Many scholars have examined the ways in which ancient Roman house design emphasized views and viewing within the domestic space; indeed, the role of the vista in the architecture of this period was so important that Roman law codified “the right to an unobstructed view.” Most villas were constructed on the principle of axiality, providing a view through the entire house, but other techniques were utilized, too, often to complement certain domestic rituals or patterns of movement. Parts of the interior that were visible to an outsider walking past the entrance, for instance, often favored “easily legible decorative schemes,” while rooms where a guest was intended to relax on a couch tended to feature more complex ornamentation such as sculptures or fountains.
Yet while many authors have described these elements of ancient Roman design, they have often done so based on work with stationary fragments like sketches or models, which privilege the single perspective frame. A new paper in the American Journal of Archaeology, “Visual Experience in a Pompeian Domestic Space: Analysis Using Virtual Reality-Based Eye Tracking and GIS,” provides a more holistic account of Roman architecture by taking into account factors like body and eye movement, and illumination. The article by authors Danilo Marco Campanaro and Giacomo Landeschi “aims to identify the nuances of social rituals in connection with visibility and proximity and the construction of the self through a study that combines space, movement, and time.” This work was made possible thanks to the Digital Archaeology Laboratory and the Humanities Lab of Lund University, Sweden.
The setting for the authors’ research was the House of the Greek Epigrams in the ruins of Pompeii. A 3D virtual reality reconstruction of the house was created, and the experiences of five participants moving through the reconstruction recorded and uploaded into a geographic information system (GIS). Specifically, the researchers tracked the participants’ position in the space of the house, their gaze, and their fixations, or what their vision focused on when their eyes were stable. Additionally, these recreations were conducted under two different light conditions—that approximating early morning on the winter solstice, and that approximating the summer solstice noon.
The House of the Greek Epigrams is decorated on the inside with many paintings and figural scenes. Through their experiment, the authors were able to observe how long their participants spent with each artwork, and how visible they found each piece. The varying light conditions, the study found, affected the participants’ relationship to each painted vignette, and so did their dynamic movement closer to or further from the scenes. “Indeed,” the authors write, “the different times of day and seasons would have created ever-changing experiences, where endless possibilities for interaction with different painted images could have been realized.” Scrutinizing a painting of Bacchus, for instance, close up in the winter gloom, would have produced a very different effect than seeing it in the glow of the summer sun. “Rather than rooms with a single view or multiple views,” conclude the authors, “the Roman house would have offered a complex visual palimpsest made up of moving views, interconnected journeys, and comings and goings, of successive investigations in search of the unexpected new detail and mnemonic connections, through the skillful play of paintings under the light and in the shadows.”
Many ancient cultures used musical instruments in ritual ceremonies. Ancient Aztec communities from the pre-Columbian period of Mesoamerica had a rich mythological codex that was also part of their ritual and sacrificial ceremonies. These ceremonies included visual and sonic iconographic elements of mythological deities of the Aztec underworld, which may also be symbolized in the Aztec death whistle. Their skull-shaped body may represent Mictlantecuhtli, the Aztec Lord of the Underworld, and the iconic screaming sound may have prepared human sacrifices for their mythological descent into Mictlan, the Aztec underworld.
Aztec death whistles have a unique instrumental construction
To understand the physical mechanisms behind the whistle’s shrill and screeching sound, a team of researchers at the University of Zurich led by Sascha Frühholz, Professor of Cognitive and Affective Neuroscience, created 3D digital reconstructions of original Aztec death whistles from the Ethnological Museum in Berlin. The models revealed a unique internal construction of two opposing sound chambers that create physical air turbulence as the source of the screeching sound. “The whistles have a very unique construction, and we don’t know of any comparable musical instrument from other pre-Columbian cultures or from other historical and contemporary contexts,” says Frühholz.
Death whistles very, very frightening
The research team also obtained sound recordings of original Aztec death whistles as well as from handmade replicas. Listeners rated these sounds as extremely chilling and frightening. The Aztec death whistle seems to acoustically and affectively mimic other deterring sounds. Most interestingly, human listeners perceived the sound of the Aztec death whistle to be partly of natural and organic origin, like a human voice or scream. “This is consistent ith the tradition of many ancient cultures to capture natural sounds in musical instruments, and could explain the ritual dimension of the death whistle sound for mimicking mythological entities,” explains Frühholz.
Affective response and symbolic association
The Aztec death whistle sounds were also played to human listeners while their brains were being recorded. Brain regions belonging to the affective neural system responded strongly to the sound, again confirming its daunting nature. But the team also observed brain activity in regions that associate sounds with symbolic meaning. This suggests a “hybrid” nature of these death whistle sounds, combining a basic psychoaffective influence on listeners with more elaborate mental processes of sound symbolism, signifying the iconographic nature.
Connecting modern humans with Aztec audiences
Music has always had strong emotional impact on human listeners in both contemporary and ancient cultures, hence its use in ritual religious and mythological contexts. Aztec communities may have specifically capitalized on the frightening and symbolic nature of the death whistle sound to influence the audience in their ritual procedures, based on the knowledge of how the sound affects modern humans. “Unfortunately, we could not perform our psychological and neuroscientific experiments with humans from ancient Aztec cultures. But the basic mechanisms of affective response to scary sounds are common to humans from all historical contexts,” says Frühholz.
TAMPA, Fla. (Nov. 15, 2024) – A University of South Florida professor found the first-ever physical evidence of hallucinogens in an Egyptian mug, validating written records and centuries-old myths of ancient Egyptian rituals and practices. Through advanced chemical analyses, Davide Tanasi examined one of the world’s few remaining Egyptian Bes mugs.
Such mugs, including the one donated to the Tampa Museum of Art in 1984, are decorated with the head of Bes, an ancient Egyptian god or guardian demon worshiped for protection, fertility, medicinal healing and magical purification. Published Wednesday in Nature’s Scientific Reports, the study sheds light on an ancient Egyptian mystery: The secret of how Bes mugs were used about 2,000 years ago.
“There’s no research out there that has ever found what we found in this study,” Tanasi said. “For the first time, we were able to identify all the chemical signatures of the components of the liquid concoction contained in the Tampa Museum of Art’s Bes mug, including the plants used by Egyptians, all of which have psychotropic and medicinal properties.”
The presence of Bes mugs in different contexts over a long period of time made it extremely difficult to speculate on their contents or roles in ancient Egyptian culture.
“For a very long time now, Egyptologists have been speculating what mugs with the head of Bes could have been used for, and for what kind of beverage, like sacred water, milk, wine or beer,” said Branko van Oppen, curator of Greek and Roman art at the Tampa Museum of Art. “Experts did not know if these mugs were used in daily life, for religious purposes or in magic rituals.”
Several theories about the mugs and vases were formulated on myths, but few of them were ever tested to reveal their exact ingredients until the truth was extracted layer by layer.
Tanasi, who developed this study as part of the Mediterranean Diet Archaeology project promoted by the USF Institute for the Advanced Study of Culture and the Environment, collaborated with several USF researchers and partners in Italy at the University of Trieste and the University of Milan to perform chemical and DNA analyses. With a pulverized sample from scraping the inner walls of the vase, the team combined numerous analytical techniques for the first time to uncover what the mug last held.
The new tactic was successful and revealed the vase had a cocktail of psychedelic drugs, bodily fluids and alcohol – a combination that Tanasi believes was used in a magical ritual reenacting an Egyptian myth, likely for fertility. The concoction was flavored with honey, sesame seeds, pine nuts, licorice and grapes, which were commonly used to make the beverage look like blood.
“This research teaches us about magic rituals in the Greco-Roman period in Egypt,” Van Oppen said. “Egyptologists believe that people visited the so-called Bes Chambers at Saqqara when they wished to confirm a successful pregnancy because pregnancies in the ancient world were fraught with dangers. So, this combination of ingredients may have been used in a dream-vision inducing magic ritual within the context of this dangerous period of childbirth.”
“Religion is one of the most fascinating and puzzling aspects of ancient civilizations,” Tanasi said. “With this study, we’ve found scientific proof that the Egyptian myths have some kind of truth and it helps us shed light on the poorly understood rituals that were likely carried out in the Bes Chambers in Saqqara, near the Great Pyramids at Giza.”
Some of the first humans to arrive in Tasmania, over 41,000 years ago, used fire to shape and manage the landscape, a new study from The Australian National University (ANU) and the University of Cambridge has found.
It is thought to be the earliest and most detailed record of humans using fire in the Tasmanian environment.
According to the researchers, early inhabitants of Tasmania were managing forests and grasslands by burning them to create open spaces, possibly for food procurement and cultural activities.
The team analysed traces of charcoal and pollen contained in ancient mud that showed how Indigenous Tasmanians (Palawa) shaped their surroundings and cared for Country over thousands of years.
Co-author and ANU palaeoecologist, Professor Simon Haberle, said the study provided important new details about life in Tasmania many centuries ago.
“Palaeoecological records show that Palawa people burned wet forest to first settle in Tasmania, as indicated by a sudden and unprecedented increase in charcoal accumulated in ancient mud 41,600 years ago,” he said.
“Earlier studies have shown that Aboriginal communities on the Australian mainland used fire to shape their habitats, but we haven’t had such detailed and deep-time records this part of Tasmania until now.”
The researchers studied ancient mud taken from islands in the Bass Strait, which is part of Tasmania today, but would have been part of the land bridge connecting Australia and Tasmania in the past.
According to study lead author Dr Matthew Adeleye, who completed his PhD at ANU and is now based at the University of Cambridge, Indigenous Tasmanians used fire as a tool to promote the type of vegetation or landscape that was important to them.
“As natural habitats adapted to cultural burning, we see the expansion of fire-adapted species such as Eucalyptus, primarily on the wetter side of the Bass Strait islands,” Dr Adeleye said.
According to the researchers, the findings provide further insight into the long-standing connection Indigenous peoples have to Country.
Professor Haberle said a greater understanding of this relationship is important for landscape management in Australia today and could also assist in defining and restoring cultural landscapes.
“These early Palawa communities were the island’s first land managers,” Professor Haberle said.
“To protect Tasmanian and Australian landscapes for future generations, it’s vital that we listen and learn from Indigenous communities who are calling for a greater role in helping to manage Australian landscapes into the future.”
The secrets of fossil teeth revealed by the synchrotron: a long childhood is the prelude to the evolution of a large brain
Could social bonds be the key to human big brains? A study of the fossil teeth of early Homo from Georgia dating back 1.77 million years reveals, thanks to the European Synchrotron (ESRF) in Grenoble, a prolonged childhood despite a small brain and an adulthood comparable to that of the great apes. This discovery suggests that an extended childhood, combined with cultural transmission in three-generation social groups, may have triggered the evolution of a large brain like that of modern humans, rather than the reverse. The study is published in Nature.
Summary
An international team of researchers from the University of Zurich (Switzerland), the European Synchrotron Radiation Facility (ESRF, Grenoble, France), and the Georgian National Museum (Georgia) has challenged the hypothesis that the long childhood of modern humans (Homo sapiens) is linked to their big brains, by studying a fossil of early Homo from Georgia dating back 1.77 million years. Using synchrotron imaging to analyse the dental development of an almost adult individual, the scientists observed that although this species reached adulthood as quickly as the great apes (around 12 years), it exhibited a sequence of tooth development similar to that of modern humans, suggesting a longer duration of childhood, and longer dependence on adults, than in the great apes.
Because the brain of early Homo was only slightly larger than that of a chimpanzee, the researchers hypothesise that this slower development was linked to the intensified cultural transmission across the generations, where the elders pass on their knowledge to the young. A longer childhood in a three-generation social context would have enabled immature group members to assimilate a growing amount of knowledge more effectively. Once this evolutionary process had been set in motion, natural selection would have acted on the traits that made cultural transmission within social groups increasingly efficient. Only in a second phase, and with increasing social information transfer, evolution would have favoured the development of ever-larger brains, which would have led to the late adulthood and long life spans characteristic of modern humans. This study published in Nature demystifies the role of large brains for the evolution of a long childhood, suggesting instead that the long childhood together with the three-generation social structure eventually led to larger brains.
Full text
Compared to the great apes, humans have an exceptionally long childhood, during which parents, grandparents and other adults contribute to their physical and cognitive development. This is a key developmental period for acquiring all the cognitive skills needed in the complex social environment of a human group. The current consensus is that the very long growth of modern humans has evolved as a consequence of the increase in brain volume, since such an organ requires significant energy resources to grow. However, the ‘big brain - long childhood’ hypothesis may need to be revised, as shown by an international team of researchers in the journal Nature, based on an analysis of the dental growth of an exceptional fossil.
Teeth are the key
The research team, made up of scientists from the University of Zurich (Switzerland), the European Synchrotron Radiation Facility (ESRF, Grenoble, France), and the Georgian National Museum (Georgia), used synchrotron imaging to study the dental development of a near-adult fossil of early Homo from the Dmanisi site in Georgia, dated to around 1.77 million years ago.
“Childhood and cognition do not fossilise, so we have to rely on indirect information. Teeth are ideal because they fossilise well and produce daily rings, in the same way that trees produce annual rings, which record their development”, explains Christoph Zollikofer from the University of Zurich and first author of the publication. “Dental development is strongly correlated with the development of the rest of the body, including brain development. Access to the details of a fossil hominid's dental growth therefore provides a great deal of information about its general growth”, adds Paul Tafforeau, scientist at the ESRF and co-author of the study.
18 years of research
The project was launched in 2005, following the initial success of non-destructive analyses of dental microstructures using phase contrast synchrotron tomography at the ESRF. This technique enabled scientists to create virtual microscopic slices through the teeth of this fossil. The exceptional quality of preservation of the growth structures in this specimen has made it possible to reconstruct all the phases of its dental growth, from birth to death, with unprecedented precision. In a way, the scientists have virtually regrown the teeth of this hominid.
This project took almost 18 years from its initial conception in 2005 to the finalisation of the results in 2023. The scientists scanned the teeth for the first time in 2006, and the first results on the fossil’s age at death were obtained in 2007.
“We expected to find either dental development typical of early hominids, close to that of the great apes, or dental development close to that of modern humans. When we obtained the first results, we couldn’t believe what we saw, because it was something different that implied faster molar crown growth than in any other fossil hominin or living great ape”, explains Paul Tafforeau. Over the next few years, five series of experiments and four complete analyses using different approaches were carried out as technical advances were made in dental synchrotron imaging. With the results all pointing in the same direction, and potentially having a strong impact on the ‘big brain - long childhood’ hypothesis, the scientists had to think outside the box to understand this fossil. “It's been a slow maturation, both technically and intellectually, to finally arrive at the hypothesis we are publishing today” concludes Paul Tafforeau.
Milk teeth used for longer
“The results showed that this individual died between 11 and 12 years of age, when his wisdom teeth had already erupted, as is the case in great apes at this age,” explains Vincent Beyrand, co-author of the study. However, the team found that this fossil had a surprisingly similar tooth maturation pattern to humans, with the back teeth lagging behind the front teeth for the first five years of their development.
“This suggests that milk teeth were used for longer than in the great apes and that the children of this early Homo species were dependent on adult support for longer than those of the great apes,” explains Marcia Ponce de León from the University of Zurich and co-author of the study. “This could be the first evolutionary experiment of prolonged childhood”.
How teeth can give clues about brain evolution
This is where the ‘big brain - long childhood’ hypothesis is put to the test. Early Homo individuals did not have much bigger brains than great apes or australopithecines, but they possibly lived longer. In fact, one of the skulls discovered at Dmanisi was that of a very old individual with no teeth left during its last few years of life. “The fact that such an old individual was able to survive without any teeth for several years indicates that the rest of the group took good care of him,” comments David Lordkipadnize of the National Museum of Georgia and co-author of the study. The older individuals are the ones with the greatest experience, so it's likely that their role in the community was to pass on their knowledge to the younger individuals. This three-generation structure is a fundamental aspect of the transmission of culture in humans.
It is well known that young children can memorise an enormous amount of information thanks to the plasticity of their immature brains. However, the more there is to memorise, the longer it takes.
This is where the new hypothesis comes in. Children's growth would have slowed down at the same time as cultural transmission increased, making the amount of information communicated from old to young increasingly important. This transmission would have enabled them to make better use of available resources while developing more complex behaviours, and would thus have given them an evolutionary advantage in favour of a longer childhood (and probably of a longer lifespan).
Once this mechanism was in place, natural selection would have acted on cultural transmission and not just to biological traits. Then, as the amount of information to be transmitted increased, evolution would have favoured an increase in brain size and a delay in adulthood, allowing us both to learn more in childhood and to have the time to grow a larger brain despite limited food resources.
Therefore, it may not have been the evolutionary increase in brain size that led to the slowdown in human development, but the extension of childhood and the three-generation structure that favoured bio-cultural evolution. These mechanisms, in turn, led to an increase in brain size, a later adulthood and a longer life span. Studying the teeth of this exceptional fossil could therefore encourage researchers to reconsider the evolutionary mechanisms that led to our own species, Homo sapiens.
A collection of perforated pebbles from an archaeological site in Israel may be spindle whorls, representing a key milestone in the development of rotational tools including wheels, according to a study published November 13, 2024 in the open-access journal PLOS ONE by Talia Yashuv and Leore Grosman from the Hebrew University of Jerusalem, Israel.
Donut-shaped objects connected to a bar, forming a wheel and axle, are a key invention springboarding technological development and are commonly associated with Bronze Age carts. Spindle whorls, round, weighted objects that are attached to a spindle stick, form a similar wheel-and-axle-like device to help the spindle rotate faster and longer, enabling it to efficiently gather up fibers such as wool or flax and spin them into yarn.
The stones studied in the new paper, recovered from the Nahal-Ein Gev II dig site in northern Israel, date back approximately 12,000 years, during the important transition to an agricultural lifestyle and the Neolithic period, long before the cart wheels of the Bronze Age. Introducing an innovative method for studying perforated objects, based on digital 3-D models of the stones and their negative holes, the authors describe more than a hundred of the mostly-limestone pebbles, which feature a circular shape perforated by a central hole. Due to this structure and composition, the authors of the new paper deduce that the stones were likely used as spindle whorls — a hypothesis also supported by successfully spinning flax using replicas of the stones.
This collection of spindle whorls would represent a very early example of humans using rotation with a wheel-shaped tool. They might have paved the way for later rotational technologies, such as the potter’s wheel and the cart wheel, which were vital to the development of early human civilizations.
The authors add: “The most important aspect of the study is how modern technology allows us to delve deep into touching the fingerprints of the prehistoric craftsman, then learn something new about them and their innovativeness, and at the same time, about our modern technology and how we’re linked.”
Citation: Yashuv T, Grosman L (2024) 12,000-year-old spindle whorls and the innovation of wheeled rotational technologies. PLoS ONE 19(11): e0312007. https://doi.org/10.1371/journal.pone.0312007
A new study by researchers from Hebrew University has identified 12,000 years old spindle whorls — early tools used to spin fibers into yarn. This discovery, recovered from the Nahal-Ein Gev II dig site in northern Israel, provides the earliest evidence of wheeled rotational technology in the Levant, offering insights into the technological advancements of the Natufian culture during the important transition to an agricultural lifestyle.
[Hebrew University of Jerusalem]– The study, recently published in PLOS ONE, was led by Talia Yashuv and Professor Leore Grosman from the Computational Archaeology Laboratory at the Hebrew University’s Institute of Archaeology. Introducing an innovative method for studying perforated objects, based on digital 3-D models of the stones and their negative holes, the authors describe more than a hundred of the mostly-limestone pebbles, which feature a circular shape perforated by a central hole. Due to this structure and composition, the authors deduce that the stones were likely used as spindle whorls — a hypothesis also supported by successfully spinning flax using replicas of the stones.
Spindle whorls, round, weighted objects that are attached to a spindle stick, form a similar wheel-and-axle-like device to help the spindle rotate faster and longer, enabling it to efficiently gather up fibers such as wool or flax and spin them into yarn. This discovery marks the earliest known evidence of this fast-spinning technology in the Levant, predating previously known textile tools by 4,000 years and highlighting an important stage in human innovation. Professor Grosman notes: “These Natufian perforated stones are actually the first wheels in form and function — a round object with a hole in the centre connected to a rotating axle, used long before the appearance of the wheel for transportation purposes”. This early use paved the way for future wheel-based rotational innovations, key advancements that revolutionized human technological history such as the potter’s wheel and the cart wheel that appears 6,000 years ago.
The Nahal Ein Gev II site, with its permanent structures, lime-plastered burials, and diversified tools, provides a rare glimpse into the end of the Natufian culture and the transition from a hunter-gatherer society to an agricultural one. The new findings underscore how the technological innovations are an important driving force in the Neolithization processes. This study not only expands our understanding of technological innovation but also showcases how advanced research tools reveal insights into prehistoric craftsmanship, underscoring humanity’s enduring drive for innovation.
In a recent study, an international team of researchers used luminescence dating and geochemical analyses to confirm the location of the oldest ochre mine in the world. It is located in the Lion Cavern in Eswatini, a country in southern Africa. Not only have the researchers dated the mine to an age of around 48,000 years, but they were also able to show how the ochre spread from the mine to nearby areas. The researchers analysed 173 samples from 15 Stone Age sites and reconstructed the methods of ochre extraction, use and transport networks. The study ‘Ochre communities of practice in Stone Age Eswatini’ was published in Nature Communications.
Ochre is a naturally occurring pigment made from iron-rich materials. It has been used by people for thousands of years – for cave paintings and to decorate symbolic objects and personal ornaments. Ochre has cultural, historical and spiritual significance in many societies and therefore offers researchers valuable insights into the growth of human society and human self-expression.
For this study, the researchers created a geochemical fingerprint of the ochre from the Lion Cavern region. For this purpose, small samples of ochre artefacts are safely made radioactive by neutron irradiation. Some of the resulting products can be radioactive. When these radioactive materials begin to decay, they emit characteristic energies. These can be measured and can thus provide information on where the material comes from and how it was created. In this way, the origin and transport routes of the artefacts can be reconstructed. In addition to this method, the researchers used an advanced laser technology, which makes the sample’s molecular bonds vibrate. This vibration indicates the mineral composition of the ochre.
Dr Svenja Riedesel from the Cologne Luminescence Laboratory at the University of Cologne’s Institute of Geography contributed to the dating of the samples. Luminescence dating is based on the fact that materials such as quartz or feldspar absorb small amounts of energy from their surroundings over the course of time. The main source of this energy is the natural radiation in the ground, which is all around us. Small defects in the crystal structure of the material store this energy. “To determine the age of a material, we take a sample and expose it to light or heat in the laboratory,” said Riedesel. “In this way, the stored energy is released again and a weak light – known as luminescence – is produced.” The amount of light released indicates how long the material has not been exposed to sunlight or heat.
Riedesel used quartz grains to date the materials inside of the now abandoned mining caves of Lion Cavern. The results of the luminescence samples show that the caves were created by mining at least 42,000 years ago. This confirms earlier geochronological findings suggesting that ochre was mined in the Lion Cavern 48,000 years ago. “With the help of Optically Stimulated Luminescence dating, we were able to prove that this is the oldest known ochre mine in the world,” summarized the geographer.
With funding from the National Science Foundation, a team of archaeologists from LSU and the University of Texas at Tyler have excavated the earliest known ancient Maya salt works in southern Belize, as reported in the journal Antiquity.
The team was led by LSU Alumni Professor Heather McKillop, who first discovered wooden buildings preserved there below the sea floor, along with associated artifacts, and the only ancient Maya wooden canoe paddle in 2004.
Her key collaborator, Assistant Professor Elizabeth Sills at the University of Texas at Tyler, began working with McKillop as a master’s student and then as a doctoral student at LSU.
Since their initial discovery of wood below the sea floor in Belize, the team has uncovered an extensive pattern of sites that include “salt kitchens” for boiling seawater in pots over a fire to make salt, residences for salt workers, and the remains of other pole and thatch buildings.
All were remarkably well preserved in red mangrove peat in shallow coastal lagoons. Since 2004, the LSU research team has mapped as many as 70 underwater sites, with 4,042 wooden posts marking the outlines of ancient buildings.
In 2023, the team returned to Belize to excavate a site called Jay-yi Nah, which curiously lacked the broken pots so common at other salt works, while a few pottery sherds were found.
“These resembled sherds from the nearby island site of Wild Cane Cay, which I had previously excavated,” McKillop said. “So, I suggested to Sills that we survey Jay-yi Nah again for posts and sea floor artifacts.”
After their excavations, McKillop stayed in a nearby town to study the artifacts from Jay-yi Nah. As reported in Antiquity, the materials they found contrasted with those from other nearby underwater sites, which had imported pottery, obsidian, and high-quality chert, or flint.
“At first, this was perplexing,” McKillop said. “But a radiocarbon date on a post we’d found at Jay-yi Na provided an Early Classic date, 250-600 AD, and solved the mystery.”
Jay-yi Nah turned out to be much older than the other underwater sites. Through their findings, the researchers learned Jay-yi Nah had developed as a local enterprise, without the outside trade connections that developed later during the Late Classic period (AD 650-800), when the inland Maya population reached its peak with a high demand for salt—a basic biological necessity in short supply in the inland cities.
Jay-yi Nah had started as a small salt-making site, with ties to the nearby community on Wild Cane Cay that also made salt during the Early Classic period. Abundant fish bones preserved in anaerobic deposits at Wild Cane Cay suggest some salt was made there for salting fish for later consumption or trade.
Scientists believe individuals of the most recently discovered “hominin” group (the Denisovans) that interbred with modern day humans passed on some of their genes via multiple, distinct interbreeding events that helped shape early human history.
In 2010, the first draft of the Neanderthal genome was published, and comparisons with modern human genomes revealed that Neanderthal and modern humans had interbred in the past. A few months later, analysis of a genome sequenced from a finger bone excavated in the Denisova cave in the Altai mountains in Siberia revealed that this bone fragment was from a newly discovered hominin group that we now call Denisovans, who also interbred with modern humans.
“This was one of the most exciting discoveries in human evolution in the last decade,” said Dr Linda Ongaro, Postdoctoral Research in Trinity College Dublin’s School of Genetics and Microbiology, and first author of a fascinating new review article published in leading international journal Nature Genetics.
“It’s a common misconception that humans evolved suddenly and neatly from one common ancestor, but the more we learn the more we realise interbreeding with different hominins occurred and helped to shape the people we are today.
“Unlike Neanderthal remains, the Denisovan fossil record consists of only that finger bone, a jawbone, teeth, and skull fragments. But by leveraging the surviving Denisovan segments in Modern Human genomes scientists have uncovered evidence of at least three past events whereby genes from distinct Denisovan populations made their way into the genetic signatures of modern humans.”
Each of these presents different levels of relatedness to the sequenced Altai Denisovan, indicating a complex relationship between these sister lineages.
In the review article, Dr Ongaro and Prof. Emilia Huerta-Sanchez outline evidence suggesting that several Denisovan populations, who likely had an extensive geographical range from Siberia to Southeast Asia and from Oceania to South America, were adapted to distinct environments.
They further outline a number of genes of Denisovan origin that gave modern day humans advantages in their different environments.
Dr Ongaro added: “Among these is a genetic locus that confers a tolerance to hypoxia, or low oxygen conditions, which makes a lot of sense as it is seen in Tibetan populations; multiple genes that confer heightened immunity; and one that impacts lipid metabolism, providing heat when stimulated by cold, which confers an advantage to Inuit populations in the Arctic.
“There are numerous future directions for research that will help us tell a more complete story of how the Denisovans impacted modern day humans, including more detailed genetic analyses in understudied populations, which could reveal currently hidden traces of Denisovan ancestry. Additionally, integrating more genetic data with archaeological information – if we can find more Denisovan fossils – would certainly fill in a few more gaps.”