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By: Thomas Schmitt Attorney on December 01, 2019 / comment : 0

Ostrich eggshell beads reveal 10,000 years of cultural interaction across Africa

By: Thomas Schmitt Attorney on November 27, 2019 / comment : 0 Africa, Archaeology, Early Humans

Ostrich eggshell beads are some of the oldest ornaments made by humankind, and they can be found dating back at least 50,000 years in Africa. Previous research in southern Africa has shown that the beads increase in size about 2,000 years ago, when herding populations first enter the region.

A string of modern ostrich eggshell beads from eastern Africa [Credit: Hans Sell]

In the current study, researchers Jennifer Miller and Elizabeth Sawchuk investigate this idea using increased data and evaluate the hypothesis in a new region where it has never before been tested.

Review of old ideas, analysis of old collections

To conduct their study, the researchers recorded the diameters of 1,200 ostrich eggshell beads unearthed from 30 sites in Africa dating to the last 10,000 years. Many of these bead measurements were taken from decades-old unstudied collections, and so are being reported here for the first time. This new data increases the published bead diameter measurements from less than 100 to over 1,000, and reveals new trends that oppose longstanding beliefs.

The ostrich eggshell beads reflect different responses to the introduction of herding between eastern and southern Africa. In southern Africa, new bead styles appear alongside signs of herding, but do not replace the existing forager bead traditions. On the other hand, beads from the eastern Africa sites showed no change in style with the introduction of herding.

Archaeological ostrich eggshell beads from southern Africa (a,b) and eastern Africa (c,d) [Credit: Jennifer Miller]

Although eastern African bead sizes are consistently larger than those from southern Africa, the larger southern African herder beads fall within the eastern African forager size range, hinting at contact between these regions as herding spread. "These beads are symbols that were made by hunter-gatherers from both regions for more than 40,000 years," says lead author Jennifer Miller, "so changes - or lack thereof - in these symbols tells us how these communities responded to cultural contact and economic change."

Ostrich eggshell beads tell the story of ancient interaction

The story told by ostrich eggshell beads is more nuanced than previously believed. Contact with outside groups of herders likely introduced new bead styles along with domesticated animals, but the archaeological record suggests the incoming influence did not overwhelm existing local traditions. The existing customs were not replaced with new ones; rather they continued and incorporated some of the new elements.

In eastern Africa, studied here for the first time, there was no apparent change in bead style with the arrival of herding groups from the north. This may be because local foragers adopted herding while retaining their bead-making traditions, because migrant herders possessed similar traditions prior to contact, and/or because incoming herders adopted local styles.

The current study reports ostrich eggshell bead data from 11 new sites, including Magubike Rockshelter [Credit: Jennifer Miller]

"In the modern world, migration, cultural contact, and economic change often create tension," says Sawchuk, "ancient peoples experienced these situations too, and the patterns in cultural objects like ostrich eggshell beads give us a chance to study how they navigated these experiences."

The researchers hope that this work inspires a renewed interest into ostrich eggshell beads, and recommend that future studies present individual bead diameters rather than a single average of many. Future research should also investigate questions related to manufacture, chemical identification, and the effects of taphonomic processes and wear on bead diameter.

"This study shows that examining old collections can generate important findings without new excavation," says Miller, "and we hope that future studies will take advantage of the wealth of artifacts that have been excavated but not yet studied."

The study is published in the open-access journal PLOS ONE.

Source: Max Planck Institute for the Science of Human History [November 27, 2019]

Inbreeding and population/demographic shifts could have led to Neanderthal extinction

By: Thomas Schmitt Attorney on November 27, 2019 / comment : 0 Anthropology, Early Humans, Europe, Genetics, Near East, Ticker

Small populations, inbreeding, and random demographic fluctuations could have been enough to cause Neanderthal extinction, according to a study published in the open-access journal PLOS ONE by Krist Vaesen from Eindhoven University of Technology, the Netherlands, and colleagues.

Small populations, inbreeding, and random demographic fluctuations could have been enough to cause Neanderthal extinction, according to a new study [Credit: Petr Kratochvil (CC0)]

Paleoanthropologists agree that Neanderthals disappeared around 40,000 years ago--about the same time that anatomically modern humans began migrating into the Near East and Europe. However, the role modern humans played in Neanderthal extinction is disputed. In this study, the authors used population modelling to explore whether Neanderthal populations could have vanished without external factors such as competition from modern humans.

Using data from extant hunter-gatherer populations as parameters, the authors developed population models for simulated Neanderthal populations of various initial sizes (50, 100, 500, 1,000, or 5,000 individuals). They then simulated for their model populations the effects of inbreeding, Allee effects (where reduced population size negatively impacts individuals' fitness), and annual random demographic fluctuations in births, deaths, and the sex ratio, to see if these factors could bring about an extinction event over a 10,000-year period.

The population models show that inbreeding alone was unlikely to have led to extinction (this only occurred in the smallest model population). However, reproduction-related Allee effects where 25 percent or fewer Neanderthal females gave birth within a given year (as is common in extant hunter-gatherers) could have caused extinction in populations of up to 1,000 individuals. In conjunction with demographic fluctuations, Allee effects plus inbreeding could have caused extinction across all population sizes modelled within the 10,000 years allotted.

The population models are limited by their parameters, which are based on modern human hunter-gatherers and exclude the impact of the Allee effect on survival rates. It's also possible that modern humans could have impacted Neanderthal populations in ways which reinforced inbreeding and Allee effects, but are not reflected in the models.

However, by showing demographic issues alone could have led to Neanderthal extinction, the authors note these models may serve as a "null hypothesis" for future competing theories--including the impact of modern humans on Neanderthals.

The authors add: "Did Neanderthals disappear because of us? No, this study suggests. The species' demise might have been due merely to a stroke of bad, demographic luck."

Source: Public Library of Science [November 27, 2019]

Barbequed clams on the menu for ancient Puerto Ricans

By: Thomas Schmitt Attorney on November 27, 2019 / comment : 0 Americas, Archaeology, Puerto Rico, South America

Scientists have reconstructed the cooking techniques of the early inhabitants of Puerto Rico by analysing the remains of clams.

Photographs of all shells analyzed in this study [Credit: Cardiff University]

Led by Philip Staudigel, who conducted the analysis as a graduate student at the University of Miami Rosenstiel School and is now a postdoctoral researcher at Cardiff University, the team has used new chemical analysis techniques to identify the exact cooking temperatures at which clams were cooked over 2500 years ago.

With cooking temperatures getting up to around 200oC according to the new analysis, the team believe the early Puerto Ricans were partial to a barbeque rather than boiling their food as a soup.

The study, which also involved academics from the University of Miami and Valencia College, has been published today in the journal Science Advances.

Whilst the results throw new light on the cultural practices of the first communities to arrive on the island of Puerto Rico, they also provide at least circumstantial evidence that ceramic pottery technology was not widespread during this period of history - it's likely that this would be the only way in which the clams could have been boiled.

Lead author of the study Dr Philip Staudigel, currently at Cardiff University's School of Earth and Ocean Sciences, said: "Much of peoples' identity draws upon on where they came from, one of the most profound expressions of this is in cooking. We learn to cook from our parents, who learned from their parents.

Measuring in excavation unit at CRNWR_P13 [Credit: Carlos Mora]

"In many parts of the world, written records extend back thousands of years, which often includes recipes. This is not the case in the Caribbean, as there were no written texts, except for petroglyphs. By learning more about how ancient Puerto Rican natives cooked their meals, we can relate to these long-gone peoples through their food."

In their study, the team analysed over 20kg of fossilised clam shells at the University of Miami's Rosenstiel School of Marine and Atmospheric Sciences Stable Isotope Lab, which were collected from an archaeological site in Cabo Rojo, Puerto Rico.

The pre-Arawak population of Puerto Rico were the first inhabitants of the island, arriving sometime before 3000 BC, and came from Central and/or South America. They existed primarily from fishing, hunting, and gathering near the mangrove swamps and coastal areas where they had settled.

The fossilised shells, dating back to around 700 BC, were cleaned and turned into a powder, which was then analysed to determine its mineralogy, as well as the abundance of specific chemical bonds in the sample.

When certain minerals are heated, the bonds between atoms in the mineral can rearrange themselves, which can then be measured in the lab. The amount of rearrangement is proportional to the temperature the mineral is heated.

Sample reacting with phosphoric acid, releasing CO2 gas which will then be analyzed using mass spectrometry [Credit: Philip Staudigel]

This technique, known as clumped isotope geochemistry, is often used to determine the temperature an organism formed at but in this instance was used to reconstruct the temperature at which the clams were cooked.

The abundance of bonds in the powdered fossils was then compared to clams which were cooked at known temperatures, as well as uncooked modern clams collected from a nearby beach.

Results showed that that the majority of clams were heated to temperatures greater than 100°C - the boiling point of water - but no greater than 200°C. The results also revealed a disparity between the cooking temperature of different clams, which the researchers believe could be associated with a grilling technique in which the clams are heated from below, meaning the ones at the bottom were heated more than the ones at the top.

"The clams from the archaeological site appeared to be most similar to clams which had been barbequed," continued Dr Staudigel.

"Ancient Puerto Ricans didn't use cookbooks, at least none that lasted to the present day. The only way we have of knowing how our ancestors cooked is to study what they left behind. Here, we demonstrated that a relatively new technique can be used to learn what temperature they cooked at, which is one important detail of the cooking process."

Source: Cardiff University [November 27, 2019]

Imaging uncovers secrets of medicine's mysterious ivory manikins

By: Thomas Schmitt Attorney on November 27, 2019 / comment : 0 Archaeology, Europe, Germany, USA, Western Europe

Little is known about the origins of manikins--small anatomical sculptures thought to be used by doctors four centuries ago--but now advanced imaging techniques have offered a revealing glimpse inside these captivating ivory dolls. Researchers using micro-CT successfully identified the material composition and components of several ancient ivory manikins, according to a new study being presented next week at the annual meeting of the Radiological Society of North America (RSNA).

This is an ivory figurine reclining on its 'bed' with all organs placed inside [Credit: Fides R. Schwartz, RSNA]

Ivory manikins are typically thought to have been carved in Germany in the late 17th century. They are reclining human figurines, 4-8 inches long, generally female, which open to reveal removable organs and sometimes a fetus attached with a fabric "umbilical" cord. The manikins have intricately carved features, and some even have pillows beneath their heads. It is believed that they were used for the study of medical anatomy or perhaps as a teaching aid for pregnancy and childbirth. By the 18th century, they had been replaced by more realistic teaching tools, such as wax models and cadavers. The manikins then became objects of curiosity and luxury status symbols in private collections.

Duke University in Durham, N.C., holds the world's largest collection of manikins (22 out of 180 known manikins worldwide). Most of the manikins in the Duke collection were purchased in the 1930s and 1940s by Duke thoracic surgeon Josiah Trent, M.D., and his wife Mary Duke Biddle Trent, prior to the 1989 ivory trade ban. The researchers noted that after being donated to the university by Trent's granddaughters, the manikins have spent most of their time in archival storage boxes or behind display glass, as they are too fragile for regular handling.

"They are usually stored in a library vault and occasionally rotated into a special display unit in the Duke Medical Library for visitors to appreciate," said Fides R. Schwartz, M.D., research fellow in the Department of Radiology at Duke.

Non-destructive imaging with X-rays and CT has been used in the past to examine fragile artwork and ancient artifacts. Imaging of relics has been extremely beneficial to the fields of archaeology and paleopathology--the study of ancient diseases.

This is an Ivory manikin after removal of the abdominal and chest wall, ribs, and part of the uterus. Internal organs such as the lungs, intestines, as well as a fetus inside the uterus are visible [Credit: Fides R. Schwartz, RSNA]

Micro-CT is an imaging technique with greatly increased resolution, compared to standard CT. It not only allows visualization of internal features, it noninvasively provides volumetric information about an object's microstructure.

Dr. Schwartz and colleagues hoped that through micro-CT imaging they could determine the ivory type used in the Duke manikins, discover any repairs or alterations that were not visible to the naked eye, and allow a more precise estimation of their age.

"The advantage of micro-CT in the evaluation of these manikins enables us to analyze the microstructure of the material used," she said. "Specifically, it allows us to distinguish between 'true' ivory obtained from elephants or mammoths and 'imitation' ivory, such as deer antler or whale bone."

The research team scanned all 22 manikins with micro-CT and found that 20 out of the 22 manikins were composed of true ivory alone, though materials like antler might have been less expensive in that time. They discovered that one manikin was made entirely of antler bone, and one manikin contained both ivory and whale bone components.

Micro-CT initial scan data. The internal organs and fetus inside the uterus are visible, similar to a photograph [Credit: Fides R. Schwartz, RSNA]

Metallic components were found in four of the manikins, and fibers in two. Twelve manikins contained hinging mechanisms or internal repairs with ivory pins, and one manikin contained a long detachable pin disguised as a hairpiece.

The most established trade routes in the 17th and 18th centuries sourced ivory from Africa, leading the researchers to believe that since nearly all of the manikins were made from true ivory, it is likely that the ivory obtained to craft the manikins was acquired from the African region.

"This may assist in further narrowing down the most probable production period for the manikins," Dr. Schwartz said. "Once historical trade routes are more thoroughly understood, it might become clear that the German region of origin had access to elephant ivory only for a limited time during the 17th and 18th century, for example, from 1650 to 1700 A.D."

Additionally, identifying non-ivory components in the manikins may provide more accessibility to carbon dating, allowing the researchers to more accurately estimate the age of some of the manikins without damage to the fragile pieces.

The researchers also hope to acquire 3D scans to create digital renderings and enable subsequent 3D printed models.

"This is potentially valuable to scientific, historic and artistic communities, as it would allow display and further study of these objects while protecting the fragile originals," Dr. Schwartz said. "Digitizing and 3D printing them will give visitors more access and opportunity to interact with the manikins and may also allow investigators to learn more about their history."

Source: Radiological Society of North America [November 27, 2019]

Unique sled dogs helped the inuit thrive in the North American Arctic

By: Thomas Schmitt Attorney on November 27, 2019 / comment : 0 Archaeology, Arctic, Genetics, Indigenous Cultures, North America, Ticker

A unique group of dogs helped the Inuit conquer the tough terrain of the North American Arctic, major new analysis of the remains of hundreds of animals shows.

A team of Greenland sled dogs working in Greenland’s Disko Bay  [Credit: Tatiana Feuerborn]

The study shows that the Inuit brought specialised dogs with them when they migrated from Alaska and Siberia instead of adopting local dogs they would have come across during their migration. They instead maintained their own dogs, suggesting they were keen to enhance or keep the special features they had. By analysing the shape of elements from 391 dogs, the study shows that the Inuit had larger dogs with a proportionally narrower cranium to these earlier dogs. The Inuit dogs are the direct ancestors of modern Arctic sledge dogs, although their appearance has continued to change over time.

Experts had thought the Inuit used dogs to pull sledges, and this is the first study which shows they introduced a new dog population to the region to do this. These dogs then spread across the North American Arctic alongside Inuit migrants.

Dr Carly Ameen, an archaeologist from the University of Exeter who led the study, said: "Dogs have lived in North America for as long as humans, but we show here that the Inuit brought new dogs to the region which were genetically distinct and physically different from earlier dogs.

"Thousands of years ago there was not the huge number of dog breeds as we know them today. Through analysing the DNA and morphology of the remains of hundreds of dogs we've found that the dogs used by the Inuit had distinctive skull and teeth shapes, and would have likely looked different in life to dogs already in the Arctic."

The ancestors of these dogs arrived with the Inuit to the North American Arctic [Credit: Tatiana Feuerborn]

Experts also examined the DNA from 921 dogs and wolves who lived during the last 4,500 years. This analysis of the DNA, and the locations and time periods in which they were found, shows dogs from Inuit sites occupied from around 2,000 years ago were genetically different from the dogs already in the region.

Study co-lead author Tatiana Feuerborn, from the Globe Institute in Denmark and the Centre for Palaeogenetics in Sweden, said: "Archaeological evidence has shown us that before the Inuit arrived in North America dog sledging was a rarity. Our analysis of the DNA suggests dogs brought by the Inuit were distinct from the earlier dogs of the North American Arctic to fill specialist role in helping communities thrive in this hostile environment by aiding with transportation and hunting. The genetic legacy of these Inuit dogs can still be seen today in Arctic sledge dogs."

The Inuit were specialised sea mammal hunters, and were more mobile than other groups living in the Arctic, migrating huge distances across the region over 1,000 years ago, with the help of dog sledges and water craft. Today, sledge dogs whose origins can be traced back to the Inuit period continue to be an important part of Arctic communities.

The article is published in the journal Proceedings of the Royal Society B.

Source: University of Exeter [November 27, 2019]

New Cretaceous mammal fossil sheds light on evolution of middle ear

By: Thomas Schmitt Attorney on November 27, 2019 / comment : 0 China, Early Mammals, Fossils, Palaeontology

Researchers from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences and the American Museum of Natural History (AMNH) have reported a new species of multituberculate - a type of extinct Mesozoic rodent - with well-preserved middle ear bones from the Cretaceous Jehol Biota of China. The findings were published in Nature.

Reconstruction of Jeholbaatar kielanae [Credit: XU Yong]

The new mammal, Jeholbaatar kielanae, has a middle ear that is distinct from those of its relatives. WANG Yuanqing and WANG Haibing from IVPP, along with MENG Jin from AMNH, proposed that the evolution of its auditory apparatus might have been driven by specialization for feeding.

Fossil evidence shows that postdentary bones were either embedded in the postdentary trough on the medial side of the dentary or connected to the dentary via an ossified Meckel's cartilage in early mammals, prior to their migration into the cranium as seen in extant mammals.

Detachment of the mammalian middle ear bones from the dentary occurred independently at least three times. But how and why this process took place in different clades of mammals remains unclear.

The Jeholbaatar kielanae specimen was discovered in the Jiufotang Formation in China's Liaoning Province (Jehol Biota). It displays the first well-preserved middle-ear bones in multituberculates, providing solid evidence of the morphology and articulation of these bony elements, which are fully detached from the dentary.

It reveals a unique configuration with more complete components than those previously reported in multituberculates. The new fossil reveals a transitional stage in the evolution of the surangular - a "reptilian" jawbone.

In light of current evidence, scientists argue that the primary (malleus-incus) and secondary (squamosal-dentary) jaw joints co-evolved in allotherians, allowing a distinct palinal (anteroposterior) jaw movement while chewing.

Detachment of the auditory apparatus of the middle ear would have gained higher selective pressure in order to increase feeding efficiency, suggesting that evolution of the middle ear was probably triggered by functional constraints on the feeding apparatus in allotherians.

Source: Chinese Academy of Sciences [November 27, 2019]