Aboriginal Australians Used Boomerangs as Retouchers

Apr 14, 2021 by News Staff / Source

New research by Griffith University and University of Cape Town scientists provides the first traceological evidence of multipurpose nature of Australian hardwood boomerangs.

Australian Luritja man demonstrating method of attack with boomerang under cover of shield, c. 1920. Image credit: National Museum of Australia.

“Australian lithic assemblages contain a great number of retouched tools,” said lead author Eva Martellott from the Australian Research Centre for Human Evolution at Griffith University and her colleagues.

“Despite this fact, however, material evidence for, and studies, on the retouching tools utilised to create these technologies are limited, especially regarding their use in percussion retouch.”

“Indirect evidence found in ethnographic literature suggests that wooden items — specifically boomerangs — were frequently utilised as retouchers.”

In the study, the researchers analyzed microscopic traces on the surfaces of 100 ancient boomerangs from across each Australian state and territory.

By using a traceological method, they were able to more clearly see what tasks the boomerangs were used for by Aboriginal Australians in the past.

Retouch-induced marks were identified on 26% of the boomerangs examined by Martellotta et al. and were comparable to those traces observed on the surfaces of ancient European bone retouchers. Image credit: Martellotta et al., doi: 10.1016/j.jasrep.2021.102967.

“Not all boomerangs come back. Most are used for hunting and fighting purposes, whereas the returning ones are often children’s toys or used for games and learning purposes,” Martellotta said.

“We found specific marks related to the shaping of stone tools.”

“These marks are not new in archaeology — they are also identified on bone fragments in archaeological sites in Europe.”

“Here, the Neanderthals used them to modify the shape of stone tools, starting 500,000 years ago.”

“Our findings constitute the first traceological identification of hardwood boomerangs being used for shaping stone tools in various Aboriginal Australian contexts and emphasises the multipurpose nature of daily tools like boomerangs in Aboriginal culture.”

The findings were published in the Journal of Archaeological Science: Reports.

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Eva Francesca Martellotta et al. 2021. New data from old collections: Retouch-induced marks on Australian hardwood boomerangs. Journal of Archaeological Science: Reports 37: 102967; doi: 10.1016/j.jasrep.2021.102967

 

Neanderthal Nuclear DNA Found in Paleolithic Cave Sediments

Apr 16, 2021 by News Staff / Source

An international team of scientists has developed new methods for the enrichment and analysis of nuclear DNA from sediments, and applied them to cave deposits in Europe and Siberia dated to between approximately 200,000 and 50,000 years ago.

Vernot et al. extracted Neanderthal nuclear DNA from cave sediments. Image credit: Tyler B. Tretsven.

Skeletal remains are important sources of Pleistocene hominin DNA, but are rarely recovered at archaeological sites.

Mitochondrial DNA (mtDNA) has been retrieved from cave sediments, but provides limited value for studying population relationships.

Although nuclear DNA contains far more information, its retrieval from sediments presents substantial challenges. It’s far less abundant than mtDNA and difficult to distinguish from other non-hominin mammalian and microbial DNA, which dominates the genetic material often present in ancient sediments.

To address these challenges, Dr. Benjamin Vernot from the Department of Evolutionary Genetics at the Max-Planck-Institute for Evolutionary Anthropology and his colleagues developed methods to recover, enrich and analyze nuclear DNA from cave sediments.

“There are lots of places in the human genome that are very similar to a bear’s DNA, for example,” Dr. Vernot said.

“We specifically targeted regions in the genome where we could be confident of isolating only human DNA, and we also designed methods to measure our success in removing non-human DNA.”

“We wanted to be confident that we weren’t accidentally looking at some unknown species of hyena.”

Specifically, the researchers applied their approach to extract nuclear DNA from more than 150 sediment samples from three caves: Galería de las Estatuas in northern Spain and Chagyrskaya and Denisova caves in the Altai Mountains of southern Siberia.

They detected a population replacement in Spain approximately 100,000 years ago, accompanied by a turnover of mtDNA.

They also identified two radiation events in Neanderthal history during the early part of the Late Pleistocene.

“The dawn of nuclear DNA analysis of sediments massively extends the range of options to tease out the evolutionary history of ancient humans,” Dr. Vernot said.

“By freeing the field of ancient DNA from the constraints of finding human remains and expanding the number of sites potentially suitable for investigation, we can now study the DNA from many more human populations, and from many more places, than has previously been thought possible,” added Dr. Matthias Meyer, also from the Department of Evolutionary Genetics at the Max-Planck-Institute for Evolutionary Anthropology.

The findings were published in the journal Science.

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Benjamin Vernot et al. Unearthing Neanderthal population history using nuclear and mitochondrial DNA from cave sediments. Science, published online April 15, 2021; doi; 10.1126/science.abf1667

 

New Fossils of Homo erectus Found in Kenya

Apr 13, 2021 by News Staff / Source

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Paleoanthropologists have uncovered two new specimens of Homo erectus at the East Turkana site in Kenya. They’ve also verified the age of a skull fragment of Homo erectus — one of the oldest specimens attributable to this species — found earlier at the same site.

This is an artist’s reconstruction of Homo erectus. Image credit: Yale University.

“Homo erectus is the first hominin that we know about that has a body plan more like our own and seemed to be on its way to being more human-like,” said Dr. Ashley Hammond, a researcher at the American Museum of Natural History.

“It had longer lower limbs than upper limbs, a torso shaped more like ours, a larger cranial capacity than earlier hominins, and is associated with a tool industry — it’s a faster, smarter hominin than Australopithecus and earliest Homo.”

In 1974, scientists at the East Turkana site in Kenya found one of the oldest specimens of Homo erectus: a 1.9-million-year-old skull fragment. The specimen is only surpassed in age by a 2-million-year-old skull specimen in South Africa.

But there was pushback within the field, with some paleoanthropologists arguing that the East Turkana specimen could have come from a younger fossil deposit and was possibly moved by water or wind to the spot where it was found.

To pinpoint the locality, Dr. Hammond and colleagues relied on archival materials and geological surveys.

‘We had to go through hundreds of pages from old reports and published research, reassessing the initial evidence and searching for new clues,” said Dr. Dan Palcu, a geoscientist at the University of São Paulo and Utrecht University.

“We also had to use satellite data and aerial imagery to find out where the fossils were discovered, recreate the scene, and place it in a larger context to find the right clues for determining the age of the fossils.”

Although located in a different East Turkana collection area than initially reported, the skull specimen was found in a location that had no evidence of a younger fossil outcrop that may have washed there. This supports the original age given to the fossil.

A partial pelvis of Homo erectus found at the East Turkana site in Kenya. Image credit: A. Hammond / American Museum of Natural History.

Within 50 m of the reconstructed location, the researchers found two new specimens: a partial pelvis and a foot bone.

“Although they could be from the same individual, there’s no way to prove that after the fossils have been separated for so long,” they said.

“But they might be the earliest postcrania specimens yet discovered for Homo erectus.”

“Our work also suggests that this early Homo erectus was found in a paleoenvironment that included primarily grazers that prefer open environments to forest areas and was near a stable body of water, as documented by freshwater sponges preserved in the rocks.”

The findings were published in the journal Nature Communications.

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A.S. Hammond et al. 2021. New hominin remains and revised context from the earliest Homo erectus locality in East Turkana, Kenya. Nat Commun 12, 1939; doi: 10.1038/s41467-021-22208-x

 

Black Phosphorus-Based Coating Has Antimicrobial Activity

Apr 13, 2021 by News Staff / Source

Few-layered black phosphorus is highly antimicrobial toward resistant bacteria and fungal species; it is one of the thinnest antimicrobial coatings developed to date and could be used on wound dressings and implants, according to a paper published in the journal ACS Applied Materials & Interfaces.

Black phosphorus is effective at killing microbes when spread in nanothin layers on surfaces like titanium and cotton. Image credit: RMIT University.

Antimicrobial resistance has rendered many conventional therapeutic measures, such as antibiotics, ineffective.

This makes the treatment of infections from pathogenic microorganisms a major growing health, social, and economic challenge.

“Finding one material that could prevent both bacterial and fungal infections is a significant advance,” said Dr. Aaron Elbourne, a researcher in the School of Science at RMIT University.

“These pathogens are responsible for massive health burdens and as drug-resistance continues to grow, our ability to treat these infections becomes increasingly difficult.”

As black phosphorus breaks down, it oxidizes the surface of bacteria and fungal cells. This process, known as cellular oxidisation, ultimately works to rip them apart.

Dr. Elbourne and colleagues tested the effectiveness of nanothin layers of black phosphorus against five common bacteria strains, including Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA), as well as five types of fungus, including Candida auris.

In just two hours, up to 99% of bacterial and fungal cells were destroyed.

Importantly, black phosphorus also began to self-degrade in that time and was entirely disintegrated within 24 hours — an important feature that shows the material would not accumulate in the body.

The authors also identified the optimum levels of black phosphorus that have a deadly antimicrobial effect while leaving human cells healthy and whole.

“Black phosphorus breaks down in the presence of oxygen, which is normally a huge problem for electronics and something we had to overcome with painstaking precision engineering to develop our technologies,” said Dr. Sumeet Walia, a researcher in the School of Engineering at RMIT University.

“But it turns out materials that degrade easily with oxygen can be ideal for killing microbes — it’s exactly what the scientists working on antimicrobial technologies were looking for. So our problem was their solution.”

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Z.L. Shaw et al. Broad-Spectrum Solvent-free Layered Black Phosphorus as a Rapid Action Antimicrobial. ACS Appl. Mater. Interfaces, published online April 12, 2021; doi: 10.1021/acsami.1c01739

 

Study: 5,200 Tons of Extraterrestrial Dust Reach Earth’s Surface Each Year

Apr 13, 2021 by Enrico de Lazaro

In a new paper published in the journal Earth and Planetary Science Letters, an international team of researchers presents the results from a long-term collection of extraterrestrial particles performed during the last two decades near the French-Italian CONCORDIA station in Antarctica.

These SEM images show cosmic spherules and unmelted micrometeorites from the CONCORDIA collection, from left to right, top to bottom: glassy cosmic spherule, stony cosmic spherule, partially melted micrometeorite, unmelted fine-grained micrometeorite. Image credit: Rojas et al., 

doi: 10.1016/j.epsl.2021.116794.

“More than a century after the discovery of cosmic spherules in deep-sea sediments, the origin, composition and magnitude of the cosmic dust accretion on Earth is still a matter of debate,” said lead author Julien Rojas from the Université Paris-Saclay and colleagues.

“Extraterrestrial dust flux studies have been performed before atmospheric entry, while collections at the Earth’s surface of both melted and unmelted micrometeorites were achieved in numerous locations such as the deep sea, deserts, sedimentary rocks and the polar ice caps.”

“Although all these studies demonstrated that the annual extraterrestrial mass input on Earth is essentially carried by sub-millimeter particles, the precise mass distribution of particles down to a few tens of μm and its integrated value at the Earth surface remain uncertain.”

The researchers performed several independent collections of micrometeorites from ultra-clean snow samples in the CONCORDIA station located at Dome C, in the central regions of Antarctica.

“Dome C is an ideal collection spot due to the low accumulation rate of snow and the near absence of terrestrial dust,” they said.

They identified a total of 1,280 unmelted micrometeorites and 808 cosmic spherules with diameters between 30 and 350 μm and analyzed them using conventional scanning electron microscopy techniques.

Within that size range, we measured mass fluxes of 3.0 μg/m2*yr for micrometeorites and 5.6 μg/m2*yr for cosmic spherules.

Extrapolated to the global flux of particles in the 12-700 μm diameter range, the mass flux of dust at Earth’s surface is 5,200 tons/yr (1,600 and 3,600 tons/yr of micrometeorites and cosmic spherules, respectively).

“This total mass flux of extraterrestrial particles at the Earth’s surface is important for many astrophysical and geophysical issues,” the authors said.

“Our numerical simulations suggest that most of micrometeorites and cosmic spherules originate from Jupiter family comets and a minor part from the main asteroid belt.”

“The total dust mass input before atmospheric entry is estimated at 15,000 tons/yr.”

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J. Rojas et al. 2021. The micrometeorite flux at Dome C (Antarctica), monitoring the accretion of extraterrestrial dust on Earth. Earth and Planetary Science Letters 560: 116794; doi: 10.1016/j.epsl.2021.116794

Yukon Wolves Survived Ice-Age Extinction Thanks to Changes in Their Diet

Apr 12, 2021 by News Staff / Source

Gray wolves (Canis lupus) from the Yukon Territory, Canada, survived the extinction at the end of the last Ice Age by adapting their diet over thousands of years — from a primary reliance on horses (Equus sp.) during the Pleistocene, to moose (Alces alces) and caribou (Rangifer tarandus) today.

Gray wolves take down a horse on the mammoth-steppe habitat of Beringia during the Late Pleistocene, around 25,000 years ago. Image credit: Julius Csotonyi.

A research team led by Dr. Danielle Fraser from the Canadian Museum of Nature, Carleton University, and Smithsonian National Museum of Natural History, investigated if and how diets of Yukon gray wolves changed from the Pleistocene (50,000 to 26,000 years ago) to the recent times.

“We can study the change in diet by examining wear patterns on the teeth and chemical traces in the wolf bones,” said Zoe Landry, a student at Carleton University.

“These can tell us a lot about how the animal ate, and what the animal was eating throughout its life, up until about a few weeks before it died.”

Dr. Fraser, Landry and their colleagues relied on established models that can determine an animal’s eating behavior by examining microscopic wear patterns on its teeth.

Scratch marks indicate the wolf would have been consuming flesh, while the presence of pits would suggest chewing and gnawing on bones, likely as a scavenger.

The analysis showed that scratch marks prevailed in both the ancient and modern wolf teeth, meaning that the wolves continued to survive as primary predators, hunting their prey.

Their modern diet is well established; the diet of the ancient wolves was assessed by looking at the ratios of carbon and nitrogen isotopes extracted from collagen in the bones. Relative levels of the isotopes can be compared with established indicators for specific species.

The results showed that horses, which went extinct during the Pleistocene, accounted for about half of the gray wolf diet. About 15% came from caribou and Dall’s sheep, with some mammoth mixed in.

At this time, the ancient wolves would have co-existed with other large predators such as scimitar cats and short-faced bears.

The eventual extinction of these predators could have created more opportunity for the wolves to transition to new prey species.

“This is really a story of Ice Age survival and adaptation, and the building up of a species towards the modern form in terms of ecological adaptation,” said Dr. Grant Zazula, a paleontologist with the Palaeontology Program of Government of Yukon.

The team’s paper was published in the journal Palaeogeography, Palaeoclimatology, Palaeoecology.

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Zoe Landry et al. 2021. Dietary reconstruction and evidence of prey shifting in Pleistocene and recent gray wolves (Canis lupus) from Yukon Territory. Palaeogeography, Palaeoclimatology, Palaeoecology 571: 110368; doi: 10.1016/j.palaeo.2021.110368

 

West Africans Hunted for Honey 3,500 Years Ago

Apr 15, 2021 by News Staff / Source

Historical and ethnographic literature from across Africa suggests bee products, honey and larvae, had considerable importance both as a food source and in the making of honey-based drinks. To investigate this, a team of researchers from the University of Bristol and Goethe University analyzed lipid residues from 458 prehistoric pottery vessels of the Nok culture, Nigeria, West Africa, an area where early farmers and foragers co-existed.

Modern-day straw beehive in a tree in Nigeria. Image credit: Dunne et al., doi: 10.1038/s41467-021-22425-4.

Today, honeybees are an integral part of socio-ecological landscapes and beekeeping plays an important global economic role with around 1.6 million tons of honey being produced annually.

Wild honey is also known to be widely collected by foragers globally, except in environments such as the Arctic and Subarctic where bees do not survive.

However, evidence for ancient human exploitation of the honeybee is rare, saved in Paleolithic rock art depicting bees and honey, found in Spain, India, Australia and Southern Africa, spanning the period 40,000-8,000 years ago.

The majority of prehistoric rock art, with over 4,000 sites portraying bees, honeycombs and honey-collecting, is located in Africa, at Didima Gorge in Namibia and other locations.

Furthermore, the archaeology of honey-collecting is largely invisible, in contrast to the, often excellent, survival of other organic materials such as animal bones or plant remains.

Recently, lipid residue analysis identified evidence for the presence of beeswax in prehistoric pottery vessels from across Neolithic Europe, the Near East and Mediterranean North Africa, providing evidence for human exploitation of the honeybee from at least the 7th millennium BCE.

However, little is known of its importance in other areas globally, for example, in the subsistence of hunter-gatherer groups and early farming communities in West Africa, a vast geographic area extending from the Atlantic Ocean in the west, and south to Cameroon.

One of the most well-known cultures in prehistoric West Africa is the Nigerian Nok culture, which spans a period of around 1,500 years, beginning around the middle of the 2nd millennium BCE.

The Nok culture is characterized by its remarkable terracotta figurines, which constitute the earliest large-sized figurative art objects in Africa outside Egypt and early evidence for iron production in West Africa, ca. 1st millennium BCE.

In new research, Dr. Julie Dunne from the University of Bristol and colleagues performed organic residue analysis on a total of 458 potsherds from 12 archaeological sites in Central Nigeria, covering the Early, Middle and Late Nok periods.

To their great surprise, the scientists revealed that around one third of the pottery vessels used by the ancient Nok people were used to process or store beeswax.

The presence of beeswax in ancient pottery is identified through a complex series of lipids, the fats, oils and waxes of the natural world.

The beeswax is probably present as a consequence either of the processing (melting) of wax combs through gentle heating, leading to its absorption within the vessel walls, or, alternatively, beeswax is assumed to act as a proxy for the cooking or storage of honey itself.

“This is a remarkable example of how biomolecular information extracted from prehistoric pottery, combined with ethnographic data, has provided the first insights into ancient honey hunting in West Africa, 3,500 years ago,” Dr. Dunne said.

“We originally started the study of chemical residues in pottery sherds because of the lack of animal bones at Nok sites, hoping to find evidence for meat processing in the pots,” said Professor Peter Breunig, a researcher at Goethe University.

“That the Nok people exploited honey 3,500 years ago, was completely unexpected and is unique in West African prehistory.”

A paper on the findings was published in the journal Nature Communications.

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J. Dunne et al. 2021. Honey-collecting in prehistoric West Africa from 3500 years ago. Nat Commun 12, 2227; doi: 10.1038/s41467-021-22425-4