New evidence that Lucy, our most famous ancestor, had superstrong arms

The Washington Post reports: In Ethiopia, she is known as “Dinkinesh” — Amharic for “you are marvelous.” It’s an apt name for one of the most complete ancient hominid skeletons ever found, an assemblage of fossilized bones that has given scientists unprecedented insight into the history of humanity.

You probably know her as Lucy.

Discovered in 1974, wedged into a gully in Ethiopia’s Awash Valley, the delicate, diminutive skeleton is both uncannily familiar and alluringly strange. In some ways, the 3.2-million-year-old Australopithecus was a lot like us; her hips, feet and long legs were clearly made for walking. But she also had long arms and dexterous curved fingers, much like modern apes that still swing from the trees.

So, for decades scientists have wondered: Who exactly was Lucy? Was she lumbering and land-bound, like us modern humans? Or did she retain some of the ancient climbing abilities that made her ancestors — and our own — champions of the treetops?

A new study suggests she was a little of both: Though her lower limbs were adapted for bipedalism, she had exceptionally strong arm bones that allowed her to haul herself up branches, researchers reported Wednesday in the journal PLoS One. [Continue reading…]

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Meet the frail, small-brained people who first trekked out of Africa

Science magazine reports: On a promontory high above the sweeping grasslands of the Georgian steppe, a medieval church marks the spot where humans have come and gone along Silk Road trade routes for thousands of years. But 1.77 million years ago, this place was a crossroads for a different set of migrants. Among them were saber-toothed cats, Etruscan wolves, hyenas the size of lions—and early members of the human family.

Here, primitive hominins poked their tiny heads into animal dens to scavenge abandoned kills, fileting meat from the bones of mammoths and wolves with crude stone tools and eating it raw. They stalked deer as the animals drank from an ancient lake and gathered hackberries and nuts from chestnut and walnut trees lining nearby rivers. Sometimes the hominins themselves became the prey, as gnaw marks from big cats or hyenas on their fossilized limb bones now testify.

“Someone rang the dinner bell in gully one,” says geologist Reid Ferring of the University of North Texas in Denton, part of an international team analyzing the site. “Humans and carnivores were eating each other.”

This is the famous site of Dmanisi, Georgia, which offers an unparalleled glimpse into a harsh early chapter in human evolution, when primitive members of our genus Homo struggled to survive in a new land far north of their ancestors’ African home, braving winters without clothes or fire and competing with fierce carnivores for meat. The 4-hectare site has yielded closely packed, beautifully preserved fossils that are the oldest hominins known outside of Africa, including five skulls, about 50 skeletal bones, and an as-yet-unpublished pelvis unearthed 2 years ago. “There’s no other place like it,” says archaeologist Nick Toth of Indiana University in Bloomington. “It’s just this mother lode for one moment in time.”

Until the discovery of the first jawbone at Dmanisi 25 years ago, researchers thought that the first hominins to leave Africa were classic H. erectus (also known as H. ergaster in Africa). These tall, relatively large-brained ancestors of modern humans arose about 1.9 million years ago and soon afterward invented a sophisticated new tool, the hand ax. They were thought to be the first people to migrate out of Africa, making it all the way to Java, at the far end of Asia, as early as 1.6 million years ago. But as the bones and tools from Dmanisi accumulate, a different picture of the earliest migrants is emerging. [Continue reading…]

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Humans aren’t the only primates that can make sharp stone tools

 

The Guardian reports: Monkeys have been observed producing sharp stone flakes that closely resemble the earliest known tools made by our ancient relatives, proving that this ability is not uniquely human.

Previously, modifying stones to create razor-edged fragments was thought to be an activity confined to hominins, the family including early humans and their more primitive cousins. The latest observations re-write this view, showing that monkeys unintentionally produce almost identical artefacts simply by smashing stones together.

The findings put archaeologists on alert that they can no longer assume that stone flakes they discover are linked to the deliberate crafting of tools by early humans as their brains became more sophisticated.

Tomos Proffitt, an archaeologist at the University of Oxford and the study’s lead author, said: “At a very fundamental level – if you’re looking at a very simple flake – if you had a capuchin flake and a human flake they would be the same. It raises really important questions about what level of cognitive complexity is required to produce a sophisticated cutting tool.”

Unlike early humans, the flakes produced by the capuchins were the unintentional byproduct of hammering stones – an activity that the monkeys pursued decisively, but the purpose of which was not clear. Originally scientists thought the behaviour was a flamboyant display of aggression in response to an intruder, but after more extensive observations the monkeys appeared to be seeking out the quartz dust produced by smashing the rocks, possibly because it has a nutritional benefit. [Continue reading…]

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Where did the first farmers live? Looking for answers in DNA

Carl Zimmer writes: Beneath a rocky slope in central Jordan lie the remains of a 10,000-year-old village called Ain Ghazal, whose inhabitants lived in stone houses with timber roof beams, the walls and floors gleaming with white plaster.

Hundreds of people living there worshiped in circular shrines and made haunting, wide-eyed sculptures that stood three feet high. They buried their cherished dead under the floors of their houses, decapitating the bodies in order to decorate the skulls.

But as fascinating as this culture was, something else about Ain Ghazal intrigues archaeologists more: It was one of the first farming villages to have emerged after the dawn of agriculture.

Around the settlement, Ain Ghazal farmers raised barley, wheat, chickpeas and lentils. Other villagers would leave for months at a time to herd sheep and goats in the surrounding hills.

Sites like Ain Ghazal provide a glimpse of one of the most important transitions in human history: the moment that people domesticated plants and animals, settled down, and began to produce the kind of society in which most of us live today.

But for all that sites like Ain Ghazal have taught archaeologists, they are still grappling with enormous questions. Who exactly were the first farmers? How did agriculture, a cornerstone of civilization itself, spread to other parts of the world?

Some answers are now emerging from a surprising source: DNA extracted from skeletons at Ain Ghazal and other early settlements in the Near East. These findings have already challenged long-held ideas about how agriculture and domestication arose. [Continue reading…]

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Can great apes read your mind?

By Christopher Krupenye, Max Planck Institute

One of the things that defines humans most is our ability to read others’ minds – that is, to make inferences about what others are thinking. To build or maintain relationships, we offer gifts and services – not arbitrarily, but with the recipient’s desires in mind. When we communicate, we do our best to take into account what our partners already know and to provide information we know will be new and comprehensible. And sometimes we deceive others by making them believe something that is not true, or we help them by correcting such false beliefs.

All these very human behaviors rely on an ability psychologists call theory of mind: We are able to think about others’ thoughts and emotions. We form ideas about what beliefs and feelings are held in the minds of others – and recognize that they can be different from our own. Theory of mind is at the heart of everything social that makes us human. Without it, we’d have a much harder time interpreting – and probably predicting – others’ behavior.

For a long time, many researchers have believed that a major reason human beings alone exhibit unique forms of communication, cooperation and culture is that we’re the only animals to have a complete theory of mind. But is this ability really unique to humans?

In a new study published in Science, my colleagues and I tried to answer this question using a novel approach. Previous work has generally suggested that people think about others’ perspectives in very different ways than other animals do. Our new findings suggest, however, that great apes may actually be a bit more similar to us than we previously thought.

[Read more…]

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The world’s most sustainable technology

Stephen E. Nash writes: To my mind, a well-made Acheulean hand ax is one of the most beautiful and remarkable archaeological objects ever found, anywhere on the planet. I love its clean, symmetrical lines. Its strength and heft impress me, and so does its persistence.

Acheulean hand ax is the term archaeologists now use to describe the distinctive stone-tool type first discovered by John Frere at Hoxne, in Suffolk, Great Britain, in the late 1700s. Jacques Boucher de Perthes, a celebrated archaeologist, found similar objects in France during excavations conducted in the 1830s and 1840s. The name Acheulean comes from the site of Saint-Acheul, near the town of Amiens in northern France, which de Perthes excavated in 1859.

The term hand ax is arguably a misnomer. While the stone tool could conceivably have been used to chop — as with a modern ax — there is little evidence the implement was attached to a handle. In the absence of a handle, the user would have seriously damaged his or her hands while holding onto the ax’s sharp edges and striking another hard substance. There is evidence, however — in the form of telltale microscopic damage to the hand-ax edges and surfaces — that these objects were used for slicing, scraping, and some woodworking activities. Hand axes also served as sources of raw material (in strict archaeological terms, they were cores) from which new, smaller cutting tools (flakes) were struck. So they likely served a range of purposes. [Continue reading…]

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Study suggests human proclivity for violence gets modulated but is not necessarily diminished by culture

A new study (by José Maria Gómez et al) challenges Steven Pinker’s rosy picture of the state of the world. Science magazine reports: Though group-living primates are relatively violent, the rates vary. Nearly 4.5% of chimpanzee deaths are caused by another chimp, for example, whereas bonobos are responsible for only 0.68% of their compatriots’ deaths. Based on the rates of lethal violence seen in our close relatives, Gómez and his team predicted that 2% of human deaths would be caused by another human.

To see whether that was true, the researchers dove into the scientific literature documenting lethal violence among humans, from prehistory to today. They combined data from archaeological excavations, historical records, modern national statistics, and ethnographies to tally up the number of humans killed by other humans in different time periods and societies. From 50,000 years ago to 10,000 years ago, when humans lived in small groups of hunter-gatherers, the rate of killing was “statistically indistinguishable” from the predicted rate of 2%, based on archaeological evidence, Gómez and his colleagues report today in Nature.

Later, as human groups consolidated into chiefdoms and states, rates of lethal violence shot up — as high as 12% in medieval Eurasia, for example. But in the contemporary era, when industrialized states exert the rule of law, violence is lower than our evolutionary heritage would predict, hovering around 1.3% when combining statistics from across the world. That means evolution “is not a straitjacket,” Gómez says. Culture modulates our bloodthirsty tendencies.

The study is “innovative and meticulously conducted,” says Douglas Fry, an anthropologist at the University of Alabama, Birmingham. The 2% figure is significantly lower than Harvard University psychologist Steven Pinker’s much publicized estimate that 15% of deaths are due to lethal violence among hunter-gatherers. The lower figure resonates with Fry’s extensive studies of nomadic hunter-gatherers, whom he has observed to be less violent than Pinker’s work suggests. “Along with archaeology and nomadic forager research, this [study] shoots holes in the view that the human past and human nature are shockingly violent,” Fry says. [Continue reading…]

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Evidence rebuts Chomsky’s theory of language learning

Paul Ibbotson and Michael Tomasello write: The idea that we have brains hardwired with a mental template for learning grammar — famously espoused by Noam Chomsky of the Massachusetts Institute of Technology — has dominated linguistics for almost half a century. Recently, though, cognitive scientists and linguists have abandoned Chomsky’s “universal grammar” theory in droves because of new research examining many different languages—and the way young children learn to understand and speak the tongues of their communities. That work fails to support Chomsky’s assertions.

The research suggests a radically different view, in which learning of a child’s first language does not rely on an innate grammar module. Instead the new research shows that young children use various types of thinking that may not be specific to language at all — such as the ability to classify the world into categories (people or objects, for instance) and to understand the relations among things. These capabilities, coupled with a unique hu­­­man ability to grasp what others intend to communicate, allow language to happen. The new findings indicate that if researchers truly want to understand how children, and others, learn languages, they need to look outside of Chomsky’s theory for guidance.

This conclusion is important because the study of language plays a central role in diverse disciplines — from poetry to artificial intelligence to linguistics itself; misguided methods lead to questionable results. Further, language is used by humans in ways no animal can match; if you understand what language is, you comprehend a little bit more about human nature. [Continue reading…]

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The race to save a dying language

Ross Perlin writes: n 2013, at a conference on endangered languages, a retired teacher named Linda Lambrecht announced the extraordinary discovery of a previously unknown language. Lambrecht – who is Chinese-Hawaiian, 71 years old, warm but no-nonsense – called it Hawaii Sign Language, or HSL. In front of a room full of linguists, she demonstrated that its core vocabulary – words such as “mother”, “pig” and “small” – was distinct from that of other sign languages.

The linguists were immediately convinced. William O’Grady, the chair of the linguistics department at the University of Hawaii, called it “the first time in 80 years that a new language has been discovered in the United States — and maybe the last time.” But the new language found 80 years ago was in remote Alaska, whereas HSL was hiding in plain sight in Honolulu, a metropolitan area of nearly a million people. It was the kind of discovery that made the world seem larger.

The last-minute arrival of recognition and support for HSL was a powerful, almost surreal vindication for Lambrecht, whose first language is HSL. For decades, it was stigmatised or ignored; now the language has acquired an agreed-upon name, an official “language code” from the International Organization for Standardization, the attention of linguists around the world, and a three-year grant from the Endangered Languages Documentation Programme at the School of Oriental and African Studies in London.

But just as linguists were substantiating its existence, HSL stood on the brink of extinction, remembered by just a handful of signers. Unless the language made a miraculous recovery, Lambrecht feared that her announcement might turn out to be HSL’s obituary.

Three years after announcing its existence, Lambrecht is still unearthing her language sign by sign. She may be the only person in the world who still uses HSL on a regular basis, signing into a camera while a linguist named James “Woody” Woodward and a handful of graduate students from the University of Hawaii document her every move. [Continue reading…]

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Cricket’s famous ‘legover’ moment and why getting the giggles is so contagious

By Sophie Scott, UCL

It is 25 years since cricket commentators Brian Johnston and Jonathan Agnew famously got the uncontrollable giggles on live radio, while reporting on that day’s Test Match between England and the West Indies. The pair were commentating on the wicket of England’s Ian Botham, when he stumbled on to his stumps and, as Agnew put it: “Didn’t get his leg over”.

The resulting infectious two minutes of laughter has since been voted the greatest moment of sporting commentary ever. It’s worth listening to again – see if you can help giggling along with them.

I research the neurobiology of human vocal communication, and recently I’ve been spending a lot of time looking at laughter, which is easily the most common non-verbal emotional expression which one comes across (though in some cultures laughter is rather impolite and can be less frequently encountered when out and about). There are four key features of the science of laughter that this the Botham clip illustrates.

[Read more…]

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Your Olympic team may be an illusion

Niko Besnier and Susan Brownell write: The parade of athletes in the opening ceremony of the Olympic Games often evokes strong feelings of national pride. After the 2012 Summer Games in London, the Armenian National Committee of America sent a letter of protest to NBC’s CEO and president, Stephen Burke, to complain about the short shrift Armenia received from the commentator, who only said four words about their country: “Armenia, now walking in.” Their grievance paled, however, in comparison to the Olympics-related protest that took place in 1996. Thousands of Chinese people and organizations in the U.S. and elsewhere collected US$21,000 to buy advertisements in prominent newspapers protesting the fact that NBC commentator Bob Costas mentioned human rights abuses, doping allegations, and property rights disputes as the Chinese delegation entered the stadium for the parade.

About a billion people are expected to watch the opening ceremony of the Rio de Janeiro Olympic Games on television on August 5. For most people, the highlight will be watching their country’s athletes walk proudly into the stadium behind their national flag.

The parade of athletes displays a neat world order filled with proud, loyal citizens. But nations are not really the clear political units presented in this happy family portrait. Beneath the surface is a mess of transnational wheeling and dealing by power brokers as well as athletes seeking to get the most reward for their hard work and talent—for themselves and for their families and friends.

In the last few years, well-heeled Persian Gulf states have attracted athletes from other countries by offering them money, training facilities, and the possibility of qualifying for the Olympics more easily than in their home countries. The diminutive but oil-rich emirate of Qatar, for example, has until now played a very modest role in world sports. But in recent years the country has made huge investments in sports and adopted a liberal citizenship policy for athletes. The Qatari national handball team, which reached the finals at the men’s 2015 Handball World Championship, had only four players originating from Qatar on their 17-person squad — the rest had been recruited from overseas. By our calculation, more than half of the 38 athletes who will represent Qatar in Rio were born elsewhere. [Continue reading…]

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Your gut bacteria predates appearance of humans, genetic study finds

The Guardian reports: The evolutionary history of the bacteria in your guts predates the appearance of humans, and mirrors that of our great ape relatives, according to a genetic study.

The research suggests that microbes in our ancestors’ intestines split into new evolutionary lineages in parallel with splits in the ape family tree.

This came as a surprise to scientists, who had thought that most of our gut bacteria came from our surroundings – what we eat, where we live, even what kind of medicine we take. The new research suggests that evolutionary history is much more important than previously thought.

“When there were no humans or gorillas, just ancestral African apes, they harboured gut bacteria. Then the apes split into different branches, and there was also a parallel divergence of different gut bacteria,” said Prof Andrew Moeller of the University of California, Berkeley who led the study, published in Science. This happened when gorillas separated somewhere between 10-15 million years ago, and again when humans split from chimps and bonobos 5 million years ago. [Continue reading…]

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