortillas, and plaster, and both processed fish, worked obsidian tools, and
cultivated crops. These activities are reconstructed through a number of means:
high densities of fish scales and high sodium soil content for fish production,
and concentrations of calcium leftover from the calcium hydroxide known to
soften corn kernels for making tortillas.
Tortilla making
from the Dresden
Agricultural activities were also carried
out by households, showing that labor
must have been scheduled so that both
subsistence foods and crafts could be
made by members of the households.
By the Middle Postclassic (1150-1350
AD), Xaltocan was a political center that
collected tribute from nearby villages
and controlled trade in the northern
Basin. Plant diversity in archaeological
remains decreased, as maize cultivation
intensified. This was either due to a
growing population or the need to meet
institutional demands from the elite, but
in all cases there was an expansion of
complex social organization and maize
surplus. Increasing hierarchy is seen not
just in the surplus production of maize,
but in the consumption of luxury goods
and architectural embellishments.
Xaltocan households (De Lucia and
Morehart 2015)
In the 13th century AD, Xaltocan was
embroiled in a lengthy war of around a
century with several neighboring
kingdoms. Feasting, display, militarism
through iconography, and consumption
of luxury goods indicates that
commoners were becoming integrated
into institutional hierarchies during
Xaltocan’s lengthy war. It is unclear why
it was a part of this war, but it did have to
do with the broader conflict between the
expansive states of Texcoco and
Azcapoltzalco that eventually led to the
formation of the Aztec empire. Under
Aztec rule, Xaltocan paid tribute to
Texcoco, Tenochtitlan, and Tlatelolco, but
the chinampas system suffered and the
potential for agricultural surplus
Sacrifice and the creation of the calendar
declined at least for several decades
with the dismembered body of the Central
during a brief abandonment. In 1521 was Mexican god Tezcatlipoca cast to the four
burned by Cortés during the Spanish
directions, Fejervary-Mayer Codex (Taube
Discussion Questions
1. We see in modern culture, this idea of New World natives being “one with
nature”. Why do you think that this idea of environmental harmony came
about with plenty of evidence showcasing that they were shapers of their
2. In Dunning, they make the argument that it was a mix of both
environmental change and political systems that led to the fall of the Maya.
One point that they mentioned was the short lived fertility of the soil. Did
fluctuations of environmental possibilism lead to the downfall of the Maya?
Discussion Questions
1.) The collapses of plains/lowlands communities like Chunchucmil and San
Bartolo illustrates how favorable environmental conditions can sometimes lead
to faster societal demise when there is perturbation; in the context of the
Mesoamerican societal structure (governing and hereditary elite) what can this
say about the active role cultural determinism might play in the collapse of
societies during environmental change? Maybe draw on the case study you
wrote about in your environmental report?
2.) Adams discusses the history of the independent research on various
communities in Mesoamerica, and the methods they employed/introduced to
the field of archaeology. Given the irreparability of excavated sites, and the
constant growth in knowledge, should archaeologists be more careful about
how they excavate important sites? How have things changed since the
Kennewick man etc.?