Bronze Age Iberia received fewer steppe invaders than the rest of Europe

The genomes of individuals who lived on the Iberian Peninsula in the Bronze Age had minor genetic input from Steppe invaders, suggesting that these migrations played a smaller role in the genetic makeup and culture of Iberian people, compared to other parts of Europe. Daniel Bradley and Rui Martiniano of Trinity College Dublin, in Ireland, and Ana Maria Silva of University of Coimbra, Portugal, report these findings July 27, 2017 in PLOS Genetics.

Between the Middle Neolithic (4200-3500 BC) and the Middle Bronze Age (1740-1430 BC), Central and Northern Europe received a massive influx of people from the Steppe regions of Eastern Europe and Asia. Archaeological digs in Iberia have uncovered changes in culture and funeral rituals during this time, but no one had looked at the genetic impact of these migrations in this part of Europe.

Researchers sequenced the genomes of 14 individuals who lived in Portugal during the Neolithic and Bronze Ages and compared them to other ancient and modern genomes. In contrast with other parts of Europe, they detected only subtle genetic changes between the Portuguese Neolithic and Bronze Age samples resulting from small-scale migration. However, these changes are more pronounced on the paternal lineage.

"It was surprising to observe such a striking Y chromosome discontinuity between the Neolithic and the Bronze Age, such as would be consistent with a predominantly male-mediated genetic influx" says first author Rui Martiniano. Researchers also estimated height from the samples, based on relevant DNA sequences, and found that genetic input from Neolithic migrants decreased the height of Europeans, which subsequently increased steadily through later generations.

The study finds that migration into the Iberian Peninsula occurred on a much smaller scale compared to the Steppe invasions in Northern, Central and Northwestern Europe, which likely has implications for the spread of language, culture and technology. These findings may provide an explanation for why Iberia harbors a pre-Indo-European language, called Euskera, spoken in the Basque region along the border of Spain and France. It has been suggested that Indo-European spread with migrations through Europe from the Steppe heartland; a model that fits these results.

Daniel Bradley says "Unlike further north, a mix of earlier tongues and Indo-European languages persist until the dawn of Iberian history, a pattern that resonates with the real but limited influx of migrants around the Bronze Age."

Present-day Lebanese descend from Biblical Canaanites

Scientists sequenced the genomes of 4,000-year-old Canaanite individuals and compared these to other ancient and present-day populations

Thousands of years ago, the Canaanite people lived in a part of the world we now recognize as Israel, Palestine, Lebanon, Syria, and Jordan, establishing a culture that became influential in the Middle East and beyond. The Canaanites created the first alphabet, established colonies throughout the Mediterranean, and were mentioned many times in the Bible. But who were they and what ultimately happened to them? Were they annihilated like the Bible says?

Now, researchers who've sequenced the first ancient Canaanite genomes along with genomes representing people from modern-day Lebanon have new information to help answer those questions. DNA evidence reported in the American Journal of Human Genetics on July 27 shows that the Canaanites did not just disappear. Instead, they survived and are the ancestors of the people now living in modern-day Lebanon.

"We found that the Canaanites were a mixture of local people who settled in farming villages during the Neolithic period and eastern migrants who arrived in the region about 5,000 years ago," said Marc Haber (@MarcHaber) of The Wellcome Trust Sanger Institute in the United Kingdom. "The present-day Lebanese are likely to be direct descendants of the Canaanites, but they have in addition a small proportion of Eurasian ancestry that may have arrived via conquests by distant populations such as the Assyrians, Persians, or Macedonians."

Marc Haber, Chris Tyler-Smith, and colleagues came to that conclusion after sequencing the complete genomes of five Canaanite individuals who lived almost 4,000 years ago in what's now the modern-day Lebanese city of Sidon. They also sequenced the genomes of 99 present-day Lebanese. Those sequences enabled the researchers to analyze the Canaanites' ancestry and assess their relationship to the people living in Lebanon today.

The researchers estimate that new Eurasian people mixed with the Canaanite population about 3,800 to 2,200 years ago at a time when there were many conquests of the region from outside. Despite all that moving around, the Lebanese derive most of their ancestry from a Canaanite-related population, they report, suggesting that there's been substantial genetic continuity in the region since at least the Bronze Age--a conclusion that agrees with the archaeological record.

"In light of the enormously complex history of this region in the last few millennia, it was quite surprising that over 90 percent of the genetic ancestry of present-day Lebanese was derived from the Canaanites," Tyler-Smith said.

The findings highlight the utility of genetic studies for elucidating the history of people like the Canaanites, who left few written records themselves. The researchers say they would now like to understand the earlier and later genetic history of Lebanon and how it relates to the surrounding regions.

 

In the most recent whole-genome study of ancient remains from the Near East, Wellcome Trust Sanger Institute scientists and their collaborators sequenced the entire genomes of 4,000-year-old Canaanite individuals who inhabited the region during the Bronze Age, and compared these to other ancient and present-day populations. The results, published today (27 July) in the American Journal of Human Genetics suggest that present-day Lebanese are direct descendants of the ancient Canaanites.

The Near East is often described as the cradle of civilisation. The Bronze Age Canaanites, later known as the Phoenicians, introduced many aspects of society that we know today - they created the first alphabet, established colonies throughout the Mediterranean and were mentioned several times in the Bible.

However, historical records of the Canaanites are limited. They were mentioned in ancient Greek and Egyptian texts, and the Bible which reports widespread destruction of Canaanite settlements and annihilation of the communities. Experts have long debated who the Canaanites were genetically, what happened to them, who their ancestors were and if they had any descendants today.

In the first study of its kind, scientists have uncovered the genetics of the Canaanite people and a firm link with people living in Lebanon today. The team discovered that more than 90 per cent of present-day Lebanese ancestry is likely to be from the Canaanites, with an additional small proportion of ancestry coming from a different Eurasian population. Researchers estimate that new Eurasian people mixed with the Canaanite population about 2,200 to 3,800 years ago at a time when there were many conquests of the region from outside.

The analysis of ancient DNA also revealed that the Canaanites themselves were a mixture of local people who settled in farming villages during the Neolithic period and eastern migrants who arrived in the area around 5,000 years ago.

In the study, researchers sequenced whole genomes of five Canaanite individuals who lived 4,000 years ago in a city known as Sidon in present-day Lebanon. Scientists also sequenced the genomes of 99 present-day Lebanese and analysed the genetic relationship between the ancient Canaanites and modern Lebanese.

Dr Marc Haber, first author from the Wellcome Trust Sanger Institute, said: "It was a pleasant surprise to be able to extract and analyse DNA from 4,000-year-old human remains found in a hot environment, which is not known for preserving DNA well. We overcame this challenge by taking samples from the petrous bone in the skull, which is a very tough bone with a high density of ancient DNA. This method of extraction combined with the lowering costs of whole genome sequencing made this study possible."

Dr Claude Doumet-Serhal, co-author and Director of the Sidon excavation site* in Lebanon, said: "For the first time we have genetic evidence for substantial continuity in the region, from the Bronze Age Canaanite population through to the present day. These results agree with the continuity seen by archaeologists. Collaborations between archaeologists and geneticists greatly enrich both fields of study and can answer questions about ancestry in ways that experts in neither field can answer alone."

Dr Chris Tyler-Smith, lead author from the Wellcome Trust Sanger Institute, said: "Genetic studies using ancient DNA can expand our understanding of history, and answer questions about the likely origins and descendants of enigmatic populations like the Canaanites, who left few written records themselves. Now we would like to investigate the earlier and later genetic history of the Near East, and how it relates to the surrounding regions."

The dynamics of prehistoric social networks in the Balkans

 

 

In the first ever archaeological study of its kind, two researchers have combined the chemical analyses of dozens of the world's earliest copper artefacts and modularity approach in order to identify prehistoric networks of co-operation during the early development of European metalmaking. This study has led them one step further: the communities that co-operated the most largely belonged to the same archaeological culture, thus revealing a novel method for an independent evaluation of the archaeological record.

Archaeological systematics, particularly in prehistory, use the accumulation of similar material traits or dwelling forms in archaeological sites to designate distinctive 'archaeological cultures'; however, what these expressions of similarity represent and at what resolution remain a major problem in the field of archaeology.

The study, published this week in the Journal of Complex Networks, takes an alternative approach by measuring the strength of links between archaeological sites instead and produces pioneering models of human interaction and cooperation that can be evaluated independently of established archaeological systematics. It focuses on a comprehensive archaeological database of copper artefacts from the Balkans, dated from c. 6200 BC to 3200 BC -- the first 3,000 years of known copper mineral and metal use in Europe.

Chemical composition of these artefacts is the sole information used for modularity analysis, hence isolated from any archaeological and spatiotemporal information. The results are, however, archaeologically and spatiotemporally meaningful for the evolution of the world's earliest copper supply network.

Dr Jelena Gruji?, physicist from the Vrije University in Brussels, explains the novelty of this method for archaeological research: "Although there are a few approaches that archaeologists use to infer models of circulation of metals in the past, and hence indicate prehistoric economic and social ties, the modularity analysis offers for the first time an option to test the significance of our results, and hence a method that is mathematically reliable and replicable".

Dr Miljana Radivojevi?, lead author and researcher at the McDonald Institute for Archaeological Research, University of Cambridge commented, "Being able to infer social groups with strong spatial and temporal significance in archaeological data using this network property is a real game changer. This study is major step towards evaluating technological, economic and social phenomena in the human past - anywhere".

Evidence of Babylonian Destruction of Jerusalem Found at the City of David

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Evidence of the destruction of Jerusalem at the hands of the Babylonians is currently being unearthed in the City of David in excavations conducted by the Israel Antiquities Authority at the Jerusalem Walls National Park, funded by the City of David Foundation (Elad). In the excavations – concentrated on the eastern slope of the City of David, dwelling places 2,500 years old, once covered by a rockslide, have been revealed. Nestled within the rockslide many findings have surfaced: charred wood, grape seeds, pottery, fish scales and bones, and unique, rare artifacts. These findings depict the affluence and character of Jerusalem, capital of the Judean Kingdom, and are mesmerizing proof of the city's demise at the hands of the Babylonians. 

Among the excavation's salient findings were dozens of jugs which served to store both grain and liquids, a stamp seal appearing on some of them. Furthermore, one of the seals discovered was that of a rosette, a six-petal rose. 

According to Ortal Chalaf and Dr. Joe Uziel, Israel Antiquities Authority excavation directors: "These seals are characteristic of the end of the First Temple Period and were used for the administrative system that developed towards the end of the Judean dynasty. Classifying objects facilitated controlling, overseeing, collecting, marketing and storing crop yields. The rosette, in essence, replaced the 'For the King' seal used by the previous administrative system."

The wealth of the Judean kingdom's capital is also manifest in the ornamental artifacts surfacing in situ. One distinct and rare finding is a small ivory statue of a woman. The figure is naked, and her haircut or wig is Egyptian in style. The quality of its carving is high, and it attests to the high caliber of the artifacts' artistic level and the skill par excellence of the artists during this era. 

According to Ortal Chalaf and Dr. Joe Uziel, Israel Antiquities Authority excavation managers, "The excavation's findings unequivocally show that Jerusalem had spread outside of the city walls before its destruction. A row of structures currently under excavation appears beyond the city wall that constituted the eastern border of the city during this period. Throughout the Iron Age, Jerusalem underwent constant growth, expressed both in the construction of the city wall and the fact that the city later spread beyond it. Excavations carried out in the past in the area of the Jewish Quarter have shown how the growth of the community at the end of the 8^th Century BCE caused the annexation of the western area of Jerusalem. In the current excavation, we may suggest that following the westward expansion of the city, structures were built outside of the wall’s border on the east as well."

Impressive 2,700-Year-Old Water System Discovered Near Rosh Ha-Ayin

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An impressively large 2,700-year-old water system was recently exposed at Israel Antiquities Authority excavations near Rosh Ha-Ayin with the help of students majoring in the Education Ministry’s Land of Israel and Archaeology studies. The excavation precedes the construction of a new residential neighborhood initiated by the Ministry of Construction and Housing.

According to Gilad Itach, director of excavations for the IAA, “It is difficult not to be impressed by the sight of the immense underground reservoir quarried out so many years ago. In antiquity, rainwater collection and storage was a fundamental necessity. With an annual rainfall of 500 mm, the region’s winter rains would easily have filled the huge reservoir. On its walls, near the entrance, we identified engravings of human figures, crosses, and a vegetal motif that were probably carved by passersby in a later period. Overall, we identified seven figures measuring 15–30 cm. Most have outstretched arms and a few appear to be holding some kind of object.”

The water system exposed is nearly 20 m long and reaches a depth of over 4 m. The excavations reveal that the reservoir was built beneath a large structure with walls that are all nearly 50 m long. Some of the potsherds found on the floors of the rooms probably belonged to vessels used to draw water from the reservoir. It is highly likely that the structure and the reservoir were built at the end of the Iron Age (late eighth or early seventh century BCE), but whereas the building was abandoned during the Persian period the reservoir was still in use until modern times.

In recent years, a number of other farmsteads built at the end of the First Temple period have been discovered near Rosh Ha-Ayin. They were probably erected after the destruction of the Kingdom of Israel in 720 BCE, when the Assyrian empire dominated the region. The establishment of farmhouses in this area is interesting, given the fact that many regions within the decimated Kingdom of Israel remained desolate. Some scholars believe that the establishment of the farmsteads was motivated by the empire’s wish to settle the area, which lay on an international route and near the western border of the Assyrian empire. According to Itach, “The structure exposed in this excavation is different from most of the previously discovered farmsteads. Its orderly plan, vast area, strong walls, and the impressive water reservoir hewn beneath it suggest that the site was administrative in nature and it may well have controlled the surrounding farmsteads.”

High-school students majoring in the Education Ministry’s Land of Israel and Archaeology track participated in the Rosh Ha-Ayin excavations as part of the Ministry and the IAA’s new educational program, which is designed to connect students with the past and train the archaeologists of tomorrow. Students opting for this track as part of their chosen matriculation assessment join an excavation for a week. They experience the various tasks involved in the excavation, discuss the research questions and archaeological considerations, and document the dig in the excavation journal as part of their research work.

Numerous pieces of jewelry, cooking artifacts found in Crusader fortress

So just how did 900-year-old rings, bracelets, earrings and hairpins come to be in the kitchen of a Crusader fortress tower in Modiin?

Tittora Hill is a unique and fascinating archaeological site within the municipal boundaries of Modi?in-Maccabim-Re?ut. Previous archaeological excavations on the hill have revealed evidence of its occupation from the Chalcolithic period (c. 6,000 years ago) up to the modern era. The hill is in a strategic location – on the main ascent route from the coastal plain to Jerusalem – and is surrounded by fertile valleys that were used as farmland and were able to support the hill’s inhabitants throughout the generations.

According to Avraham Tendler, excavation director for the Israel Antiquities Authority, “The students and volunteers from Modi?in have exposed the inner courtyard of the Crusader fortress. Here, the fortress’s occupants cooked and baked for hundreds of years during the Middle Ages, some 900 years ago. Ancient clay ovens (tabuns), cooking pots, jars, serving dishes, and a table were discovered in the ancient kitchen, as well as numerous remains of food such as olive pits, pulses, charred grape pips, and animal bones. It seems that the cooks of the time were not sufficiently careful with the jewelry they wore while cooking and baking, since numerous pieces of jewelry have been found in the excavation, some made of bronze and silver.” 

Most of the jewelry has been found by volunteer archaeologist Mati Yohananoff, who is a regular participant in the excavation. “Throughout the entire site, we have found many metal objects including coins, rings, bracelets and cosmetic tools,” he said. “These finds indicate the kind of activity traditionally associated with women’s domestic work.” Long-standing residents of the town coming to excavate with other volunteers are exploring the foundations of the fortress and skillfully exposing a large building from the Roman period hidden beneath the Crusader fortress.

Evidence of the Last Battle for Jerusalem from 2,000 Years Ago

The Israel Antiquities Authority has unveiled evidence from 2,000 year ago of the battle of Jerusalem on the eve of the destruction of the Second Temple, at the City of David in the Jerusalem Walls National Park. Arrowheads and stone ballista balls were discovered on the main street that ascended from the city’s gates and the Pool of Siloam to the Temple, which was excavated in recent years with funding provided by the City of David Society (Elad).

These finds tell the story of the last battle between the Roman forces and the Jewish rebels who had barricaded themselves in the city, a battle that resulted in the destruction of Jerusalem. This battle is described by the historian Flavius Josephus: "On the following day the Romans, having routed the brigands from the town, set the whole on fire as far as Siloam" (Josephus, Wars, Book 6:363)

According to Nahshon Szanton and Moran Hagbi, the directors of the excavation on the stepped-street on behalf of the Israel Antiquities Authority, “Josephus’ descriptions of the battle in the lower city come face-to-face for the first time with evidence that was revealed in the field in a clear and chilling manner. Stone ballista balls fired by catapults used to bombard Jerusalem during the Roman siege of the city, were discovered in the excavations. Arrowheads, used by the Jewish rebels in the hard-fought battles agains the Roman legionnaires were found exactly as described by Josephus."

So far, a section of the road c. 100 m long and 7.5 m wide, paved with large stone slabs as was customary in monumental construction throughout the Roman Empire, has been exposed in the excavations. The archeological excavations on the street utilize a combination of advanced and pioneering research methods, the results of which so far strengthen the understanding that Herod the Great was not solely responsible for the large construction projects of Jerusalem at the end of the Second Temple period.

Recent research indicates that the street was built after Herod’s reign, under the auspices of the Roman procurators of Jerusalem, and perhaps even during the tenure of the Roman governor Pontius Pilate, who is also known for having sentenced Jesus to death by crucifixion.

According to the exacvation's directors,  Szanton and Hagbi, , "This conclusion in fact sheds new light on the history of Jerusalem in the late Second Temple Period, and reinforces recognition of the importance of the Roman procurators’ rule in shaping the character of Jerusalem".

 “Two thousand years after the destruction of Jerusalem and fifty years since its liberation”, the archaeologists added, “we are going back to the water cisterns, the market and the city square on the eve of its destruction. Naomi Shemer certainly never dreamed of re-discovering Jerusalem in the days of the Second Temple”.

 According to Dr. Yuval Baruch, the Jerusalem region archaeologist for the Israel Antiquities Authority, "We intend to uncover the entire length and width of the street within five years, and thereby complete the excavation of this unique site which had already drawn the attention of archaeologists from around the world about one hundred years ago. In fact, one can consider the current excavations in the City of David a natural continuation of the previous archaeological excavations of the site, which were begun in the past by European and American scholars.

About four years ago archeological excavations were renewed along the street, this time in order to expose its full length and width”. Baruch added, “When the excavations are completed, the remains of the street will be conserved and developed and made ready to receive the tens of thousands of visitors who will walk along it”.

In recognizing the importance of the site and the finds, IAA researchers chose to utilize advanced cutting-edge research methods from the fields of natural science, biology and geology in their excavations. A combination of these advanced techniques makes the excavation of the stepped-street in the City of David exceptional in its scientific quality and importance in the development of archaeological research in Jerusalem and Israel in general, and they enable researchers to address questions that have not yet been studied.

The current excavations also focus on exposing the area adjacent to the street, and the shops that were alongside it. Finds revealed in the excavations will allow researchers to answer such intriguing questions as: What did the main street that led to the Temple look like? What was the urban nature of the Lower City that extended on either side of the magnificent road? What did they eat in Jerusalem during the difficult siege, etc.? In order to answer these questions, a multidisciplinary study is being conducted, as well as careful wet sifting at the sifting site in the Zurim Valley National Park, where even the smallest finds are collected.

 It seems that it will not be long before it will be possible for the first time to walk along one of the main streets of ancient Jerusalem, to see how it looked, and receive answers to fascinating historical questions that have been asked for 100 years relating to the history of Jerusalem from the time of the Second Temple, at the height of its splendor, and from the moments of its destruction.

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A Rare Stone Slab c. 9,000 Years Old was Exposed that was used to Ignite Fire

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An exceptional find uncovered about a week ago demonstrates how to start a fire in the field without matches or a lighter. A rare stone slab that was apparently used by the country’s ancient inhabitants for lighting fire nine thousand years ago was exposed in an archaeological excavation of the Israel Antiquities Authority, in which students of the Hannaton pre-military preparatory program participated. The excavations are taking place at the junction of Highway 38 and Virginia Boulevard in Ramat Bet Shemesh as part of an upgrade and expansion project funded by Netivei Israel, and they attest to the existence of advanced technology for igniting fire.

According to prehistorian Anna Eirikh-Rose, excavation director on behalf of the Israel Antiquities Authority, "The ancient people who lived here during the Pre-pottery Neolithic B period (the New Stone Age) prepared a thick limestone slab with two depressions in it and grooves between them that connected the hollows. Some think this is an ancient game board but according to researchers at the Hebrew University of Jerusalem, such slabs were used for starting fire: this device made it possible to rapidly rotate a wooden branch in the hollow (similar to a drill). The rotational energy was translated into heat, and when it came in contact with a flammable material placed inside the hollow, it began to burn and the fire was lit. There are only about ten similar slabs from this period in the National Treasures; thus it is a rare artifact. Additional finds uncovered in the excavation include a fragment of a bracelet, flint tools, and numerous animal bones”.

 The Ackerstein Company, which is managing the Highway 38 project on behalf of Netivei Israel, said, “It is exciting every time a rare piece of history is found thanks to the innovative infrastructure work that Netivei Israel is implementing in building the country”.

 Evidence of producing fire in the region, in the form of ash and charcoal, already exists from the Old Stone Age – about 800,000 years ago; burnt seeds and flint chips were exposed at Gesher Bnot Ya?akov in the north of the country. The use of fire became significantly more important some 10,000 years ago, during the Neolithic period. Evidence of this is reflected by various finds from the period that are related to different fire-generating technologies.

Neanderthal-derived gene variants contribute to modern mentadisorders

Researchers at the National Institute of Mental Health (NIMH) have produced the first direct evidence that parts of our brains implicated in mental disorders may be shaped by a "residual echo" from our ancient past. The more a person's genome carries genetic vestiges of Neanderthals, the more certain parts of his or her brain and skull resemble those of humans' evolutionary cousins that went extinct 40,000 years ago, says NIMH's Karen Berman, M.D. NIMH is part of the National Institutes of Health.

In particular, the parts of our brains that enable us to use tools and visualize and locate objects owe some of their lineage to Neanderthal-derived gene variants that are part of our genomes and affect the shape of those structures -- to the extent that an individual harbors the ancient variants. But this may involve trade-offs with our social brain. The evidence from MRI scans suggests that such Neanderthal-derived genetic variation may affect the way our brains work today -- and may hold clues to understanding deficits seen in schizophrenia and autism-related disorders, say the researchers.

Dr. Berman, Michael Gregory, M.D., of the NIMH Section on Integrative Neuroimaging, and colleagues, report on their magnetic resonance imaging (MRI) study published online, July 24, 2017 in the journal Scientific Reports.

During their primordial migration out of Africa, ancestors of present-day humans are thought to have interbred with Neanderthals, whose brain characteristics can be inferred from their fossilized skulls. For example, these indicate that Neanderthals had more prominent visual systems than modern humans.

"It's been proposed that Neanderthals depended on visual-spatial abilities and toolmaking, for survival, more so than on the social affiliation and group activities that typify the success of modern humans -- and that Neanderthal brains evolved to preferentially support these visuospatial functions," Berman explained. "Now we have direct neuroimaging evidence that such trade-offs may still be operative in our brains."

Might some of us, more than others, harbor Neanderthal-derived gene variants that may bias our brains toward trading sociability for visuospatial prowess -- or vice versa? The new study adds support to this possibility by showing how these gene variants influence the structure of brain regions underlying those abilities.

To test this possibility, Gregory and Berman measured the impact of Neanderthal variants on MRI measures of brain structure in a sample of 221 participants of European ancestry, drawn from the NIMH Genetic Study of Schizophrenia.

The new MRI evidence points to a a gene variant shared by modern-day humans and Neanderthals that is likely involved in development of the brain's visual system. Similarly, Neanderthal variants impacting development of a particular suspect brain area may help to inform cognitive disability seen in certain brain disorders, say the researchers.

Isotopes in prehistoric cattle teeth suggest herding strategies used during the Neolithic

Analysis of strontium isotopes in teeth from Neolithic cattle suggest that early Europeans used different specialized herding strategies, according to a study published July 26, 2017 in the open-access journal PLOS ONE by Claudia Gerling from University of Basel, Basel, Switzerland, and colleagues.

Over the course of the Neolithic, secondary products from cattle such as milk, manure and animal power became more important. This led to larger herds, and the increased demand for grazing resources could have led to herding strategies that took advantage of grazing grounds away from the permanent settlement. However, until now there was little direct evidence for prehistoric cattle mobility.

To reconstruct cattle mobility and infer herding management, the researchers analyzed strontium isotopes in 39 molars from 25 cattle in a Neolithic settlement in what is now Switzerland. The settlement, which was occupied for 15 years, had 27 houses and the teeth could be assigned to 12 of them. Strontium signatures reflect local soil and plants, and can vary over relatively short distances.

The researchers found that the cattle molars had three strontium patterns, which likely reflected different herding strategies. The first pattern was consistent with the local strontium baseline, suggesting local cattle herding; the second pattern was a mix of local and non-local strontium signatures, suggesting seasonal movement; and the third was mostly non-local strontium signatures, suggesting year-round herding away from the site.

In addition, the researchers found that these three herding strategies were not uniformly represented in various areas of the settlement. This suggests differential access to the most favorable grazing grounds, which could have contributed to social inequalities between groups or households.

Consequently, say the researchers, the increasing importance of cattle may have been a starting point for the socioeconomic differentiation that later became widespread during the European Bronze Age.

Archaeologists find key to tracking ancient wheat in frozen Bronze Age box

A Bronze Age wooden container found in an ice patch at 2,650m in the Swiss Alps could help archaeologists shed new light on the spread and exploitation of cereal grains following a chance discovery.

The team of archaeologists were expecting to find a milk residue left behind in the container -- perhaps from a porridge-type meal wolfed down by a hunter or herder making their way through a snowy Alpine pass.

But instead they discovered lipid-based biomarkers for whole wheat or rye grain, called alkylresorcinols.

The team say the discovery of these biomarkers in the residue could be used as a new tool to help archaeologists map and trace the development of early farming in Eurasia.

The domestication of plants, such as wheat, was one of the most significant cultural and evolutionary steps of our species, but direct evidence of their use in early culinary practices and economies has remained frustratingly elusive.

Plants quickly degrade in archaeological deposits therefore archaeologists are increasingly using molecular techniques to look for their remains.

Dr André Colonese, from BioArCh, Department of Archaeology, University of York, said : "We didn't find any evidence of milk, but we found these phenolic lipids, which have never been reported before in an archaeological artefact, but are abundant in the bran of wheat and rye cereals and considered biomarkers of wholegrain intake in nutritional studies."

"This is an extraordinary discovery if you consider that of all domesticated plants, wheat is the most widely grown crop in the world and the most important food grain source for humans, lying at the core of many contemporary culinary traditions.

"One of the greatest challenges of lipid analysis in archaeology has been finding biomarkers for plants, there are only a few and they do not preserve very well in ancient artefacts. You can imagine the relevance of this study as we have now a new tool for tracking early culinary use of cereal grains, it really is very exciting. The next step is to look for them in ceramic artefacts," Dr Colonese added.

The team combined microscopic and molecular analyses to identify lipids and proteins using gas chromatography mass spectrometry, a technique routinely applied to ceramic artefacts. Over the last 30 years, thousands of ceramic artefacts from Europe have been analyzed for their molecular content, most revealing evidence of milk and meat products, but hardly any evidence of cereals.

Dr Jessica Hendy, from the Max Planck Institute for the Science of Human History, said: "The evidence of cereals came from the detection of lipids, but also from preserved proteins. This analysis was able to tell us that this vessel contained not just one, but two types of cereal grains -- wheat and barley or rye grains.

Combining these two kinds of molecular analysis, along with microscopy, is strong evidence that cereals were being transported across this alpine pass."

"Detecting a molecular marker for cereals also has widespread implications for studying early farming. It enables us to piece together when and where this important food crop spread through Europe," Dr Hendy added.

Dr Francesco Carrer, from Newcastle University, said: "This evidence sheds new light on life in prehistoric alpine communities, and on their relationship with the extreme high altitudes. People travelling across the alpine passes were carrying food for their journey, like current hikers do. This new research contributed to understanding which food they considered the most suitable for their trips across the Alps."

Cultural flexibility was key for early humans to survive extreme dry periods in southern Africa

The flexibility and ability to adapt to changing climates by employing various cultural innovations allowed communities of early humans to survive through a prolonged period of pronounced aridification.

The early human techno-tradition, known as Howiesons Poort (HP), associated with Homo sapiens who lived in southern Africa about 66 000 to 59 000 years ago indicates that during this period of pronounced aridification they developed cultural innovations that allowed them to significantly enlarge the range of environments they occupied.

This cultural flexibility may have been the key to success for modern humans, says a team of international researchers, made up of archaeologists, paleo climatologists, and climate modellers from the French CNRS1 and the EPHE PSL Research University, Bergen University as well as Wits University. Their research was published in the Proceedings of the National Academy of Sciences.

"The most distinct of the many cultural innovations in the HP culture were the invention of the bow and arrow, different methods of heating raw materials (stone) before knapping to produce arrow heads, engraving ostrich eggshells with elaborate patterns, intensive use of hearths and relatively intense hunting and gathering practices," says Professor Christopher Henshilwood, one of the team members from Wits and Bergen Universities.

Howiesons Poort is a techno-tradition in the Middle Stone Age in Africa named after the Howieson's Poort Shelter archaeological site near Grahamstown in South Africa. It lasted around 5 000 years between roughly 65 800 and 59 500 years ago.

Using paleo climatic data and paleo climatic simulations, the researchers of the current study found that the HP tradition developed during a period of pronounced aridity.

This paleo climatic data and the distribution of archaeological sites associated with the HP, as well of that of the Still Bay tradition, which existed in the same environments about 5 000 years before (76 000 to 71 000 years ago), enabled the researchers to model the emergence of these traditions with two predictive algorithms that permitted them to reconstruct the ecological niche associated with each tradition and determine whether these niches differed significantly through time.

The results clearly indicate that HP populations were capable, despite the pronounced aridity that characterised the period in which they lived, to exploit territories and ecosystems that the preceding Still Bay people did not occupy.

While the Still Bay era is also characterised by highly innovative technologies - including engraving of ochre, use of personal ornaments, manufacture of highly stylised bone tools, heating silcrete (red rock) to produce better material for knapping bifacial points (spear points) using hard hammer and finally pressure flaking technology - the research team points out that HP's ecological niche expansion coincides with the development of technological innovations that were both efficient and more flexible than those of the Still Bay.

"It seems from the little evidence that we have that the population of Homo sapiens in southern Africa was considerably larger during the Howiesons Poort period," says Henshilwood.

"There are many more HP sites than Still Bay sites in southern Africa and their location is widespread across southern Africa. Note that neither the Still Bay or HP is found outside of southern Africa."
Henshilwood says the Still Bay people did not disappear. There just seems to be a gap between 72 000 years ago to 66 000 years ago, where there is almost no evidence of any people in southern Africa.

This study, which documents the oldest known case of an eco-cultural niche expansion, demonstrates that the processes that allowed our species to develop modern behaviours must be examined at regional scales and in conjunction with past climatic data.

About early human development:
The emergence of our species (Homo sapiens) in Africa, at least 260 000 years ago, was not immediately accompanied by the development of behavioural characteristics of more recent prehistoric and historically documented populations. For tens of thousands of years after their emergence (anatomically), modern human populations in Africa continued to use technologies that differed little from those of the non-modern populations that preceded them or that inhabited other regions both inside and outside the African continent.

A number of archaeological discoveries during the past twenty years have shown that from at least 100 000 years ago some populations in Africa, especially those in southern Africa, made pigmented compounds, wore personal ornaments, made abstract engravings, and manufactured bone tools. It is within this period, and those that follow, that archaeologists are able to recognize distinct techno- traditions, to determine with a certain degree of precision their age, and place these time periods within their proper climatic contexts.

Adaptation and cultural diversification found among early North American stone tools

Using new methods to analyze stone projectile points crafted by North America's earliest human inhabitants, Smithsonian scientists have found that these tools show evidence of a shift toward more experimentation in their production beginning about 12,500 years ago, following hundreds of years of consistent stone-tool production created using uniform techniques. The findings provide clues into changes in social interactions during a time when people are thought to have been spreading into new parts of North America and adapting to different environments, beginning a period of cultural diversification.

The research team, led by Sabrina Sholts, a curator in the Department of Anthropology at the Smithsonian's National Museum of Natural History, and Sebastian Wärmländer at Stockholm University, used digital 3-D models to scrutinize the angles and contours on the surfaces of North American projectile points. In doing so, they discovered a turning point at which the techniques used to produce the points became more variable. That variability suggests that individual toolmakers, who may have had fewer opportunities than their predecessors to learn from others, began working out how to make the tools on their own. The findings were reported July 12 in the journal PLOS ONE.
"Our study really allows stone tools to speak in a new way," said Joseph Gingerich, a research associate at the museum and assistant professor of anthropology at Ohio University. "By being able to document subtle changes in stone tool technology, we can better understand how social interactions among artisans changed in North America over 12,000 years ago."

The earliest well-documented group of people in North America, known as Clovis, is recognized by distinctive pointed stone projectiles that appear about 13,500 years ago. These culture-defining tools, called Clovis points, are sharp-edged and symmetrical, with a groove near the base--called a flute--where a spear shaft may have fit. Anthropologists consider them to be a very sophisticated technology.

The highly mobile hunter-gatherers of the Clovis culture spread quickly across North America, and Clovis points have been found all over the continent. In 2012, Sholts and colleagues analyzed 50 authentic and replicate Clovis points, examining how their surfaces had been shaped as flakes of stone were chipped away to craft the tool. Using an approach Sholts and Wärmländer originally developed for studying bones, the researchers laser scanned each point to create a three-dimensional model and then analyzed its contours, measuring and comparing subtle surface features that cannot be discerned by eye. "It's a way to capture all the individual actions to reduce the core, which reflect the technique used to shape it," Sholts said.

The analysis revealed remarkable consistency among the ancient artifacts compared to almost perfect copies made by a modern knapper, an artisan that crafts stone tools using ancient techniques. The team concluded that the manufacturing technique used by the Clovis people was so uniform that it must have been passed on directly from one knapper to another.

According to the archaeological record, Clovis technology was used for several hundred years. A variety of other styles emerged later, though they never spread across the continent like Clovis points did. To learn more about the groups that manufactured these later styles, the authors of the new study analyzed the surface features of 100 projectile points from collections at several museums, including the Smithsonian collection, which is curated by anthropologist Dennis Stanford.


Using new methods to analyze stone projectile points crafted by North America's earliest human inhabitants, Smithsonian scientists have found that these tools show evidence of a shift toward more experimentation in their production beginning about 12,500 years ago, following hundreds of years of consistent stone-tool production created using uniform techniques. The findings provide clues into changes in social interactions during a time when people are thought to have been spreading into new parts of North America and adapting to different environments, beginning a period of cultural diversification.

The new study included Clovis points and samples of four later styles of fluted points, which had been recovered from sites in the eastern United States. The team analyzed the points' surface contours as they had done in the earlier study and also introduced a new method of analyzing digital models to assess the objects' three-dimensional asymmetry.

Using another new technique developed by Wärmländer and co-author Stefan Schlager of the University of Freiburg, the team determined that the overall three-dimensional shapes of the points did not vary significantly. However, they did find increased variability in the surface contours among some of the later styles of points, indicating that those tools had not been produced using a consistent technique.

The increase in variability among the later points suggests a decrease in social learning and possibly a reduction in overall interactions among North American populations beginning around 12,500 years ago, the researchers say. This is consistent with anthropologists' current thinking about how people were living during this time. "There seems to be evidence of increased experimentation during this period, due to groups moving away from each other and pushing into new environments," Sholts said.
"For a long time in North America, the archaeological record shows both consistency in stone tool technology and other aspects of culture," Gingerich said. "In documenting a change in stone tool technology, we likely document the start of greater regional adaptations among some of the first hunter-gatherers in North America."

Advances in Methods and Data Reveal the Broad Patterns of Cultural Evolution

Over the past 10,000 years human cultures have expanded from small groups of hunter-gatherers to colossal and complexly organized societies. The secrets to how and why this major cultural transition occurred have largely remained elusive. In an article published on July 24 by Russell Gray and Joseph Watts in PNAS they outline how advances in computational methods and large cross-cultural datasets are beginning to reveal the broad patterns and processes underlying our cultural histories.

Caption

Powerful new phylogenetic comparative methods can be applied to D-Place, a massive open-access database of places, language, culture and environment, and other databases in order to reconstruct the history of cultures and test theories about major transitions in human history. The map here shows the global distribution of independent vs. extended family living.

Credit

Map taken from https://d-place.org

Ten thousand years ago most humans lived in small, kin based, relatively egalitarian groups. Today we live in colossal nation states with distantly related members, complex hierarchical organization, and huge social inequality. This change in size and structure of human social organization over this time represents a major transition in human's evolutionary history, one that we still know remarkably little about.

To date, most research on cultural evolution focuses on microevolution; changes that occur within cultural groups over relatively short periods of time. However, as Russell Gray, Director of the Department of Linguistic and Cultural Evolution at MPI-SHH points out "processes observed at the micro level do not necessarily explain the macroevolutionary patterns and major transitions we observed in deeper human history."

In a new article by Russell Gray and Joseph Watts in Proceedings of the National Academy of Sciences (PNAS) present a "plea" for research on cultural macroevolution. The authors highlight the exciting potential to combined cutting edge statistical methods and comprehensive cross-cultural database to resolve longstanding debates about the major cultural transitions in human prehistory.

Recent years have seen the growth of large cross-cultural databases that document the features and diversity of human cultures. For example, the database called Lexibank contains data on 2,500 of languages, the Database of Religious History documents hundreds of different religious beliefs and practices, and D-Place documents our means of subsistence, kinship systems and a striking array of marital, sexual, and child-rearing norms. These databases are open access and allow anyone to visualize and download data on the diversity of human cultural systems.

Powerful new phylogenetic comparative methods can be applied to these databases in order to reconstruct the history of cultures and test theories about major transitions in human history. Gray, Watts and colleagues have begun to use these methods to reconstruct the ancestral history of Indo-European languages as well as test the role of Big Gods and human sacrifice in the evolution of large, complex societies. According to Watts "we're entering a new age of research in the humanities, one in which theories about the major transitions in human history are built and tested using powerful computational methods."

New Kingdom Egypt: The goldsmith’s tomb

Ludwig-Maximilians-Universitaet (LMU) in Munich Egyptologist Julia Budka is studying the impact of intercultural contacts in Ancient Egypt. Her excavations in Sudan have uncovered a tomb dating to around 1450 BC on the island of Sai in the Nile.

A previously unknown tomb, some 3400 years old, has recently been uncovered on the island of Sai in the River Nile. It was in use for some time and contains the remains of up to 25 persons. Further analysis of the finds could elucidate the multicultural nature of the island's population during this period.

The island was then located in Nubia, which was the primary source of gold for the New Kingdom of the Egyptian Pharaohs at that time. The tomb was most probably built for a master goldsmith by the name of Khnummose, and was discovered during excavations conducted by Julia Budka, Professor of Egyptian Archaeology and Art. Investigation of the tomb's contents and inscriptions has so far revealed that, following the conquest by the Pharaoh Thutmose III of the local African Kerma kingdom of Kerma, the local elites were rapidly integrated by the new regime. The earliest Egyptian-style burials on Sai date to the reign of this king.

Over the past 5 years, Budka has carried out parallel studies on three different Egyptian settlements that were established during the period of the so-called New Kingdom between 1500 und 1200 BC. The excavations on the island of Sai, which lies in what is now the Sudanese section of the Nile, not only provide insights into the relationship between the official representatives of the occupying power and the local Nubian population, they also demonstrate that the island was inhabited for longer than hitherto assumed.

"It had been thought that the settlement on the island was abandoned after the foundation of a new town at Amara West. Our finds, on the other hand, prove that Hornakht, one of Egypt's highest ranking bureaucrats during the reign of Ramses II, not only had his official residence on the island, but was also buried there," says Budka. This clearly shows that the town on Sai survived until about 1200 BC.

Another early hominin species, not Neanderthals or Denisovans, interbred in Africa.

In saliva, scientists have found hints that a "ghost" species of archaic humans may have contributed genetic material to ancestors of people living in Sub-Saharan Africa today.

The research adds to a growing body of evidence suggesting that sexual rendezvous between different archaic human species may not have been unusual.

Past studies have concluded that the forebears of modern humans in Asia and Europe interbred with other early hominin species, including Neanderthals and Denisovans. The new research is among more recent genetic analyses indicating that ancient Africans also had trysts with other early hominins.

"It seems that interbreeding between different early hominin species is not the exception -- it's the norm," says Omer Gokcumen, PhD, an assistant professor of biological sciences in the University at Buffalo College of Arts and Sciences.

"Our research traced the evolution of an important mucin protein called MUC7 that is found in saliva," he says. "When we looked at the history of the gene that codes for the protein, we see the signature of archaic admixture in modern day Sub-Saharan African populations."

The research was published on July 21 in the journal Molecular Biology and Evolution. The study was led by Gokcumen and Stefan Ruhl, DDS, PhD, a professor of oral biology in UB's School of Dental Medicine.

A tantalizing clue in saliva

The scientists came upon their findings while researching the purpose and origins of the MUC7 protein, which helps give spit its slimy consistency and binds to microbes, potentially helping to rid the body of disease-causing bacteria.

As part of this investigation, the team examined the MUC7 gene in more than 2,500 modern human genomes. The analysis yielded a surprise: A group of genomes from Sub-Saharan Africa had a version of the gene that was wildly different from versions found in other modern humans.

The Sub-Saharan variant was so distinctive that Neanderthal and Denisovan MUC7 genes matched more closely with those of other modern humans than the Sub-Saharan outlier did.

"Based on our analysis, the most plausible explanation for this extreme variation is archaic introgression -- the introduction of genetic material from a 'ghost' species of ancient hominins," Gokcumen says. "This unknown human relative could be a species that has been discovered, such as a subspecies of Homo erectus, or an undiscovered hominin. We call it a 'ghost' species because we don't have the fossils."

Given the rate that genes mutate during the course of evolution, the team calculated that the ancestors of people who carry the Sub-Saharan MUC7 variant interbred with another ancient human species as recently as 150,000 years ago, after the two species' evolutionary path diverged from each other some 1.5 to 2 million years ago.

Why MUC7 matters

The scientists were interested in MUC7 because in a previous study they showed that the protein likely evolved to serve an important purpose in humans.

In some people, the gene that codes for MUC7 holds six copies of genetic instructions that direct the body to build parts of the corresponding protein. In other people, the gene harbors only five sets of these instructions (known as tandem repeats).

Prior studies by other researchers found that the five-copy version of the gene protected against asthma, but Gokcumen and Ruhl did not see this association when they ran a more detailed analysis.

The new study did conclude, however, that MUC7 appears to influence the makeup of the oral microbiome, the collection of bacteria within the mouth. The evidence for this came from an analysis of biological samples from 130 people, which found that different versions of the MUC7 gene were strongly associated with different oral microbiome compositions.

"From what we know of MUC7, it makes sense that people with different versions of the MUC7 gene could have different oral microbiomes," Ruhl says. "The MUC7 protein is thought to enhance the ability of saliva to bind to microbes, an important task that may help prevent disease by clearing unwanted bacteria or other pathogens from the mouth."

Artifacts suggest humans arrived in Australia earlier than thought

When and how the first humans made their way to Australia has been an evolving story.

While it is accepted that humans appeared in Africa some 200,000 years ago, scientists in recent years have placed the approximate date of human settlement in Australia further and further back in time, as part of ongoing questions about the timing, the routes and the means of migration out of Africa.

Now, a team of researchers, including a faculty member and seven students from the University of Washington, has found and dated artifacts in northern Australia that indicate humans arrived there about 65,000 years ago -- more than 10,000 years earlier than previously thought. A paper published July 20 in the journal Nature describes dating techniques and artifact finds at Madjedbebe, a longtime site of archaeological research, that could inform other theories about the emergence of early humans and their coexistence with wildlife on the Australian continent.

The new date makes a difference, co-author and UW associate professor of anthropology Ben Marwick said. Against the backdrop of theories that place humans in Australia anywhere between 47,000 and 60,000 years ago, the concept of earlier settlement calls into question the argument that humans caused the extinction of unique megafauna such as giant kangaroos, wombats and tortoises more than 45,000 years ago.

"Previously it was thought that humans arrived and hunted them out or disturbed their habits, leading to extinction, but these dates confirm that people arrived so far before that they wouldn't be the central cause of the death of megafauna," Marwick said. "It shifts the idea of humans charging into the landscape and killing off the megafauna. It moves toward a vision of humans moving in and coexisting, which is quite a different view of human evolution."

Since 1973, digs at Madjedbebe, a rock shelter in Australia's Northern Territory, have unearthed more than 10,000 stone tools, ochres, plant remains and bones. Following the more recent excavations in 2012 and 2015, a University of Queensland-led research team, which included the UW, evaluated artifacts found in various layers of settlement using radiocarbon dating and optical stimulated luminescence (OSL).

The new research involved extensive cooperation with the local Aboriginal community, Marwick added. The Gundjeihmi Aboriginal Corporation, representing the Mirarr people, joined much of the excavation and reviewed the findings, Marwick said. Researchers had both a memorandum of understanding and a contract with the community, which gave control to the Mirarr as senior custodians, oversight of the excavation and curation of the finds. The Mirarr were interested in supporting new research into the age of the site and in knowing more about the early human occupants, particularly given environmental threats posed by nearby modern-day mining activities.

Noteworthy among the artifacts found were ochre "crayons" and other pigments, what are believed to be the world's oldest edge-ground hatchets, and evidence that these early humans ground seeds and processed plants. The pigments indicate the use of paint for symbolic and artistic expression, while the tools may have been used to cut bark or food from trees.

Labs in Australia used OSL to identify the age range, Marwick explained. Radiocarbon dating, which requires a certain level of carbon in a substance, can analyze organic materials up to about 45,000 or 50,000 years old. But OSL is used on minerals to date, say, the last time a sand grain was exposed to sunlight -- helpful in determining when an artifact was buried -- up to 100,000 years ago or more. That process measured thousands of sand grains individually so as to establish more precise ages.

The UW researchers worked in the geoarchaeology lab on the Seattle campus, testing sediment samples that Marwick helped excavate at Madjedbebe. One graduate student and six undergraduate students studied the properties of hundreds of dirt samples to try to picture the time in which the ancient Australian humans lived.

Using a scanning electron microscope, the students examined the composition of the sediment layers, the size of the grains of dirt and any microscopic plant matter. For another test, the students baked soil samples at various temperatures, then measured the mass of each sample, said UW doctoral student Gayoung Park, another author on the paper. Because organic matter turns into gases at high heat, a loss of mass indicated how much matter was in a given sample. This helped create a picture of the environments across the sedimentary layers of the site. The team found that when these human ancestors arrived, northern Australia was wetter and colder.

"Together, we were working on establishing questions: What kind of environments did these people live in? What was the climate like? Were there any disturbances to the site, and were artifacts mixed up from different ages?" Marwick said. "I'm proud of being able to involve UW students in this research in a really substantial way."

One of the authors, Mara Page, was a senior double-majoring in archaeology and Earth and space sciences when she joined the project. She analyzed stable carbon isotopes found in sediment, which can reveal the types of plants present in the past and the kinds of environments they lived in. She determined that the vegetation at Madjedbebe remained stable during the time of human occupation, which suggests that there was no major environmental change that might have prompted humans to leave the area.

"I feel that I contributed something important by being able to rule something out of the story we were telling," Page explained.

By placing the date of Australian settlement at around 65,000 years ago, researchers confirm some of the shifting theories about when the first humans left Africa. A common view is that humans moved into Asia 80,000 years ago, and if they migrated to Australia some to 15,000 years later, it means those ancestors co-existed with another early human in Asia, Homo florensiensis. It also means that these early Australians preceded early Europeans, who are believed to have entered that continent 45,000 years ago. A related question is whether these early human species left Africa at one time, gradually spreading the population through Asia, Europe and Australia, or whether there were multiple waves of migration.

In recent years, new evidence, obtained through DNA testing of a 90-year-old hair sample of an Aboriginal Australian man, suggests Australia was settled as far back as 70,000 years ago.

Marwick believes the Madjedbebe results, because they rely on so many artifacts and intensive analysis of sediment samples, confirm that early humans occupied Australia at least 65,000 years ago and support the theory that Homo sapiens, the species of modern-day humans, evolved in Africa before dispersing to other continents. The findings also suggest Homo sapiens' predecessors, Neanderthals and Denisovans, overlapped with humans for a long period of time, and suggest a larger role for Australia, and the Eastern Hemisphere in general, in the story of humankind.

Marwick, who advocates for open science, particularly in data collection and the code used to analyze it, noted that the Nature paper is also pushing new frontiers because it combines three strands of reproducibility. Researchers examined a field site that has been excavated in the past; they've made available their raw data and code; and they consulted an outside lab for third-party OSL verification.

DNA of early Neanderthal gives timeline for new modern human-related dispersal from Africa

Ancient mitochondrial DNA from the femur of an archaic European hominin is helping to resolve the complicated relationship between modern humans and Neanderthals. The genetic data recovered by the research team, led by scientists from the Max Planck Institute for the Science of Human History and the University of Tübingen, provides a timeline for a proposed hominin migration out of Africa that occurred after the ancestors of Neanderthals arrived in Europe by a lineage more closely related to modern humans. These hominins interbred with Neanderthals already present in Europe, leaving their mark on the Neanderthals' mitochondrial DNA. The study, published today in Nature Communications, pushes back the possible date of this event to between 470,000 and 220,000 years ago.

Mitochondria are the energy-producing machinery of our cells. These mitochondria have their own DNA, which is separate from our nuclear DNA. Mitochondria are inherited from mother to child and can thus be used to trace maternal lineages and population split times. In fact, changes due to mutations in the mitochondrial DNA over time can be used to distinguish groups and also to estimate the amount of time that has passed since two individuals shared a common ancestor, as these mutations occur at predictable rates.

Complicated relationship between Neanderthals and modern humans

Prior research analyzing nuclear DNA from Neanderthals and modern humans estimated the split of the two groups at approximately 765,000 to 550,000 years ago. However, studies looking at mitochondrial DNA showed a much more recent split of around 400,000 years ago. Moreover, the mitochondrial DNA of Neanderthals is more similar to that of modern humans, and thus indicates a more recent common ancestor, than to that of their close nuclear relatives the Denisovans. There has been debate about the cause of these discrepancies, and it has been proposed that a hominin migration out of Africa might have occurred prior to the major dispersal of modern humans. This human group, more closely related to modern humans than to Neanderthals, could have introduced their mitochondrial DNA to the Neanderthal population in Europe through genetic admixture, as well as contributing a small amount of nuclear DNA to Neanderthals but not to Denisovans as recently detected. However, more data was needed to evaluate the feasibility of this scenario and to define the temporal limits of the proposed event.

The femur of a Neanderthal excavated from the Hohlenstein-Stadel Cave in southwestern Germany provided just such an opportunity. "The bone, which shows evidence of being gnawed on by a large carnivore, provided mitochondrial genetic data that showed it belongs to the Neanderthal branch," explains Cosimo Posth of the Max Planck Institute for the Science of Human History, lead author of the study. Traditional radiocarbon dating did not work to assess the age of the femur, which was instead estimated using the mutation rate as approximately 124,000 years old. This makes this Neanderthal specimen, designated HST by the researchers, among the oldest to have its mitochondrial DNA analyzed to date. Interestingly, it represents a different mitochondrial lineage than the Neanderthals previously studied. The mitochondrial lineage of HST and of all other known Neanderthals separated from each other very deeply in time, at a minimum of 220,000 years ago. The differences between their mitochondrial DNA indicate that there was more mitochondrial genetic diversity in the Neanderthal population than was previously thought. This suggests that the Neanderthal population size once was much bigger than that estimated for the final stage of their existence.

Timeline for additional migration of hominins out of Africa

The proposed scenario is that after the divergence of Neanderthals and modern human mitochondrial DNA (dated to a maximum of 470,000 years ago), but before HST and the other Neanderthals diverged (dated to a minimum of 220,000 years ago), a group of hominins moved from Africa to Europe, introducing their mitochondrial DNA to the Neanderthal population. Thus this intermediate migration out of Africa would have occurred between 470,000 and 220,000 years ago. "Despite the large interval, these dates provide a temporal window for possible hominin connectivity and interaction across the two continents in the past," says Posth.

This influx of hominins would have been small enough that it did not result in a large impact on the Neanderthals' nuclear DNA. However, it would have been large enough to completely replace the existing mitochondrial lineage of Neanderthals, more similar to the Denisovans, with a type more similar to modern humans. "This scenario reconciles the discrepancy in the nuclear DNA and mitochondrial DNA phylogenies of archaic hominins and the inconsistency of the modern human-Neanderthal population split time estimated from nuclear DNA and mitochondrial DNA," explains Johannes Krause, also of the Max Planck Institute for the Science of Human History, senior author of the study.

Nuclear data from the HST femur would be pivotal in assessing its genomic relationships with Neanderthals, Denisovans and modern humans, but it is extremely challenging to retrieve nuclear DNA from HST due to poor preservation and high levels of modern human contamination. In any case, however, high quality nuclear genome data from more than one individual would be necessary to fully investigate this proposed wave of human migration out of Africa, and is an intriguing area for future study.

Breakthrough in dating Viking fortress

In 2014 archaeologists from the Museum of South East Denmark and Aarhus University discovered the previously unknown Viking fortess at Borgring south of Copenhagen. Since then the search has been on to uncover the life, function, destruction and, not least, the precise dating of the Viking fortress. Now a new find has produced a break-through in the investigation.

In the period 2016-18 a programme of new excavations is made possible by a grant from the A.P. Møller Foundation. The team from the Museum of South East Denmark and Aarhus University are joind by leading experts from the Environmental Archeology and Materials Research at the Danish National Museum and the National Police Department's Section for arson investigation. Prior to this year's excavations it was only known that the massive, 150m wide fortress dated to the tenth century. Experts suspected that it was built in the reing of Viking king Harold Bluetooth (c.958-c.987), but the association could not be proven.

The carved oak timber object recently found in peat layers just outside the south gateway of the fortress. The piece has been cut and sampled for dendrochronological sampling (left). The function of the piece is unknown, but it may be a part of a door or building.
CREDIT
The Museum of South East Denmark / Nanna Holm.

On Monday 26 June, the archaeological team opened new trenches is the meadow next to the fortress to search for evidence of the landscape surrounding the fortress. Around 2.5 meters below the current surface of the valley was found a c. 1m long piece of carved oak wood with drilled holes and several wooden pegs in situ. The wood carries clear traces of wear, but it is not currently possible to say what function the wood piece has had.

Leading specialist in dendrochronological dating, Associate Professor Aoife Daly from the University of Copenhagen and the owner of dendro.dk, has just completed his study of the piece of wood and says: "The plank is oak and the conserved part of the tree trunk has grown in the years 829-950 In the Danish area. A comparison with the material from the Trelleborg fortress in Sjælland shows a high statistical correlation that confirms the dating. Since no splints have been preserved, it means that the tree has fallen at some point after year 966 ".

Research leader Jens Ulriksen says: "The wood piece was found on top of a peat layer, and is fully preserved as it is completely water-logged. We now have a date of wood in the valley of Borgring, which corresponds to the dating from the other ring fortresses from Harold Bluetooth's reign. With the dendrochronological dating, in conjunction with the traces of wear the piece has, it is likely that the piece ended as waste in the late 900s, possibly in the early 1000's. "

"In the coming week, the National Museum's environmental archaeologists will take samples of wet depositions in the valley with the aim of uncovering how the layers have evolved from the earliest strata we have dated to the Bronze Age and over time." Says excavation leader Nanna Holm. Nanna Holm, of course, hopes that the studies will particularly clarify one of the unclear questions archaeologists have, namely where the river was exactly when the fortress was built in the Viking Age, and how passable it was.

Søren M. Sindbæk, professor in Archaeology at Aarhus University and part of the excavation team says: "This find is the major break-through, which we have been searching for. We finally have the dating evidence at hand to prove that this is a late tenth century fortress. We lack the exact year, but since the find also shows us where the river flowed in the Viking Age, we also know where to look for more timbers from the fortress."

How seawater strengthens ancient Roman concrete

Around A.D. 79, Roman author Pliny the Elder wrote in his Naturalis Historia that concrete structures in harbors, exposed to the constant assault of the saltwater waves, become "a single stone mass, impregnable to the waves and every day stronger."

He wasn't exaggerating. While modern marine concrete structures crumble within decades, 2,000-year-old Roman piers and breakwaters endure to this day, and are stronger now than when they were first constructed. University of Utah geologist Marie Jackson studies the minerals and microscale structures of Roman concrete as she would a volcanic rock. She and her colleagues have found that seawater filtering through the concrete leads to the growth of interlocking minerals that lend the concrete added cohesion. The results are published today in American Mineralogist.

Roman concrete vs. Portland cement

Romans made concrete by mixing volcanic ash with lime and seawater to make a mortar, and then incorporating into that mortar chunks of volcanic rock, the "aggregate" in the concrete. The combination of ash, water, and quicklime produces what is called a pozzolanic reaction, named after the city of Pozzuoli in the Bay of Naples. The Romans may have gotten the idea for this mixture from naturally cemented volcanic ash deposits called tuff that are common in the area, as Pliny described.

The conglomerate-like concrete was used in many architectural structures, including the Pantheon and Trajan's Markets in Rome. Massive marine structures protected harbors from the open sea and served as extensive anchorages for ships and warehouses.

Modern Portland cement concrete also uses rock aggregate, but with an important difference: the sand and gravel particles are intended to be inert. Any reaction with the cement paste could form gels that expand and crack the concrete.

"This alkali-silica reaction occurs throughout the world and it's one of the main causes of destruction of Portland cement concrete structures," Jackson says.

Rediscovering Roman concrete

Jackson's interest in Roman concrete began with a sabbatical year in Rome. She first studied tuffs and then investigated volcanic ash deposits, soon becoming fascinated with their roles in producing the remarkable durability of Roman concrete.

Along with colleagues, Jackson began studying the factors that made architectural concrete in Rome so resilient. One factor, she says, is that the mineral intergrowths between the aggregate and the mortar prevent cracks from lengthening, while the surfaces of nonreactive aggregates in Portland cement only help cracks propagate farther.

In another study of drill cores of Roman harbor concrete collected by the ROMACONS project in 2002-2009, Jackson and colleagues found an exceptionally rare mineral, aluminous tobermorite (Al-tobermorite) in the marine mortar. The mineral crystals formed in lime particles through pozzolanic reaction at somewhat elevated temperatures. The presence of Al-tobermorite surprised Jackson. "It's very difficult to make," she says of the mineral. Synthesizing it in the laboratory requires high temperatures and results in only small quantities.

Seawater corrosion

For the new study, Jackson and other researchers returned to the ROMACONS drill cores, examining them with a variety of methods, including microdiffraction and microfluorescence analyses at the Advanced Light Source beamline 12.3.2 at Lawrence Berkeley National Laboratory. They found that Al-tobermorite and a related zeolite mineral, phillipsite, formed in pumice particles and pores in the cementing matrix. From previous work, the team knew that the pozzolanic curing process of Roman concrete was short-lived. Something else must have caused the minerals to grow at low temperature long after the concrete had hardened. "No one has produced tobermorite at 20 degrees Celsius," she says. "Oh -- except the Romans!"

"As geologists, we know that rocks change," Jackson says. "Change is a constant for earth materials. So how does change influence the durability of Roman structures?"

The team concluded that when seawater percolated through the concrete in breakwaters and in piers, it dissolved components of the volcanic ash and allowed new minerals to grow from the highly alkaline leached fluids, particularly Al-tobermorite and phillipsite. This Al-tobermorite has silica-rich compositions, similar to crystals that form in volcanic rocks. The crystals have platy shapes that reinforce the cementing matrix. The interlocking plates increase the concrete's resistance to brittle fracture.

Jackson says that this corrosion-like process would normally be a bad thing for modern materials. "We're looking at a system that's contrary to everything one would not want in cement-based concrete," she says. "We're looking at a system that thrives in open chemical exchange with seawater."

Modern Roman concrete

Given the durability advantages of Roman concrete, why isn't it used more often, particularly since manufacturing of Portland cement produces substantial carbon dioxide emissions?

"The recipe was completely lost," Jackson says. She has extensively studied ancient Roman texts, but hasn't yet uncovered the precise methods for mixing the marine mortar, to fully recreate the concrete.

"Romans were fortunate in the type of rock they had to work with," she says. "They observed that volcanic ash grew cements to produce the tuff. We don't have those rocks in a lot of the world, so there would have to be substitutions made."

She is now working with geological engineer Tom Adams to develop a replacement recipe, however, using materials from the western U.S. The seawater in her experiments comes from the Berkeley, California, marina, collected by Jackson herself.

Roman concrete takes time to develop strength from seawater, and features less compressive strength than typical Portland cement. For those reasons, it's unlikely that Roman concrete could become widespread, but could be useful in particular contexts.

Jackson recently weighed in on a proposed tidal lagoon to be built in Swansea, United Kingdom, to harness tidal power. The lagoon, she says, would need to operate for 120 years to recoup the costs incurred to build it. "You can imagine that, with the way we build now, it would be a mass of corroding steel by that time." A Roman concrete prototype, on the other hand, could remain intact for centuries.

Jackson says that while researchers have answered many questions about the mortar of the concrete, the long-term chemical reactions in the aggregate materials remain unexplored. She intends to continue the work of Pliny and other Roman scholars who worked assiduously to discover the secrets of their concrete. "The Romans were concerned with this," Jackson says. "If we're going to build in the sea, we should be concerned with it too."