Humans

Proto-cities built from 6200 years ago in eastern Europe upend our ideas about when civilisation began and why people made the move from rural to urban living

Humans 24 February 2021
By Laura Spinney
Stuart Mcreath
AROUND 6200 years ago, farmers living on the eastern fringes of Europe, in what is now Ukraine, did something inexplicable. They left their neolithic villages and moved into a sparsely inhabited area of forest and steppe. There, in an area roughly the size of Belgium between the modern cities of Kiev and Odessa, they congregated at new settlements up to 20 times the size of their old ones.
This enigmatic culture, known as the Cucuteni-Trypillia, predates the earliest known cities in Mesopotamia, a civilisation that spanned part of the Middle East, and in China. It persisted for 800 years, but then, as mysteriously as it had begun, this experiment in civilisation failed. The inhabitants left the lightest of footprints in the landscape, and no human remains have been found. “Not a pinkie, not a tooth,” says palaeogeneticist Alexey Nikitin at Grand Valley State University in Michigan.
This puzzling lack of evidence has fuelled a lively debate about what Nikitin calls the “Dark Ages” of European prehistory. “You talk to five Trypillian archaeologists, you get five different opinions,” he says.
But the data gap hasn’t stifled interest – quite the opposite. Several projects in recent years have tried to make sense of the Trypillian proto-cities. Despite big disagreements, what is emerging is a picture of an early and unique attempt at urbanisation. It may be the key to understanding how modern Europe emerged from the Stone Age – and even throw new light on the emergence of human civilisation in general.

Uruk and Tell Brak, which … More

We too often turn to insulting people’s brain power – and that closes off our ability to understand others, argues Melanie Challenger

Humans | Comment 24 February 2021Michelle D’urbano
BELITTLING the minds of others is commonplace. Stupid! Brainless! Imbecile! Dozy! Just scroll through the comments on pretty much any contentious article and you will find criticism by mental slander. Social media is littered with words like “unthinking” and “idiot”, especially when people are confronted with views with which they disagree.
Indeed, Twitter is a lightning rod of prejudices about minds. Former US president Donald Trump was perhaps the kingpin here, before Twitter banned him. Not only did he routinely boast of his own mental prowess – “sorry losers and haters, but my I.Q. is one of the highest” – but he persistently used mental slurs to silence critics: “dummy!”.
Yet we can all be guilty of mental slander. Right-wing supporters frequently call those on the left “libtards”. Meanwhile, according to the Oxford English Dictionary’s New Monitor Corpus, conservative voters in the US are often derided as “nutjobs”. Mental slurs are a fast and simple trick to silence an unwanted voice and to lower trust in evidence we resist. A growing body of research is allowing us to understand where this prejudice comes from.

Advertisement

Humans are group-living animals. Probing and judging other minds is a part of how we coordinate with each other, cooperate and make and break alliances. By the age of 5, children make assumptions about people’s mental states, such as understanding that someone can be mistaken in their beliefs. Particular parts of the brain are implicated: the medial prefrontal cortex, the temporal poles and the posterior superior temporal sulcus. These work in concert to enable us to detect and make judgements about minds – both our own and those of others.
All this doesn’t stop at the neck. When we bond in a group – whether that is with kin or co-workers, friends or football fans – our bodies produce hormones like oxytocin that play a role in bringing us together. But, as psychologist Carsten De Dreu points out, these hormones don’t just unite us; they encourage exclusivity. This – directly or indirectly – can alter our views on other minds. In effect, we believe those in our group more readily, often exaggerating the mental abilities of those with whom we feel allegiance.
What follows from this is that we can undervalue the intelligence of those whose views differ from our own. Even more troubling, we can find ourselves responding more slowly to signals of emotion or experience from outsiders. Social psychologists Susan Fiske and Lasana Harris have used neurological imaging and behaviour studies to show that we shut down the medial prefrontal cortex, which is involved in social cognition, when confronted with minds we wish to ignore. When we suspend parts of our brain key to recognising another’s mental and emotional states, we not only close our minds to one another, we cease to care.
All this has real-world consequences for whom we listen to and whose voices we trust. In an age of political polarisation and misinformation, the echo chambers created by social media do more than just seal us off from diverse possibilities and points of view; they muffle our ability to care about those whose views we might not like.

What can we do about it? First, we need to recognise the biases that prevent us from keeping one another in mind. We must make it less socially acceptable to use mental slander in the service of an argument. Beyond this, we would benefit from greater opportunities to hear one another out.
This pandemic is a reminder that we have very few mechanisms for listening and deliberating together. That needs to change. But a more radical option lies in a much larger paradigm shift. Is it time for our species to stop using the idea of own superior cognition as validation?
More on these topics: More

By Karina Shah
A bone fragment, found in south-east Alaska, belonging to a dog that lived more than 10,000 years ago
Douglas Levere / University at Buffalo
Dogs were domesticated at least 27,000 years ago, and they have been tagging along with humans ever since. Now, we may have the strongest evidence yet that early dogs even accompanied the first Americans as they moved along the Pacific coast.
Charlotte Lindqvist and her colleagues at the University at Buffalo in New York extracted DNA from the oldest known dog remains found in the Americas, and found the genetic signature is consistent with the idea that dogs first arrived in the region between 17,000 and 16,000 years ago – which is also roughly in line with the currently accepted time for the arrival of the first Americans.

Advertisement

The small bone – a piece of the dome-like head of a thighbone – measures 1 centimetre in diameter and was originally found in the late 1990s in Lawyer’s cave, a site in south-east Alaska.
About 15 years ago it was carbon dated to a little more than 10,000 years old, although at the time the small bone fragment was assumed to have come from a bear. Only when Lindqvist and her colleagues studied DNA from the specimen did they realise it belonged to a dog, which makes it the earliest evidence of dogs found so far in the Americas.
The team isolated mitochondrial DNA from the bone to understand the dog’s genetic history. “The mitochondrial DNA gives us a history of the dog’s mother because it contains maternally inherited DNA,” says Lindqvist.
The DNA sequence showed that the ancient Alaskan dog was closely related to the lineage of domestic dogs that were living in the Americas before European contact and colonisation. In detail, the exact lineage the Alaskan dog belonged to branched off from these “precontact dogs” about 14,500 years ago. The genetic data also showed that the Alaskan dog’s lineage branched off from dogs living in Siberia roughly 16,700 years ago.

“This dog belonged to a descent of very early dogs that moved into the New World soon after the ice age around 17,000 years ago,” says Lindqvist.
Archaeological and genetic evidence suggests humans also moved into the Americas roughly 17,000 years ago – several thousand years earlier than once thought. This has led to a reassessment of how they did so.

Originally it was thought early Americans migrated along an internal corridor between the two large ice sheets that were covering the land after the last peak in glacial activity. This would have seen them enter what is now the lower 48 states of the US via what is now Montana. But this route didn’t become viable to travel through until 13,000 years ago, so the very first Americans must have taken a different route.
Many researchers now think the early Americans travelled along the coast of what is now Alaska and British Columbia, probably because the ice sheet at the North Pacific coast began retreating earlier and provided an ice-free coastal corridor. If dogs also moved into the Americas about 17,000 years ago, they presumably did so with these coastal human communities.
“Humans must have moved over Siberia and Alaska into the New World via a route along the coast, and they brought their dogs with them,” says Lindqvist.
The dog bone found in south-east Alaska is around 250 years older than the previously confirmed earliest dog remains reported from a site in Illinois in 2018. “I am very happy to lose our record for the earliest dogs in the Americas, as this new Alaskan dog represents an important piece of the puzzle,” says Angela Perri at Newcastle University, UK, who led the research in 2018 and wasn’t involved in this new study.
Journal reference: Proceedings of the Royal Society B: Biological Sciences, DOI: 10.1098/rspb.2020.3103
More on these topics: More

By Alison George
A colour-enhanced image of the ancient kangaroo artwork
Damien Finch
A life size kangaroo painted in red ochre around 17,300 years ago is Australia’s oldest known rock art. This indicates that the earliest style of rock art in Australia focused on animals, similar to the early cave art found in Indonesia and Europe.
Thousands of rock art sites are found all over Australia, with the Kimberley region of Western Australia containing a particularly rich record. But dating the images is challenging as the minerals and organic material needed to determine when the art was created are hard to find.

Advertisement

Stylistically, Australian rock art has been categorised into five different phases, with the oldest thought to be the so-called naturalistic phase depicting mainly animals and sometimes plants such as yams. But with no firm dates, no one knew for sure.
Now, Damien Finch at the University of Melbourne and his colleagues have dated the images in eight rock shelters in Balanggarra Country, which lies in the north-eastern Kimberley region. Finch and his colleagues worked with the Balanggarra Aboriginal Corporation, which represents the Traditional Owners of the land, and members of the Corporation reviewed their research paper.
They dated the images by measuring the radiocarbon signal from ancient wasp nests that lie beneath and on top of the artwork.

They discovered that a kangaroo image (pictured above) on the ceiling of a rock shelter containing thousands of ancient mud wasp nests was painted between 17,500 and 17,100 years ago. “This is an amazing site, with wonderful paintings all over the place,” says Finch. And, crucially for the dating, “wasps have been building nests at this site pretty much consistently for 20,000 years“, he says.
This kangaroo painting is around 2 metres long, with details of its fur depicted within an outline of its shape.
“The dating of this oldest known painting in an Australian rock shelter holds a great deal of significance for Aboriginal people and Australians and is an important part of Australia’s history,” said Cissy Gore-Birch, Chair of the Balanggarra Aboriginal Corporation, in a media statement.

Analysis of 15 other images, including a 3-metre-long snake and a lizard-like creature, as well as other kangaroo-like animals, showed that this naturalistic style of animal paintings proliferated between 17,000 and 13,000 years ago.
After this, it seems to have been superseded by the so-called Gwion style of rock art, which predominantly features images of humans. A 2020 study by Finch, also using wasp nest dating, showed that this style of art proliferated from around 12,000 years ago.
The kangaroo is unlikely to be Australia’s oldest painting. Humans may have reached Australia as early as 65,000 years ago and the researchers have studied a tiny number of images in the rock art. “We have only worked on a fraction of the Kimberly. The chances are we haven’t found the oldest painting,” says Finch.
Journal reference: Nature Human Behaviour, DOI: 10.1038/s41562-020-01041-0
More on these topics: More

By Priti Parikh
A pit latrine toilet in Kayunga District, Uganda
Sean Sprague/Alamy
Nature sanitises around 38 million tonnes of human waste per year – the equivalent of around £3.2-billion-worth of commercial water treatment.
Alison Parker at Cranfield University in the UK and colleagues looked at 48 cities in Africa, Asia, North America and South America. They analysed how much human waste is produced and where it ends up by reviewing existing data from interviews, observations and direct field measurements.

Advertisement

The team looked at waste management not connected to sewers. This included pit latrines and septic tanks where waste is primarily contained on-site – in a hole below the ground for pit latrines and in box tanks for septic tanks.
Liquid waste from pit latrines and excess water from septic tanks can gradually filter through soil – a process that cleans it before it reaches groundwater. However, this doesn’t happen in cities where the water table is shallow or where large volumes of waste are discharged in a crowded area. Instead, the liquids can contaminate ground water, posing a health risk.
With 892 million people, predominantly in low and middle income countries, using this type of waste management, the researchers estimate that nature safely treats around 38 million tonnes of human waste per year. The team did not look at how much waste is not safely treated.
More than 4 billion people don’t have access to safe sanitation services, with one-third living in low income countries. Unsafe sanitation is responsible for 775,000 deaths each year.
“Sanitation that involves the ground naturally treating waste can be part of the solution,” says Parker. However, pit latrines, septic tanks and other natural waste management options only work if the soils can filter the waste or if the waste dumped in rivers can be diluted safely without causing harm to the environment, which is not always the case.
Duncan Mara at the University of Leeds, UK, says that approaches like this cannot be the “be-all and end-all” as every person on this planet should be given access to sanitation which is safe for the environment and protects human health. This should include also sewers in crowded areas as they are safer.

Journal reference: Cell Press: One Earth, DOI: S2590-3322(21)00049-X
More on these topics: More

By Joshua Rapp Learn
Carbonised barley malt from the Viking Age settlement at Hundborg in northern Jutland
Peter Steen Henriksen/National Museum of Denmark
Ancient malted barley grains have revealed that Danes were likely brewing beer and raising their drinking horns at least two millennia ago.
The oldest known beers in the world trace back to the beginning of agriculture in the Middle East. In Scandinavia, the oldest evidence of beer is based on residue in a bark bucket from roughly 1370 BC which was found in the grave of a Bronze Age teenager known as the Egtved Girl. But chemical analysis shows that beer … More

PixabayExplore
Is Capitalism Compatible With Environmentalism asks broadcaster Jon Snow of a panel of experts in climate science, policy and economics at the Science Museum in London. Watch online at 7.30 pm on 26 February.

Read
Hidden Wonders are revealed by French physicist étienne Guyon and his co-authors in a fascinating book that explores the mathematical elegance in everyday objects and physical mechanisms, from crumpled paper to sandcastles.
Courtesy of EPIX
Watch
Pennyworth, on Amazon Prime Video from 28 February (StarzPlay subscription required), starts its second counterfactual season with Batman’s future butler still in the UK, embroiled in a devastating civil war.
More on these topics: More

Curiosity about how well our bodies are ageing has fuelled an industry around telomere length tests, but the much touted “biological clock” in our DNA isn’t what we thought

Life 17 February 2021
By Marta Zaraska
Martin Leon Barreto

WHEN David Nurse turned 30, he wanted to find out how his biological age compared with his chronological one. A life coach with the US National Baseball Association, he hoped that the ultra-healthy lifestyle he advocates to players had kept his own body young and healthy, too. So he took a test to assess the length of his telomeres. It revealed his biological age to be 28 years. That was in 2017. Two years later, he took another test. “I was down to 25, so that was great,” he says.
If you google “telomeres”, you are likely to find them described as an ageing clock. They are segments of DNA at the ends of each chromosome that become shorter every time a cell divides. If this shortening happens slowly, it suggests that your body is wearing well. Say you are a 60-year-old with telomeres as long as those of an average 50-year-old, your mortality risk is equivalent to that of someone 10 years younger – or so the story goes. Increasing numbers of people want this information, and many companies offer tests like the one Nurse took, together with various pills claimed to lengthen your telomeres and, in turn, your lifespan.
If only it were that simple. We are now discovering that telomeres are an unreliable ageing clock, which raises questions about the validity of ageing tests based on them. The links between telomere length and lifestyle choices also aren’t as straightforward as we once thought. In fact, long telomeres can even be bad news. Nevertheless, there are some surprising ways we can look after our … More