Welcome back, everybody!  This is Rick Pettigrew.  Here’s your latest weekly batch of top news stories that appeared on Archaeologica!  Send us feedback on The Archaeology Channel Facebook page or post a message on our social networking site, ArchaeoSeek!

A new study just about to be published claims that, unlike the common wisdom, Aztec writing was very sophisticated.  Research now suggests that early hominids were hypercarnivores rather than omnivores.  Another research result suggests that Paleolithic cave art is associated with the mental state generated by hypoxia. And excavations on the Cahokoa  floodplain in Illinois find no evidence of the deforestation that some proposed to account for the abandonment of the nearby Native American city.

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And now, here’s Laura Pettigrew with the Audio News from Archaeologica.  We hope you find this to be a valuable part of your day!

Welcome to the Audio News from Archaeologica!  I’m Laura Pettigrew, and these are the headlines in archaeological and historical news from Archaeologica for the week of April 4th through the 10th, 2021.

We begin our week’s coverage with a rare Aztec manuscript that’s causing renewed interest in the unusual way the Aztec written language expressed their intellectual ideas.

As reported by Yahoo! News, the Aztecs used a hieroglyphic writing system, in which the symbols represented objects or actions as well as spoken sound.  The Aztec lexicon included tens of thousands of words, and before the Spanish conquest, Aztec libraries included books of poetry, history, law, and rhetoric.

In 1521, however, the Spanish military destroyed three libraries, one at the Aztec capital of Tenochtitlan, and two in their allied cities of Tetzcoco and Tlacopan.  These would have been among the largest in the world at that time.  

After the conquest, merely possessing an Aztec religious text could lead to death.  Only one or two pre-conquest Aztec books appear to have survived destruction.

Around 30 manuscripts, however, were written out by scribes of Aztec descent, in the later 1500s. 

Now Gordon Whittaker, a British linguistic anthropologist, has used those post-conquest examples to rediscover how the Aztec writing system worked.  His research soon will be described in a book, entitled Deciphering Aztec Hieroglyphs: A Guide to Nahuatl Writing., which will be published and available on April 19, 2021.

According to Whittaker, in terms of organization, concept and sophistication, the Aztecs had the western hemisphere’s most complex writing system, equal to those used in ancient Egypt, India, Greece, and Rome.

The earliest writing in Mesoamerica may have been that of the Olmec, living along the Gulf of Mexico coast around 800 BC, but virtually no examples of it have survived.  By AD 300, the great highland city of Teotihuacan created a different writing system, which was further refined by the Toltecs, and then by the Aztecs. 

Over the centuries, many scholars dismissed the Aztec hieroglyphic system as mere pictographs.  However, like ancient Egyptian hieroglyphs, Aztecs could use their symbols to convey not just words and syllables, but all the sounds in their language of Nahuatl.  This flexibility allowed for the expression of often multi-syllabic words, phonetically.

Our second story looks at a multidisciplinary study that challenges long-held beliefs about human evolution.  In this huge study, a group led by researchers from Tel Aviv University examined how dietary choices made by our ancestors continue to impact the human body’s physiology today.

In a novel approach, the team began from a new premise, noting that human behavior changes much more rapidly than the human body.  This means that while the ecosystem around us has changed dramatically in biodiversity and resource distribution, and our behavior has changed as well, the human body’s systems still show the adaptations made over millennia.  These long, slow changes in physiology and anatomy are clues to our past behavior.

The conclusion of this reconstruction, which combined archaeological evidence with other previous research, is a claim that humans were carnivorous apex predators for at least 2 million years, and only adopted a more omnivorous diet when their favorite larger species went extinct.

As reported at the website, Phys.org, the research was led by Dr. Miki Ben-Dor and Professor Ran Barkai of Tel Aviv University, working along with Raphael Sirtoli, of Portugal. 

Analyzing dozens of lines of evidence presented in approximately 400 different scientific papers from disciplines including genetics, metabolism and morphology, the researchers identified several critical aspects of human anatomy and physiology to support their hypothesis.

Carnivores typically expend large amounts of energy to maintain a high enough level of acidity within their intestinal tracts to protect them from the potentially harmful bacteria often found in their meat-based diets.  

As primarily carnivores in ancestry, human beings developed high stomach acid levels as a way to support the digestion of large prey animals, and that has become hard-wired into our genetic being.

The way the human body stores fat in our cells is also consistent with that of other predator species, with a high number of smaller fat cells than would be found in the cellular make-up of an omnivore’s body type.

Archaeological evidence that supports this hypothesis includes finds of large animal carcasses across countless sites of known human occupation, in addition to specially designed tools supporting the harvesting and processing of large prey animals.  Evidence of tools that process vegetable materials for food suggests this developed long after hunting tools like spearheads and arrow points.   

The human reliance on large animal hunting may have led to extinction of many of the species early people relied on for food.  

The new study was published in the Yearbook of the American Physical Anthropology Association.

Our next story again features Tel Aviv University, where researchers have also been studying the process of making cave art deep underground, and the results suggest that some of the amazing qualities of the art might result from decreased oxygen levels affecting the artists as they worked.

As reported in the British newspaper, The Independent, the new research presents a novel hypothesis as to what led Upper Paleolithic peoples to explore and decorate deep, dark caves. 

Many of the depictions found in these caves are located in halls or narrow passageways found inside the cave interior.  These passages could be navigated only with some artificial light source, such as a handheld torch or small fire. 

To explore the ramifications of such activities, researchers Yafit Kedar and Ran Barkai used software designed for modern architecture and engineering design to simulate the effect of torches on oxygen concentrations in structures similar to known Paleolithic decorated caves.  This research is published as a paper in Time and Mind: The Journal of Archaeology, Consciousness and Culture, under the title, “Hypoxia in Paleolithic decorated caves.”

The results showed that the oxygen supply would quickly decrease to levels known to induce a state of hypoxia, and that extended exposure could be deadly. 

This sheds new light on the notion that cave environments were not just art galleries, but transitional spaces where early humans connected with the cosmos.  Entering these spaces was a choice, in spite of or even because of the dangers of change in mental state through partial or even fatal asphyxiation. 

Hypoxia, the loss of adequate oxygen to the brain, increases the release of dopamine, which can give a feeling of euphoria, hallucinations, and out-of-body experiences. 

According to Kedar and Barkai, the practice of repeatedly entering the cave systems was part of a sacred ritual.  The cave acted as a portal to the world beyond, providing contact with unseen entities beyond the reach of normal human sensory perception. 

In this sense, people didn’t go into the caves to decorate them, but rather, the caves were decorated because of the reasons people went in.  

The study doesn’t apply to well-ventilated caves with large mouths, where fire creates distinct upper and lower layers of air.  When the air heated by torches or fires rises up in an open cave, it vents out, drawing fresh air in from outside.  In these caves there is no danger of hypoxia, so the new research applies only to caves with narrow mouths, or where markings are deep inside along corridors.

Many cultures, such as the Cherokee in North America, have identified caves and crevices as portals to another world.  Cherokee writing in one cave was backwards, in a mirror form, as if made by or for a spirit on the other side of the wall.

The use of caves for sacred art, for worship and for rituals is widespread, indicating universal expressions of death and rebirth from these transitional spaces.

The new research posits that the oxygen depletion in subterranean spaces could help make the experience even more transformative for some people.  Thus, their drawings were not made for the tribe to see, but to forge and maintain their relationship with the cosmos that they contacted deep within the cave.

A persistent hypothesis about the collapse of Cahokia, the pre-Columbian Native American city in southwestern Illinois that was once home to more than 15,000 people, claims that the people wreaked such ecological destruction on their habitat that their city and culture collapsed.  However, new research now suggests that whatever ultimately led people to abandon Cahokia, it was not because of deforestation.

As reported in the journal, Geoarchaeology, archaeologists from Washington University in St. Louis studied sediment cores to document land changes.  The cores came from an earthen mound on the Cahokia Creek floodplain constructed during the Mississippian Period, from AD 1050–1400.  Analysis focused on evidence of changes in soil density, or other signs of flooding, erosion, sedimentation, or other large-scale changes that would result from intensive land use and tree clearing.

According to Caitlin Rankin, an assistant research scientist at the University of Illinois at Urbana-Champaign, who conducted this work as part of her graduate studies at Washington University, which issued the news about this study, the evidence shows no such over-intensive land use practices.  Rather, it suggests that the ground surface on which the mound was constructed remained stable until industrial development of the mid-1800s.

Archaeologists have often applied narratives of ecocide, or environmental overuse and collapse, to help to explain the decline of past civilizations around the world.

Data often indicate steadily growing populations, and more mouths to feed, resulting in overconsumption of available food and water resources.   

At Cahokia, one thread in this past narrative emerged because of the impressive defensive wooden stockades known as “palisades.”   Building these around the site’s perimeter would have originally required tens of thousands of trees to be felled.  However, as Rankin pointed out, the occasional remodeling of these could have used existing timbers, rather than freshly cut trees.

Even if the local forests became depleted, the new evidence shows it didn’t necessarily cause local flooding.  The new study should help to refocus research onto discovering what actually did cause the inhabitants to relocate.

That wraps up the news for this week!

For more stories and daily news updates, visit Archaeologica on the World Wide Web at www.archaeologica.org where all the news is history!

I’m Laura Pettigrew and I’ll see you next week!