Researchers doing reconnaissance in the Crooked Tree Wildlife Sanctuary CTWS where they discovered evidence of a large-scale pre-Columbian fish-trapping facility.
Credit: Courtesy Belize River East Archaeology (BREA) Project
DURHAM, N.H.—(November 22, 2024)—An archaeologist from the University of New Hampshire and her team have collected data which indicates the presence of a large-scale pre-Columbian fish-trapping facility. Discovered in the Crooked Tree Wildlife Sanctuary (CTWS), the largest inland wetland in Belize, the team dated the construction of these fisheries to the Late Archaic period (cal. 2000-1900 BCE), pre-dating Amazonian examples by a thousand years or more.
“The network of canals was designed to channel annual flood waters into source ponds for fish trapping and would have yielded enough fish to feed as many as 15,000 people year-round, conservatively,” said Eleanor Harrison-Buck, professor of anthropology and director of the Belize River East Archaeology (BREA) project. “The dates indicate that the fisheries were initially constructed by Late Archaic hunter-gatherer-fishers and continued to be used by their Formative Maya descendants (approximately 2000 BCE to 200 CE). For Mesoamerica in general, we tend to regard agricultural production as the engine of civilization, but this study tells us that it wasn’t just agriculture—it was also potential mass harvesting of aquatic species.”
Published in the journal Science Advances, the research used 26 radiocarbon dates from test excavation sites in the CTWS, which indicate that such landscape-scale wetland enhancements may have been an adaptive response to long-term climate disturbance recorded in Mesoamerica between 2200 and 1900 BCE.
“The early dates for the canals surprised us initially because we all assumed these massive constructions were built by the ancient Maya living in the nearby city centers,” said Harrison-Buck. “However, after running numerous radiocarbon dates, it became clear they were built much earlier.”
Sediment samples were collected along the walls of the excavation units and sequenced for specific elements, such as nitrogen and carbon, to look for environmental changes over time. The sediment showed a strong tropical forest dominance during that period and no evidence of crop cultivation, specifically maize. Along with a lack of any pollen from domesticated crops, there were not any signs of ditched and drained agricultural fields in the immediate area dating to that time. The multiproxy data gathered suggests the distinctive long linear zigzag channels served primarily as large-scale fish-trapping facilities.
“It seems likely that the canals allowed for annual fish harvests and social gatherings, which would have encouraged people to return to this area year after year and congregate for longer periods of time,” said Marieka Brouwer Burg, professor of anthropology at the University of Vermont and BREA co-director. “Such intensive investments in the landscape may have led ultimately to the development of the complex society characteristic of the pre-Columbian Maya civilization, which subsequently occurred in this area by around 1200 BCE.”
“Wetlands have always been a critical ecosystem for humans across the globe,” said Samantha Krause, professor of geography and environmental studies at Texas State University. “Knowing how to manage wetland resources responsibly is essential for the continued resilience of these ecosystems both in the past and today. The Archaic hunter-gatherer-fishers knew how to protect their resources and use them in a way that could sustain these habitats, not exhaust them, which explains their long-lasting occupation in this area.”
With the support of the local community, the team plans to return to Crooked Tree to investigate a larger sample of these landscape-scale modifications that they have identified across a broad area of northern Belize, hoping to more fully understand the complexity of human-wetland interactions in the past.
Other co-authors include Mark Willis, department of archaeology, Flinders University, Adelaide, South Australia; Angelina Perrotti, Palynology & Environmental Archaeology Research Lab; Monona, Wisconsin; and Katie Bailey, department of anthropology, University of Vermont.
This research was funded by a grant from the Alphawood Foundation Chicago. Additional support was provided by a collaborative research grant from the National Science Foundation. The Belize Institute of Archaeology provided an archaeological permit, granting permission to excavate in the Crooked Tree Wildlife Sanctuary. The Crooked Tree Village Council welcomed the research team and permitted them to map and excavate in the wetlands around their community.
Caption: Researchers doing reconnaissance in the Crooked Tree Wildlife Sanctuary CTWS where they discovered evidence of a large-scale pre-Columbian fish-trapping facility.
Credit: Courtesy Belize River East Archaeology (BREA) Project
The term “social distancing” spread out across the public vocabulary in recent years as people around the world changed habits to combat the Covid pandemic. New research led by UT Professor Alex Bentley, however, reveals the practice of organized elbow room could date back approximately 6,000 years.
Bentley, from the Department of Anthropology, published research on “Modeling cultural responses to disease spread in Neolithic Trypillia mega-settlements” inthe Journal of The Royal Society Interface. His coauthors include Simon Carrignon, a former UT postdoctoral researcher who was a research associate at the Cambridge University’s McDonald Institute for Archaeological Research while working on this project.
“New ancient DNA studies have shown that diseases such as salmonella, tuberculosis, and plague emerged in Europe and Central Asia thousands of years ago during the Neolithic Era, which is the time of the first farming villages,” said Bentley. “This led us to ask a new question, which is whether Neolithic villagers practiced social distancing to help avoid the spread of these diseases.”
Urban Planning Over the Centuries
As computational social scientists, Bentley and Carrignon have published on both ancient adaptive behaviors and the spread of disease in the modern world. This project brought these interests together. They found that the “mega-settlements” of the ancient Trypillia culture in the Black Sea region, circa 4,000 BC, were a perfect place to test their theory that boundaries of personal space have long been integral parts of public-health planning.
They focused on a settlement called Nebelivka, in what is now Ukraine, where thousands of wooden homes were regularly spaced in concentric patterns and clustered in neighborhoods.
“This clustered layout is known by epidemiologists to be a good configuration to contain disease outbreaks,” said Bentley. “This suggests and helps explain the curious layout of the world’s first urban areas—it would have protected residents from emerging diseases of the time. We set out to test how effective it would be through computer modeling.”
Carrignon and Bentley adapted models developed in a previous National Science Foundation-funded project at UT. Bentley was co-investigator with research lead Professor Nina Fefferman in this work modeling the effects of social distancing behaviors on the spread of Covid-like pandemics to study what effects these practices—such as reducing interaction between neighborhoods—might have had on prehistoric settlements.
“These new tools can help us understand what the archaeological record is telling us about prehistoric behaviors when new diseases evolved,” said Bentley. “The principles are the same—we assumed the earliest prehistoric diseases were foodborne at first, rather than airborne.”
Following the Trail
Their current study simulated the spread of foodborne disease, such as ancient salmonella, on the detailed plan of Nebelivka.
They teamed with:
John Chapman and Bisserka Gaydarska, archaeologists from England’s Durham University, who excavated Nebelivka;
Brian Buchanan, a researcher at Eastern Washington University researcher who did a detailed digital map of the site;
and Mike O’Brien, a cultural evolution expert from Texas A&M in San Antonio.
They ran the archeological data through millions of simulations to test the effects of different possible disease parameters.
“The results revealed that the pie-shaped clustering of houses at Nebelivka, in distinct neighborhoods, would have reduced the spread of early foodborne diseases,” said Bentley. “Fighting disease might also explain why the residents of Nebelivka regularly burned their wooden houses to replace them with new ones. The study shows that neighborhood clustering would have helped survival in early farming villages as new foodborne diseases evolved.”
Applications for Today
With their success in modeling from sparse archaeological data, this approach could be applied to contemporary and future situations when disease data are sparse, even for airborne illnesses.
“In the early 2020 days of the Covid epidemic, for example, few US counties were reporting reliable infection statistics,” said Bentley. “By running millions of simulations with different parameter values, this approach—known as ‘Approximate Bayesian Computation’—can be applied to test different models versus contemporary disease data, such as infection numbers in US counties over time.”
The team’s mix of ancient solutions and modern applications exemplifies the innovative approaches that Volunteer researchers in the College of Arts and Sciences bring to making lives better for Tennesseans and beyond.
Journal
Journal of The Royal Society Interface
Method of Research
Observational study
Subject of Research
People
Article Title
Modelling cultural responses to disease spread in Neolithic Trypillia mega-settlements
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.”
3D reconstruction of the fossil skull of the sub-adult early Homo from the Dmanisi site in Georgia. The green, orange and red colors represent the preserved teeth (imaged respectively with the synchrotron at 5um, with the synchrotron at 47um, and with an industrial scanner at 250um). The blue teeth are missing ones added by mirroring their symmetrical counterparts. The purple first lower incisors have not been recovered, and have been extrapolated form the second lower incisor. Then the right upper canine is showed at 5um resolution to illustrate the visibility of growth lines on its surface, as well as on virtual slices in its enamel and dentine. A second level of zoom is done to reach the 0.7umm resolution that shows the daily lines increments in enamel. All the teeth are then virtually extracted from the skull and disposed in order to show the final dentition state at the death of this individual. Based on the dental increments observed in all the teeth, a virtual growth series has been computed every 6 months from the birth to the death of this sub-adult individual that occurred at 11.42 years.
Credit: Credit: ESRF/Paul Tafforeau, Vincent Beyrand
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.
