Evidence of the Importance of Animal Management for the Maya in Ceibal, Guatemala

Earliest isotopic evidence in the Maya region for animal management and long-distance trade at the site of Ceibal, Guatemala 

Authors: 

Sharpe et al 

Abstract: 

This study uses a multiisotope (carbon, nitrogen, oxygen, and strontium) approach to examine early animal management in the Maya region. An analysis of faunal specimens across almost 2,000 years (1000 BC to AD 950) at the site of Ceibal, Guatemala, reveals the earliest evidence for live-traded dogs and possible captive-reared taxa in the Americas. These animals may have been procured for ceremonial functions based on their location in the monumental site core, suggesting that animal management and trade began in the Maya area to promote special events, activities that were critical in the development of state society. Isotopic evidence for animal captivity at Ceibal reveals that animal management played a greater role in Maya communities than previously believed.

Lessons From Mayan Astronomy

Lessons from Mayan Astronomy

Author:

Loeb

Abstract:

The Mayan culture collected exquisite astronomical data for over a millennium. However, it failed to come up with the breakthrough ideas of modern astronomy because the data was analyzed within a mythological culture of astrology that rested upon false but mathematically sophisticated theories about the Universe. Have we learned the necessary lessons to prevent our current scientific culture from resembling Mayan Astronomy? Clearly, data collection by itself is not a guarantee for good science as commonly assumed by funding agencies. A vibrant scientific culture should cultivate multiple approaches to analyzing existing data and to collecting new data.

Climate had a big Impact on the Maya

An extended and higher-resolution record of climate and land use from stalagmite MC01 from Macal Chasm, Belize, revealing connections between major dry events, overall climate variability, and Maya sociopolitical changes

Authors:

Akers et al

Abstract:

The stalagmite MC01 was recovered from Macal Chasm cave on the Vaca Plateau of Belize in 1995, and an initial paleoclimate interpretation was published in 2007. Additional uranium-thorium ages have extended the paleoenvironmental record back from 3250 to 5250 cal yr BP, and the stable isotope (δ18O and δ13C) record is dramatically improved by 660 new values. A series of major dry events (MDEs) evident in stable isotopes, ultraviolet-stimulated luminescence, and petrography began ~ 3100 cal yr BP, and the initiation of these events coincides with an increase in El Niño dominance and southern shift in the Intertropical Convergence Zone. Three MDEs, centered at 1750 cal yr BP (200 CE), 1100 cal yr BP (850 CE), and 850 cal yr BP (1100 CE) and found in other regional climate records, coincide with Maya sociopolitical changes. Residuals from regression of δ13C versus δ18O are interpreted as a proxy for maize cultivation and land clearing, with residual values gradually increasing at the start of Preclassic Period settlement (3950 cal yr BP/2000 BCE), peaking after 2250 cal yr BP (300 BCE) during major Maya development in the Late Preclassic and Classic Periods, and dropping to pre-Preclassic values after regional land abandonment (~ 850 cal yr BP/1100 CE). Regional Maya population growth and cultural expansion may have been aided by abnormally low precipitation variability, as stable isotope variability suggests the Late Preclassic through the Late Classic was the most stable precipitation regime of the past 4000 years. This additional research on MC01 complements other regional paleoenvironmental records that suggest that MDEs coincided with disruptions in Maya society from the Preclassic through the Postclassic Periods. Although it is clear that not all significant sociopolitical changes can be attributed to the MDEs, these events likely played an antagonistic role in social stability.

How did the Southeast Maya Survive Volcanic Eruptions?

Across the centuries, forming cooperative networks beyond cultural boundaries has been a way to overcome natural disasters.

A Nagoya University researcher and his leading international research group discovered a Great Platform built with different kinds of stone at the archeological site of San Andrés, El Salvador, and challenged the prevailing theory regarding the sociocultural development of Southeastern Maya frontier.

San Andrés is located in the Zapotitan Valley, El Salvador, known as Southeastern Maya zone. Archaeological investigation conducted during 40's and 90's has shown that San Andrés had long human occupation beginning from the Middle Preclassic (ca. 600 BC) until the Early Postclassic (ca. AD 1200), in which had role as political, economic and religious center during the Late Classic period (AD 600-900). As San Andrés has been affected by numerous explosive eruptions -- at least three or four -- during the past two millennia, archaeologists have been interested to understand the role of volcanic eruptions in human history.

Between February and May of 2016, the research group led by Assistant Prof. Akira Ichikawa of the Institute for Advanced Research and at the Graduate School of Letters, Nagoya University, made a new discovery that allowed them to reconsider the recovery process from the volcanic eruption of Ilopango (ca. AD 400-450), which was one of the greatest Holocene eruptions in Central America. Assistant Prof. Ichikawa explained: "We have discovered a masonry platform just above the ash caused by the Ilopango eruption in San Andrés, which could prove that people reoccupied in such a devastated area even immediately after the enormous disaster occurred."

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How did the Maya Manage Their Water Resources?

Collection, storage and management of water were top priorities for the ancient Maya, whose sites in Mexico, Belize and Guatemala were forced to endure seven months out of the year with very little rainfall. As researchers expand their explorations of the civilization outside of large, elite-focused research site centers, aerial imagery technology is helping them locate and study areas that are showing them how less urbanized populations conserved water for drinking and irrigation. The NSF-supported research by Jeffrey Brewer, a doctoral student in the University of Cincinnati's Department of Geography, and Christopher Carr, a UC research assistant professor of geography, was presented at the 81st annual meeting of the Society of American Archaeology. The meeting takes place April 6-10, in Orlando, Florida.

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Archaeology of Cerén Shows a Different Side to the Maya

For decades scientists thought that, in order to maintain a prosperous and powerful empire along the territories which make up what today is El Salvador, Honduras, Guatemala, Belize and the southwest of Mexico, the Mayan elite must have exerted strict control over the nation’s people, customs and economy.

But new signs found at Cerén, an archaeological park located barely 35 kilometers west of San Salvador, tell a very different story of this civilization that emerged near 1,000 B.C. and developed until it collapsed in the sixteenth century.

Nicknamed “The Pompeii of the Americas”, Cerén’s archaeological remains were discovered in 1976 by Payson Sheets, an anthropologist with Colorado University at Boulder. The ruins existed under a five-meter thick layer of ash, generated by an eruption of the Loma Caldera volcano approximately 1,400 years ago.

Almost four decades after the find, a team of US and El Salvador archaeologists and anthropologists led by Sheets excavated the citadel and found hundreds of daily life objects preserved in excellent condition thanks to the protective ash cover. Scientists believe the volcano eruption was so strong that people were forced to abandon the city, leaving their belongings behind. “This makes Cerén one of the richest archaeological sites in the region,” Sheets says.

The data at the excavation site tells the story of a community that seemed to have plenty of freedom to make crucial decisions about family organization, religion and food crops, according to a story published in Latin American Antiquity.

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Precolumbian Mexican City of Teotihuacan may Have Kept Carnivores Captive

From Roman gladiatorial combat to Egyptian animal mummies, capturing and manipulating wild carnivores has long been a way for humans to demonstrate state or individual power. Historians and scientists alike have attempted to determine when humans first began to use carnivores to establish their place on the social ladder, one of the earliest examples being Moctezuma's 14th century zoo at the Aztec capital of Tenochtitlan. A recent PLOS ONE study, however, reveals evidence from the ruins of the Mexican city of Teotihuacan that may push back the date of captivating carnivores by 1000 years.

Between the first and sixth centuries A.D., Teotihuacan was one of the largest and most powerful urban cities in Mesoamerica and was home to at least 25,000 people. When the city reached the height of its influence around 1300-1500 A.D., its architects designed massive temples to show off the city's power. The ruins of three of these incredible temples still stand: the Temple of Quetzalcoatl, the Pyramid of the Sun, and the Pyramid of the Moon.

During excavations from 1998-2004, the authors of this study found rare artifacts and human and animal remains in chambers in the Pyramids of the Sun and the Moon. The authors focused the present study on the 194 animal remains, as they are evidence of one of the largest known animal sacrifices in Mesoamerica.

Of particular interest to the authors were the remains of carnivores like wolves, eagles, jaguars, and pumas, as we have little information about how humans related to carnivores prior to Montezuma's zoo in Tenochtitlan. Using isotope analysis and visual inspection of the bones, the authors were able to draw possible conclusions about the relationship between the carnivores in the chamber and the ancient inhabitants of Teotihuacan.

Visual examination of the animal skeletons suggested that some of the carnivores were kept in captivity. The authors found bone breaks and stress characteristic of captive animals – for example, three eagle skeletons showed stress on the lower part of the legs, where they may have been tied to a perch. Other deformities in the animal skeletons, such as bone fusion or abnormal growth, were evidence of infection, which typically only occur when animals are kept in close together in captivity.

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Copper Isotope Analysis may Allow for Tracing North American PreColumbian Turquoise Trade Routes

A new study from geoscience researchers has important implications for studies of Mesoamerica and North America prior to the arrival of European settlers. Using isotope geochemistry, scientists at Pennsylvania's Dickenson College and the University of Arizona are trying to identify if turquoise mineral specimens record the signature of their parent ore deposits.

Turquoise is a copper aluminum phosphate mineral that forms from water percolating through bedrock near copper ore deposits. Scientists thought that they should see signatures of the ore body where a specimen formed reflected in lead and strontium isotopes in the turquoise, and initial results suggest that they do. Learn what these chemical fingerprints say about where turquoise originates, and how this could improve our understanding of ancient trade routes in North America

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Mayan Pompeii From 660 AD/CE Gives Glimpse of Daily Village Life

A continuing look at a Maya village in El Salvador--frozen in time by a blanket of volcanic ash from 1,400 years ago--shows the farming families who lived there went about their daily lives with virtually no strong-arming by the elite royalty lording over the valley.

Instead, archaeological evidence indicates significant interactions at the village of Ceren took place among families, village elders, craftspeople and specialty maintenance workers. This research comes from a new University of Colorado Boulder (CU-Boulder) study, funded by the National Science Foundation (NSF).

Ceren is the best-preserved ancient Maya village in all of Latin America. In A.D. 660, the village was blasted by toxic gas, pummeled by lava bombs and then choked by a 17-foot layer of ash falling over several days after the Loma Caldera volcano, less than half a mile away, erupted.

Discovered in 1978 by CU-Boulder anthropology Professor Payson Sheets, Ceren has been called the "New World Pompeii." The degree of preservation is so great researchers can see marks of finger swipes in ceramic bowls, and human footprints in gardens that host ghostly ash casts of corn stalks. Researchers have also uncovered thatched roofs, woven blankets and bean-filled pots.

Some Maya archaeological records document "top-down" societies, where the elite class made most political and economic decisions, at times exacting tribute or labor from villages, said Sheets. But at Ceren, the villagers appear to have had free reign regarding their architecture, crop choices, religious activities and economics.

"This is the first clear window anyone has had on the daily activities and the quality of life of Maya commoners back then," said Sheets, who is directing the excavation. "At Ceren we found virtually no influence and certainly no control by the elites."

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Evidence of the Lives of Mayan Lower Classes Through Their Bones

Most of what we know about Mayan civilization relates to kings, queens and their elaborate temples. To understand what life was like for the 99 percent, one researcher turned to ancient animal bones stored at the Florida Museum of Natural History.

Ashley Sharpe, a doctoral student at the museum on the UF campus, says the picture researchers have painted of the Maya people isn't broad enough.

"When you think about the Romans and the Greeks, we know a lot about all of the different social classes -- from the Caesars down to the commoners -- but although there were tens of thousands of middle-class and lower-income Maya in big cities, we still don't know much about the everyday lives of most people."

For the first time in Maya archaeology research, 22,000 animal remains at the museum, one of the largest collections of its kind outside of Central America, were used as clues about life in the Maya lower classes. The bones revealed that the civilization known for its art and astronomy also had political and economic systems that were more complex than previously thought - systems similar to modern societies. The details are described in a new study appearing online this month in the Journal of Anthropological Archaeology.

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Rise and Fall of MesoAmerican, South American PreColumbian Agrarian Societies Tied to Climate Variability

Climate variability is one of the major forces in the rise and fall of agrarian states in Mexico and Peru, according to a team of researchers looking at both climate and archaeological records.

"We are arguing that the climate information in both areas is good enough to establish that climate is playing some role in the rise and fall of these city states," said Douglas Kennett, professor of environmental archaeology. "Now we need to further refine the archaeological data."

Kennett, working with Norbert Marwan, climatologist and statistician, Potsdam Institute for Climate Impact Research, Germany, looked at climate records for central Mexico gleaned from a stalagmite collected from Juxtlahuaca Cave in the state of Guerrero. They also looked at the climate record preserved in the Quelccaya ice cape in the Cordillera Vilcanota portion of the Peruvian Andes.

In both cases the climate records are based on oxygen isotope measurements on datable layers of ice or stalagmite cave deposition. These records show annual changes in rainfall and temperature for 2,000 years in Mexico and 1,800 years in Peru.

"There is a long tradition of archaeology in both central Mexico and the Peruvian highlands," said Kennett. "There are also new high resolution climate records available that have not yet been capitalized on by archaeologists."

The researchers note that some refinement in archaeological dating in some areas is still needed, but that the rise and fall of major polities is reasonably well known.

Comparing the climate record with organized agrarian state level societies in Mexico, Kennett and Marwan looked at the rise and falls of three states -- Teotihuacán from 100 BCE to 650 CE, Toltec from 900 to 1150 CE and the Aztec Empire from 1400 to 1519.

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The "Mayacene:" How the Maya's Impact on Their Environment

Evidence from the tropical lowlands of Central America reveals how Maya activity more than 2,000 years ago not only contributed to the decline of their environment but continues to influence today's environmental conditions, according to researchers at The University of Texas at Austin.

Synthesizing old and new data, researchers were the first to show the full extent of the "Mayacene" as a microcosm of the early anthropocene -- a period when human activity began greatly affecting environmental conditions.

"Most popular sources talk about the anthropocene and human impacts on climate since the industrial revolution, but we are looking at a deeper history," said lead author Tim Beach, the C.B. Smith Sr. Centennial Professor of Geography and the Environment. "Though it has no doubt accelerated in the last century, humans' impact on the environment has been going on a lot longer."

By looking at Maya impacts on climate, vegetation, hydrology and lithosphere from 3,000 to 1,000 years ago, researchers propose that the Maya's advanced urban and rural infrastructure altered ecosystems within globally important tropical forests.

The researchers identified six stratigraphic markers -- or "golden spikes" -- that indicate a time of large-scale change, including: "Maya clay" rocks; unique soil sequences; carbon isotope ratios; widespread chemical enrichment; building remains and landscape modifications; and signs of Maya-induced climate change.

"These spikes give us insight into how and why Mayas interacted with their environment, as well as the scope of their activity," said Sheryl Luzzadder-Beach, co-author and chair of the Department of Geography and the Environment.

Maya clay and soil sequences indicated erosion, human land-use changes and periods of instability. Soil profiles near wetlands revealed heightened carbon isotope ratios due to agriculture and corn production; and researchers noted a three- to fourfold increase in phosphorus throughout Maya-age sediments.

However, the most visual indication of human impact was found in building material remains and landscape modifications. Researchers believe that these clues reveal how the Maya used water management to adapt to climate change.

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1700 year Old PreColumbian Pyramid Comparable to El Mirador in MExico

Researchers discover immense pyramid in Mexico, larger than Teotihuacan’s Pyramid of the Sun. Researchers in Mexico have discovered a Pyramid that, according to initial measurements, is larger than the Great Pyramid of the Sun in Teotihuacan. Initial excavations were done in 2010.

The Pyramid, 75 meters in height, was explored by specialists from the National Institute of Anthropology and History (INAH) on the acropolis of Tonina, Chiapas, estimated to be around 1700 years old.

Emiliano Gallaga, director of the archaeological zone, explained that work has been done in the last two years, and by means of a “three-dimensional, researchers verified that in the northeastern part of the site, stands one of the largest construction in Mesoamerica, comparable in size only to great Mayan cities like Tikal and El Mirador in Guatemala.

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Parrots Push Chaco Canyon (Anasazi/Puebloan) Culture/MesoAmerican Trade Origin Between 800 to 900 AD

Somehow, colorful tropical scarlet macaws from tropical Mesoamerica -- the term anthropologists use to refer to Mexico and parts of northern Central America -- ended up hundreds of miles north in the desert ruins of an ancient civilization in what is now New Mexico.

Early scientists began excavating the large Pueblo settlements in Chaco Canyon in northwestern New Mexico and found the birds' remains in the late 1890s, but only recent radiocarbon dating of the physical evidence has pushed back the time period of sophisticated Pueblo culture by at least 150 years, according to a paper published today in the Proceedings of the National Academy of Sciences.

Co-author and archaeologist Stephen Plog, the University of Virginia's David A. Harrison Professor of Anthropology, worked with Adam S. Watson of the American Museum of Natural History, Douglas J. Kennett of Pennsylvania State University and a team of researchers from the museum and other universities to have macaw bones dated and interpret the results.

Using accelerator mass spectrometry radiocarbon methods with high precision in dating, the researchers found the macaw skeletal remains were much older than previously thought -- from as early as the late A.D. 800s -- signaling what researchers theorize was a Pueblo culture established enough to form relationships with Mesoamerican cultures to the south. Plog said archaeologists had typically put the beginning of the apex of ancestral Pueblo civilization in Chaco at A.D. 1040, based on other means such as tree-ring dating that suggested a major architectural expansion began at that time.

Anthropologists had already determined that the ancient Pueblo developed a complex social and religious hierarchy in the canyon, reflected in their distinctive architecture. They have posited that Chaco's 'golden century' or the Chaco 'florescence' occurred from A.D. 1040 to 1110, coinciding with a major expansion of the 'great houses.' These great houses contained clustered complexes of rooms for large gatherings, lodgings, storage, burial and religious rituals. Pueblo Bonito, with about 650 rooms in the largest of the great houses of Chaco Canyon, is where most of the macaws were recovered.

'In general, most researchers have argued that emergence of hierarchy, and of extensive trade networks that extended into Mexico coincided with what we see as other aspects of the Chaco florescence: Roads being built outward from Chaco and the formation of what are called Chaco outliers that mimic the architecture seen in the cultural center,' Plog said.

The radiocarbon dating project, led by Plog, Watson, and Kennett, showed that the bird remains came from as early as the late A.D. 800s to mid 900s. The earlier dating suggests that the rise of Pueblo sociopolitical complexity developed earlier than previously thought.

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How Drought Brought Down the Classical Maya Despite Climate Adaptations

Drought, agricultural adaptation, and sociopolitical collapse in the Maya Lowlands

Authors:

Douglas et al

Abstract:

Paleoclimate records indicate a series of severe droughts was associated with societal collapse of the Classic Maya during the Terminal Classic period (∼800–950 C.E.). Evidence for drought largely derives from the drier, less populated northern Maya Lowlands but does not explain more pronounced and earlier societal disruption in the relatively humid southern Maya Lowlands. Here we apply hydrogen and carbon isotope compositions of plant wax lipids in two lake sediment cores to assess changes in water availability and land use in both the northern and southern Maya lowlands. We show that relatively more intense drying occurred in the southern lowlands than in the northern lowlands during the Terminal Classic period, consistent with earlier and more persistent societal decline in the south. Our results also indicate a period of substantial drying in the southern Maya Lowlands from ∼200 C.E. to 500 C.E., during the Terminal Preclassic and Early Classic periods. Plant wax carbon isotope records indicate a decline in C4 plants in both lake catchments during the Early Classic period, interpreted to reflect a shift from extensive agriculture to intensive, water-conservative maize cultivation that was motivated by a drying climate. Our results imply that agricultural adaptations developed in response to earlier droughts were initially successful, but failed under the more severe droughts of the Terminal Classic period.

Liquid Mercury Found Beneath Teotihuacan's Pyramid of the Feathered Serpent in Mexico

An archaeologist has discovered liquid mercury at the end of a tunnel beneath a Mexican pyramid, a finding that could suggest the existence of a king’s tomb or a ritual chamber far below one of the most ancient cities of the Americas.

Mexican researcher Sergio Gómez announced on Friday that he had discovered “large quantities” of liquid mercury in a chamber below the Pyramid of the Feathered Serpent, the third largest pyramid of Teotihuacan, the ruined city in central Mexico.

Gómez has spent six years slowly excavating the tunnel, which was unsealed in 2003 after 1,800 years. Last November, Gómez and a team announced they had found three chambers at the tunnel’s 300ft end, almost 60ft below the the temple. Near the entrance of the chambers, they a found trove of strange artifacts: jade statues, jaguar remains, a box filled with carved shells and rubber balls.

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Teotihuacan's Collapse due to Internal Strife?

The demise of Mexico's enigmatic pre-Hispanic city of Teotihuacan stemmed from a conflict among the civilization's elite classes, with buildings set ablaze in the clash, according to a study.

The famed pyramids of the Sun and Moon are among the majestic structures that remain at the tourist site near Mexico City, centuries after Teotihuacan's population vanished.

What caused the civilization to abandon the sprawling city in the 7th century has been the subject of many studies, with political, economic and social problems believed to be behind the exodus.

Linda Manzanilla, an anthropologist at the National Autonomous University of Mexico, now says the collapse was the result of a confrontation between the city's rulers and an "intermediate elite" comprised of entrepreneurs.

The governing class ruled like a "corporate organization" that distributed power among each other, without dynasties or kings -- unlike the Mayan civilization elsewhere in Mexico.

The city, which at some point housed 125,000 people, was divided into neighborhoods where "mid-rank nobles who acted like entrepreneurs" competed to show off the best luxury goods, she told AFP.

"They competed among themselves to bring raw materials, and luxury goods from distant regions, and demonstrate the most attractive and rarest items," said Manzanilla.

This rivalry gave rise to tensions within the city, said Manzanilla, whose conclusions were published in the Proceedings of the National Academy of Sciences in the United States.

The clash, she said, finally took place when "the governing elite realized that the neighborhood elites around the center of the city were getting richer and functioning in an autonomous way."

"They tried to take control, but it was too late," the researcher said.

Around 550 A.D., the revolt of the neighborhood entrepreneur led to the destruction of the Street of the Dead, which is now a major tourist site, and the main buildings of the ruling elite.

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Lost City, Rumored "City of the Monkey God," Discovered in Honduran Rain Forest

An expedition to Honduras has emerged from the jungle with dramatic news of the discovery of a mysterious culture's lost city, never before explored. The team was led to the remote, uninhabited region by long-standing rumors that it was the site of a storied "White City," also referred to in legend as the "City of the Monkey God."

Archaeologists surveyed and mapped extensive plazas, earthworks, mounds, and an earthen pyramid belonging to a culture that thrived a thousand years ago, and then vanished. The team, which returned from the site last Wednesday, also discovered a remarkable cache of stone sculptures that had lain untouched since the city was abandoned.

In contrast to the nearby Maya, this vanished culture has been scarcely studied and it remains virtually unknown. Archaeologists don't even have a name for it.

Christopher Fisher, a Mesoamerican archaeologist on the team from Colorado State University, said the pristine, unlooted condition of the site was "incredibly rare." He speculated that the cache, found at the base of the pyramid, may have been an offering.

"The undisturbed context is unique," Fisher said. "This is a powerful ritual display, to take wealth objects like this out of circulation."

The tops of 52 artifacts were peeking from the earth. Many more evidently lie below ground, with possible burials. They include stone ceremonial seats (called metates) and finely carved vessels decorated with snakes, zoomorphic figures, and vultures.

The most striking object emerging from the ground is the head of what Fisher speculated might be "a were-jaguar," possibly depicting a shaman in a transformed, spirit state. Alternatively, the artifact might be related to ritualized ball games that were a feature of pre-Columbian life in Mesoamerica.

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Climate Change's Impact on PreColumbian Cantona, Mexico

Cultural implications of late Holocene climate change in the Cuenca Oriental, Mexico

Authors:

Bhattacharya et al

Abstract:

There is currently no consensus on the importance of climate change in Mesoamerican prehistory. Some invoke drought as a causal factor in major cultural transitions, including the abandonment of many sites at 900 CE, while others conclude that cultural factors were more important. This lack of agreement reflects the fact that the history of climate change in many regions of Mesoamerica is poorly understood. We present paleolimnological evidence suggesting that climate change was important in the abandonment of Cantona between 900 CE and 1050 CE. At its peak, Cantona was one of the largest cities in pre-Columbian Mesoamerica, with a population of 90,000 inhabitants. The site is located in the Cuenca Oriental, a semiarid basin east of Mexico City. We developed a subcentennial reconstruction of regional climate from a nearby maar lake, Aljojuca. The modern climatology of the region suggests that sediments record changes in summer monsoonal precipitation. Elemental geochemistry (X-ray fluorescence) and δ18O from authigenic calcite indicate a centennial-scale arid interval between 500 CE and 1150 CE, overlaid on a long-term drying trend. Comparison of this record to Cantona’s chronology suggests that both the city’s peak population and its abandonment occurred during this arid period. The human response to climate change most likely resulted from the interplay of environmental and political factors. During earlier periods of Cantona’s history, increasing aridity and political unrest may have actually increased the city’s importance. However, by 1050 CE, this extended arid period, possibly combined with regional political change, contributed to the city’s abandonment.

Maize had a Complex Path Into the American Southwest

After it was first domesticated from the wild teosinte grass in southern Mexico, maize, or corn, took both a high road and a coastal low road as it moved into what is now the U.S. Southwest, reports an international research team that includes a UC Davis plant scientist and maize expert.

The study, based on DNA analysis of corn cobs dating back over 4,000 years, provides the most comprehensive tracking to date of the origin and evolution of maize in the Southwest and settles a long debate over whether maize moved via an upland or coastal route into the U.S.

Study findings, which also show how climatic and cultural impacts influenced the genetic makeup of maize, will be reported Jan. 8 in the journal Nature Plants.

The study compared DNA from archaeological samples from the U.S. Southwest to that from traditional maize varieties in Mexico, looking for genetic similarities that would reveal its geographic origin.

"When considered together, the results suggest that the maize of the U.S. Southwest had a complex origin, first entering the U.S. via a highland route about 4,100 years ago and later via a lowland coastal route about 2,000 years ago," said Jeffrey Ross-Ibarra, an associate professor in the Department of Plant Sciences.

The study further provided clues to how and when maize adapted to a number of novel pressures, ranging from the extreme aridity of the Southwest climate to different dietary preferences of the local people.

Excavations of multiple stratigraphic layers of Tularosa cave in New Mexico allowed researchers to compare genetic data from samples from different time periods.

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