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MCGILL UNIVERSITY—Deforestation is suspected to have contributed to the mysterious collapse of Mayan civilization more than 1,000 years ago. A new study* shows that the forest-clearing also decimated carbon reservoirs in the tropical soils of the Yucatan peninsula region long after ancient cities were abandoned and the forests grew back.

The findings, published in the journal Nature Geoscience, underscore how important soils and our treatment of them could be in determining future levels of greenhouse gases in the planet’s atmosphere.

The Maya began farming around 4,000 years ago, and the spread of agriculture and building of cities eventually led to widespread deforestation and soil erosion, previous research has shown. What’s most surprising in the new study is that the soils in the region haven’t fully recovered as carbon sinks in over a millennium of reforestation, says McGill University geochemist Peter Douglas, lead author of the new paper.

Ecosystem ‘fundamentally changed’

“When you go to this area today, much of it looks like dense, old-growth rainforest,” says Douglas, an Assistant Professor of Earth and Planetary Sciences at McGill. “But when you look at soil carbon storage, it seems the ecosystem was fundamentally changed and never returned to its original state.”

Soil is one of the largest storehouses of carbon on Earth, containing at least twice as much carbon as today’s atmosphere. Yet scientists have very little understanding of how soil carbon reservoirs change on timescales longer than a decade or so. The new study, along with other recently published research, suggests that these reservoirs can change dramatically on timescales spanning centuries or even millennia.

To investigate these long-term effects, Douglas and his co-authors examined sediment cores extracted from the bottom of three lakes in the Maya Lowlands of southern Mexico and Guatemala. The researchers used measurements of radiocarbon, an isotope that decays with time, to determine the age of molecules called plant waxes, which are usually stored in soils for a long time because they become attached to minerals. They then compared the age of wax molecules with that of plant fossils deposited with the sediments.

The team – which included scientists from Yale University, ETH Zurich, the University of Florida and the University of Wisconsin-Superior – found that once the ancient Maya began deforesting the landscape, the age difference between the fossils and the plant waxes went from being very large to very small. This implies that carbon was being stored in soils for much shorter periods of time.

The project stemmed from research that Douglas had done several years ago as a PhD student at Yale, using plant-wax molecules to trace past climate change affecting the ancient Maya. At the same time, work by other researchers was indicating that these molecules were a good tracer for changes in soil-carbon reservoirs. “Putting these things together, we realized there was an important data-set here relating ancient deforestation to changes in soil carbon reservoirs,” Douglas explains.

Protecting old-growth tropical forests

“This offers another reason – adding to a long list – to protect the remaining areas of old-growth tropical forests in the world,” Douglas says. “It could also have implications for how we design things like carbon offsets, which often involve reforestation but don’t fully account for the long-term storage of carbon.” (Carbon offsets enable companies or individuals to offset their greenhouse-gas emissions by purchasing credits from environmental projects, such as tree-planting.)

The technique used by the researchers has been developed only recently. In the years ahead, “it would be great to analyze tropical forests in other regions of the world to see if the same patterns emerge—and to see if past human deforestation and agriculture had an impact on soil carbon reservoirs globally,” Douglas says. “I’m also very interested in applying this technique to permafrost regions in Canada to see what happened to carbon stored in permafrost during previous periods of climate change.”

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Researchers sampling lake sediment in one of the three lakes in Guatemala studied in this paper. Mark Brenner

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The ruins of Cahal Pech, an ancient Maya city in Belize. Denis Barthel, Wikimedia Commons

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Article Source: McGill University news release

*”A long-term decrease in the persistence of soil carbon caused by ancient Maya land use”, Peter M. J. Douglas et al, Nature Geoscience, published Aug. 20, 2018. http://dx.doi.org/10.1038/s41561-018-0192-7

UNIVERSITY OF YORK—It is the first time that extensive tests have been carried out on an intact prehistoric mummy, consolidating the researchers’ previous findings that embalming was taking place 1,500 years earlier than previously accepted.

Dating from c.3700-3500 BC, the mummy has been housed in the Egyptian Museum in Turin since 1901, but unlike the majority of other prehistoric mummies in museums, it has never undergone any conservation treatments, providing a unique opportunity for accurate scientific analysis.

Like its famous counterpart Gebelein Man A in the British Museum, the Turin mummy was previously assumed to have been naturally mummified by the desiccating action of the hot, dry desert sand.

Using chemical analysis, the scientific team led by the Universities of York and Macquarie uncovered evidence that the mummy had in fact undergone an embalming process, with a plant oil, heated conifer resin, an aromatic plant extract and a plant gum/sugar mixed together and used to impregnate the funerary textiles in which the body was wrapped.

This ‘recipe’ contained antibacterial agents, used in similar proportions to those employed by the Egyptian embalmers when their skill was at its peak some 2,500 years later.

The study* builds on the previous research from 2014 which first identified the presence of complex embalming agents in surviving fragments of linen wrappings from prehistoric bodies in now obliterated tombs at Mostagedda in Middle Egypt.

The team, which includes researchers from the Universities of York, Macquarie, Oxford, Warwick, Trento and Turin, highlight the fact that the mummy came from Upper (southern) Egypt, which offers the first indication that the embalming recipe was being used over a wider geographical area at a time when the concept of a pan-Egyptian identity was supposedly still developing.

Archaeological chemist and mummification expert, Dr Stephen Buckley, from the University of York’s BioArCh facility, said: “Having identified very similar embalming recipes in our previous research on prehistoric burials, this latest study provides both the first evidence for the wider geographical use of these balms and the first ever unequivocal scientific evidence for the use of embalming on an intact, prehistoric Egyptian mummy.

“Moreover, this preservative treatment contained antibacterial constituents in the same proportions as those used in later ‘true’ mummification. As such, our findings represent the literal embodiment of the forerunners of classic mummification, which would become one of the central and iconic pillars of ancient Egyptian culture.”

Dr Jana Jones, Egyptologist and expert on ancient Egyptian burial practices from Macquarie University, said: “The examination of the Turin body makes a momentous contribution to our limited knowledge of the prehistoric period and the expansion of early mummification practices as well as providing vital, new information on this particular mummy.

“By combining chemical analysis with visual examination of the body, genetic investigations, radiocarbon dating and microscopic analysis of the linen wrappings, we confirmed that this ritual mummification process took place around 3600 BC on a male, aged between 20 and 30 years when he died.”

Professor Tom Higham, Deputy Director Oxford Radiocarbon Accelerator Unit, said: “There are very few mummies of this ‘natural’ type available for analysis. Our radiocarbon dating shows it dates to the early Naqada phase of Egyptian prehistory, substantially earlier than the classic Pharaonic period, and this early age offers us an unparalleled glimpse into funerary treatment before the rise of the state.

“The results change significantly our understanding of the development of mummification and the use of embalming agents and demonstrate the power of interdisciplinary science in understanding the past.”

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The mummy has been housed in the Egyptian Museum in Turin since 1901. Dr Stephen Buckley, University of York

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*The study, A prehistoric Egyptian mummy: evidence for an ’embalming recipe’ and the evolution of early formative funerary treatments, is published in the Journal of Archaeological Science.

Article Source: University of York news release

UNIVERSITY OF ARIZONA—New analyses that use tree rings could settle the long-standing debate about when the volcano Thera erupted by resolving discrepancies between archeological and radiocarbon methods of dating the eruption, according to new University of Arizona-led research.

“It’s about tying together a timeline of ancient Egypt, Greece, Turkey and the rest of the Mediterranean at this critical point in the ancient world – that’s what dating Thera can do,” said lead author Charlotte Pearson, an assistant professor of dendrochronology at the UA Laboratory of Tree-Ring Research.

“What we can say now is that the radiocarbon evidence is compatible with the archeological evidence for an eruption of Thera in the 16th century BC,” Pearson said.

Thera’s explosive eruption on Santorini more than 3,400 years ago buried the Minoan settlement on the island in a layer of ash and pumice more than 130 feet (40 meters) deep. The effects of the eruption were felt as far away as Egypt and what is now Istanbul in Turkey.

“The volcano erupts and represents one short moment in time,” she said. “If you can date precisely when that moment is, then whenever you find evidence of that moment at any archeological site, you suddenly have a very precise marker point in time – and that’s really powerful for examining human/environmental interactions around that time period.”

Archeologists have estimated the eruption as occurring sometime between 1570 and 1500 BC by using human artifacts such as written records from Egypt and pottery retrieved from digs. Other researchers estimated the date of the eruption to about 1600 BC using measurements of radiocarbon, sometimes called carbon-14, from bits of trees, grains and legumes found just below the layer of volcanic ash.

By using radiocarbon measurements from the annual rings of trees that lived at the time of the eruption, the UA-led team dates the eruption to someplace between 1600 and 1525, a time period which overlaps with the 1570-1500 date range from the archeological evidence.

“There’s been a huge debate about the timing of the Thera eruption and radiocarbon versus archeological dating,” Pearson said. “Our data indicate that radiocarbon dating can overlap with various lines of archeological evidence for the eruption date.”

The current radiocarbon calibration curve that was developed over the past 50 years using tree rings extends 14,000 years into the past. At that time, the scientists needed to use chunks of wood that combined 10 to 20 years of a tree’s annual rings to have enough wood to test for radiocarbon.

Work conducted at the UA Accelerator Mass Spectrometry Laboratory contributed substantially to the radiocarbon calibration curve currently in use worldwide.

Now radiocarbon testing requires just slivers of wood, so Pearson and her colleagues could test the annual growth rings of trees from 1500 back to 1700 BC – before, during and after the time Thera was thought to have erupted. The 285 samples of annual tree rings were analyzed for radiocarbon at the UA AMS lab.

Co-author Gregory Hodgins, director of the UA AMS lab, said, “Charlotte is redoing the calibration curve at an annual scale. What fell out of that was that the old calibration curve wasn’t precisely correct during this time frame.”

The paper, “Annual radiocarbon record indicates sixteenth century BC date for the Thera eruption,” by Pearson and her colleagues is scheduled to publish online Aug. 15 in Science Advances.

Her other UA co-authors are Peter Brewer, Timothy Jull, Todd Lange and Matthew Salzer. Other co-authors are David Brown of Queen’s University in Belfast, UK, and Timothy Heaton of University of Sheffield, UK.

Pearson learned about the Thera eruption while studying archeology in college and has been fascinated by the eruption and its aftermath ever since.

Narrowing the date for the Minoan-era eruption of the volcano Thera is so important for Mediterranean archeology that there have been whole conferences about when that eruption occurred, she said.

Pearson wanted to know whether current dendrochronological and radiocarbon techniques could provide a more precise date for the eruption.

“Every tree ring is a time capsule of the radiocarbon at the year in which it grew, so we can say here’s a tree ring from 1600 BC and here’s how much radiocarbon is in it,” she said.

The radioactive carbon-14 within an annual tree ring decays at a steady rate and can act as a clock indicating when the tree grew that ring.

Pearson and her colleagues used two different tree-ring chronologies from long-lived trees that were alive at the time of the Thera eruption but were growing 7,000 miles apart. Salzer’s extensive work on long-lived bristlecone pines living in California and Nevada provided the 200 tree-ring samples representing each year from 1700 to 1500 BC. Brown provided 85 Irish oak annual tree-ring samples that spanned the same years.

Because Irish oaks and bristlecone pines add a growth ring every year, the rings laid down year-by-year represent an environmental history going back thousands of years in time.

A massive volcano such as Thera ejects so much material into the atmosphere that it cools the earth. For cold-climate trees such as Irish oaks and bristlecones, that exceptionally cold year shows up as a much narrower tree ring. Salzer’s work reveals at least four different years within the new radiocarbon age range for Thera where the bristlecone pines had exceptionally narrow rings that might indicate a huge volcanic eruption.

“What we’re doing in this study is using the annual nature of tree rings to improve the existing calibration curve for radiocarbon,” Pearson said. “We wanted to tackle this time period in hopes we could use this to shed new light on the Thera debate.”

Hodgins said, “This research is about Thera, but really, the implications of it are profound for anyone that uses radiocarbon dating throughout the world for this time span. There’s a kind of revolution in the radiocarbon community to revise the calibration curve using these more precise measurements.”

Other research teams are also finding discrepancies between their radiocarbon measurements using annual tree rings and the current radiocarbon calibration curve, he said.

Pearson, still fascinated by Thera, hopes future research can nail the eruption down to a particular year.

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Akrotiri is the Minoan town on Santorini that was damaged by earthquakes building up to the eruption and then buried under ash once Thera erupted. The whole town site has a modern roof structure over it to protect the fragile site from the elements. Gretchen Gibbs

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Using calendar-dated tree rings, Charlotte Pearson and her colleagues created an annual resolution radiocarbon time series to shed new light on the long-running debate between radiocarbon and archaeological dating evidence for Thera. Bob Demers/UA News

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Charlotte Pearson and her team measured single tree rings of known age from low-altitude oak (pictured) and high-altitude bristlecone pine, and compared those measurements with the internationally agreed radiocarbon calibration curve. Peter Brewer

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Charlotte Pearson at her lab in the University of Arizona Laboratory of Tree-Ring Research. Bob Demers/UA News

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Article Source: University of Arizona news release

FIELD MUSEUM—You probably know Easter Island as “the place with the giant stone heads.” This remote island 2,300 miles off the coast of Chile has long been seen as mysterious—a place where Polynesian seafarers set up camp, built giant statues, and then destroyed their own society through in-fighting and over-exploitation of natural resources. However, a new article in the Journal of Pacific Archaeology hints at a more complex story—by analyzing the chemical makeup of the tools used to create the big stone sculptures, archaeologists found evidence of a sophisticated society where the people shared information and collaborated.

“For a long time, people wondered about the culture behind these very important statues,” says Field Museum scientist Laure Dussubieux, one of the study’s authors. “This study shows how people were interacting, it’s helping to revise the theory.”

“The idea of competition and collapse on Easter Island might be overstated,” says lead author Dale Simpson, Jr., an archaeologist from the University of Queensland. “To me, the stone carving industry is solid evidence that there was cooperation among families and craft groups.”

The first people arrived on Easter Island (or, in the local language, Rapa Nui) about 900 years ago. “The founding population, according to oral tradition, was two canoes led by the island’s first chief, Hotu Matua,” says Simpson, who is currently on the faculty of the College of DuPage. Over the years, the population rose to the thousands, forming the complex society that carved the statues Easter Island is known for today. These statues, or moai, often referred to as “Easter Island heads,” are actually full-body figures that became partially buried over time. The moai, which represent important Rapa Nui ancestors, number nearly a thousand, and the largest one is over seventy feet tall.

According to Simpson, the size and number of the moai hint at a complex society. “Ancient Rapa Nui had chiefs, priests, and guilds of workers who fished, farmed, and made the moai. There was a certain level of sociopolitical organization that was needed to carve almost a thousand statues,” says Simpson.

Recent excavations of four statues in the inner region of Rano Raraku, the statue quarry, were conducted by Jo Anne Van Tilburg of the Cotsen Institute of Archaeology, UCLA and director of the Easter Island Statue Project, along with her Rapa Nui excavation team. To better understand the society that fabricated two of the statues, Simpson, Dussubieux, and Van Tilburg took a detailed look at twenty one of about 1,600 stone tools made of volcanic stone called basalt that had been recovered in Van Tilburg’s excavations. About half of the tools, called toki, recovered were fragments that suggested how they were used.

For Van Tilburg, the goal of the project was to gain a better understanding of how tool makers and statue carvers may have interacted, thus gaining insight into how the statue production industry functioned. “We wanted to figure out where the raw materials used to manufacture the artifacts came from,” explained Dussubieux. “We wanted to know if people were taking material from close to where they lived.”

There are at least three different sources on Easter Island that the Rapa Nui used for material to make their stone tools. The basalt quarries cover twelve square meters, an area the size of two football fields. And those different quarries, the tools that came from them, and the movement between geological locations and archaeological sites shed light on prehistoric Rapa Nui society.

“Basalt is a grayish rock that doesn’t look like anything special, but when you look at the chemical composition of the basalt samples from different sources, you can see very subtle differences in concentrations of different elements,” explains Dussubieux. “Rock from each source is different because of the geology of each site.”

Dussubieux led the chemical analysis of the stone tools. The archaeologists used a laser to cut off tiny pieces of stone from the toki and then used an instrument called a mass spectrometer to analyze the amounts of different chemical elements present in the samples. The results pointed to a society that Simpson believes involved a fair amount of collaboration.

“The majority of the toki came from one quarry complex—once the people found the quarry they liked, they stayed with it,” says Simpson. “For everyone to be using one type of stone, I believe they had to collaborate. That’s why they were so successful—they were working together.”

To Simpson, this level of large-scale cooperation contradicts the popular narrative that Easter Island’s inhabitants ran out of resources and warred themselves into extinction. “There’s so much mystery around Easter Island, because it’s so isolated, but on the island, people were, and still are, interacting in huge amounts,” says Simpson. While the society was later decimated by colonists and slavery, Rapa Nui culture has persisted. “There are thousands of Rapa Nui people alive today—the society isn’t gone,” Simpson explains.

Van Tilburg urges caution in interpreting the study’s results. “The near exclusive use of one quarry to produce these seventeen tools supports a view of craft specialization based on information exchange, but we can’t know at this stage if the interaction was collaborative. It may also have been coercive in some way. Human behavior is complex. This study encourages further mapping and stone sourcing, and our excavations continue to shed new light on moai carving.” In addition to potentially paving the way for a more nuanced view of the Rapa Nui people, Dussubieux notes that the study is important because of its wider-reaching insights into how societies work. “What happens in this world is a cycle, what happened in the past will happen again,” says Dussubieux. “Most people don’t live on a small island, but what we learn about people’s interactions in the past is very important for us now because what shapes our world is how we interact.”

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Examples of the Easter Island statues, or moai. Dale Simpson, Jr.

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Article Source: A Field Museum news release

AUSTRALIAN NATIONAL UNIVERSITY—New archaeological research from The Australian National University (ANU) has found that Homo erectus, an extinct species of primitive humans, went extinct in part because they were ‘lazy’.

An archaeological excavation of ancient human populations in the Arabian Peninsula during the Early Stone Age, found that Homo erectus used ‘least-effort strategies’ for tool making and collecting resources.

This ‘laziness’ paired with an inability to adapt to a changing climate likely played a role in the species going extinct, according to lead researcher Dr Ceri Shipton of the ANU School of Culture, History and Language.

“They really don’t seem to have been pushing themselves,” Dr Shipton said.

“I don’t get the sense they were explorers looking over the horizon. They didn’t have that same sense of wonder that we have.”

Dr Shipton said this was evident in the way the species made their stone tools and collected resources.

“To make their stone tools they would use whatever rocks they could find lying around their camp, which were mostly of comparatively low quality to what later stone tool makers used,” he said.

“At the site we looked at there was a big rocky outcrop of quality stone just a short distance away up a small hill.

“But rather than walk up the hill they would just use whatever bits had rolled down and were lying at the bottom.

“When we looked at the rocky outcrop there were no signs of any activity, no artifacts and no quarrying of the stone.

“They knew it was there, but because they had enough adequate resources they seem to have thought, ‘why bother?'”.

This is in contrast to the stone tool makers of later periods, including early Homo sapiens and Neanderthals, who were climbing mountains to find good quality stone and transporting it over long distances.

Dr Shipton said a failure to progress technologically, as their environment dried out into a desert, also contributed to the population’s demise.

“Not only were they lazy, but they were also very conservative,” Dr Shipton said.

“The sediment samples showed the environment around them was changing, but they were doing the exact same things with their tools.

“There was no progression at all, and their tools are never very far from these now dry river beds. I think in the end the environment just got too dry for them.”

The excavation and survey work was undertaken in 2014 at the site of Saffaqah near Dawadmi in central Saudi Arabia.

The research has been published in a paper for the PLoS One scientific journal.

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The site at Saffaqah in central Saudi Arabia. ANU

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Dr. Ceri Shipton on site at Saffaqah in central Saudi Arabia. ANU

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Dr. Ceri Shipton in the Arabian Peninsula. ANU

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Article Source: Australian National University news release

Amid ongoing debate related to resolving the route by which people first entered the Americas – a topic that has generated decades of scholarly studies – researchers led by Ben Potter and David Reich evaluate claims made based on current genetic, archaeological, and other data. They ultimately conclude that although the ice-free corridor (IFC) route is more often supported by data, the North Pacific Coast (NPC) route was viable, too, and in fact both theories should be considered as viable pathways to the Americas. The authors go on to call for new multidisciplinary research to explore the implications of their analysis. “As geneticists and archaeologists and Indigenous communities work together in a respectful and mutually beneficial manner,” they say, “the opportunities to analyze additional human remains to infer population history in the Americas grow.” Currently, there are several theories as to how humans first populated the Americas, all differing in timing, route and population source. For much of the 20th century, archaeologists firmly believed that the initial pathway into the Americas was via the ice-free corridor, a route from interior Alaska that snaked into the high plains of North America between two massive sheets of ice. Over the past 20 years, however, this consensus has been challenged and for many, overturned, by data that support the “kelp highway” hypothesis – a postulated route that is said to have followed the coastline of western North America. In this Review, Ben A. Potter, David Reich and colleagues examined claims based on genetic, archeological, and paleoecological data to identify strengths and weakness of both the IFC and NPC routes for the peopling of the Americas. Based on their assessment, Potter et al. say evidence supports Native American expansion having happened after 16,000 years ago via IFC, NPC or a combination of both. Neither theory can conclusively be accepted nor rejected, they say.

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Northwest North America with archeological sites older than 10,000 calibrated years before the present (Supplementary Materials) and proposed colonization routes: IFC and NPC.
Potter et al., Sci. Adv. 2018;4: eaat5473.

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Excavation of early site in Beringia. Ben A. Potter

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Typical vantage point of an early Paleoindian site in Beringia (Alaska). Ben A. Potter

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Article Credit: Science Advances, published by AAAS, the nonprofit science society.

UNIVERSITY OF HELSINKI—The prehistoric settlement submerged under Lake Kuolimojarvi provides us with a clearer picture of the human occupation in South Karelia during the Mesolithic and Early Neolithic Stone Age (about 10,000 – 6,000 years ago) and it opens up a new research path in Finnish archaeology.

In the early Stone Age, the water levels in the small lakes located in the southern parts of what are today Lake Kuolimojarvi and Saimaa were several metres below the present levels. After this period, the water levels started rising as a result of uneven land uplift and the tilting of lakes and rivers. The rise in water levels ended with the outburst of River Vuoksi through the Salpausselka; Ridge about 6,000 years ago when water masses carved a new southeastern outflow channel towards Lake Ladoga.

With the rise in water levels, areas that were on dry land in the early Stone Age have been buried in the bottom of the lake and its littoral deposits.

The aim of the three-year study carried out by the University of Helsinki has been to find traces of early Stone Age settlements under water and from wetlands at lakes Kuolimojarvi and Saimaa.

“This means that there is a huge gap in our archaeological knowledge of this particular area because we have not yet found the earliest Stone Age sites,” explains postdoctoral researcher Satu Koivisto who heads the project.

So far the oldest sites have been settled after the breakthrough of River Vuoksi (from 6,000 years ago and onwards). However, there has definitely been human habitation in this area for thousands of years before that, as is shown by the traces of settlements of more than 10,000 years old discovered at Kuurmanpohja in Joutseno further to the south.

Charcoal, burned rocks and quartz flakes have been found at the site

In June 2018, archaeologists carried out underwater excavations and equipment testing at Kammarlahti bay in Savitaipale in cooperation with Nordic Maritime Group (NMG) and the underwater unit of the Finnish Heritage Agency. Archaeologists from Denmark and Sweden also took part in the work.

The work started with a thorough study of the lakebed the purpose of which was to find archaeological remains by mapping the best-preserved areas.

“The western side of the Kammarlahti bay is sheltered from wind and waves and for this reason, the prehistoric dry land areas are best preserved in that part. In one of the test pits, we found a distinct layer of burned soil, charcoal and burned rocks. Quartz flakes were also found in the surrounding test pits and these remains show that quartz artifacts had been made at the site during the Stone Age,” Koivisto explains.

The hearth feature and associated find materials indicate that a submerged Stone Age settlement site has now been located at Lake Kuolimojarvi – the first undisputed observation of this kind in Finland. The nearest similar sites are located in northwestern Russia and southern parts of Scandinavia. It is clear that the hearth feature, which today lies at a depth of about one meter, and the other finds are from the period before the rise of the water level (about 9,000 to 8,000 years ago). The archaeologists managed to take a soil sample of the burned layer around the hearth and are now trying to find datable material from it.

“With the excavation equipment tested in the underwater research at Kammarlahti, we may also be able to find other submerged sites at similar locations. For this reason, the discovery opens up an entirely new era in the research into the Finnish Stone Age. Many of our large lakes, such as Vanajavesi, Pielinen and Oulujarvi have also gone through similar fluctuations in water levels. This means that a huge and largely untapped archaeological resource is hidden in Finnish lakes. Moreover, extremely old organic materials may also have been preserved in these environments for thousands of years,” Satu Koivisto says, describing Finland’s underwater archaeological potential.

The excavation sites were located in a preliminary study

A thorough preliminary work prompted the archaeologists to select Kammarlahti for underwater excavations. The most promising areas for the preservation of submerged sites were located already in a desk-based assessment and a field survey was carried out in them in Lappeenranta, Savitaipale and Taipalsaari in 2015. More detailed investigations were carried out in 2017 and 2018 at Rajalamminsuo and Kammarlahti at Lake Kuolimojarvi as well as at Sarviniemi and Ahoselka; at Lake Saimaa. In the summer of 2017, peatland excavations were conducted at Rajalamminsuo while Kammarlahti was combed by divers. These investigations also produced clear evidence that in the early Stone Age, the level of Lake Kuolimojarvi was several meters below present levels. This finding prompted experts to revise their previous assumptions of the history of the lake. The peatland excavations also revealed a distinct charcoal-rich layer underneath the peat, which had been created as a result of human activity, starting at the Late Neolithic and extending to the Iron Age (about 2000 BCE – 600 CE). The divings carried out at Kammarlahti revealed a small number of old wooden structures and signs of interesting areas that were selected for further underwater excavations in 2018. The three-year archaeological project ‘Lost Inland Landscapes’ of the University of Helsinki will be concluded at the end of the year. The funding for the project comes from the University’s three-year research grants and it is headed by archaeologist Satu Koivisto, who works as a postdoctoral researcher at the university.

This is in many ways a multidisciplinary project and cutting-edge technology has also been used in the planning of the field work and in the modeling of the previous stages of the lakes and underwater topography. An international reference group, with members from Sweden, Germany, Denmark, Latvia, Russia and Finland, has been set up for the project. The group brings together archaeologists and geologists who are experts on similar environments and archaeological sites in the Baltic region. In this manner, the group promotes international cooperation in an archaeological sector that is extremely challenging but also important in terms of research.

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Satu Koivisto and Jørgen Dencker examining bottom sediments. Eveliina Salo/Nordic Maritime Group

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Drone photo over Kammarlahti. The raft anchored in the research area. Jesse Jokinen/Museovirasto

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Eveliina Salo taking samples of the hearth structure. Jesse Jokinen/Museovirasto

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Article Source: University of Helsinki news release

UNIVERSITY OF CAMBRIDGE—The Icelandic Sagas tell of Erik the Red: exiled for murder in the late 10th century he fled to southwest Greenland, establishing its first Norse settlement.

The colony took root, and by the mid-12th century there were two major settlements with a population of thousands. Greenland even gained its own bishop.

By the end of the 15th century, however, the Norse of Greenland had vanished – leaving only abandoned ruins and an enduring mystery.

Past theories as to why these communities collapsed include a change in climate and a hubristic adherence to failing farming techniques.

Some have suggested that trading commodities – most notably walrus tusks – with Europe may have been vital to sustaining the Greenlanders. Ornate items including crucifixes and chess pieces were fashioned from walrus ivory by craftsmen of the age. However, the source of this ivory has never been empirically established.

Now, researchers from the universities of Cambridge and Oslo have studied ancient DNA from offcuts of tusks and skulls, most found on the sites of former ivory workshops across Europe, in order to trace the origin of the animals used in the medieval trade.

In doing so they have discovered an evolutionary split in the walrus, and revealed that the Greenland colonies may have had a “near monopoly” on the supply of ivory to Western Europe for over two hundred years.

For the latest study, published today in the journal Proceedings of the Royal Society B, the research team analyzed walrus samples found in several medieval trading centers – Trondheim, Bergen, Oslo, Dublin, London, Schleswig and Sigtuna – mostly dating between 900 and 1400 CE.

The DNA showed that, during the last Ice Age, the Atlantic walrus divided into two ancestral lines, which researchers term “eastern” and “western”. Walruses of the eastern lineage are widespread across much of the Arctic, including Scandinavia. Those of the western, however, are unique to the waters between western Greenland and Canada.

Finds from the early years of the ivory trade were mostly from the eastern lineage. Yet as demand grew from the 12th century onwards, the research team discovered that Europe’s ivory supply shifted almost exclusively to tusks from the western lineage.

They say that ivory from western linage walruses must have been supplied by the Norse Greenlanders – by hunting and perhaps also by trade with the indigenous peoples of Arctic North America.

“The results suggest that by the 1100s Greenland had become the main supplier of walrus ivory to Western Europe – a near monopoly even,” said Dr James H. Barrett, study co-author from the University of Cambridge’s Department of Archaeology.

“The change in the ivory trade coincides with the flourishing of the Norse settlements on Greenland. The populations grew and elaborate churches were constructed.

“Later Icelandic accounts suggest that in the 1120s, Greenlanders used walrus ivory to secure the right to their own bishopric from the king of Norway. Tusks were also used to pay tithes to the church,” said Barrett.

He points out that the 11th to 13th centuries were a time of demographic and economic boom in Europe, with growing demand from urban centers and the elite served by transporting commodities from increasingly distant sources.

“The demands for luxury goods produced from ivory may have helped the far-flung Norse communities in Greenland survive for centuries,” said Barrett.

Co-author Dr Sanne Boessenkool of the University of Oslo said: “We knew from the start that analyzing ancient DNA would have the potential for new historical insights, but the findings proved to be particularly spectacular.”

The new study tells us less about the end of the Greenland colonies, say Barrett and colleagues. However, they note that it is hard to find evidence of walrus ivory imports to Europe that date after 1400.

Elephant ivory eventually became the material of choice for Europe’s artisans. “Changing tastes could have led to a decline in the walrus ivory market of the Middle Ages,” said Barrett.

Ivory exports from Greenland could have stalled for other reasons: over-hunting can cause walrus populations to abandon their coastal “haulouts”; the “Little Ice Age” – a sustained period of lower temperatures – began in the 14th century; the Black Death ravaged Europe.

Whatever caused the cessation of Europe’s trade in walrus ivory, it must have been significant for the end of the Norse Greenlanders,” said Barrett. “An over-reliance on a single commodity, the very thing which gave the society its initial resilience, may have also contained the seeds of its vulnerability.”

The heyday of the walrus ivory trade saw the material used for exquisitely carved items during Europe’s Romanesque art period. The church produced much of this, with major ivory workshops in ecclesiastical centers such as Canterbury, UK.

Ivory games were also popular. The Viking board game hnefatafl was often played with walrus ivory pieces, as was chess, with the famous Lewis chessmen among the most stunning examples of Norse carved ivory.

Tusks were exported still attached to the walrus skull and snout, which formed a neat protective package that was broken up at workshops for ivory removal. These remains allowed the study to take place, as DNA extraction from carved artifacts would be far too damaging.

Co-author Dr Bastiaan Star of the University of Oslo said: “Until now, there was no quantitative data to support the story about walrus ivory from Greenland. Walruses could have been hunted in the north of Russia, and perhaps even in Arctic Norway at that time. Our research now proves beyond doubt that much of the ivory traded to Europe during the Middle Ages really did come from Greenland”.

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A walrus rostrum (upper jaw bone) with tusks used in the study. It can be dated to c.1200-1400 CE based on the characteristics of a runic inscription in Old Norse. It is from the collections of Musée Vert, muséum d’histoire naturelle du Mans, and may once have been part of an ecclesiastical treasury in France (catalogue number MHNLM 2004.3.53). Musées du Mans

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One of 16 walrus rostrums (upper jaw bones) found during excavations in Bergen, Norway (catalogue number BRM708/1125, University Museum, University of Bergen). This is an example of the remains of a “package” of walrus ivory once the tusks have been removed. Dr James H. Barrett

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This is an example of an elaborately-carved ecclesiastical walrus ivory plaque from the beginning of the medieval walrus ivory trade, featuring the figure of Christ, together with St Mary and St Peter, and believed to date from the 10th or 11th century. Found in North Elmham, Norfolk, UK, in the 19th century, and currently exhibited in the University of Cambridge’s Museum of Archaeology and Anthropology. Museum of Archaeology and Anthropology, University of Cambridge

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Article Source: University of Cambridge news release

UNIVERSITY OF CAMBRIDGE—The severity of drought conditions during the demise of the Maya civilization about one thousand years ago has been quantified, representing another piece of evidence that could be used to solve the longstanding mystery of what caused the downfall of one of the ancient world’s great civilizations.

Researchers from the University of Cambridge and the University of Florida developed a method to measure the different isotopes of water trapped in gypsum, a mineral that forms during times of drought when the water level is lowered, in Lake Chichancanab in Mexico’s Yucatán Peninsula where the Maya were based.

Based on these measurements, the researchers found that annual precipitation decreased between 41% and 54% during the period of the Maya civilization’s collapse, with periods of up to 70% rainfall reduction during peak drought conditions, and that relative humidity declined by 2% to 7% compared to today. The results are reported in the journal Science.

“The role of climate change in the collapse of Classic Maya civilization is somewhat controversial, partly because previous records are limited to qualitative reconstructions, for example whether conditions were wetter or drier,” said Nick Evans, a PhD student in Cambridge’s Department of Earth Sciences and the paper’s first author. “Our study represents a substantial advance as it provides statistically robust estimates of rainfall and humidity levels during the Maya downfall.”

Maya civilization is divided into four main periods: the Preclassic (2000 BCE – 250 CE), Classic (250 CE – 800 CE), terminal Classic (800 – 1000 CE) and Postclassic (1000 CE – 1539 CE). The Classic period was marked by the construction of monumental architecture, intellectual and artistic development, and the growth of large city-states.

During the 9th century however, there was a major political collapse in the central Maya region: their famous limestone cities were abandoned and dynasties ended. And while the Maya people survived beyond this period, their political and economic power was depleted.

There are multiple theories as to what caused the collapse of the Maya civilization, such as invasion, war, environmental degradation and collapsing trade routes. In the 1990s, however, researchers were able to piece together climate records for the period of the Maya collapse, and found that it correlated with an extended period of extreme drought.

Professor David Hodell, Director of Cambridge’s Godwin Laboratory for Palaeoclimate Research and the senior author of the current paper, provided the first physical evidence of a correlation between this period of drought at Lake Chichancanab and the downfall of the Classic Maya civilization in a paper published in 1995.

Now, Hodell and his colleagues have applied a new method and estimated the extent of this drought. Using a new geochemical method to measure the water locked within gypsum from Chichancanab, the researchers have built a complete model of hydrological conditions during the terminal Classic Period when the Maya collapsed.

The researchers analyzed the different isotopes of water trapped within the crystal structure of the gypsum to determine changes in rainfall and relative humidity during the Maya downfall.

They measured three oxygen and two hydrogen isotopes to reconstruct the history of the lake water between 800 and 1000 CE. When gypsum forms, water molecules are incorporated directly into its crystalline structure, and this water records the different isotopes that were present in the ancient lake water at the time of its formation. “This method is highly accurate and is almost like measuring the water itself,” said Evans.

In periods of drought, more water evaporates from lakes such as Chichancanab, and because the lighter isotopes of water evaporate faster, the water becomes heavier. A higher proportion of the heavier isotopes, such as oxygen-18 and hydrogen-2 (deuterium), would therefore indicate drought conditions. By mapping the proportion of the different isotopes contained within each layer of gypsum, the researchers were able to build a model to estimate past changes in rainfall and relative humidity over the period of the Maya collapse.

This quantitative climate data can be used to better predict how these drought conditions may have affected agriculture, including yields of the Maya’s staple crops, such as maize.

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Edzná ruins, Campeche. Pictured is the 31 m tall Pirámide de los Cinco Pisos (pyramid of the five storeys), located in the Great Plaza. Sarah Collins, Cambridge University

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Mask of the Maya rain God ͚Chaac͛ on a building at Labná in the Puuc region of the northern Yucatán Peninsula. The prevalence of Chaac masks in the architecture throughout the Maya region is a testament to the importance of rainfall to the Maya. Mark Brenner

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Image of the sediment core used in this study shown versus depth below the bottom of the lake. The sediment layers consist of dark layers that are composed of organic-rich deposits, and light-colored layers that are composed of the mineral gypsum (calcium sulfate dihydrate; CaSO4·2H2O). Gypsum forms when the lake level was lowered during times of drought. The hydration water in gypsum was used in this study to reconstruct the changes in rainfall of the region. The panel on the right displays the sediment density record of the core. Periods of gypsum precipitation are indicated by density values of >1.1 g/cm3. The interval from 165 to 125 cm spans the time from ~620 to ~1100 CE. The gypsum layers between 154 and 125 cm correspond approximately to the time of the decline of Classic Maya civilization. Credit: after Hodell et al. (2005)

Article Source: University of Cambridge news release

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PRINCETON UNIVERSITY—Two pygmy populations on the same tropical island. One went extinct tens of thousands of years ago; the other still lives there. Are they related?

It’s a simple question that took years to answer.

As no one has been able to recover DNA from the fossils of Homo floresiensis (nicknamed the “hobbit”), researchers had to create a tool for finding archaic genetic sequences in modern DNA.

The technique was developed by scientists in the lab of Joshua Akey, a professor of ecology and evolutionary biology and the Lewis-Sigler Institute for Integrative Genomics at Princeton University.*

“In your genome—and in mine—there are genes that we inherited from Neanderthals,” said Serena Tucci, a postdoctoral research associate in Akey’s lab. “Some modern humans inherited genes from Denisovans [another extinct species of humans], which we can check for because we have genetic information from Denisovans.

“But if you want to look for another species, like Floresiensis, we have nothing to compare, so we had to develop another method: We ‘paint’ chunks of the genome based on the source. We scan the genome and look for chunks that come from different species—Neanderthal, Denisovans, or something unknown.”

She used this technique with the genomes of 32 modern pygmies living in a village near the Liang Bua cave on Flores Island in Indonesia, where H. floresiensis fossils were discovered in 2004.

“They definitely have a lot of Neanderthal,” said Tucci, who was the first author on a paper published Aug. 3 in the journal Science that detailed their findings. “They have a little bit of Denisovan. We expected that, because we knew there was some migration that went from Oceania to Flores, so there was some shared ancestry of these populations.”

But there were no chromosomal “chunks” of unknown origins.

“If there was any chance to know the hobbit genetically from the genomes of extant humans, this would have been it,” said Richard “Ed” Green, an associate professor of biomolecular engineering at the University of California-Santa Cruz (UCSC) and a corresponding author on the paper. “But we don’t see it. There is no indication of gene flow from the hobbit into people living today.”

The researchers did find evolutionary changes associated with diet and short stature. Height is very heritable, and geneticists have identified many genes with variants linked to taller or shorter stature. Tucci and her colleagues analyzed the Flores pygmy genomes with respect to height-associated genes identified in Europeans, and they found a high frequency of genetic variants associated with short stature.

“It sounds like a boring result, but it’s actually quite meaningful,” Green said. “It means that these gene variants were present in a common ancestor of Europeans and the Flores pygmies. They became short by selection acting on this standing variation already present in the population, so there’s little need for genes from an archaic hominin to explain their small stature.”

The Flores pygmy genome also showed evidence of selection in genes for enzymes involved in fatty acid metabolism, called FADS enzymes (fatty acid desaturase). These genes have been associated with dietary adaptations in other fish-eating populations, including the Inuit in Greenland.

Fossil evidence indicates H. floresiensis was significantly smaller than the modern Flores pygmies, standing about 3.5 feet tall (106 centimeters, shorter than the average American kindergartener), while modern pygmies average about 15 inches taller (145 centimeters). Floresiensis also differed from H. sapiens and H. erectus in their wrists and feet, probably due to the need to climb trees to evade Komodo dragons, said Tucci.

Dramatic size changes in animals isolated on islands is a common phenomenon, often attributed to limited food resources and freedom from predators. In general, large species tend to get smaller and small species tend to get larger on islands. At the time of H. floresiensis, Flores was home to dwarf elephants, giant Komodo dragons, giant birds and giant rats, all of which left bones in the Liang Bua cave.

“Islands are very special places for evolution,” Tucci said. “This process, insular dwarfism, resulted in smaller mammals, like hippopotamus and elephants, and smaller humans.”

Their results show that insular dwarfism arose independently at least twice on Flores Island, she said, first in H. floresiensis and again in the modern pygmies.

“This is really intriguing, because it means that evolutionarily, we are not that special,” she said. “Humans are like other mammals; we are subject to the same processes.”

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A modern pygmy population evolved short stature independently of the extinct ‘hobbit’ pygmy species that lived on the same island — Indonesia’s Flores Island — tens of thousands of years earlier, report Princeton’s Serena Tucci, Joshua Akey and an international team of researchers. In this illustration, the modern pygmy village, Rampasasa, is shown at left; in the center, a modern Rampasasa pygmy wearing the traditional head covering and clothing is juxtaposed against the face of a Homo floresiensis reconstruction; at right, pygmy elephants play in the Liang Bua cave where the H. floresiensis fossils were discovered in 2004. Matilda Luk, Office of Communications, Princeton University

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This figure shows the relative heights of a modern Indonesian (5′ 2), a modern pygmy living on the island of Flores (4′ 10) and Homo floresiensis (3′ 5, which is the height of an average American 4-year-old). Courtesy of Dr. Serena Tucci, Department of Ecology and Evolutionary Biology, Princeton University

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Article Source: Princeton University news release

*”Evolutionary history and adaptation of a human pygmy population of Flores Island, Indonesia,” by Serena Tucci, Samuel Vohr, Rajiv McCoy, Benjamin Vernot, Matthew Robinson, Chiara Barbieri, Brad Nelson, Wenqing Fu, Gludhug Purnomo, Herawati Sudoyo, Evan Eichler, Guido Barbujani, Peter Visscher, Joshua Akey and Richard Green (DOI:10.1126/science.aar8486), published in the Aug. 3 issue of Science, was supported by the National Institutes of Health (R01-GM110068), the Searle Scholars Program, the Gordon and Betty Moore Foundation, the Lewis and Clark Fellowship for Exploration and Field Research (American Philosophical Society), the University of Ferrara-Italy Young Researcher Fellowship program, the European Research Council (ERC-2011-AdG_295733), the Australian Research Council (DP160102400), the Australian National Health and Medical Research Council (1078037 and 1113400), and the Ministry of Research and Technology of the Republic of Indonesia.

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UNIVERSITY OF OXFORD—Despite over a century of intense study, we still know very little about the people buried at Stonehenge or how they came to be there. Now, a new University of Oxford research collaboration, published in Scientific Reports suggests that a number of the people that were buried at the Wessex site had moved with and likely transported the bluestones used in the early stages of the monument’s construction, sourced from the Preseli Mountains of west Wales.

Conducted in partnership with colleagues at the UCL, Université Libre de Bruxelles & Vrije Universiteit Brussel), and the Muséum National d’Histoire Naturelle de Paris, France, the research combined radiocarbon-dating with new developments in archaeological analysis, pioneered by lead author Christophe Snoeck during his doctoral research in the School of Archaeology at Oxford.

While there has been much speculation as to how and why Stonehenge was built, the question of ‘who’ built it has received far less attention. Part of the reason for this neglect is that many of the human remains were cremated, and so it was difficult to extract much useful information from them. Snoeck demonstrated that that cremated bone faithfully retains its strontium isotope composition, opening the way to use this technique to investigate where these people had lived during the last decade or so of their lives.

With permission from Historic England and English Heritage, the team analyzed skull bones from 25 individuals to better understand the lives of those buried at the iconic monument. These remains were originally excavated from a network of 56 pits in the 1920s, placed around the inner circumference and ditch of Stonehenge, known as ‘Aubrey Holes’.

Analysis of small fragments of cremated human bone from an early phase of the site’s history around 3000 BC, when it was mainly used as a cemetery, showed that at least 10 of the 25 people did not live near Stonehenge prior to their death. Instead, they found the highest strontium isotope ratios in the remains were consistent with living in western Britain, a region that includes west Wales – the known source of Stonehenge’s bluestones. Although strontium isotope ratios alone cannot distinguish between places with similar values, this connection suggests west Wales as the most likely origin of at least some of these people.

While the Welsh connection was known for the stones, the study shows that people were also moving between west Wales and Wessex in the Late Neolithic, and that some of their remains were buried at Stonehenge. The results emphasize the importance of inter-regional connections involving the movement of both materials and people in the construction and use of Stonehenge, providing rare insight into the large scale of contacts and exchanges in the Neolithic, as early as 5,000 years ago.

Lead author Christophe Snoeck said: “The recent discovery that some biological information survives the high temperatures reached during cremation (up to 1000 degrees Celsius) offered us the exciting possibility to finally study the origin of those buried at Stonehenge.”

John Pouncett, a lead author on the paper and Spatial Technology Officer at Oxford’s School of Archaeology, said: ‘The powerful combination of stable isotopes and spatial technology gives us a new insight into the communities who built Stonehenge. The cremated remains from the enigmatic Aubrey Holes and updated mapping of the biosphere suggest that people from the Preseli Mountains not only supplied the bluestones used to build the stone circle, but moved with the stones and were buried there too.’

Rick Schulting, a lead author on the research and Associate Professor in Scientific and Prehistoric Archaeology at Oxford, explained: ‘To me the really remarkable thing about our study is the ability of new developments in archaeological science to extract so much new information from such small and unpromising fragments of burnt bone.

“Some of the people’s remains showed strontium isotope signals consistent with west Wales, the source of the bluestones that are now being seen as marking the earliest monumental phase of the site.”

Commenting on how they came to develop the innovative technique, Prof Julia Lee-Thorp, Head of Oxford’s School of Archaeology and an author on the paper, said: “This new development has come about as the serendipitous result of Dr Snoeck’s interest in the effects of intense heat on bones, and our realization that that heating effectively “sealed in” some isotopic signatures.”

The technique could be used to improve our understanding of the past using previously excavated ancient collections. Dr Schulting said: “Our results highlight the importance of revisiting old collections. The cremated remains from Stonehenge were first excavated by Colonel William Hawley in the 1920s, and while they were not put into a museum, Col Hawley did have the foresight to rebury them in a known location on the site, so that it was possible for Mike Parker Pearson (UCL Institute of Archaeology) and his team to re-excavate them, allowing various analytical methods to be applied.”

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Stonehenge as it appears today. Bernard Gagnon

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The excavation crew around Aubrey Hole 7 following excavations in 2008.
Adam Stanford, Aerial-Cam Ltd

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Stonehenge AH7 pit, Aubrey Hole 7 following excavation in 2008.
Christie Willis, UCL

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Stonehenge AH7 pitfill, Aubrey Hole 7 during excavation in 2008.
Christie Willis, UCL

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Three of the cremated cranial fragments used in the study on a black background. Christie Willis, UCL

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Carn Goedog bluestone outcrop: Excavations at one of the recently identified bluestone quarries, at Carn Goedog, Pembrokeshore, west Wales. Adam Stanford, Aerial-Cam Ltd

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Article Source: University of Oxford news release

*Strontium isotope analyses on cremated human remains from Stonehenge support links with west Wales

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PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES—Researchers report* early metal use and crematory practices by indigenous groups in the southeastern United States. The long-distance trade of goods such as copper during the Archaic Period, around 3,000-8,000 years ago, contributed to social complexity among indigenous groups in eastern North America. Although widespread in certain areas of eastern North America, Archaic Period copper is largely absent from archaeological sites in the southeastern United States. Matthew Sanger, David Thomas, and colleagues report a copper band alongside the cremated remains of at least seven individuals at a burial site in coastal Georgia, where, in addition to copper, Archaic Period cremations are absent from the archaeological record. The copper band and burials were located in the center of a Late Archaic shell ring–circular deposits likely used in ritual gatherings and feasting events. Radiometric dating indicated that the remains were from the Late Archaic Period, and elemental composition analysis of the band revealed that the copper originated in the Great Lakes region, extending previously documented boundaries of Archaic Period copper exchange by nearly 1,000 km. Additionally, the cremation practices at the site resembled those native to the Great Lakes region, indicating long-distance cultural exchange among Archaic Period indigenous groups in the region. According to the authors, the findings lend insight into emergent patterns of hierarchical social organization in the Archaic southeastern United States.

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A Late Archaic copper artifact from a shell ring in coastal Georgia. American Museum of Natural History

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*”Early metal use and crematory practices in the American Southeast,” by Matthew Sanger et al.

Article Source: PNAS news release

MAX PLANCK INSTITUTE FOR THE SCIENCE OF HUMAN HISTORY—Critical review of growing archaeological and palaeoenvironmental datasets relating to the Middle and Late Pleistocene (300-12 thousand years ago) hominin dispersals within and beyond Africa, published today in Nature Human Behaviour, demonstrates unique environmental settings and adaptations for Homo sapiens relative to previous and coexisting hominins such as Homo neanderthalensis and Homo erectus. Our species’ ability to occupy diverse and ‘extreme’ settings around the world stands in stark contrast to the ecological adaptations of other hominin taxa, and may explain how our species became the last surviving hominin on the planet.

The paper, by scientists from the Max Planck Institute for the Science of Human History and the University of Michigan suggests investigations into what it means to be human should shift from attempts to uncover the earliest material traces of ‘art’, ‘language’, or technological ‘complexity’ towards understanding what makes our species ecologically unique. In contrast to our ancestors and contemporary relatives, our species not only colonized a diversity of challenging environments, including deserts, tropical rainforests, high altitude settings, and the palaeoarctic, but also specialized in its adaptation to some of these extremes.

Ancestral ecologies – the ecology of Early and Middle Pleistocene Homo

Although all hominins that make up the genus Homo are often termed ‘human’ in academic and public circles, this evolutionary group, which emerged in Africa around 3 million years ago, is highly diverse. Some members of the genus Homo (namely Homo erectus) had made it to Spain, Georgia, China, and Indonesia by 1 million years ago. Yet, existing information from fossil animals, ancient plants, and chemical methods all suggest that these groups followed and exploited environmental mosaics of forest and grassland. It has been argued that Homo erectus and the ‘Hobbit’, or Homo floresiensis, used humid, resource-scarce tropical rainforest habitats in Southeast Asia from 1 million years ago to 100,000 and 50,000 years ago, respectively. However, the authors found no reliable evidence for this.

It has also been argued that our closest hominin relatives, Homo Neanderthalensis – or the Neanderthals – were specialized to the occupation of high latitude Eurasia between 250,000 and 40,000 years ago. The basis for this includes a face shape potentially adapted to cold temperatures and a hunting focus on large animals such as woolly mammoths. Nevertheless, a review of the evidence led the authors to again conclude that Neanderthals primarily exploited a diversity of forest and grassland habitats, and hunted a diversity of animals, from northern Eurasia to the Mediterranean.

Deserts, rainforests, mountains, and the arctic

In contrast to these other members of the genus Homo, our species – Homo sapiens – had expanded to higher-elevation niches than its hominin predecessors and contemporaries by 80-50,000 years ago, and by at least 45,000 years ago was rapidly colonizing a range of palaeoarctic settings and tropical rainforest conditions across Asia, Melanesia, and the Americas. Furthermore, the authors argue that the continued accumulation of better-dated, higher resolution environmental datasets associated with our species’ crossing the deserts of northern Africa, the Arabian Peninsula, and northwest India, as well as the high elevations of Tibet and the Andes, will further help to determine the degree to which our species demonstrated novel colonizing capacities in entering these regions.

Finding the origins of this ecological ‘plasticity’, or the ability to occupy a number of very different environments, currently remains difficult in Africa, particularly back towards the evolutionary origins of Homo sapiens 300-200,000 years ago. However, the authors argue that there are tantalizing hints for novel environmental contexts of human habitation and associated technological shifts across Africa just after this timeframe. They hypothesize that the drivers of these changes will become more apparent with future work, especially that which tightly integrates archaeological evidence with highly resolved local palaeoecological data. For example, lead author of the paper, Dr. Patrick Roberts, suggests, “although a focus on finding new fossils or genetic characterization of our species and its ancestors has helped rough out the broad timing and location of hominin specifications, such efforts are largely silent on the various environmental contexts of biocultural selection”.

The ‘generalist specialist’ – a very sapiens niche

One of the main new claims of the authors is that the evidence for human occupation of a huge diversity of environmental settings across the majority of the Earth’s continents by the Late Pleistocene hints at a new ecological niche, that of the ‘generalist specialist’. As Roberts states “A traditional ecological dichotomy exists between ‘generalists’, who can make use of a variety of different resources and inhabit a variety of environmental conditions, and ‘specialists’, who have a limited diet and narrow environmental tolerance. However, Homo sapiens furnish evidence for ‘specialist’ populations, such as mountain rainforest foragers or palaeoarctic mammoth hunters, existing within what is traditionally defined as a ‘generalist’ species”.

This ecological ability may have been aided by extensive cooperation between non-kin individuals among Pleistocene Homo sapiens, argues Dr. Brian Stewart, co-author of the study. “Non-kin food sharing, long-distance exchange, and ritual relationships would have allowed populations to ‘reflexively’ adapt to local climatic and environmental fluctuations, and outcompete and replace other hominin species.” In essence, accumulating, drawing from, and passing down a large pool of cumulative cultural knowledge, in material or idea form, may have been crucial in the creation and maintenance of the generalist-specialist niche by our species in the Pleistocene.

Implications for our pursuit of ancient humanity

The authors are clear that this proposition remains hypothetical and could be disproven by evidence for the use of ‘extreme’ environments by other members of the genus Homo. However, testing the ‘generalist specialist’ niche in our species encourages research in more extreme environments that have previously been neglected as unpromising for palaeoanthropological and archaeological work, including the Gobi Desert and Amazon rainforest. The expansion of such research is particularly important in Africa, the evolutionary cradle of Homo sapiens, where more detailed archaeological and environmental records dating back to 300-200,000 years ago are becoming increasingly crucial if we are to track the ecological abilities of the earliest humans.

It is also clear that growing evidence for hominin interbreeding and a complex anatomical and behavioral origin of our species in Africa highlights that archaeologists and paleoanthropologists should focus on looking at the environmental associations of fossils. “While we often get excited by the discovery of new fossils or genomes, perhaps we need to think about the behavioral implications of these discoveries in more detail, and pay more attention to what these new finds tell us about the passing of ecological thresholds” says Stewart. Work focusing on how the genetics of different hominins may have led to ecological and physical benefits such as high-altitude capacities or UV tolerance remain highly fruitful ways forward in this regard.

“As with other definitions of human origins, problems of preservation also make it difficult to pinpoint the origins of humans as an ecological pioneer. However, an ecological perspective on the origins and nature of our species potentially illuminates the unique path of Homo sapiens as it rapidly came to dominate the Earth’s diverse continents and environments”, concludes Roberts. The testing of this hypothesis should open up new avenues for research and, if correct, new perspectives as to whether the ‘generalist specialist’ will continue to be an adaptive success in the face of growing issues of sustainability and environmental conflict.

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Our species is ecologically unique in its ability to occupy, and specialize in, a variety of different environments, as demonstrated when it began to colonize the entire planet between approximately 300 and 60 thousand years ago. Image by John Klausmeyer, concept by Brian Stewart, University of Michigan. Aerial view of reindeer herd from zanskar / iStock.

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Map of the potential distribution of archaic hominins, including H. erectus, H. floresiensis, H. neanderthalensis, Denisovans and archaic African hominins, in the Old World at the time of the evolution and dispersal of H. sapiens between approximately 300 and 60 thousand years ago. Roberts and Stewart. 2018. Defining the ‘generalist specialist’ niche for Pleistocene Homo sapiens. Nature Human Behavior. 10.1038/s41562-018-0394-4.

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Map showing the youngest suggested dates of persistent occupation of the different environmental extremes discussed by our species based on current evidence. Maps from NASA Worldview. In Roberts and Stewart. 2018. Defining the ‘generalist specialist’ niche for Pleistocene Homo sapiens. Nature Human Behaviour. 10.1038/s41562-018-0394-4.

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For more about recent discoveries related to our species’ journey across the globe in prehistory, see the Popular Archaeology premium articles: One Small Arabian Finger Bone, Olorgesailie, and Pushing the Prehistoric Fringe.

Above Article Credit: Max Planck Institute for the Science of Human History news release

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PLOS—The remains of domesticated crop plants at an archaeological site in southwest Amazonia supports the idea that this was an important region in the early history of crop cultivation, according to a study published July 25, 2018 in the open-access journal PLOS ONE by Jennifer Watling from the Museum of Archaeology and Ethnology at the University of São Paulo, Brazil and colleagues.

Genetic analysis of plant species has long pointed to the lowlands of southwest Amazonia as a key region in the early history of plant domestication in the Americas, but systematic archaeological evidence to support this has been rare. The new evidence comes from recently-exposed layers of the Teotonio archaeological site, which has been described by researchers as a “microcosm of human occupation of the Upper Madeira [River]” because it preserves a nearly continuous record of human cultures going back approximately 9,000 years.

In this study, Watling and colleagues analyzed the remains of seeds, phytoliths, and other plant materials in the most ancient soils of the site as well as on artifacts used for processing food. They found some of the earliest evidence of cultivated manioc, a crop which geneticists say was domesticated here over 8,000 years ago, as well as squash, beans, and perhaps calathea, and important tree crops such as palms and Brazil nut. They also saw evidence of disturbed forest and a soil type called “Anthropogenic Dark Earths” which both result from human alteration of local environments.

These findings suggest that the people of this region transitioned from early hunter-gatherer lifestyles to cultivating crops before 6,000 years ago, much earlier than previously thought. Along with plant domestication also came the familiar human habit of landscape modification, suggesting that human impact on Amazonian forests in this region goes back many thousands of years. Altogether, these results point to the Upper Madeira as a key locality to explore the earliest days of crop domestication in the New World.

Watling notes: “This discovery at the Teotonio waterfall in Southest Amazonia is some of the oldest evidence for plant cultivation in lowland South America, confirming genetic evidence”.

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The authors believe that the Teotonio waterfall is what attracted people to this location for over 9,000 years, as it was an extremely rich fishing location and an obligatory stopping point for people traveling by boat on this stretch of the Madeira river. It was the location of a fishing village (the village of Teotonio) until 2011, when residents were forced to move inland ahead of dam construction. The dam submersed the village and the waterfall. Eduardo Neves, 2011

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*Watling J, Shock MP, Mongeló GZ, Almeida FO, Kater T, De Oliveira PE, et al. (2018) Direct archaeological evidence for Southwestern Amazonia as an early plant domestication and food production centre. PLoS ONE 13(7): e0199868. https://doi.org/10.1371/journal.pone.0199868

BINGHAMTON UNIVERSITY—BINGHAMTON, N.Y. – Researchers at Binghamton University, State University at New York have used a new image-based analysis technique to identify once-hidden North American mounds, which could reveal valuable information about pre-contact Native Americans.

“Across the East Coast of the United States, some of the most visible forms for pre-contact Native American material culture can be found in the form of large earthen and shell mounds,” said Binghamton University anthropologist Carl Lipo. “Mounds and shell rings contain valuable information about the way in which past people lived in North America. As habitation sites, they can show us the kinds of foods that were eaten, the way in which the community lived, and how the community interacted with neighbors and their local environments.

In areas that are deeply wooded or consist of bayous and swamps, there exist mounds that have eluded more than 150 years of archaeological survey and research. Due to vegetation, these kinds of environments make seeing more than a couple of dozen feet difficult, and even large mounds can be hidden from view, even when one systematically walks on the terrain.

The use of satellites and new kinds of aerial sensors such as LiDAR (light detection and ranging) have transformed the way archaeologists can gather data about the archaeological record, said Lipo. Now scientists can study landscapes from images and peer through the forest canopy to look at the ground. LiDAR has been particularly effective at showing the characteristic rises in topography that mark the presence of mounds. The challenge to archaeologists, however, is to manage such a vast array of new data that are available for study. Object based image analysis (OBIA) allows archaeologists to configure a program to automatically detect features of interest. OBIA is a computer-based approach to use data from satellite images and aerial sensors to look for shapes and combinations of features that match objects of interest. Unlike traditional satellite image analyses that looks at combinations of light wavelengths, OBIA adds characteristics of shape to the search algorithm, allowing archaeologists to more easily distinguish cultural from natural phenomena.

Lipo’s team systematically identified over 160 previously undetected mound features using LiDAR data from Beaufort County, S.C., and an OBIA approach. The result improves the overall knowledge of settlement patterns by providing systematic knowledge about past landscapes, said Lipo.

“Through the use of OBIA, archaeologists can now repeatedly generate data about the archaeological record and find historic and pre-contact sites over massive areas that would be cost-prohibitive using pedestrian survey. We can now also peer beneath the dense canopy of trees to see things that are otherwise obscured. In areas like coast South Carolina, with large swaths of shallow bays, inlets and bayous that are covered in forest, OBIA offers us our first look at this hidden landscape.”

Having demonstrated the effectiveness for using OBIA in conditions of dense vegetation and after optimizing our processing, Lipo and his team are expanding their efforts to include much-larger areas.

“Fortunately, satellite and LiDAR data are now available for much of the eastern seaboard, so undertaking a large-scale project is now a task that is achievable,” said Lipo. “Due to climate change and sea-level rise, many major mounds and middens on the East Coast are threatened by erosion and inundation. It is urgent we document this pre-contact landscape as soon as possible, in order to learn as much as we can about the past before it is gone forever.”

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Four shell ring features identified using the object-based image analysis (OBIA) algorithm. The ring on the top right has been confirmed as a shell ring site. Carl Lipo

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The team’s approach successfully identified ring and mound sites (indicated by arrows) within a stretch of forest that had not been previously surveyed by archaeologists. Carl Lipo

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Two previously identified shell rings on Daws Island, S.C. These features were also picked up by the new approach utilized by Davis, Sanger, and Lipo (2018). Carl Lipo

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Article Source: Binghamton University news release

*The paper, “Automated mound detection using LiDAR and Object-Based Image Analysis in Beaufort County, SC,” was published in Southeastern Archaeology.

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SOUTHERN METHODIST UNIVERSITY, DALLAS (SMU) – Native American communities actively managed North American prairies for centuries before Christopher Columbus’ arrival in the New World, according to a new study led by Southern Methodist University (SMU) archaeologist Christopher I. Roos.

Fire was an important indigenous tool for shaping North American ecosystems, but the relative importance of indigenous burning versus climate on fire patterns remains controversial in scientific communities. The new study, published in Proceedings of the National Academy of Sciences (PNAS), documents the use of fire to manipulate bison herds in the northern Great Plains. Contrary to popular thinking, burning by indigenous hunters combined with climate variability to amplify the effects of climate on prairie fire patterns.

The relative importance of climate and human activities in shaping fire patterns is often debated and has implications for how we approach fire management today.

“While there is little doubt that climate plays an important top-down role in shaping fire patterns, it is far less clear whether human activities – including active burning – can override those climate influences,” said Roos. “Too often, if scientists see strong correlations between fire activity and climate, the role of humans is discounted.”

Anthropologists and historians have documented a wide variety of fire uses by Native peoples in the Americas but fire scientists have also documented strong fire-climate relationships spanning more than 10,000 years.

“People often think that hunter-gatherers lived lightly on the land,” said Kacy L. Hollenback, an anthropologist at SMU and co-author of the study. “Too often we assume that hunter-gatherers were passive in their interaction with their environment. On the Great Plains and elsewhere, foragers were active managers shaping the composition, structure, and productivity of their environments. This history of management has important implications for contemporary relationships between Native American and First Nations peoples and their home landscapes – of which they were ecosystem engineers.”

Working in partnership with the Blackfeet Tribe in northern Montana, Roos and colleagues combined landscape archaeology and geoarchaeology to document changes in prairie fire activity in close spatial relationship to stones piled in formations up to a mile long that were used to drive herds of bison off of cliffs to be harvested en masse. These features are known as drivelines.

“We surveyed the uplands for stone features that delineate drivelines within which bison herds would be funneled towards a jump,” said anthropologist María Nieves Zedeño of the University of Arizona, co-author of the study. “By radiocarbon dating prairie fire charcoal deposits from the landscape near the drivelines, we were able to reconstruct periods of unusually high fire activity that are spatially associated with the drivelines,” says Roos.

The overlap between peak periods of driveline use (ca. 900-1650 CE) and prairie fire activity (ca. 1100-1650 CE) suggests that fire was an important tool in the hunting strategy involving the drivelines. Roos and colleagues suggest that fire was used to freshen up the prairie near the mouth of the drivelines to attract herds of bison, who prefer to graze recently burned areas. Episodes of high fire activity also correspond to wet climate episodes, when climate would have produced abundant grass fuel for prairie fires.

The absence of deposits indicating high prairie fire activity before or after the period of driveline use, even though comparable wet climate episodes occurred, suggests that anthropogenic burning by Native hunters amplified the climate signal in prairie fire patterns during the period of intensive bison hunting.

“We need to consider that humans and climate have more complicated and interacting influences on historical fire patterns,” said Roos. “Moreover, we need to acknowledge that hunter-gatherers can be active influences in their environments, particularly through their use of fire as a landscape tool. We expect that future studies of human/climate/fire interactions will further document the complexity of these relationships. Understanding that complexity may prove important as we try to navigate the complex wildfire problems we face today.”

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Bison (or buffalo) jump near Ulm, Montana. Formerly called Ulm Pishkun, now called First People’s Buffalo Jump. Square Butte in background. Naawada2016, Wikimedia Commons

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Article Source: Southern Methodist University news release

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UNIVERSITY OF COPENHAGEN – FACULTY OF HUMANITIES—At an archaeological site in northeastern Jordan, researchers have discovered the charred remains of a flatbread baked by hunter-gatherers 14,400 years ago. It is the oldest direct evidence of bread found to date, predating the advent of agriculture by at least 4,000 years. The findings suggest that bread production based on wild cereals may have encouraged hunter-gatherers to cultivate cereals, and thus contributed to the agricultural revolution in the Neolithic period.

A team of researchers from the University of Copenhagen, University College London and University of Cambridge have analyzed charred food remains from a 14,400-year-old Natufian hunter-gatherer site – a site known as Shubayqa 1 located in the Black Desert in northeastern Jordan. The results, which are published today in the journal Proceedings of the National Academy of Sciences, provide the earliest empirical evidence for the production of bread:

“The presence of hundreds of charred food remains in the fireplaces from Shubayqa 1 is an exceptional find, and it has given us the chance to characterize 14,000-year-old food practices. The 24 remains analyzed in this study show that wild ancestors of domesticated cereals such as barley, einkorn, and oat had been ground, sieved and kneaded prior to cooking. The remains are very similar to unleavened flatbreads identified at several Neolithic and Roman sites in Europe and Turkey. So we now know that bread-like products were produced long before the development of farming. The next step is to evaluate if the production and consumption of bread influenced the emergence of plant cultivation and domestication at all,” said University of Copenhagen archaeobotanist Amaia Arranz Otaegui, who is the first author of the study.

University of Copenhagen archaeologist Tobias Richter, who led the excavations at Shubayqa 1 in Jordan, explained:

“Natufian hunter-gatherers are of particular interest to us because they lived through a transitional period when people became more sedentary and their diet began to change. Flint sickle blades as well as ground stone tools found at Natufian sites in the Levant have long led archaeologists to suspect that people had begun to exploit plants in a different and perhaps more effective way. But the flat bread found at Shubayqa 1 is the earliest evidence of bread making recovered so far, and it shows that baking was invented before we had plant cultivation. So this evidence confirms some of our ideas. Indeed, it may be that the early and extremely time-consuming production of bread based on wild cereals may have been one of the key driving forces behind the later agricultural revolution where wild cereals were cultivated to provide more convenient sources of food.”

Charred remains under the microscope

The charred food remains were analysed with electronic microscopy at a University College London lab by PhD candidate Lara Gonzalez Carratero (UCL Institute of Archaeology), who is an expert on prehistoric bread:

“The identification of ‘bread’ or other cereal-based products in archaeology is not straightforward. There has been a tendency to simplify classification without really testing it against an identification criteria. We have established a new set of criteria to identify flat bread, dough and porridge like products in the archaeological record. Using Scanning Electron Microscopy we identified the microstructures and particles of each charred food remain,” said Gonzalez Carratero.

“Bread involves labour intensive processing which includes dehusking, grinding of cereals and kneading and baking. That it was produced before farming methods suggests it was seen as special, and the desire to make more of this special food probably contributed to the decision to begin to cultivate cereals. All of this relies on new methodological developments that allow us to identify the remains of bread from very small charred fragments using high magnification,” said Professor Dorian Fuller (UCL Institute of Archaeology).

Research into prehistoric food practices continues

A grant recently awarded to the University of Copenhagen team will ensure that research into food making during the transition to the Neolithic will continue:

“The Danish Council for Independent Research has recently approved further funding for our work, which will allow us to investigate how people consumed different plants and animals in greater detail. Building on our research into early bread, this will in the future give us a better idea why certain ingredients were favored over others and were eventually selected for cultivation,” said Tobias Richter.

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One of the stone structures of the Shubayqa 1 site. The fireplace, where the bread was found, is in the middle. Alexis Pantos

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Dr. Amaia Arranz-Otaegui and Ali Shakaiteer sampling cereals in the Shubayqa area. Joe Roe

Article Source: University of Copenhagen, Faculty of Humanities news release

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UNIVERSITY OF YORK—A study into some of the earliest known pottery remains has suggested that the rise of ceramic production was closely linked with intensified fishing at the end of the last Ice Age.

Scientists examined 800 pottery vessels in one of the largest studies ever undertaken, focussing mainly on Japan- a country recognized as being one of the earliest centers for ceramic innovation.

A three year study led by researchers at BioArCh, the University of York, concluded that the ceramic vessels were used by our hunter-gatherer ancestors to store and process fish, initially salmon, but then a wider range including shellfish, freshwater and marine fish and mammals as fishing intensified.

Scientists say this association with fish remained stable even after the onset of climate warming, including in more southerly areas, where expanding forests provided new opportunities for hunting game and gathering plants.

The research team was able to determine the use of a range of ceramic vessels through chemical analysis of organic food compounds that remained trapped in the pots despite ca. 10,000 years of burial.

The samples analyzed are some of the earliest found and date from the end of the Late Pleistocene – a time when our ancestors were living in glacial conditions – to the post-glacial period when the climate warmed close to its current temperature and when pottery began to be produced in much greater quantity.

The study has shed new light on how prehistoric hunter-gatherers processed and consumed foods over this period – until now virtually nothing was known of how or for what early pots were used.

As part of the study, researchers recovered diagnostic lipids from the charred surface deposits of the pottery with most of the compounds deriving from the processing of freshwater or marine organisms.

Lead author, Dr Alex Lucquin, from BioArCh, Department of Archaeology, University of York, said: “Thanks to the exceptional preservation of traces of animal fat, we now know that pottery changed from a rare and special object to an every-day tool for preparing fish.

“I think that our study not only reveals the subsistence of the ancient Jomon people of Japan but also its resilience to a dramatic change in climate.

Professor Oliver Craig, from the Department of Archaeology and Director of the BioArCh research center at York, who led the study, said: “Our results demonstrate that pottery had a strong association with the processing of fish, irrespective of the ecological setting.

“Contrary to expectations, this association remained stable even after the onset of warming, including in more southerly areas, where expanding forests provided new opportunities for hunting and gathering.

“The results indicate that a broad array of fish was processed in the pottery after the end of the last Ice Age, corresponding to a period when hunter-gatherers began to settle in one place for longer periods and develop more intensive fishing strategies”

“We suggest this marks a significant change in the role of pottery of hunter-gatherers, corresponding to massively increased volume of production, greater variation in forms and sizes and the onset of shellfish exploitation.”

Dr Simon Kaner, from the University of East Anglia, who was involved in the study, added: “The research highlights the benefits of this kind of international collaboration for unlocking some of the big questions about the human past, and the potential of engaging with established research networks as created by the Sainsbury Institute over the years.”

The findings are published in Proceedings of the National Academy of Sciences and the study was funded by the AHRC. It was an international collaboration including researchers in Japan, Sweden and the Netherlands.

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This is incipient Jomon pottery from Hanamiyama site, Yokohama-shi, Kanagawa Prefecture, Japan. Nara National Research Institute for Cultural Properties

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Article Source: University of York news release

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