Wednesday, December 7, 2016

Polluted river from before Bronze Age


Industrial pollution may seem like a modern phenomenon, but in fact, an international team of researchers may have discovered what could be the world's first polluted river, contaminated approximately 7,000 years ago.

In this now-dry riverbed in the Wadi Faynan region of southern Jordan, Professor Russell Adams, from the Department of Anthropology at the University of Waterloo, and his colleagues found evidence of early pollution caused by the combustion of copper. Neolithic humans here may have been in the early stages of developing metallurgy by learning how to smelt.

The research findings, published in Science of the Total Environment, shed light on a turning point in history, when humans began moving from making tools out of stones to making tools out of metal. This period, known as the Chalcolithic or Copper Age, is a transitional period between the late Neolithic or Stone Age and the beginning of the Bronze Age.

"These populations were experimenting with fire, experimenting with pottery and experimenting with copper ores, and all three of these components are part of the early production of copper metals from ores," said Adams. "The technological innovation and the spread of the adoption and use of metals in society mark the beginning of the modern world."

People created copper at this time by combining charcoal and the blue-green copper ore found in abundance in this area in pottery crucibles or vessels and heating the mixture over a fire. The process was time-consuming and labour-intensive and, for this reason, it took thousands of years before copper became a central part of human societies.

Many of the objects created in the earliest phase of copper production were primarily symbolic and fulfilled a social function within society. Attaining rare and exotic items was a way in which individuals attained prestige.

As time passed, communities in the region grew larger and copper production expanded. People built mines, then large smelting furnaces and factories by about 2600 BC.

"This region is home to the world's first industrial revolution," said Adams. "This really was the centre of innovative technology."

But people paid a heavy price for the increased metal production. Slag, the waste product of smelting, remained. It contained metals such as copper, lead, zinc, cadmium, and even arsenic, mercury and thalium. Plants absorbed these metals, people and animals such as goats and sheep ate them, and so the contaminants bioaccumulated in the environment.

Adams believes the pollution from thousands of years of copper mining and production must have led to widespread health problems in ancient populations. Infertility, malformations and premature death would have been some of the effects. Researchers have found high levels of copper and lead in human bones dating back to the Roman period.

Adams and his international team of researchers are now trying to expand the analysis of the effects of this pollution to the Bronze Age, which began around 3200 BC. The Faynan region has a long history of human occupation, and the team is examining the extent and spread of this pollution at the time when metals and their industrial scale production became central to human societies.


Researchers find overwhelming evidence of malaria's existence 2,000 years ago


An analysis of 2,000-year-old human remains from several regions across the Italian peninsula has confirmed the presence of malaria during the Roman Empire, addressing a longstanding debate about its pervasiveness in this ancient civilization.

The answer is in mitochondrial genomic evidence of malaria, coaxed from the teeth of bodies buried in three Italian cemeteries, dating back to the Imperial period of the 1st to 3rd centuries Common Era.

The genomic data is important, say researchers, because it serves as a key reference point for when and where the parasite existed in humans, and provides more information about the evolution of human disease.

"Malaria was likely a significant historical pathogen that caused widespread death in ancient Rome," says evolutionary geneticist Hendrik Poinar, director of McMaster's Ancient DNA Centre where the work was conducted.

A serious and sometimes fatal infectious disease that is spread by infected mosquitoes, malaria and its parasite Plasmodium falciparum, is responsible for nearly 450,000 deaths every year, the majority of them children under the age of five.

"There is extensive written evidence describing fevers that sound like malaria in ancient Greece and Rome, but the specific malaria species responsible is unknown," says Stephanie Marciniak, a former post doctoral student in the Ancient DNA Centre and now a postdoctoral scholar at Pennsylvania State University.

"Our data confirm that the species was likely Plasmodium falciparum, and that it affected people in different ecological and cultural environments. These results open up new questions to explore, particularly how widespread this parasite was, and what burden it placed upon communities in Imperial Roman Italy," she says.

Marciniak sampled teeth taken from 58 adults and 10 children interred at three Imperial period Italian cemeteries: Isola Sacra, Velia and Vagnari. Located on the coast, Velia and Isola Sacra were known as important port cities and trading centres. Vagnari is located further inland and believed to be the burial site of labourers who would have worked on a Roman rural estate.

Using techniques developed at McMaster and abroad, researchers mined tiny DNA fragments from dental pulp taken from the teeth. They were able to extract, purify and enrich specifically for the Plasmodium species known to infect humans.

It was a difficult and painstaking process, complicated by the very nature of the disease.

Usable DNA is challenging to extract because the parasites primarily dwell within the bloodstream and organs, including the spleen and liver, which decompose and break down over time--in this instance, over the course of two millennia.

Marciniak, Poinar, and Tracy Prowse from McMaster, alongside Luca Bandioli from the Luigi Pigorini National Museum of Prehistory and Ethnography in Rome and Edward Holmes from the University of Sydney recovered more than half of the P. falciparum mitochondrial genome from two individuals from Velia and Vagnari.

P. falciparum remains the most prevalent malaria parasite in sub-Saharan Africa and the most-deadly anywhere, responsible for the largest number of malaria-related deaths globally.

The findings are published in the journal Current Biology.

Prehistoric plant remains highlight diverse origins of cereal domestication


A study from the University of the Basque Country (UPV-EHU) and the University of Copenhagen shows that the process of cultivation and domestication of cereals occurred at different times across southwest Asia. The analyses of plant remains from archaeological sites dated to around 11,600-10,700 years ago suggest that in regions such as Turkey, Iran and Iraq, legumes, fruits and nuts dominated the diet, whereas cereals were the preferred types of plants in Jordan, Syria, Palestine and Israel. This means that Neolithic plant-based subsistence strategies were regionally diverse and that cereals were not staple foods in all regions.

Recent archaeological studies have suggested that the cultivation of morphologically wild plant species (pre-domestication cultivation), a precursor of agriculture, developed across southwest Asia around 11,600-10,700 years ago, during the co-called Pre-Pottery Neolithic A. In a new study published in PNAS - only for reporters with access to embargoed PNAS content, researchers from the University of the Basque Country and the University of Copenhagen document regional diversity in the types of plant species that were exploited during this period:

"We have studied the available archaeobotanical evidence (charred plant remains) from Pre-Pottery Neolithic sites in southwest Asia dated to approximately 11,600 to 10,700 years ago, and we can conclude that the importance we have hitherto attributed to cereals such as wheat and barley needs to be re-evaluated as other plants such as legumes - e.g. lentils, beans and peas - also played a crucial role during this time period, particularly in the eastern Fertile Crescent, e.g. Iran and Iraq, and southeast Turkey" says postdoc and archaeobotanist Amaia Arranz-Otaegui from the Centre for the Study of Early Agricultural Societies at the University of Copenhagen.

The origins of domesticated cereals

Not only did Neolithic communities from various regions across southwest Asia exploit a different range of plants - and did thus not rely exclusively on cereals - but the evidence also suggests that the different plant exploitation strategies could have contributed to important chronological dissimilarities during the emergence of morphologically domesticated species:

"Our results indicate that in the southern Levant (e.g. modern-day Jordan, Israel, Palestine and southern Syria), cereals were predominant during the Pre-Pottery Neolithic A (PPNA, 11,600-10,700 years ago) and domesticated cereals, which eventually became the cornerstones of agriculture, appeared around 10,700-10,200 years ago. But in the eastern Fertile Crescent, where cereals were not commonly exploited during the PPNA, domesticated cereals appear around 400-1000 years later. We know that plant domestication was a process that occurred in multiple regions and involved several plant species, so it is likely that in those regions where cereal exploitation was not common practice, similar management processes involving plants such as legumes could have existed," Amaia Arranz-Otaegui points out.



Tuesday, December 6, 2016

Mummified remains identified as Egyptian Queen Nefertari


A team of international archaeologists believe a pair of mummified legs on display in an Italian museum may belong to Egyptian Queen Nefertari - the favourite wife of the pharaoh Ramses II.

The team, which included Dr Stephen Buckley and Professor Joann Fletcher from the University of York's Department of Archaeology, used radiocarbon dating, anthropology, palaeopathology, genetics and chemical analysis to identify the remains.

They conclude that "the most likely scenario is that the mummified knees truly belong to Queen Nefertari".

As the favourite wife of the pharaoh Ramses II, Nefertari was provided with a beautifully decorated tomb in the Valley of the Queens to which Professor Fletcher was recently given access.

Although plundered in ancient times, the tomb, first excavated by Italian archaeologists in 1904, still contained objects which were sent to the Egyptian Museum in Turin.

This included a pair of mummified legs which could have been part of a later interment as was often the case in other tombs in the region. But as the legs had never been scientifically investigated, it was decided to undertake the recent study to find out if the legs could actually represent all that remained of one of Egypt's most legendary queens.

The study, published in the journal PLOS ONE, revealed that the legs are those of an adult woman of about 40 years of age.

Dr Buckley's chemical analysis also established that the materials used to embalm the legs are consistent with 13th Century BC mummification traditions, which when taken in conjunction with the findings of the other specialists involved, led to the identification.

Professor Fletcher said: "This has been the most exciting project to be part of, and a great privilege to be working alongside with some of the world's leading experts in this area.

"Both Stephen and myself have a long history studying Egypt's royal mummies, and the evidence we've been able to gather about Nefertari's remains not only complements the research we've been doing on the queen and her tomb but really does allow us to add another piece to the jigsaw of what is actually known about Egyptian mummification."


Plant-based menu of prehistoric man


A tiny grape pip (scale 1mm), left on the ground some 780,000 years ago, is one of more than 9,000 remains of edible plants discovered in an old Stone Age site in Israel on the shoreline of Lake Hula in the northern Jordan valley, dating back to the Acheulian culture from 1.75-0.25 million years ago. The floral collection provides rich testimony of the plant-based diet of our prehistoric ancestors.

While around the world remains of Paleolithic plants are scarce, this unique macro-botanical assemblage has allowed researchers from the Hebrew University of Jerusalem and Bar Ilan University to study the vegetal diet of humans from early-mid-Pleistocene, which is central to understanding the evolution, adaptation and exploitation of the environment by hominins.

The findings were recovered during archeological excavations at the waterlogged site of Gesher Benot Ya'aqov, where the earliest evidence of human-controlled fire in western Asia was discovered in recent years.

Prof. Naama Goren-Inbar of the Institute of Archeology at the Hebrew University of Jerusalem, who conducted the excavations with colleagues, have long studied findings of hominid occupations in the Levantine Corridor, through which several hominin waves dispersed out of Africa.

In a research paper that will be published in the Proceedings of the National Academy of Sciences (PNAS) on December 5, titled "The plant component of an Acheulian diet: a case study from Gesher Benot Ya'aqov, Israel", Prof. Goren-Inbar reveals the discovery of the ancient macrobotanical remains, which for the first time indicate to the rich variety of plant assortments and subsistence opportunities that were available to the early humans on the transition from an African-based to a Eurasian diet.

"In recent years we were met with a golden opportunity to reveal numerous remains of fruits, nuts and seeds from trees, shrubs and the lake, alongside the remains of animals and man-made stone tools in one locality," Prof. Goren-Inbar said.

Of the remains found on site, Prof. Goren-Inbar and Dr. Yoel Melamed of the Faculty of Life Sciences at Bar Ilan University have identified 55 species of edible plants, including seeds, fruits, nuts, leaves, stems, roots and tubers.

The findings, many of them minor in size, have been preserved for hundreds of thousands of years thanks to the damp conditions in the vicinity of the site, said Dr. Melamed. The basalts under and in the site were dated by Ar/Ar and the dates were further confirmed by results of paleomagnetic analyses.

"This region is known for the wealth of plants, but what surprised us were the sources of plant food coming from the lake. We found more than 10 species that existed here in prehistoric times but no longer today, such as two types of water nuts, from which seven were edible," explained Dr. Melamed.

The site was submerged under the Jordan River and the Hula Lake in conditions of humidity and lack of oxygen, aided by the fast covering of layers of sediments, in which archaeologists also found stone tools and animal fossils.

Gesher Benot Ya'aqov is also the place where Prof. Goren-Inbar found the earliest evidence of the use of fire in Eurasia (LINK). "The use of fire is very important because a lot of the plants are toxic or inedible. Using fire, like roasting nuts and roots for example, allows the use of various parts of the plant and increases the diversity of the plant component of the Acheulian diet, alongside aquatic and terrestrial fauna," said Prof. Goren-Inbar.

The use of fire and the availability of a diverse range of flora highlight the ability of prehistoric man to adjust to a new environment, to exploit the environment for his own benefit and to colonize beyond Africa.


Neolithic Syrians were first to domesticate cereals


11,000 years ago, a Syrian community began a practice which would change man's relationship with his surroundings forever: the initiation of cereal domestication and, with it, the commencement of agriculture, a process which lasted several millennia. The discoveries, made at the Tell Qarassa North archaeological site, situated near the city of Sweida in Syria, are the oldest evidence of the domestication of three species of cereal: one of barley and two of wheat (spelt and farrow).

The team from the Spanish National Research Council (CSIC) and the Universities of Cantabria and the Basque Country (both in northern Spain) was led by CSIC's Juan José Ibáñez, and excavated in the area between 2009 and 2010. Scientific investigators from the Universities of Copenhagen and London also collaborated in the study which is published in the latest edition of the magazine Proceedings of the National Academy of Sciences (PNAS).

The Neolithic man in question lived at a time of huge changes. They gathered wild wheat and barley and gradually began the process of domesticating them. That is to say, they began to build a local economy based around controlling the reproduction of the foods they ate.

The origins of agriculture

Although it was already known that cereal breeding took place in the Near East, it was not known whether the first domesticated cereals appeared in one region or in several regions simultaneously, or, if the first case were true, in which region. "The process began when hunter gatherer communities started collecting wild cereals, leading in turn to these wild cereals being sown, then reaped using sickles. This initial crop husbandry led to the selective breeding of cereal grains. Gradually, domestic traits became more and more dominant", explains Ibañez.

To be precise, it is this work at Tell Qarrassa which allows samples of cereals from the very first phase in the domestication process to be identified. Of all the cereals which were grown at the site, around 30% show domestic traits whilst the remainder continue to show traits which are characteristic of wild cereals.

"We now know that the cereals from Tell Qarassa were sown in autumn and harvested in February and March, before reaching full maturity to prevent the risk- given that they were still partially wild- of heads breaking off and being lost at harvest. The crop was cut close to the ground so as to make full use of the straw and, once collected, it would be thrashed and the grain cleaned in the courtyards outside their homes before being stored inside. Prior to being eaten, the grain was crushed in a mortar and pestle then ground in hand mills", explains the CSIC investigator.

The information obtained at Tell Qarassa shows both the advanced level of technical development of these first farming communities and also that the domestication process of cereals unfolded at varying rates in the different regions of the Near East. "It has yet to be discovered whether the later appearance of domesticated cereals in these regions was due to the use of those cereals originating in the south of Syria which we have been studying, or whether other independent domestication processes took place elsewhere", concludes Ibañez.


Friday, December 2, 2016

Bitumen from Middle East discovered in 7th century buried ship in UK


Middle Eastern Bitumen, a rare, tar-like material, is present in the seventh century ship buried at Sutton Hoo, according to a study published in the open-access journal PLOS ONE on December 01, 2016 by Pauline Burger and colleagues from the British Museum, UK and the University of Aberdeen.

The seventh century ship found within a burial mound at Sutton Hoo, UK was first excavated in 1939 and is known for the spectacular treasure it contained including jewellery, silverware, coins, and ceremonial armour. The site is thought to be an example of the European ship-burial rites of the time, and also includes a burial chamber where a corpse was likely laid. Fragments of black organic material found in this chamber were originally identified as locally-produced 'Stockholm Tar' and linked to repair and maintenance of the ship. The authors of the present study re-evaluated these previously-identified samples, as well as other tar-like materials found at the site, using imaging techniques and isotopic analysis and found the samples had been originally misidentified.

By comparing the samples from Sutton Hoo to various reference materials, the researchers' analysis revealed that the previously-identified 'Stockholm Tar' lumps actually displayed the molecular and isotopic characteristics of archaeological bitumen, and specifically bitumen from the Middle East rather than from a local British source. Archaeological finds of bitumen from this period in Britain are extremely rare and the authors state that this finding is the first material evidence for trading of Middle Eastern bitumen northwards into the British Isles.

While the original form and purpose of the bitumen could not be discerned from the remaining fragments, the authors suggest that it may have been included deliberately in the burial chamber, possibly the remaining components of ornamental objects adorning the grave, or perhaps included as a prestigious raw material.