Thursday, April 28, 2016

Neandertals and Upper Paleolithic Homo sapiens had different dietary strategies


When fluctuating climates in the Ice Age altered habitats, modern humans may have adapted their diets in a different way than Neandertals, according to a study published April 27, 2016 in the open-access journal PLOS ONE by Sireen El Zaatari of the University of Tübingen, Germany, and colleagues.

The Neandertal lineage survived for hundreds of thousands of years despite the severe temperature fluctuations of the Ice Age. The reasons for their decline around 40 thousand years ago remain unclear. The authors of this study investigated the possible influence of dietary strategies using the fossilized molars of 52 Neandertals and Upper Paleolithic Homo sapiens (modern humans). They analysed the type and degree of microwear on the teeth to attempt to draw conclusions about diet type and to establish a relationship with prevalent climactic conditions.

They found that as the climate fluctuated and habitats altered, Neandertals may have adapted their diet to the resources that were most readily available, eating mainly meat when in open, cold steppe environments, and supplementing their diet with more plants, seeds, and nuts when in forested landscapes.

Meanwhile, modern humans seemed to stick to their dietary strategy regardless of slight environmental changes and retained a relatively large proportion of plant-based foods in their diet. "To be able to do this, they may have developed tools to extract dietary resources from their environment"" says Sireen El Zaatari. The researchers concluded that Upper Paleolithic modern humans' differing dietary strategies may have given them an advantage over the Neandertals.

The Neandertals may have maintained their opportunistic approach of eating whatever was available in their changing habitats over hundreds of thousands of years. However, modern humans seem to have invested more effort in accessing food resources and significantly changed their dietary strategies over a much shorter period of time, in conjunction with their development of tools, which may have given them an advantage over Neanderthals.

The European Neandertal and modern human individuals analysed in this study do not temporally overlap and thus would not inform us about direct dietary competition between these two groups. Nevertheless, if the behavioral differences detected in this study were already established at the time of contact between them, these differences might have contributed to the demise of the Neandertals and the survival of modern humans.


Friday, April 15, 2016

Headdress reconstruction throws light on hunter-gatherer rituals


A research team led by archaeologists at the University of York used traditional techniques to create replicas of ritual headdresses made by hunter-gatherers 11,000 years ago in North Western Europe.

Flint blades, hammerstones and burning were among the tools and techniques they employed to fashion reproductions of shamanic headdresses discovered during excavations at the Early Mesolithic site at Star Carr in North Yorkshire.

The research published today in PLOS ONE is the first scientific analysis of the oldest known evidence of a shamanic costume in Europe. It challenges previously held assumptions over the care and time invested in the modification of the animal's "skull cap" in order to create these ritualistic artefacts.

Instead the study, part of a five-year project supported by the European Research Council, Historic England and the Vale of Pickering Research Trust, suggests that hunter-gatherers achieved this through expedient manufacturing techniques. These may have involved packing the skull with damp clay and placing it in a bed of embers for up to four hours both to facilitate skin removal and make the bone easier to work.

Archaeologists unearthed a total 24 red deer headdresses at Star Carr representing around 90 percent of all such known artefacts across early prehistoric Europe. The artefacts are formed from the upper part of a male red deer skull with the antlers attached - the lower jaw and cranial bones having been removed and the frontal bone perforated.

The majority of the headdresses were discovered during archaeological investigations at Star Carr in the 1940s though researchers unearthed a further three during excavations in 2013. The most complete of these is likely to have come from a male adult red deer though the animal was 50 per cent larger than its modern counterparts.

Using techniques including 3D laser scanning allowed the team to observe and analyse a number of cut marks radiating out of perforations on both sides of the crania.

The researchers, which also involved researchers from the universities of Bradford, Chester, Manchester, Groningen and Leiden, concluded that hunter-gatherers were likely to have removed the head and superficially cleaned it before starting work on producing the headdress.

The first stage of the process may have involved removal of a large amount of antler possibly to reduce the weight of the headdress and make it easier to work. Some of the removed antler may have formed 'blanks' for the production of barbed projectile tips used for hunting and fishing.

But it is also possible that, in some cases, antler blank removal happened much later after the headdress had been used; in which case the process may have been a form of decommissioning of the headdress and/or the recycling of antler. The researchers say that given the amount of worked antler present at Star Carr, including over 200 barbed projectile tips, this is a plausible theory.

Lead author Dr Aimée Little, of the BioArCh research centre in the Department of Archaeology at York, said: "This research shows how experimental archaeology can give important insights into rare ancient artefacts. Knowing fire was used invokes a real sense of atmosphere surrounding the making of these ritual shamanic headdresses."

Professor Nicky Milner, co-director of the excavations at Star Carr, added: "These headdresses are incredibly rare finds in the archaeological record. This is the only site in Britain where they are found, and there are only a few other headdresses known from Germany. This work into how they might have been made has given us an important glimpse into what life was like 11,000 years ago."

Dr Andrew Wilson, Senior Lecturer and co-director of Bradford Visualisation in the School of Archaeological Sciences at the University of Bradford, said: 'This exciting collaboration enabled the team to use a range of complementary 3D capture methods to document and investigate the modification of the deer crania at a variety of scales, before these waterlogged organic artefacts were subject to conservation treatment. This is a great showcase for how 3D documentation and analysis can transform our ability to understand objects of past societies."

Tuesday, April 12, 2016

Clues for dating of Old Testament texts: handwriting dating to 600 BCE suggests widespread literacy


Scholars have long debated how much of the Hebrew bible was composed before the destruction of Jerusalem and the Kingdom of Judah in 586 BCE. While scholars agree that key biblical texts were written starting in the 7th century BCE, the exact date of the compilation of these books remains in question.

A new Tel Aviv University study published in PNAS (Shira Faigenbaum-Golovin, Arie Shaus, Barak Sober, David Levin, Nadav Na’aman, Benjamin Sass, Eli Turkel, Eli Piasetzky, Israel Finkelstein. Algorithmic handwriting analysis of Judah’s military correspondence sheds light on composition of biblical texts. Proceedings of the National Academy of Sciences, 2016; 201522200 DOI: 10.1073/pnas.1522200113)  suggests that widespread literacy was required for this massive undertaking and provides empirical evidence of that literacy in the final days of the Kingdom of Judah. A profusion of literate individuals in Judah may have set the stage for the compilation of biblical works that constitute the basis of Judahite history and theology, such as the early version of the books of Deuteronomy to Second Kings, according to the researchers.

"There's a heated discussion regarding the timing of the composition of a critical mass of biblical texts," said Prof. Israel Finkelstein of TAU's Department of Archaeology and Ancient Near Eastern Civilizations, who led the research together with Prof. Eliezer Piasetzky of TAU's School of Physics and Astronomy. "But to answer this, one must ask a broader question: What were the literacy rates in Judah at the end of the First Temple period? And what were the literacy rates later on, under Persian rule?"

The interdisciplinary study was conducted by Shira Faigenbaum-Golovin, Arie Shaus and Barak Sober, under the supervision of Prof. Eli Turkel and Prof. David Levin, all of TAU's Department of Applied Mathematics. Other collaborators included Prof. Nadav Na'aman of TAU's Department of Jewish History and Prof. Benjamin Sass of TAU's Department of Archaeology and Ancient Near Eastern Civilizations.

Literacy in the First Temple period

Using cutting-edge computerized image processing and machine learning tools, the TAU team analyzed 16 inscriptions unearthed at an excavation in the remote fort of Arad, and deduced that the texts had been written by at least six authors. The content of the inscriptions disclosed that reading and writing abilities existed throughout the military chain of command, from the highest echelon all the way down to the deputy quartermaster of the fort.

"We designed an algorithm to distinguish between different authors, then composed a statistical mechanism to assess our findings," said Sober. "Through probability analysis, we eliminated the likelihood that the texts were written by a single author."

The inscriptions found at Arad consisted of instructions for troop movements and the registration of expenses for food. The tone and nature of the commands precluded the role of professional scribes. Considering the remoteness of Arad, the small garrison stationed there, and the narrow time period of the inscriptions, this finding indicates a high literacy rate within Judah's administrative apparatus -- and provides a suitable background for the composition of a critical mass of biblical texts.

Literacy more widespread than previously believed

"We found indirect evidence of the existence of an educational infrastructure, which could have enabled the composition of biblical texts," said Prof. Piasetzky. "Literacy existed at all levels of the administrative, military and priestly systems of Judah. Reading and writing were not limited to a tiny elite."

"Now our job is to extrapolate from Arad to a broader area," said Prof. Finkelstein. "Adding what we know about Arad to other forts and administrative localities across ancient Judah, we can estimate that many people could read and write during the last phase of the First Temple period. We assume that in a kingdom of some 100,000 people, at least several hundred were literate.

"Following the fall of Judah, there was a large gap in production of Hebrew inscriptions until the second century BCE, the next period with evidence for widespread literacy. This reduces the odds for a compilation of substantial Biblical literature in Jerusalem between ca. 586 and 200 BCE."

Related article

The Oldest Glassworks Ever Found in Israel was a World Center for Glass Production in Antiquity




An extraordinary archaeological discovery was revealed in an excavation of the Israel Antiquities Authority prior to the construction of a road being built at the initiative of the Netivei Israel Company. During the excavation, carried out as part of the Jezreel Valley Railway Project between Ha-‘Emekim Junction and Yagur Junction, remains of the oldest kilns in Israel were discovered where commercial quantities of raw glass were produced. These kilns, c. 1,600 years old (dating to the Late Roman period), indicate that the Land of Israel was one of the foremost centers for glass production in the ancient world.

According to Yael Gorin-Rosen, head curator of the Israel Antiquities Authority Glass Department, “This is a very important discovery with implications regarding the history of the glass industry both in Israel and in the entire ancient world. We know from historical sources dating to the Roman period that the Valley of ‘Akko was renowned for the excellent quality sand located there, which was highly suitable for the manufacture of glass. Chemical analyses conducted on glass vessels from this period which were discovered until now at sites in Europe and in shipwrecks in the Mediterranean basin have shown that the source of the glass is from our region. Now, for the first time, the kilns have been found where the raw material was manufactured that was used to produce this glassware”.

The excavation of the kilns has caused great excitement in recent weeks among glass researchers throughout the world, some of whom have come especially to Israel in order to see this discovery first hand. According to Professor Ian Freestone of the University College London, who specializes in identifying the chemical composition of glass, "This is a sensational discovery and it is of great significance for understanding the entire system of the glass trade in antiquity. This is evidence that Israel constituted a production center on an international scale; hence its glassware was widely distributed throughout the Mediterranean and Europe”.

This enormously important site was discovered by chance last summer by archaeologist Abdel Al-Salam Sa‘id, an inspector with the Israel Antiquities Authority. While overseeing infrastructure work being conducted on the new railway line from Haifa to the east, he suddenly observed chunks of glass, a floor and an ash layer inside a trench. He halted construction work at the site and began preparations for an archaeological excavation, the important results of which are now evident.

According to Abdel Al-Salam Sa‘id, the excavation direction, “We exposed fragments of floors, pieces of vitrified bricks from the walls and ceiling of the kilns, and clean raw glass chips. We were absolutely overwhelmed with excitement when we understood the great significance of the finds”.

The kilns that were revealed consisted of two built compartments: a firebox where kindling was burnt to create a very high temperature, and a melting chamber – in which the raw materials for the glass (clean beach sand and salt) were inserted and melted together at a temperature of c. 1,200 C degrees. The glass was thus heated for a week or two until enormous chunks of raw glass were produced, some of which weighed in excess of ten tons. At the end of the manufacturing process the kilns were cooled; the large glass chunks that were manufactured were broken into smaller pieces and were sold to workshops where they were melted again in order to produce glassware.

During the Early Roman period the use of glass greatly expanded due to its characteristics: its transparency, beauty, the delicacy of the vessels and the speed with which they could be produced by blowing – an inexpensive technique adopted at the time that lowered production costs. Glass was used in almost every household from the Roman period onward, and it was also utilized in the construction of public buildings in the form of windows, mosaics and lighting fixtures. Consequently, large quantities of raw glass were required which were prepared on an industrial scale in specialized centers. The installation that was discovered in the excavation is an example of one of these ancient production facilities.

According to a price edict circulated by the Roman emperor Diocletian in the early fourth century CE, there were two kinds of glass: the first was known as Judean glass (from the Land of Israel) and the second – Alexandrian glass (from Alexandria, Egypt). Judean glass was a light green color and less expensive than Egyptian glass. The question was: Where were the centers that manufactured this Judean glass that was a branded product known throughout the Roman Empire and whose price was engraved on stone tablets so as to ensure fair trade. The current discovery completes the missing link in the research and indicates the location where the famous Judean glass was produced.

In a few months time the public will be able to see this discovery first-hand when it will be exhibited at the "Carmel Zvulun" Regional High school, in the Zevulun Regional Council.

Additional Background Information:

Glass production kilns that date to the sixth or early seventh century CE were previously found at Apollonia in Herzliya and are c. 200 years later than the current discovery. The largest glass production facility from antiquity that has been found so far was exposed in the Bet Eliezer neighborhood in Hadera where it was dated to the seventh–eighth centuries CE, and the latest evidence we have of glass production in the country was revealed at Bet She‘arim (next to Khirbat ‘Asafna), dated to the late eighth and early ninth centuries CE.

The kilns that were just recently found are the earliest ones to be discovered so far in Israel. Their relatively good state of preservation will make it possible to better understand the production process. Researchers now hope that by means of its chemical composition they will be able to trace the export of the glass throughout the Roman Empire.

The raw glass industry at Khirbat ‘Asafna was part of an extensive industrial zone where there were oil presses, wine presses and a glassware workshop which was excavated in the 1960’s by an American archaeological expedition.


Friday, April 8, 2016

Neanderthal Y chromosome offers clues to what kept us separate species


Researchers reporting in the American Journal of Human Genetics, published by Cell Press, have completed the first in-depth genetic analysis of a Neanderthal Y chromosome. The findings offer new insights into the relationship between Neanderthals and modern humans and some of the genetic factors that might have kept the two lineages apart.

The Y chromosome was the main component remaining to be analyzed from the Neanderthal genome, the researchers say.

"Characterizing the Neanderthal Y chromosome helps us to better understand the population divergence that led to Neanderthals and modern humans," says Fernando Mendez of Stanford University. "It also enables us to explore possible genetic interactions between archaic and modern [gene] variants within hybrid offspring."

Mendez and his colleagues, including Carlos Bustamante, also at Stanford, and Sergi Castellano, from the Max Planck Institute for Evolutionary Anthropology in Germany, analyzed the Y chromosome from a Neanderthal male found in El Sidrón, Spain. Their analysis suggests that Neanderthals and modern humans diverged almost 590,000 years ago, consistent with earlier evidence.

The researchers say that the Neanderthal Y chromosome they sequenced is distinct from any Y chromosome observed in modern humans, suggesting that the lineage in question is to be extinct. They also found some intriguing protein-coding differences between genes on the Neanderthal and modern human Y chromosomes.

Three of those changes are missense mutations in genes known in humans to produce male-specific minor histocompatibility antigens. Antigens derived from one of these genes, known as KDM5D, are thought to elicit an immune response in some pregnant mothers against their male fetuses and lead to miscarriages.

The researchers speculate that incompatibilities at one or more of these genes might have played a role in driving ancient humans and Neanderthals apart by discouraging interbreeding between them.

"The functional nature of the mutations we found suggests to us that the Y chromosome may have played a role in barriers to gene flow," Bustamante says.

"The finding that most of the functional differences associate with these genes, rather than with genes involved in [sperm production], came as a surprise," Mendez adds.


Tuesday, April 5, 2016

Special Bronze Implements were Discovered in Archaeological Excavations at Magdala – a 2,000 Year Old Jewish Settlement on the Sea of Galilee






A decorated bronze incense shovel (used for transferring embers from place to place) and a bronze jug were recently uncovered in archaeological excavations in Magdala on the western shore of the Sea of Galilee. The Israel Antiquities Authority is leading archaeological excavations slated for the construction of a guesthouse at Magdala. The land is owned by Arke New Gate.




The Hebrew word for incense shovel is mahta, which is derived from the action of raking or gathering embers, and is mentioned in the Bible in Exodus 27:1–3: “You shall make the altar…you shall make pots for it to receive its ashes, and shovels and basins and forks and fire pans; all its utensils you shall make of bronze”. The mahta is thought to have been a sacred implement like the rest of the items that were utilized in the Temple where it was mainly used for transferring embers from place to place. Incense shovels frequently appear in Jewish art as one of the religious articles associated with the Temple, and they have been depicted on mosaic floors of synagogues alongside the menorah, lulav and etrog.

The incense shovel after having been cleaned in the Israel Antiquities Authority metallurgical laboratories. Photo: Clara Amit, courtesy of the Israel Antiquities Authority.

According to Dina Avshalom-Gorni, the Chief archaeologist on behalf of the Israel Antiquities Authority, “The incense shovel that was found is one of ten others that are known in the country from the Second Temple period. From early research in the world it was thought that the incense shovel was only used for ritual purposes, care for the embers and incense that were burnt in ritual ceremonies. Over the years, after incense shovels were also discovered in non-cultic context, apparently were also used as tools for daily tasks. The incense shovel and jug found in our excavation were exposed lying next to each other on the floor in one of the room, at the storehouses that is locate adjacent the dock of a large Jewish settlement, on the shore of Sea of Galilee, in the late Second Temple period. These implements might have been saved in the storeroom as heirlooms by a Jewish family living at Magdala, or they may have been used for daily work as well”.

In recent years the Israel Antiquities Authority has been leading extensive excavations at the site, overseen by the archaeologists Dina Avshalom-Gorni and Arfan Najar, in partnership with the Anahuac University of Mexico, led by the Mexican Archaeologist, Dr. Marcela Zapata-Meza. During the archaeological dig at Magdala, a Jewish settlement dating to the time of the Second Temple was exposed, uncovering, Jewish ritual baths (miqwe’ot), streets, a marketplace and industrial facilities, as well as a synagogue whose walls were decorated with colored plaster and mosaics floor along the pavement. In the middle of the synagogue’s main hall a stone was uncovered, well-known as the Magdala Stone, depicting the Second Temple of Jerusalem, within a carved seven-branched menorah (candelabrum) on one of its sides ever founded. The synagogue is dated to the early first century CE, Second Temple Period and Jesus' Public Ministry around Galilee. The synagogue is one of the seventh oldest synagogues from this period uncovered so far in Israel.

According to Eyad Bisharat, who supervised the work in the excavation area on behalf of the Israel Antiquities Authority, "The volunteers were absolutely thrilled. They simply could not calm down knowing that these artifacts had been waiting just below the surface for 2,000 years. Even we veteran excavators were extremely excited because it’s not every day that one uncovers such rare artifacts as these, and in such a fine state of preservation”.

According Arfan Najar, Archaeologist leading the excavations on behalf of the Israel Antiquities Authority, “A similar incense shovel and jug as those found here in Migdal were discovered by Yigael Yadin in a cache dating to the time of the Bar Kokhba uprising which was revealed in the Cave of the Letters in the Judean Desert. Incense shovels have also been found in the Galilee at Bethsaida, Taiyaba and in Wadi Hammam, and across the country, but all-in-all this is a very rare find”.

The excavation season was located alongside the pier of the large Jewish settlement of Magdala. Volunteers from Chile, Mexico, Italy and Spain came to Magdala in order to help and continue the excavations at the site. Next summer, a group of volunteers and students from Mexico will continue digging on the southern area of the site and restoring remains of discoveries along the excavations.

Magdala is already open daily to the public and visitors can tour the remains of a first century Jewish town and Duc In Altum, a new prayer center at the site. The site is considered as the crossroads of Jewish and Christian History for its historical and religious significance for Jews and Christians. www.magdala.org


About Magdala
The site is located near the town of Migdal along the western shore of Sea of Galilee. Migdal (its Greek name is Taricheae, meaning “place where fish are salted” – possibly alluding to the main source of income of the city’s inhabitants 2,000 years ago) was a large Jewish settlement in the Early Roman period. It is mentioned in Jewish sources, and at the time of the destruction of the Second Temple it served as Josephus’ main military base in his war against the Romans in the Galilee. Evidence of Migdal’s existence is also found in historical and Christian sources, where according to Christian tradition this was the birthplace of Mary Magdalene, the Apostle of the apostles of Jesus. According to the Gospel of Luke, "Mary, called Magdalene, from whom seven demons had gone out...”, follows Jesus until His crucifixion and according to John´s Gospel became the first witness of His resurrection.

Monday, April 4, 2016

Microbiologists unmask the Hannibal route enigma


Microbiologists based in the Institute for Global Food Security and School of Biological Sciences at Queen's University Belfast have recently released results that may have answered one of ancient history's greatest enigmas: Where did Hannibal cross the Alps?

Hannibal was the Commander-in-Chief of the Carthaginian army during the Second Punic War with Rome (218 -201 BC). He famously led his troops (thirty thousand men, just thirty seven elephants and over fifteen thousand horses and mules) across the Alps to invade Italia - bringing the Roman army to its knees. While the great general was ultimately defeated at Zama in 202 BC, this campaign is rightly regarded today as one of the finest military endeavours of antiquity. We can say, in retrospect, that these events ultimately shaped the future Roman Republic, eventually with Caesar morphing into the Empire, and therefore into European civilisation as we know it.

For over two thousand years, historians, statesmen and academics have argued about the route Hannibal took across the Alps. Until now, no solid archaeological evidence has been forthcoming. However, this week - publishing on-line in the Journal Archaeometry - Queen's University's microbiologist Dr Chris Allen and his international team of colleagues, led by Professor Bill Mahaney (York University, Toronto), have finally provided solid evidence for the most likely transit route that took Hannibal's forces across the Alps via the Col de Traversette pass (~3000 m). This crossing point was first proposed over a half century ago by the biologist and polymath Sir Gavin de Beer, but has not previously been widely accepted by the academic community.

Using a combination of microbial metagenome analysis, environmental chemistry, geomorphic and pedological investigation, pollen analyses and various other geophysical techniques, the researchers have shown that a 'mass animal deposition' event occurred near the Col de Traversette - that can be directly dated to approximately 2168 cal yr BP, i.e. 218 BC.

Dr Chris Allen, from the Institute for Global Food Security at Queen's University Belfast, said: "The deposition lies within a churned-up mass from a 1-metre thick alluvial mire, produced by the constant movement of thousands of animals and humans. Over 70 per cent of the microbes in horse manure are from a group known as the Clostridia, that are very stable in soil - surviving for thousands of years. We found scientifically significant evidence of these same bugs in a genetic microbial signature precisely dating to the time of the Punic invasion."


Friday, April 1, 2016

Ancient DNA shows European wipe-out of early Americans




Llull Maiden: DNA of The Doncela (The Maiden) Incan mummy found at Mount Llullaillaco, Argentina, in 1999, was used in the study.
CREDIT
Credit Johan Reinhard


The first large scale study of ancient DNA from early American people has confirmed the devastating impact of European colonisation on the Indigenous American populations of the time.

Led by the University of Adelaide's Australian Centre for Ancient DNA (ACAD), the researchers have reconstructed a genetic history of Indigenous American populations by looking directly into the DNA of 92 pre-Columbian mummies and skeletons, between 500 and 8600 years old.

Published today in Science Advances, the study reveals a striking absence of the pre-Columbian genetic lineages in modern Indigenous Americans; showing extinction of these lineages with the arrival of the Spaniards.

"Surprisingly, none of the genetic lineages we found in almost 100 ancient humans were present, or showed evidence of descendants, in today's Indigenous populations," says joint lead author Dr Bastien Llamas, Senior Research Associate with ACAD. "This separation appears to have been established as early as 9000 years ago and was completely unexpected, so we examined many demographic scenarios to try and explain the pattern."

"The only scenario that fit our observations was that shortly after the initial colonisation, populations were established that subsequently stayed geographically isolated from one another, and that a major portion of these populations later became extinct following European contact. This closely matches the historical reports of a major demographic collapse immediately after the Spaniards arrived in the late 1400s."

The research team, which also includes members from the University of California at Santa Cruz (UCSC) and Harvard Medical School, studied maternal genetic lineages by sequencing whole mitochondrial genomes extracted from bone and teeth samples from 92 pre-Columbian--mainly South American--human mummies and skeletons.

The ancient genetic signals also provide a more precise timing of the first people entering the Americas--via the Beringian land bridge that connected Asia and the north-western tip of North America during the last Ice Age.

"Our genetic reconstruction confirms that the first Americans entered around 16,000 years ago via the Pacific coast, skirting around the massive ice sheets that blocked an inland corridor route which only opened much later," says Professor Alan Cooper, Director of ACAD. "They spread southward remarkably swiftly, reaching southern Chile by 14,600 years ago."

"Genetic diversity in these early people from Asia was limited by the small founding populations which were isolated on the Beringian land bridge for around 2400 to 9000 years," says joint lead author Dr Lars Fehren-Schmitz, from UCSC. "It was at the peak of the last Ice Age, when cold deserts and ice sheets blocked human movement, and limited resources would have constrained population size. This long isolation of a small group of people brewed the unique genetic diversity observed in the early Americans."

Dr Wolfgang Haak, formerly at ACAD and now at the Max Planck Institute for the Science of Human History, says: "Our study is the first real time genetic record of these key questions regarding the timing and process of the peopling of the Americas. To get an even fuller picture, however, we will need a concerted effort to build a comprehensive dataset from the DNA of people alive today and their pre-Columbian ancestors, to further compare ancient and modern diversity."

Ancient Southwest marked by repeated periods of boom and bust


Researchers link climate changes and large social disruption






 Pueblo Bonito, one of the largest Great Houses in New Mexico's Chaco Canyon, grew out of one of several cultural transformations that researchers have documented in the ancient Southwest.
CREDIT
Nate Crabtree

 The heavily studied yet largely unexplained disappearance of ancestral Pueblo people from southwest Colorado is "the most vexing and persistent question in Southwestern archaeology," according to the New York Times.

But it's not all that unique, say Washington State University scientists. Writing in the journal Science Advances, they say the region saw three other cultural transitions over the preceding five centuries. The researchers also document recurring narratives in which the Pueblo people agreed on canons of ritual, behavior and belief that quickly dissolved as climate change hurt crops and precipitated social turmoil and violence.

"The process of releasing one's self from those canons, the process of breaking that down, can occur very quickly and occurred very quickly four times in the Pueblo past," said Kyle Bocinsky, a WSU adjunct faculty member in anthropology and director of sponsored projects for the Crow Canyon Archaeological Center in Cortez, Colo. The article grew out of work toward Bocinsky's WSU doctorate.

Funded by the National Science Foundation, Bocinsky, WSU Regents Professor Tim Kohler and colleagues analyzed data from just over 1,000 southwest archaeological sites and nearly 30,000 tree-ring dates that served as indicators of rainfall, heat and time. Their data-intensive approach, facilitated by climate reconstructions run at the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign, gives a remarkably detailed picture of year-to-year changes.

This is particularly important as droughts of just five or ten years were enough to prompt major shifts in the small niches where Pueblo people grew maize, their major crop.

The niches, said Kohler, were "woven together with a web of ceremony and ritual that required belief in the supernatural" to ensure plentiful rain and good crops. When rains failed to appear, he said, the rituals were delegitimized.

"Then there's a point where people say, 'This isn't working. We're leaving,'" he said.

That starts a period of exploration in which people look for new places to live and develop new ways of living, followed by a period of exploitation in a new niche with different behaviors and values.

"There's a new period of wealth creation, investment in architecture and culture change," said Kohler.

The researchers said the first period of exploitation, known as Basketmaker III, took place between 600 and 700 A.D. It ended with a mild drought and was followed by a period known as Pueblo I, in which the practice of storing maize in underground chambers gave way to storage in rooms above ground.

The researchers think this represents a shift from unrestricted sharing of food to more restricted exchanges controlled by households or family groups. The period ended around 890 with a slightly larger drought.

The exploitation phase of the Pueblo II period ran from 1035 to 1145 and was marked by large shared plazas and great houses--what we would today call McMansions--in the Chaco Canyon area south of Mesa Verde, Colo.

"We're talking some of the largest--actually, the largest--prehistoric masonry structures in North America north of Mexico," said Kohler. "These things are huge."

Wood for roofs had to come from 50 to 75 miles away, requiring an unprecedented level of coordination. The mix of large and small buildings also suggests a more hierarchal social structure with someone in charge.

Pueblo III, which peaked around 1250, featured restricted access to civic and ceremonial spaces and has some of the greatest evidence of social inequality. This period ended with the largest and most widespread of the four droughts. By contrast, the ensuing Pueblo IV period had big rectangular pueblos with apartments surrounding large shared plazas and civic ceremonial spaces.

"It's as if everybody has equal access to where all the important stuff happens," said Bocinsky. "That's been interpreted as being far more egalitarian in how people were organizing themselves as a society than what we see during any of the previous periods."

"There's a total reorganization," said Kohler.

The researchers hope their analysis of societal expansion and collapse, as well as periods of exploration and exploitation, can be applied to other Neolithic societies whose economic, organizational and ritual practices collapsed when they failed to meet expectations.

To varying degrees, Bocinsky and Kohler also draw parallels to the current dissatisfaction among people who have yet to recover from the last recession.

"A lot of the nation has not recovered since 2008, and what you're seeing is a populist movement to radically reorganize the way that politics is done in this country," said Bocinsky. "We're seeing that need to reorganize four times in the Pueblo record."