Humans

Adrià Voltà
Do newborn babies consciously hear sounds and feel pain? In the past, infant boys undergoing circumcision were often not given anaesthetic, partly because it was thought that their brains were immature and they couldn’t consciously feel pain. Even today, there remains much uncertainty. Babies cannot tell us what they are experiencing, so it is hard to know what they are conscious of.
Recently, neuroscientists have uncovered evidence suggesting newborn infants perceive the world consciously. When newborns encounter certain surprising stimuli, their brain reacts strikingly similarly to the way conscious adult brains react.
One method to investigate uses the oddball paradigm.… More

Animal etchings into rocks along the Orinoco river in South AmericaPhilip Riris et al.
Prehistoric engravings of giant snakes along South America’s Orinoco river are among the largest examples of rock art we know of anywhere in the world, with some stretching for more than 40 metres.
The Orinoco is one of the world’s largest rivers, flowing through Venezuela and along its border with Colombia. “There’s an outstanding record of rock art along the Orinoco, especially on the Venezuelan side,” says José Oliver at University College London. “Usually, they are paintings found in rock shelters.”
Engravings are common in many open-air sites along the river, he says, but not all of them have been officially recorded.Advertisement

Since 2015, Oliver and his colleagues have taken several trips to areas along the Colombian and Venezuelan margins of the river to build a better picture of its rock engravings.
“It wasn’t difficult to encounter new sites,” says team member Philip Riris at Bournemouth University in the UK. “Every time you go round a corner, there was always more.”
Of the 157 rock art sites that the team has managed to visit, 13 were made up of engravings that were at least 4 metres tall. “Anything that size is monumental in our view,” says Riris. “That means they’re often visible from quite far away, maybe 500 metres to a kilometre.”
Most of the engravings depict people, mammals, birds, centipedes, scrolls and geometric shapes, but snakes were among the largest motifs, with the biggest measuring 42 metres across. In the mythology of the Indigenous Orinoco people, anacondas and boa constrictors are primordial creators, so are held in high regard, says Riris.
The prominence of the rock art along the river suggests that the ancient carvings may have been a territorial marker to signal that a certain group lives there, but not necessarily a warning to stay away. “The engravings may not be exclusionary, but rather an inclusionary practice that was shared among the communities,” says Riris.
Ceramics unearthed in the region and dated to 2000 years ago have similar motifs to the ones on the engravings, which suggests that the rock art was similarly created two millennia ago.

The team hopes to discover even more of these carvings and collect clues about their origins and purpose. For example, many of them appear near rock shelters with burial grounds, which suggests they may be connected to ancient funerary practices.
“This is a valuable piece of research,” says Andrés Troncoso at the University of Chile. “It sheds light about the rock art of a non-well-known area of South America, continuing to fill up our knowledge of this region.”
“Euro-American minds often jump to the mammoths, cave lions and large mammals of Pleistocene cave sites in western Europe when they think of rock art,” says Patrick Roberts at the Max Planck Institute of Geoanthropology in Germany. “However, the giant snake engravings studied in the paper are some of the largest single rock art images anywhere in the world and come from the heart of a lowland tropical environment.”

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Joel Redman/Gallery Stock
If you were to take one step to improve your health, what would it be: change what you eat, be more active or invest more time in your friendships?
Most people know that diet and exercise have huge impacts on well-being. Fewer realise that social connection is just as important. A slew of studies has shown that feeling supported and loved can help protect you from common conditions, including diabetes, Alzheimer’s disease, stroke and heart attack. And the benefits don’t end there. In the workplace, good relationships are linked with greater creativity and job satisfaction – and a lower risk of burnout.
The obvious upshot is that we should put more effort into building strong and meaningful relationships. But many people find the idea of supercharging their social lives daunting. Up to now, science hasn’t been of much practical help because research was focused on environmental factors linked with lonelines, such as increasing urbanisation and reliance on technology. That might help explain why people seeking the secrets of better connection often turn to self-help gurus, whose advice is based on anecdote rather than data. But now there is a better way to think about this problem.
In recent years, researchers have made great strides in revealing the psychological barriers that undermine our attempts to build good relationships, and in discovering ways to overcome them. As I explain in my new book, The Laws of Connection: 13 social strategies that will change your life, most of us are needlessly pessimistic about our capacity to build bridges with those around us, and it is often surprisingly simple to cultivate better habits.
One… More

A modern replica of 3500-year-old armour from the Mycenaean civilisationAndreas Flouris and Marija Marković
Modern military volunteers donned replicas of ancient Greek armour and engaged in exercises inspired by Homer’s epic poem The Iliad. The demonstration shows how elite Bronze Age warriors could have fought in heavy protective gear during sustained combat.
The experiment’s results strongly suggest that the 3500-year-old Dendra armour suit – one of the oldest complete suits of metal armour from Europe’s Bronze Age – was indeed suitable for battle. Some scholars have argued that it was merely a ceremonial outfit for the Mycenaean civilisation that once dominated mainland Greece and the Aegean Sea’s islands.

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Andreas Flouris at the University of Thessaly in Greece and his colleagues recruited modern Greece’s Hellenic Marines to wear 23-kilogram Dendra armour replicas as each participant walked, ran, rode on a replica chariot and performed combat moves involving a sword, spear, bow and arrow and even a stone.
These activities followed Homer’s descriptions of heavily armoured elite warriors, surrounded by bands of followers, roaming the battlefield, periodically attacking the enemy and retreating to safety behind the main battle lines to rest and eat, says co-author Ken Wardle at the University of Birmingham in the UK.

“Homeric fighting activity was characterised by hit-and-run tactics, a form of physical effort described in modern physiology as ‘high-intensity interval exercise’,” says Flouris.
Throughout the 11-hour exercise period, the researchers recorded the armour wearers’ heart rate, core body temperature and average skin temperature, tested their blood and measured the energy cost of each activity. They also assigned an Iliad-inspired Mediterranean meal plan, featuring heavier breakfasts and dinners along with snacks such as dry bread, honey, goat cheese and onions.
The armour-wearing volunteers successfully endured the regimen, despite reporting signs of fatigue and soreness. But they could have probably exerted even more effort in a real combat situation “had their life depended on it”, says team member Yiannis Koutedakis, also at the University of Thessaly.
The team also used a computer-based mathematical model to show how a warrior wearing the Dendra armour could have lasted the entire 11-hour combat period in all but the most extreme outdoor conditions and high temperatures.
“Though few archaeologists would view Homer as a reliable source for Bronze Age warfare, and indeed the study only engages lightly with archaeological studies of warfare and bronze armour, their rigorous protocols for testing the armour are important for measuring its practicality for sustained use in battle,” says Barry Molloy at the University College Dublin in Ireland.
The study’s Dendra armour demonstration may help interpret similar artefacts, such as armour discovered in the so-called Griffin Warrior Tomb in Greece, say Sharon Stocker and Jack Davis at the University of Cincinnati in Ohio. “Though we doubt that the Hellenic Marines will adopt it as their official gear any time soon,” says Stocker.

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An excavation at Laili cave in East Timor in 2019 Mike Morley
A cave on the island of Timor has given archaeologists a vital clue to the route taken by ancient humans when they first made their way to the Australian continent.
It is known from archaeological evidence in Australia’s Northern Territory that people were there at least 65,000 years ago. At this time, when sea levels were lower, Australia and New Guinea were part of a larger landmass known as Sahul.

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Researchers believe there are two likely routes people could have taken from South-East Asia to Sahul. One is a southern route via Timor. Alternatively, Homo sapiens could have travelled via Sulawesi, an island to the north of Timor.
Now, Sue O’Connor at the Australian National University in Canberra and her colleagues believe they have found evidence ruling out the possibility that the first arrivals came through Timor.
In other locations on Timor, the oldest evidence of human occupation was less than 50,000 years old. Archaeologists were unable to look for older artefacts as, at all the other sites they studied, they hit bedrock rather than sediment layers that could potentially contain evidence of an earlier presence, says O’Connor.
In 2019, her team dug a new pit at a cave called Laili, on the north coast of East Timor, and discovered a rich deposit of archaeological evidence including tens of thousands of stone tools, proving that humans had occupied the island for 44,000 years.
Crucially, however, this layer of occupation was underlain by sediments with no evidence of humans. This means it is likely that before 44,000 years ago, people were absent, says O’Connor.
“This is the first time in Timor that we have sterile, non-occupation layers below evidence of people’s presence,” she says.
O’Connor says such a clear boundary between no evidence of humans followed by tens of thousands of years of artefacts is called an “arrival signature”.

The cave’s prominent location and access to resources gives the researchers confidence that it is unlikely to have been missed by any early humans travelling through the area.
“It’s a really, really big cave with a big flowing river in a braided floodplain and very close to the coast,” says O’Connor. “It’s a perfect place for people to establish an occupation base camp. You couldn’t find a more ideal setting.”
Because of the evidence that people were in Australia 65,000 years ago but not in Timor until 44,000 years ago, it means humans most likely migrated via the islands to the north, says O’Connor.
“Looking at the layers in Laili cave, it’s like ‘bang’ – you can really see clearly when the people arrive,” she says. “It was like a line had been drawn between the two layers – before people and after people. It was so clear.”
Peter Veth at the University of Western Australia says the case for a later date for the occupation of Timor is building. He says ancient Australians were not as isolated as was once believed and that there were probably multiple waves of migration to Sahul.
“I think an earlier northern route seems plausible. This is a highly significant site as, based on a broad suite of shellfish, fish, crustacea and other resources found in the cave, it shows there was a fully fledged maritime economy in place when Timor was settled.”

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Pollen records show the landscape was dominated by pasture animals, suggesting the presence of nomadic herdersDIMITRIOS TILIS/Getty Omages
An analysis of pollen from Lake Volvi in Greece has unexpectedly revealed that nomads thrived in this region for centuries after the chaos unleashed by the collapse of the Roman Empire.
Adam Izdebski at the Max Planck Institute of Geoanthropology in Germany and his colleagues were studying sediment cores from the lake as part of a larger study. As lake sediments build up, changes in the abundance of various kinds of pollen in the sediment layers can record how nearby vegetation changed over time.

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In some other places around the Mediterranean, the team has found signs of reforestation after the collapse of the Western Roman Empire around AD 476. But at Lake Volvi, from around AD 540, the team found less tree pollen but more pollen from plants associated with nomadic livestock herders. These nomads were returning to the same areas seasonally, so planted some crops, such as barley.
“We have this moment when the Roman agriculture disappears almost completely due to plague, climate change and warfare, but you don’t get reforestation – you actually get less forest very quickly,” says Izdebski.
“The landscape was dominated by pasture animals even in the high mountain areas. This was a complete shift from how the Romans farmed the lowlands for several hundred years.”
This means those earlier farmers moved away, died or adopted a nomadic lifestyle, he says.
Greece was nominally under the control of the Eastern Roman, or Byzantine, Empire around at the time of this shift. It is known that the region was raided by Bulgar nomads around AD 540, but it wasn’t known that nomads lived in this region for several centuries.
The only historical information that correlates with the team’s findings is an account of a Byzantine emperor being ambushed by Bulgar nomads around AD 700.
“It seems that there was a local society that didn’t want any emperor to be around,” says Izdebski, who presented the findings at the meeting of the European Geosciences Union in Vienna, Austria, last month.
Around AD 850, the Byzantine Empire reasserted control and the signs of nomads disappear. Instead, there was reforestation.
The findings provide rare evidence of the presence of nomadic peoples at a particular place and time, says Izdebski. “We know very little about their history because the states were not interested in recording them.”
Historians didn’t write about nomadic peoples as they weren’t part of the elites, he says. And because nomads were difficult to tax, there are no tax records either – tax records can be a rich source of information about past populations.

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The Red Pyramid at Dahshur in Egypt was one of many built close to a lost branch of the NileEman Ghoneim
Many of the pyramids of ancient Egypt were built along a now extinct branch of the river Nile, geological surveys have revealed. This could explain why these pyramids, including the famed Great Pyramid of Giza, are clustered in a thin strip of arid, inhospitable land.
“Since ancient times, the Nile has provided sustenance to Egyptian settlements, and it functions as the main water corridor that allowed for the transportation of goods and building materials in the past,” says Tim Ralph at Macquarie University in Sydney, Australia. “For this reason, most of the key cities and monuments were built in close proximity to the banks of the Nile and its peripheral branches.”

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More than 100 pyramids were constructed between 4700 and 3500 years ago as grand tombs for Egypt’s pharaohs. Thirty-one of these, including the pyramids of Dahshur, Giza and Saqqara, are dotted along the edge of Egypt’s Western desert, several kilometres away from the Nile.
To transport the enormous number of people and resources necessary to build these pyramids, researchers have long thought that the Nile may have once had an offshoot that flowed by the construction sites.
To investigate further, Ralph and his colleagues looked at radar satellite imagery and land elevation data of the region. Depressions in the landscape indicated that the old water channel may have stretched 64 kilometres past the pyramid fields between the northern city of Giza and the village of Lisht in the south. It was also close to the ancient Egyptian capital of Memphis and the Abusir, Saqqara and Dahshur pyramid complexes.
Once the researchers had a rough idea of the branch’s location, they took soil and sediment core samples along its path and discovered a riverbed of sand hidden under what is now farmland or desert.
“We guess that it was roughly between 200 and 700 metres wide, and at least 8 metres deep at its deepest,” says Ralph.
Causeways that have been found around the 31 pyramids seem to end at the banks of this ancient Nile branch – a sign that the water channel was used to transport building materials thousands of years ago.
The ancient offshoot, dubbed the Ahramat branch after the Arabic word for pyramid, eventually dried up after a severe drought hit the region around 4200 years ago, says Ralph.
The course of the ancient Ahramat branch of the NileEman Ghoneim et al.
“The existence of the channel is an excellent result,” says Penny Wilson at Durham University, UK. “Mapping all of this is a wonderful addition to the ancient landscape that has been buried and shows a cost-efficient way to reconstruct and re-evaluate the economic and social systems of the pharaonic state.”
Campbell Price at the University of Liverpool, UK, says: “I think people often imagine Egyptian pyramids being marooned in the middle of the desert.”
“This research seems to further demonstrate that they were in fact closely connected with the agricultural life of pharaonic Egypt – and the river Nile,” he says.

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Humans have an exceptional ability to run long distancessportpoint / Alamy Stock Photo
Before the advent of rifles, many cultures around the world hunted by pursuing prey over long distances. The energy gained by hunting in this way can far exceed the energy spent running, researchers have found, strengthening the argument that humans evolved for endurance running.
“I think our paper makes a very strong case for its importance in the past,” says Eugene Morin at Trent University in Canada. “Something that was thought to be marginal is now shown to be a common strategy worldwide.”

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Humans are exceptional endurance athletes, capable even of outrunning animals such as horses over distances of tens of kilometres. We have muscles built for stamina rather than power, and can keep cool by sweating a lot.
“These traits can only be explained in the context of running,” says Morin. “And there are not many reasons for humans to run for long distances other than hunting.”
It has been suggested that humans evolved to chase prey until the prey became too exhausted or overheated to run any further.
This idea, known as the endurance running hypothesis, has been hotly debated. One criticism is that running uses a lot of energy compared with walking. Another is that there are hardly any reports of modern humans using this hunting technique, suggesting it isn’t very efficient.
So, Morin and Bruce Winterhalder at the University of California, Davis, first estimated the energy expended to catch prey during persistence hunting versus the energy gained by catching prey of various sizes. For all but the smallest prey, running beats walking, according to their modelling.
That’s because running doesn’t use much more energy per kilometre but can greatly shorten the duration of a chase. Running 4 kilometres to catch an animal is more efficient than walking 8 kilometres, for instance.
In practice, walking wouldn’t usually work at all, says Morin, because endurance hunting often relies on pushing prey so hard that they overheat. “In most cases, this requires running,” he says.
Morin and Winterhalder also searched through accounts of various peoples written by anthropologists or missionaries from the 1500s onwards. They found around 400 descriptions of endurance hunting from all over the world, most from before 1850.
For example, an account of the Beothuk people of Newfoundland describes a lengthy pursuit of a stag. “The stag at first easily outstrips his pursuer, but after a run of four or five miles he stops and is by and bye [sic] overtaken; again he sets off, and again he is overtaken; again, and again, he is overtaken,” it says. Another account describes endurance hunting of herds of goats in Hawaii.
Running over snow
To Morin’s surprise, there were also accounts from colder regions, whereas previously known examples were from hot, arid regions. “We hunted the moose by running him down on snowshoes, and we could run all day, such as wolves,” an individual of the Gwichʼin people of Alaska and Canada is reported as saying.
The ideal conditions for this were thick snow with a crust strong enough to support a person wearing snowshoes but not strong enough to support heavier prey, says Morin.
He also points out that being able to run long distances used to be a highly valued ability, with numerous accounts of long-distance running races being part of the culture of peoples all around the world.
“It’s hard to argue with the results of their analysis, which clearly support other anatomical, physiological, archaeological and genetic evidence that humans evolved to run long distances to hunt,” says Daniel Lieberman at Harvard University, one of the proponents of the endurance running hypothesis. “Until the invention of modern technologies, persistence hunting by endurance running was widespread and very successful.”

“I think their review is super interesting,” says Cara Wall-Scheffler at Seattle Pacific University, who has been critical of the hypothesis. But she also points out that endurance running is mentioned in just 2 per cent of all the accounts of hunting the study looked at.
Henry Bunn at the University of Wisconsin-Madison says he remains sceptical of the hypothesis. Bunn thinks the method wouldn’t have worked in the bushlands where humans evolved, where hunters would quickly lose sight of fleeing prey. He also thinks endurance hunters would catch mostly young or old animals, but his team found teeth from butchered animals in their prime at one 2-million-year-old site.
On the basis of similar accounts of hunting, Wall-Scheffler recently argued that women took part in hunts much more often than thought. Morin says there are “copious” examples of women and girls taking part in running races, but he and his colleagues found that only 2 per cent of the accounts of endurance hunting they looked at describe women doing it.

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