Humans

It’s easy to be disheartened by the puniness of our existence – yet perhaps for the first time in human history, everything depends on decisions each one of us makes

Humans 9 December 2020
By Joshua Howgego

JohnnyGreig/Getty Images

Do you matter?
LET’S start with the big picture: if it is significance on this Earth you are looking for, then the numbers are increasingly against you.
Go back 2000 years and there were fewer than 200 million people on the planet. When the industrial revolution kicked in from the 18th century, however, new methods emerged of feeding vastly more people and combating the infectious diseases that had kept our numbers in check. Our numbers began to shoot up, reaching nearly 7.7 billion now. Today, you are, to a greater extent than in all history, just a face in a crowd.
That doesn’t mean you matter any less to your closest friends and family. And perhaps you or your offspring may be one of those few who change the world for better (or for worse). But that is statistically unlikely. Even in spheres where we like to think we are important, such as parenting, the evidence suggests individuals don’t matter that much. Geneticist Robert Plomin at King’s College London has pointed out, for instance, that identical twins brought up in different families generally end up with the same level of cognitive ability.
It isn’t just about you
But there is another, contrary, line of thinking, that collectively all of us can make a difference on a grand scale. In the broad sweep of human history, these are pivotal times. With the development of nuclear weapons in the mid-20th century, humanity reached a point where we can destroy ourselves. In this century, existential risks have only increased thanks to the threat of catastrophic climate change, … More

Covid-19 continues to split some people along party lines. We are now beginning to work out why, writes Graham Lawton

Humans | Comment 9 December 2020
By Graham Lawton

REUTERS/Mike Blake

LIKE the majority of people in my local area, I follow the rules on face coverings. It’s an inconvenience, but I consider putting on a mask a small sacrifice to protect my health and that of other people. Every day, I see many people – more than could possibly have a legitimate exemption – flagrantly flouting the rules and it really gets up my nose.
The refuseniks annoy me on multiple levels. They are selfishly putting me and other people at risk. They think they know better than experts. They often fall for conspiracy theories. And even if they are … More

According to the many-worlds interpretation of quantum mechanics, the universe is constantly dividing and taking you with it – so would you recognise your other selves if you met them?

Humans 9 December 2020
By Daniel Cossins

Jonathan Knowles/Getty Images

Is there more than one of you?
BIOLOGICALLY speaking, there is definitively only one you (see “How likely are you?”). Physics might give you pause for thought, however. The most bewildering argument against your uniqueness comes from quantum mechanics, the fundamental theory that describes the often counter-intuitive behaviour of subatomic particles. It might imply not only that there are multiple, identical versions of you, but even that there are an infinite number of yous out there.
The quantum realm is notoriously fuzzy: quantum objects such as particles are described in terms of probabilities, encoded in mathematical widgets called wave functions that give you the odds on any number of different states the object might be in. Only when you observe or measure it does the object take on one of those states, at least from your perspective.
“Quantum theory might imply there are an infinite number of yous out there”
The truth of what happens at this point – and indeed what, if anything, the wave function itself is trying to tell us about reality – divides physicists. Many stick with a cop-out known as the Copenhagen interpretation: essentially, that we can never know what is happening in this fuzzy pre-measurement realm. In other words, quantum theory makes predictions about reality, but says nothing about what goes on under the hood.
That isn’t good enough for some. Physicists who subscribe to the rival “many worlds” interpretation insist that all the possibilities encoded in the wave function are real, and that they continue to exist in different universes that split off from ours every time a quantum … More

Quantum information can never be destroyed, so some of the essence of you could live on after death – but it’s not going to help the physical you

Humans 9 December 2020
By Joshua Howgego
Is death the end, or does part of us live on?
Getty Images

What happens when you die?
MICHELLE FRANCL-DONNAY will never forget 15 April 1987. Her husband Tom was due to pick her up from an evening meeting, but decided to take a swim first. He had an undiagnosed heart condition, and while in the pool had a catastrophic aneurysm. Michelle rode with him in the ambulance. That was the last time she spoke to him.
“When I saw Tom’s body the next morning, he clearly wasn’t there anymore,” says Francl-Donnay, a chemist at Bryn Mawr College in Pennsylvania and an adjunct scholar at the Vatican Observatory who writes extensively on both science and spirituality. Over the years, she found herself mulling a question humans have asked for a long time: where had he gone?
Even those of us who rationally reject the idea of an afterlife have trouble letting go of the idea. That might be down to our theory of mind. Because we habitually put ourselves in other people’s shoes and imagine their thoughts and feelings, it can be hard to believe that those thoughts and feelings can just cease to be when ours still feel so real.
Yet we have no evidence for anything different. When you die, blood stops flowing, the muscles cool and consciousness, whatever that is, slips away. If your body were simply let be, other organisms would rapidly digest it, from microbes already living inside you to newly arrived blowflies.
Human burial rites just change the timescale or manner of your physical disappearance: if your remains are cremated, for instance, the … More

By Colin Barras
Living in darkness, or even hibernating, could have left ancient humans with bone lesions
gorodenkoff/Getty Images

Some of the ancient humans living in Europe half a million years ago had a remarkable strategy for dealing with winter: they hibernated. At least, that is the claim being made by two researchers. Others dispute the evidence – but ongoing research suggests that it might be possible to induce a hibernation-like state in modern humans.
Sima de los Huesos – the “pit of bones” – lies in northern Spain and is one of the world’s most important sites for studying human evolution. Excavations at … More

By Luke Taylor
The rock art may be 12,500 years old
Courtesy of Jose Iriarte

An extensive collection of ancient rock art and archaeological remains found deep in the Colombian Amazon offers a rare glimpse into the lives of the earliest people to inhabit the region.
The images and remains suggest that people lived in the northern Amazon at the same time as now-extinct mega-mammals. They also show that the ancient humans had a varied diet, indicating that they adapted quickly to their new environment.
The as-yet unnamed site in the Serranía La Lindosa, a large, rocky outcrop in southern Colombia, was found by an international team of researchers investigating the Guaviare region. It is the earliest secure evidence of people in the Colombian Amazon, they say.

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A wealth of Indigenous artwork has been documented across Guaviare, particularly in Chiribiquete National Park. The artwork documented at La Lindosa is new to science, and appears to be unknown even to local people, according to the researchers. It is remarkable in both its detail and its scale, the team says. The collage of images includes geometric patterns, handprints, people and animals. It stretches across approximately 5 kilometres of rock face, and could take decades to fully study.

The archaeological team – co-led by Francisco Javier Aceituno at the University of Antioquia, Colombia – was thrilled to find depictions of what appear to be now-extinct megafauna alongside more familiar fish, birds and lizards still alive today.
“We knew that megafauna was in the region and went extinct around 10 to 12,000 years before the present,” says José Iriarte at the University of Exeter, UK, and a member of the research team. If people were depicting them in their art, the humans must have been present in the region at least 12,500 years ago, he argues.
Iriarte says it is “quite clear” that a palaeolama, an extinct stumpy-legged, long-necked camelid, is depicted. Other drawings have been tentatively identified as giant sloths due to their unique proportions, and mastodons – ancient relatives of elephants – due to their trunks.
“The realism for South American standards is really impressive,” says Iriarte.

Others are less sure.
“The horses are clear,” says Hans ter Steege, an expert on Amazonian plant diversity at the Naturalis Biodiversity Center in the Netherlands, who wasn’t involved in the research. “But the palaeolama could be a poor representation of a deer to me.”
Further study will be made of the artwork to gain more certainty of the depictions and their age, say the researchers.

However, additional archaeological evidence makes clear that humans were present in the region 12,500 years ago. The researchers have excavated an area at the base of one section of rock face and uncovered evidence of ancient human activity in the form of processed animal bones. Some of the remains occur in layers of dirt containing charred palms that radiocarbon dating shows are about 12,500 years old. The 12,500-year-old layers also contain fragments of ochre similar to that used to draw the rock art.
Establishing the presence of humans during this period — in which megafauna roamed the region and the climate was warming — is significant, says Aceituno.
“The most important thing has been to obtain good radiocarbon dates to specify the early peopling of the area,” he says.
It shows that humans shared the region with immense beasts, but also helps paint a picture of how their world would have looked.
No megafauna remains have been found at the site, perhaps suggesting that humans didn’t hunt the animals or they were processed elsewhere. There were no remains of medium-sized animals like monkeys either, a staple food for Indigenous groups inhabiting the region today. “It could mean they had not developed blowgun technology at this stage to hunt prey in the treetops,” says Iriarte.
Around half the remains were fish — including piranhas — but diets were broad. Reptiles like iguanas and snakes were consumed as well as rodents like paca and capybara.
There is also evidence that various fruits were eaten. The diversity of animals and plants consumed suggests humans adapted quickly to the Amazon, says ter Steege.
Journal reference: Quaternary International, DOI: 10.1016/j.quaint.2020.04.026
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By Donna Lu
Archaeologists have built replica Stone Age rafts to attempt the crossing to the Ryukyu islands
Yosuke Kaifu

Stone Age humans crossed the sea from Taiwan to the Ryukyu islands of south-west Japan tens of thousands of years ago – and it looks like they did so deliberately, even though the islands are too far away to be reliably visible from Taiwan.
Archaeological sites on several of the Ryukyu islands suggest humans had reached the islands by about 30,000 to 35,000 years ago. Yosuke Kaifu at the University of Tokyo and his colleagues suspect the ancient people did so by travelling north-east from Taiwan – a journey that involved ocean crossings of tens to hundreds of kilometres to hop from island to island. The researchers have even repeated some of these ocean crossings themselves using bamboo rafts of the kind that Stone Age humans might have built.
But it hadn’t been clear whether the crossing occurred deliberately or by accident. The Kuroshio current, which flows from Luzon in the Philippines past Taiwan and Japan, is one of the strongest ocean currents in the world, and in some parts is 100 kilometres wide.

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“The speed of the Kuroshio in the east of Taiwan is normally 1 to 2 metres per second,” says Kaifu.

To find out if people could have arrived at the islands by drifting on this current, the researchers looked at existing data from 138 satellite-tracked buoys, released into the world’s oceans as part of the Global Drifter Program. The 138 buoys all drifted past Taiwan or Luzon between 1989 and 2017.
Kaifu and his colleagues found that only four buoys travelled to within 20 kilometres of any of the Ryukyu islands. In all four cases this occurred as a result of adverse weather conditions, including a typhoon.
The finding suggests that the Kuroshio current directs drifters away from, rather than towards, the Ryukyu islands. Because the flow of the current is thought to have stayed the same for the past 100,000 years, it seems likely that Stone Age people reached the Ryukyu islands through deliberate voyaging rather than accidental drifting.
“Now we can tell with confidence that Palaeolithic people set sail deliberately even to a remote invisible island,” says Kaifu.

“Most people probably think that Palaeolithic people were just primitive and conservative, but I now see something different from that general image,” he says.
Journal reference: Scientific Reports, DOI: 10.1038/s41598-020-76831-7
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In Watch Dogs: Legion you can play as or team up with any of the characters of the game, and strolling around its digital version of London is a real treat, says Jacob Aron

Humans 2 December 2020
By Jacob Aron
Key London landmarks like The Shard appear in Watch Dogs: Legion
Ubisoft

Watch Dogs: LegionUbisoftPC, PlayStation 4 and 5, Xbox One, Series X and S
NEW SCIENTIST closed its offices on 13 March, a week or so before the UK went into national lockdown. Since then, I have spent most of this year in a small radius around my north London flat and have been into the city centre only a handful of times.
As a native Londoner, it is strange to be so cut off from the city, which is why the opening moments of Watch … More