Archive for the ‘Archaeology’ Category

Capuchin monkeys have a 3,000-year archaeological record

June 24th, 2019
Capuchin monkeys have a 3,000-year archaeological record

Enlarge (credit: By Tiago Falótico - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=60386655)

The archaeological record of human tools use dates back about 2.5 million years, and archaeologists use changes in stone tool technology to trace changes in human evolution, culture, and lifestyles. Now a team of archaeologists in Brazil has excavated capuchin monkey stone tools dating back to 3,000 years ago, and they reveal changes in behavior and diet over thousands of years—just like the early human archaeological record but on a compressed time scale.

Archaeology: not just for humans

Bearded capuchin monkeys are more versatile tool-users than chimpanzees. They select rocks of the right sizes and shapes for a variety of tasks, from digging to cracking open a range of nuts and seeds (each has its own size and weight specifications for the perfect cracking tool). Female capuchins even flirt with potential mates by throwing rocks at them.

At Brazil’s Serra de Capivara National Park, a group of capuchins crack open cashews with round quartzite cobbles, which they choose and carry to the cashew grove from a dry streambed about 25m (82 feet) away. Capuchins have been processing their food at the same spot for at least 3,000 years—and leaving behind their distinctively banged-up tools. That’s about 450 monkey generations, and during that time, archaeologists noticed some major changes in the stone hammers and how they were used.

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Posted in animal archaeology, Archaeology, capuchin monkeys, monkeys, primate archaeology, primates, science, stone tools | Comments (0)

Ancient Peruvian engineering could help solve modern water shortages

June 24th, 2019
Photo of ancient canal.

Enlarge / Diversion canals channel water into earth-bottomed infiltration canals like this one, where water can begin to soak into the ground on its way to a pond or basin. (credit: Musuq Briceño, CONDESAN, 2012.)

Rain seldom falls on the desert lowlands of coastal Peru, so people in the area have always depended on the water that flows down from the Andes during the rainy season. But streams in this part of the world come and go quickly, so indigenous people built a system of canals and ponds to channel excess rainwater and create groundwater. Now a group of researchers says that a scaled-up version could help improve Peru’s water management.

Ancient engineers (not aliens)

1,400 years ago, Chavin and Wari indigenous communities on the slopes of the Andes Mountains dug systems of stone-lined and earthen canals to channel excess rainwater from streams to areas where the ground could soak up more of the water. From there, the water gradually trickled through sediment and cracks in the rock until it reached springs downslope. “Water is stored in the soils and travels much slower beneath the surface than it would as overland flow,” Boris Ochoa-Tocachi, a civil engineer at Imperial College London, told Ars Technica. Water that would otherwise have been lost to flooding feeds springs that remain active even into the dry season.

Today, most of these once-widespread canals—called amunas in the Quechua language—lie abandoned or clogged. But in a few rural communities, like Huamantanga in the central Andes, people have used and maintained parts of the ancient amunas for centuries. 11 of the original canals still operate, feeding 65 active springs and 14 small ponds.

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Posted in ancient infrastructure, ancient people did stuff, ancient south america, Archaeology, civil engineering, peru, Pre-Columbian civilizations, science, wari, water infrastructure | Comments (0)

New study takes a bird’s-eye view of the Nasca Lines

June 20th, 2019
New study takes a bird’s-eye view of the Nasca Lines

Enlarge (credit: Masaki Eda)

At first glance, one of the most famous figures of Peru's Nasca Lines looks like a fairly generic hummingbird. But the details of the drawing—and those of several other ancient drawings, paintings, and sculptures of animals and plants around the world—reveal a lot of information about the actual species. The bird has three toes, all pointed in the same direction, a long, thin beak, and the feathers at the center of its tail are long and straight.

Those are trademarks of birds called hermits, a genus in the hummingbird family. Other hummingbird species in Peru have forked or fan-shaped tails (which is the kind of detail the Nasca artists likely would have gotten right).

"Until now, the birds in these drawings have been identified based on general impressions or a few morphological traits present in each figure," said zooarchaeologist Masaki Eda of the Hokkaido University Museum and his colleagues in a statement. That team examined the hermit and 15 other bird geoglyphs in detail, noting the shapes and relative sizes of their beaks, heads, necks, bodies, wings, and feet. Like biologists trying to identify a new specimen in the field, the researchers compared those details to the birds that live in Peru today.

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Posted in Archaeology, guano, hummingbirds, inca, Nasca, Nasca Lines, pelicans, peru, science | Comments (0)

This 2,400-year-old bark shield took a beating in an Iron Age fight

May 31st, 2019
Photo of ancient shield in pieces.

Enlarge / This is what the shield looked like after being excavated and conserved. (credit: Michael Bamforth)

When they found the shield, University of York archaeologists Michael Bamforth and his colleagues thought it must have been ceremonial, because surely bark couldn’t hold up against heavy iron-tipped spears and iron axes. After all, every other Iron Age shield archaeologists have found in Europe so far has been made of wood or metal. But it turned out that the tough, springy bark would have been perfectly capable of repelling arrows. Its lightness may even have made an Iron Age warrior more agile on the battlefield.

Welcome to the Iron Age; we’ve got swords and spears

By around 400 BCE, even small villages across Britain surrounded themselves with ditches, embankments, and palisades. At farmsteads scattered between villages, people grew wheat and barley or herded sheep and cattle. Local or regional chiefs ruled these farming tribes. No written sources tell us how often fighting broke out, or whether the bearer of this shield would’ve seen more action in cattle raids or in pitched combat, but the palisaded settlements hardly suggest a peaceful bucolic landscape.

“It is debatable how much fighting there would have been between these groups,” Bamforth told Ars Technica. “However, the Iron Age is a time of increasing personal wealth and power and one imagines that violence may have erupted over access to resources, trade, and all the other things that groups of people fight about today.”

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Posted in ancient britain, ancient europe, ancient people did stuff, ancient warfare, Archaeology, iron age, science | Comments (0)

14,000-year-old footprints record an underground Stone Age family outing

May 29th, 2019
Photo of archaeologists studying ancient footprints.

Enlarge / The clay-rich mud of Basura Cave preserved these footprints for 14,000 years. (credit: Emily Packer (Marcomms))

There was a lot more to Paleolithic life than hunting, gathering, and leaving well-preserved bones for archaeologists. A 14,000-year-old set of footprints and crawl tracks preserves a snapshot of an ancient family’s exploration of a cave in northern Italy—something they apparently did just for the heck of it. The tracks were left in an ancient layer of clay and record how a small group of hunter-gatherers, carrying makeshift torches, waded through ponds and sometimes crawled on their hands and knees to explore the cave. And they apparently brought their young children with them on the adventure.

“Most likely they were pushed into the cave by simple curiosity and a sense of wonder for unexplored places,” archaeologist Marco Romano of the University of Witwatersrand in South Africa, told Ars Technica.

A dangerous idea of family fun

About 180 tracks from the prehistoric explorers remain in the cave floor. Footprints show where they walked; impressions of hands, knees, and the tops of feet show where they crawled through a low tunnel to the cave’s innermost chamber. Based on the size and number of the tracks, at least five people entered the cave, including three children. The youngest child would have been around 3 years old at the time, and their tiny footprints record the small, unsteady steps of a toddler. It’s a rare look at what childhood must have been like for Paleolithic hunter-gatherers.

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Posted in ancient people did stuff, Archaeology, Footprints, science | Comments (0)

We probably don’t descend from Australopithecus sediba

May 21st, 2019
Photo of A. sediba skull.

Enlarge / According to Du and Alemseged, A. sediba is probably not our direct ancestor. (credit: Brett Eloff courtesy Profberger and Wits University)

Sometime around 2 million years ago, a group of bipedal hominins in Eastern Africa gradually evolved into something that looked and acted enough like us to be part of our genus, Homo. This was an important moment in the evolutionary history of our species, but paleoanthropologists aren’t sure yet exactly which species actually gave rise to our branch of the hominin family tree. A new study, however, suggests that we can probably rule out one of the contenders.

Where did we come from?

The top contenders include a species called Australopithecus sediba, known from the fossilized remains of two adults and four children who apparently fell to their deaths in Malapa Cave around 1.9 million years ago. The other top contender is called A. afarensis, best known from the 3.2-million-year-old skeleton nicknamed Lucy and a set of preserved footprints near Laetoli, Tanzania.

Both species walked on two legs and probably made stone tools, but their shoulders, arms, and hands were also still built for climbing trees. So which species is actually our ancestor, and which is just a distant cousin?

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Posted in anthropology, Archaeology, australopithecus, hominins, human evolution, lucy, paleoanthropology, science | Comments (0)

Archaeologists find DNA in a 10,000-year-old piece of chewing gum

May 17th, 2019
Archaeologists find DNA in a 10,000-year-old piece of chewing gum

Enlarge (credit: Kashuba et al. 2019)

The people who lived at Huseby-Kiev in western Sweden 10,000 years ago made their living by hunting and fishing. That doesn't sound surprising until you consider that this was a landscape that had, until recently, been covered by ice sheets 4 km (2.5 miles) thick. How they occupied the re-emerging landscape is a bit of a mystery. We don't know much about who they actually were, where they came from, or how they made their way into Sweden as the ice receded.

In the 1990s, archaeologists recovered a few chewed-up lumps of birch bark pitch, some of which still held fingerprints and tooth marks left behind from millennia ago. Using this ancient chewing gum, archaeologist Natalija Kashuba of Uppsala University recently recovered DNA from two women and one man who had lived, worked, and apparently chewed gum on the shores of ancient Sweden. That means we can now link DNA from ancient people to their artifacts, and that's a big clue about how people migrated into Scandinavia after the Ice Age.

Two groups of hunter-gatherers met in Sweden

Birch bark pitch, like other saps and resins from various trees around the world, makes a decent chewing gum. When chewed and softened, it's also a handy glue for repairing cracked pottery or gluing bone points onto stone blades to make a vicious-looking composite point (see gallery). That's how people at Huseby-Kiev seem to have used it.

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Posted in ancient DNA, ancient europe, ancient people did stuff, Archaeology, ice age, mesolithic, science, stone tools | Comments (0)

Mass grave in Poland embodies the violent beginning of the Bronze Age

May 15th, 2019
This is the Late Neolithic mass grave at Koszyce, Poland.

Enlarge / This is the Late Neolithic mass grave at Koszyce, Poland. (credit: Image courtesy of Piotr Wodarczak)

Sometime between 2880 and 2776 BCE, 15 family members were hastily buried together in a single pit, their shattered skulls telling a story of violent death. Yet someone interred the dead with the pottery, tools, and ornaments typical of a proper burial in their culture, a culture we know today by the name of its most common ceramic artifact: the Globular Amphora. And someone seems to have made the effort to put the closest family members alongside one another in the pit.

Today, the grave near the village of Koszyce in southern Poland is the only record of one particular act of brutal violence during a turbulent time in European prehistory.

Out of the blue

It seems that no one in the seasonal camp of pastoralists was prepared for the raiders. Nearly all of the dead are women and children. Though women in the past (and today) could be formidable fighters, no weapons are buried with them to suggest that was the case here. Almost none of their bones show signs of broken limbs raised in defense (known as parry fractures), so it doesn’t look like they went down fighting. Instead, most appear to have died from crushing blows to the back of their skulls, as if they’d been captured and executed.

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Posted in ancient DNA, ancient europe, Archaeology, biological archaeology, bronze age, mass grave, neolithic, science | Comments (0)

Ancient Bolivian ritual kit contains traces of hallucinogens

May 6th, 2019
This is a view of the Cueva del Chileno excavation site.

Enlarge / This is a view of the Cueva del Chileno excavation site. (credit: José Capriles, Penn State)

In a rock shelter in the highlands of southwest Bolivia amid the rubble of an area once set aside for funerary rituals, archaeologists found a leather-wrapped bundle of tools for preparing and inhaling snuff. They radiocarbon-dated the bundle to between 905 and 1170 CE, which is when the Tiwanaku Empire (a predecessor of the Inca and rival of the nearby Wari) was crumbling into smaller regional states. Chemical analysis reveals that the bundle once contained a small assortment of psychoactive plants, including coca leaves and ayahuasca.

Unwrapping a shaman’s bundle

Archaeologists Melanie Miller, José Capriles, and their colleagues used mass spectrometry to identify traces of cocaine, along with four other compounds, inside a hide pouch sewn from the skins of three fox snouts.

One compound, harmine, points to a plant called ayahuasca. Amazonian people brew it into a mind-altering tea, which also has traditional medicinal uses. Mixed with a plant called chacruna, the brew can produce vivid hallucinations. Small amounts of a compound called DMT could come from chacruna or from the seeds of a tree called vilca (whose name means “sacred” in the Quechua language of Peru). So it’s hard to say whether this was a ritual blend or a medicinal one. There’s not much archaeological evidence for ayahuasca, aside from traces of harmine in the hair of two Tiwanaku mummies from northern Chile who date from between 400 and 900 CE. So anthropologists still don’t agree on how long ago people started using it.

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Posted in ancient south america, Archaeology, ayahuasca, Bolivia, cocaine, mass spectrometry, Pre-Columbian civilizations, science, South American archaeology, Tiwanaku | Comments (0)

Study says ancient Romans may have built “invisibility cloaks” into structures

May 3rd, 2019
The Roman Colosseum is an oval amphitheatre in the center of the city of Rome. French scientists suggest its structure might have helped protect it from earthquake damage.

Enlarge / The Roman Colosseum is an oval amphitheatre in the center of the city of Rome. French scientists suggest its structure might have helped protect it from earthquake damage. (credit: Alex Livesey/Danehouse/Getty Images))

Scientists are hard at work developing real-world "invisibility cloaks" thanks to a special class of exotic manmade "metamaterials." Now a team of French scientists has suggested in a recent preprint on the physics arXiv that certain ancient Roman structures, like the famous Roman Colosseum, have very similar structural patterns, which may have protected them from damage from earthquakes over the millennia.

Falling within the broader class of photonic band gap materials, a "metamaterial" is technically defined as any material whose microscopic structure can bend light in ways it doesn't normally bend. That property is called an index of refraction, i.e., the ratio between the speed of light in a vacuum and how fast the top of the light wave travels. Natural materials have a positive index of refraction; certain manmade metamaterials—first synthesized in the lab in 2000—have a negative index of refraction, meaning they interact with light in such a way as to bend light around even very sharp angles.

That's what makes metamaterials so ideal for cloaking applications—any "invisibility cloak" must be able to bend electromagnetic waves around whatever it's supposed to be cloaking. (They are also ideal for making so-called "super lenses" capable of seeing objects at much smaller scales than is possible with natural materials, because they have significantly lower diffraction limits.) Most metamaterials consist of a highly conductive metal like gold or copper, organized in specific shapes and arranged in carefully layered periodic lattice structures. When light passes through the material, it bends around the cloaked object, rendering it "invisible." You can see anything directly behind it but never perceive the object itself.

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Posted in Archaeology, invisibility cloak, meta-materials, Physics, science | Comments (0)