Welcome back, everybody!  I’m Rick Pettigrew.  In just a minute, you’ll hear our four top news stories from this past week of Archaeologica.  Send us feedback on The Archaeology Channel Facebook page or post a message on our social networking site, ArchaeoSeek!

A landmark study proposes a powerful new explanation to account for the creation of the complex Sumerian irrigation system and the world’s first urban society.  Computer simulations and genetic analysis are the basis for a new model of the interactions between hunter-gatherers and newly arriving farmers in the European Neolithic.  A genetic study in the Americas stunningly concludes that Denisovan genes sandwiched between Neanderthal genes helped the first Americans to adapt to their new environments.   And a cow’s tooth from Stonehenge is another connection to Wales and the source of the bluestones.

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And now, here’s Laura Kennedy 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 Kennedy, and these are the headlines in archaeological and historical news for the week of August 17th through the 23rd, 2025.

We begin this week in the ancient region of southern Mesopotamia, where the earliest network of city-states, closely knit by shared cultural traditions and economic interests, emerged some 5,000 years ago.  Collectively referred to as Sumer, it was an agrarian civilization supported by large-scale irrigation systems.  

As reported by Phys.org, a new study published in PLOS One has detailed the dynamic between the infrastructure built by early Persian Gulf communities and the rivers, tides and sediments at the head of the Persian Gulf . 

The research team was led by Liviu Giosan, Senior Scientist Emeritus in Geology & Geophysics at the Woods Hole Oceanographic Institution, and Reed Goodman, Assistant Professor of Environmental Social Science at Clemson University.  They combined existing data with state-of-the-art satellite-acquired topography of a new drill core recovered on the lower Mesopotamian Plain, revealing why early Persian Gulf communities were forced to switch from short irrigation canals to such large-scale infrastructure. 

The results also contribute to the long-running Lagash Archaeological Project, a collaboration led by Iraqi archaeologists and the Penn Museum at the University of Pennsylvania.

Their work demonstrated that, between about 7000 and 5000 years ago, daily tides pushed fresh water up the Tigris and Euphrates rivers, enabling farmers to irrigate their fields with short canals.  Then, around 5000 years ago, as rivers built deltas at the head of the Gulf, tidal access to the interior was cut off.  This triggered an ecological and economic crisis that demanded major irrigation and flood protection projects--efforts that sparked some of history's first intensive farming, created the world's first urban society, and defined Sumer's golden age.

The study also explores the cultural impact of this massive shift, one that connected the flood myths of Mesopotamia with the water-focused gods of Sumeria.  According to Giosan, Sumer was built on the rhythms of water, a relationship whose cyclical patterns of tides, together with delta dynamics, were deeply woven into the culture’s myths and daily ways of life. 

He adds that the team's work highlights both the opportunities and the perils of social reinvention in the face of a severe environmental crisis.

Next, we take a look at a pivotal change in human history: the replacement of hunter-gatherer lifestyles with agriculture.  The initial stage of this Neolithic transition in Europe was the migration of farmers up the Danube River valley from Anatolia and the Aegean basin.  

As reported by Phys.org, scientists have long debated whether this shift happened as farming communities shared their knowledge, or via gradual interbreeding between populations as the farmers migrated.  Detailing their work in Science Advances, researchers assessed how population dynamics between indigenous European hunter-gatherers and incoming farmers varied across space and time.  

A team from the University of Geneva, in collaboration with the University of Fribourg and Johannes Gutenberg University in Mainz, captured the dynamics of the inter-population interaction by running computer simulations that modeled the Neolithic expansion.  To build these simulations, they included geographic positions, interaction variables including genetic admixture rates and potential competition, and biological parameters from migration patterns to reproduction rates.  

Once they had generated thousands of genetic scenarios, they held up their results against high quality genetic data from 67 prehistoric individuals who had lived in those regions. 

According to Alexandros Tsoupas, first author of the study, the Neolithic transition was the result of prolonged coexistence that led to increasing levels of interbreeding, rather than violent confrontation or complete replacement.   

Based on their analysis, population mixing increased locally over time, at each stage of the farmers' advance along the Danube route toward Central Europe.  Their findings also indicate that the two cultures coexisted for several generations before the hunter-gatherer lifestyle was fully replaced.  They also estimated that the early farmers in the region had a distinct demographic advantage—their population was roughly five times larger than that of the hunter-gatherers. 

These findings bring a nuanced viewpoint to a longstanding debate: the Neolithization of Europe was not a simple colonization, but a complex process involving contact, cohabitation and gradually increasing population mingling.  The study also highlights the power of combining ancient genetics with cutting-edge modeling approaches to reconstruct key chapters in human history.

We now make our way to the Americas, where a team of scientists has demonstrated that the first individuals to arrive in the Western Hemisphere carried DNA from two extinct Eurasian groups:, the Neanderthals and the Denisovans.  This genetic relic may have helped them fight diseases in their new environment.

As reported by Live Science, a group led by the University of Colorado Boulder has proposed in the journal Science that these early indigenous Americans did not have to wait for new genetic mutations to develop in order to fight off new pathogens. 

Researchers also detailed their analysis of MUC19, a protein-coding gene whose functions include coding for the consistency of mucus.  They found that one in three living Mexicans has an MUC19 gene similar to that of Denisovans, a group of ancient humans who lived throughout Asia from about 200,000 to 30,000 years ago.  

Previous studies have found that the gene became more common over time in indigenous populations because it was adaptively advantageous.  The new study also showed that the actual length of the Denisovian MUC19 gene has increased over time.  

To explore whether this variant had a biological advantage, researchers analyzed genetic data from people of Mexican, Peruvian, Colombian, and Puerto Rican descent, as well as sequences from 23 ancient Indigenous Americans, three Neanderthals, and one Denisovan.  Modern DNA came from the 1000 Genomes Project, while ancient samples dated back to times before the 13th century.

The Denisovan-linked MUC19 variant appeared in roughly 33% of Mexicans, 20% of Peruvians, and only about 1% of Colombians and Puerto Ricans.  Researchers believe this pattern reflects varying levels of Indigenous American ancestry, which is highest on average in people of Mexican descent.

Genes like MUC19 offer a record of a stunning adaptation: Indigenous Americans went from a common ancestor living around the Bering Strait to adapting biologically and culturally to a new continent with the world’s complete range of biomes.

The team described the gene’s structure as resembling a sandwich, with Denisovan DNA nestled between Neanderthal segments.  This marks the first time scientists have found a Denisovan gene that "hitched a ride" to modern humans via Neanderthals.  According to study co-author Fernando Villanea, a population geneticist at the University of Colorado Boulder, whether this is the only instance of this happening is a question archaeologists and geneticists are still trying to answer. 

Finally, we make our way to Britain where a new analysis of a 5,000-year-old cow's tooth is providing support for a longstanding hypothesis regarding the creation of Stonehenge.  

As reported by Greekreporter.com, the findings of this study point to the use of cattle for transporting the enormous bluestone megaliths used to build the Wiltshire site.  

The research team, composed of scientists from the British Geological Survey, Cardiff University and University College London, conducted an isotope analysis on a third molar tooth from a cow’s jawbone that was recovered at Stonehenge in 1924.  The jawbone had been carefully placed beside the ancient monument's south entrance.  It dates back to the monument's very beginning in 2995 to 2900 BC and was placed in a ritually significant position.

The team worked to glean clues about the animal’s diet, environment and movement. The isotope analysis showed that the animal had grazed in an area of Paleozoic rock typical of the area where the bluestones originated.  These results confirmed the link between Stonehenge and two quarries in Wales, believed to be the sources of the Wiltshire landmark’s legendary standing bluestones.  This connection was first identified by archaeologists and geologists a decade ago, when the bluestones were geologically matched to two quarries in the Preseli Hills.

This marks the first time scientists have seen evidence linking cattle remains from Stonehenge to Wales, adding further weight to proposals that cows were used to transport the enormous rocks across the country.  The study also offers the first new piece of evidence since research from 2018 that the boulders were taken to the ancient site with the help of cattle, rather than being dragged there by humans.

While an early idea that glaciers moved the stones 500,000 years ago has largely been dismissed, disagreement remains over whether they were dragged cross-country by sledges or transported over sea and river using rafts.  This latest evidence seems to weigh in on the side of the sledges.

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! Also, be sure to check out our growing subscription platform, Heritage Broadcasting Service, at heritagetac.org!

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