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…]
Paige Madison writes: Last September, scientists announced the discovery of a never-before-seen human relative (hominin), now known as Homo naledi, deep in a South African cave. The site yielded more than 1,500 bone fragments, an astonishing number in a field that often celebrates the identification of a single tooth. That rich fossil cache revealed much about the creatures, yet it left one glaring question unanswered: when did Homo naledi live? The scientists had no evidence for how old the fossils were. Without that information, it was very hard to know where the new species fits on the tangled human family tree, and to figure out its true meaning.
Difficulties in dating fossils have plagued anthropology since its inception. In 1856, a fossilised skeleton discovered in a small cave in the Neander Valley in Germany became the first hominin ever recognised by science. Quarry workers uncovered the fossils while clearing out a limestone cave, but before the bones were flagged as important, the workers had shovelled them out of the cave mouth. The fossils tumbled to the valley floor 20 metres below, obscuring contextual information that could have provided clues to their age – for example, how deep the skeleton was buried, and whether any fossilised animals had been found nearby.
Identifying the age of this Neanderthal (‘man from the Neander Valley’) was crucial for interpreting his significance. The skeleton had been found right around the time Charles Darwin published On the Origin of Species (1859), and its vaguely human appearance suggested it had the potential to illuminate the human past, but only if it were truly ancient. Some scientists suggested the Neanderthal was an ape-like ancestor or belonged to an ancient European race. Others dismissed him as a recent human, explaining away his strange skull shape by calling him a diseased idiot. [Continue reading…]
Jane Qiu writes: On the outskirts of Beijing, a small limestone mountain named Dragon Bone Hill rises above the surrounding sprawl. Along the northern side, a path leads up to some fenced-off caves that draw 150,000 visitors each year, from schoolchildren to grey-haired pensioners. It was here, in 1929, that researchers discovered a nearly complete ancient skull that they determined was roughly half a million years old. Dubbed Peking Man, it was among the earliest human remains ever uncovered, and it helped to convince many researchers that humanity first evolved in Asia.
Since then, the central importance of Peking Man has faded. Although modern dating methods put the fossil even earlier — at up to 780,000 years old — the specimen has been eclipsed by discoveries in Africa that have yielded much older remains of ancient human relatives. Such finds have cemented Africa’s status as the cradle of humanity — the place from which modern humans and their predecessors spread around the globe — and relegated Asia to a kind of evolutionary cul-de-sac.
But the tale of Peking Man has haunted generations of Chinese researchers, who have struggled to understand its relationship to modern humans. “It’s a story without an ending,” says Wu Xinzhi, a palaeontologist at the Chinese Academy of Sciences’ Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing. They wonder whether the descendants of Peking Man and fellow members of the species Homo erectus died out or evolved into a more modern species, and whether they contributed to the gene pool of China today.
Keen to get to the bottom of its people’s ancestry, China has in the past decade stepped up its efforts to uncover evidence of early humans across the country. It is reanalysing old fossil finds and pouring tens of millions of dollars a year into excavations. And the government is setting up a US$1.1-million laboratory at the IVPP to extract and sequence ancient DNA. [Continue reading…]
Since the evolution of dogs from wolves tens of thousands of years ago, they have been selectively bred for various roles as guards, hunters, workers and companions. But dogs are not the only animal humans have domesticated, which suggests that although dogs get all the attention, there’s reason to argue other species could also deserve the title of “man’s best friend”.
Anthrozoology, the study of human-animal relationships, has established that dogs demonstrate complex communication with humans. Charles Darwin thought that dogs experienced love, but it was only in 2015 that Japanese scientists demonstrated what we all intuitively knew. Miho Nagasawa and colleagues sprayed the “love hormone” oxytocin up dogs’ noses, measured the loving gaze between dog and human, and then measured the oxytocin levels in the humans’ urine, finding them to be higher. Rest assured, dog owners, that science has verified your bond with your faithful hound.
Horses also show intentional communicative behaviour with humans, and another recent paper published in the Royal Society’s Biology Letters from researchers at Queen Mary University of London has shown that goats also demonstrate an affinity with humans. The experiments tested goats’ intelligence and ability to communicate with humans. What the team found may come as no surprise to anyone who has worked with livestock: goats are highly intelligent, capable of complex communication with humans, and are able to form bonds with us – treating us as potential partners to help in problem-solving situations.
Our attitudes to animals tend to reflect the familiarity we have with them. Dogs score higher in perceived intelligence ratings than cows, for example, yet a study in the 1970s demonstrated that in a test cows could navigate a maze as well as dogs, and only slightly less well than children. The point was made that our perception of an animal’s ability is influenced by how we test them.
Daniel A Gross writes: The word “noise” comes from a Latin root meaning either queasiness or pain. According to the historian Hillel Schwartz, there’s even a Mesopotamian legend in which the gods grow so angry at the clamor of earthly humans that they go on a killing spree. (City-dwellers with loud neighbors may empathize, though hopefully not too closely.)
Dislike of noise has produced some of history’s most eager advocates of silence, as Schwartz explains in his book Making Noise: From Babel to the Big Bang and Beyond. In 1859, the British nurse and social reformer Florence Nightingale wrote, “Unnecessary noise is the most cruel absence of care that can be inflicted on sick or well.” Every careless clatter or banal bit of banter, Nightingale argued, can be a source of alarm, distress, and loss of sleep for recovering patients. She even quoted a lecture that identified “sudden noises” as a cause of death among sick children.
Surprisingly, recent research supports some of Nightingale’s zealous claims. In the mid 20th century, epidemiologists discovered correlations between high blood pressure and chronic noise sources like highways and airports. Later research seemed to link noise to increased rates of sleep loss, heart disease, and tinnitus. (It’s this line of research that hatched the 1960s-era notion of “noise pollution,” a name that implicitly refashions transitory noises as toxic and long-lasting.)
Studies of human physiology help explain how an invisible phenomenon can have such a pronounced physical effect. Sound waves vibrate the bones of the ear, which transmit movement to the snail-shaped cochlea. The cochlea converts physical vibrations into electrical signals that the brain receives. The body reacts immediately and powerfully to these signals, even in the middle of deep sleep. Neurophysiological research suggests that noises first activate the amygdalae, clusters of neurons located in the temporal lobes of the brain, associated with memory formation and emotion. The activation prompts an immediate release of stress hormones like cortisol. People who live in consistently loud environments often experience chronically elevated levels of stress hormones.
Just as the whooshing of a hundred individual cars accumulates into an irritating wall of background noise, the physical effects of noise add up. In 2011, the World Health Organization tried to quantify its health burden in Europe. It concluded that the 340 million residents of western Europe—roughly the same population as that of the United States—annually lost a million years of healthy life because of noise. It even argued that 3,000 heart disease deaths were, at their root, the result of excessive noise.
So we like silence for what it doesn’t do—it doesn’t wake, annoy, or kill us—but what does it do? When Florence Nightingale attacked noise as a “cruel absence of care,” she also insisted on the converse: Quiet is a part of care, as essential for patients as medication or sanitation. It’s a strange notion, but one that researchers have begun to bear out as true. [Continue reading…]
Adam Piore writes: It started with one man quietly sipping a Tom Collins in the lounge car of the Cleveland-bound train.
“God bless America,” he sang, “land that I love …”
It didn’t take long. Others joined in. “Stand beside her … and guide her …” Soon the entire train car had taken up the melody, belting out the patriotic song at the top of their lungs.
It was 1940 and such spontaneous outpourings, this one described in a letter to the song’s creator Irving Berlin, were not unusual. That was the year the simple, 32-bar arrangement was somehow absorbed into the fabric of American culture, finding its way into American Legion halls, churches and synagogues, schools, and even a Louisville, Kentucky, insurance office, where the song reportedly sprang to the lips of the entire sales staff one day. The song has reemerged in times of national crisis or pride over and over, to be sung in ballparks, school assemblies, and on the steps of the United States Capitol after 9/11.
Berlin immigrated to the U.S. at age 5. His family fled Russia to escape a wave of murderous pogroms directed at Jews. His mother often murmured “God Bless America” as he was growing up. “And not casually, but with emotion which was almost exaltation,” Berlin later recalled.
“He always talked about it like a love song,” says Sheryl Kaskowitz, the author of God Bless America, the Surprising History of an Iconic Song. “It came from this really genuine love and a sense of gratitude to the U.S.”
It might seem ironic that someone born in a foreign land would compose a song that so powerfully expressed a sense of national belonging—that this song embraced by an entire nation was the expression of love from an outsider for his adopted land. In the U.S., a nation of immigrants built on the prospect of renewal, it’s not the least bit surprising. It is somehow appropriate.
Patriotism is an innate human sentiment. It is part of a deeper subconscious drive toward group formation and allegiance. It operates as much in one nation under God as it does in a football stadium. Group bonding is in our evolutionary history, our nature. According to some recent studies, the factors that make us patriotic are in our very genes.
But this allegiance—this blurring of the lines between individual and group—has a closely related flipside; it’s not always a warm feeling of connection in the Cleveland-bound lounge car. Sometimes our instinct for group identification serves as a powerful wedge to single out those among us who are different. Sometimes what makes us feel connected is not a love of home and country but a common enemy. [Continue reading…]
Nature reports: Two Middle Eastern populations independently developed farming and then spread the technology to Europe, Africa and Asia, according to the genomes of 44 people who lived thousands of years ago in present-day Armenia, Turkey, Israel, Jordan and Iran.
Posted on 17 June on the bioRxiv preprint server1, the research supports archaeological evidence about the multiple origins of farming, and represents the first detailed look at the ancestry of the individuals behind one of the most important periods in human history — the Neolithic revolution.
Some 11,000 years ago, humans living in the ancient Middle East region called the Fertile Crescent shifted from a nomadic existence, based on hunting game and gathering wild plants, to a more sedentary lifestyle that would later give rise to permanent settlements. Over thousands of years, these early farmers domesticated the first crops and transformed sheep, wild boars and other creatures into domestic animals.
Dozens of studies have examined the genetics of the first European farmers, who emigrated from the Middle East beginning some 8,000 years ago, but the hot climes of the Fertile Crescent had made it difficult to obtain ancient DNA from remains found there. Advances in extracting DNA from a tiny ear bone called the petrous allowed a team led by Iosif Lazaridis and David Reich, population geneticists at Harvard Medical School in Boston, Massachusetts, to analyse the genomes of the 44 Middle Eastern individuals, who lived between 14,000 and 3,500 years ago. [Continue reading…]
Jay Schwartz writes: In late 2013, the Nonhuman Rights Project (NhRP) filed a first-ever lawsuit to free a pet chimpanzee named Tommy from the inadequate conditions provided by his owner. The NhRP, a legal group focused on animal protection, argued that Tommy is an autonomous being who is held against his will and that he is entitled to a common-law writ of habeas corpus, a legal means of determining the legality of imprisonment. Granting habeas corpus to a chimpanzee would mean viewing chimpanzees as legal persons with rights, rather than as mere things, so this case was rather controversial.
The Tommy case came to a close on December 4, 2014, as the Appellate Division of the New York State Supreme Court’s five-judge panel ruled against the NhRP. (The state’s highest court is the Court of Appeals.) Justice Karen K. Peters, the presiding judge, wrote: “Needless to say, unlike human beings, chimpanzees cannot bear any legal duties, submit to societal responsibilities or be held legally accountable for their actions. In our view, it is this incapability to bear any legal responsibilities and societal duties that renders it inappropriate to confer upon chimpanzees the legal rights … that have been afforded to human beings.” [Continue reading…]
A lot of people will regard the effort to confer legal rights to non-humans as being driven by anthropomorphism. But consider the court’s argument. Could not the exact same line of reasoning be used to argue that small children or adults with developmental disabilities be deprived of legal rights? Of course, such an argument would rightly be decried as inhuman and barbaric.
Science News reports: Prehumans living around 800,000 years ago in what’s now southeastern Spain were, literally, trailblazers. They lit small, controlled blazes in a cave, a new study finds.
Discoveries in the cave provide the oldest evidence of fire making in Europe and support proposals that members of the human genus, Homo, regularly ignited fires starting at least 1 million years ago, say paleontologist Michael Walker of the University of Murcia in Spain and his colleagues. Fire making started in Africa (SN: 5/5/12, p. 18) and then moved north to the Middle East (SN: 5/1/04, p. 276) and Europe, the researchers conclude in the June Antiquity.
If the age estimate for the Spain find holds up, the new report adds to a “surprising number” of sites from deep in the Stone Age that retain evidence of small, intentionally lit fires, says archaeologist John Gowlett of the University of Liverpool in England.
Excavations conducted since 2011 at the Spanish cave, Cueva Negra del Estrecho del Río Quípar, have uncovered more than 165 stones and stone artifacts that had been heated, as well as about 2,300 animal-bone fragments displaying signs of heating and charring. Microscopic and chemical analyses indicate that these finds had been heated to between 400° and 600° Celsius, consistent with having been burned in a fire. [Continue reading…]
Emily Singer writes: Early human history was a promiscuous affair. As modern humans began to spread out of Africa roughly 50,000 years ago, they encountered other species that looked remarkably like them — the Neanderthals and Denisovans, two groups of archaic humans that shared an ancestor with us roughly 600,000 years earlier. This motley mix of humans coexisted in Europe for at least 2,500 years, and we now know that they interbred, leaving a lasting legacy in our DNA. The DNA of non-Africans is made up of roughly 1 to 2 percent Neanderthal DNA, and some Asian and Oceanic island populations have as much as 6 percent Denisovan DNA.
Over the last few years, scientists have dug deeper into the Neanderthal and Denisovan sections of our genomes and come to a surprising conclusion. Certain Neanderthal and Denisovan genes seem to have swept through the modern human population — one variant, for example, is present in 70 percent of Europeans — suggesting that these genes brought great advantage to their bearers and spread rapidly.
“In some spots of our genome, we are more Neanderthal than human,” said Joshua Akey, a geneticist at the University of Washington. “It seems pretty clear that at least some of the sequences we inherited from archaic hominins were adaptive, that they helped us survive and reproduce.”
But what, exactly, do these fragments of Neanderthal and Denisovan DNA do? What survival advantage did they confer on our ancestors? Scientists are starting to pick up hints. Some of these genes are tied to our immune system, to our skin and hair, and perhaps to our metabolism and tolerance for cold weather, all of which might have helped emigrating humans survive in new lands.
“What allowed us to survive came from other species,” said Rasmus Nielsen, an evolutionary biologist at the University of California, Berkeley. “It’s not just noise, it’s a very important substantial part of who we are.” [Continue reading…]
Justin E H Smith writes: A poet, somewhere in Siberia, or the Balkans, or West Africa, some time in the past 60,000 years, recites thousands of memorised lines in the course of an evening. The lines are packed with fixed epithets and clichés. The bard is not concerned with originality, but with intonation and delivery: he or she is perfectly attuned to the circumstances of the day, and to the mood and expectations of his or her listeners.
If this were happening 6,000-plus years ago, the poet’s words would in no way have been anchored in visible signs, in text. For the vast majority of the time that human beings have been on Earth, words have had no worldly reality other than the sound made when they are spoken.
As the theorist Walter J Ong pointed out in Orality and Literacy: Technologizing the Word (1982), it is difficult, perhaps even impossible, now to imagine how differently language would have been experienced in a culture of ‘primary orality’. There would be nowhere to ‘look up a word’, no authoritative source telling us the shape the word ‘actually’ takes. There would be no way to affirm the word’s existence at all except by speaking it – and this necessary condition of survival is important for understanding the relatively repetitive nature of epic poetry. Say it over and over again, or it will slip away. In the absence of fixed, textual anchors for words, there would be a sharp sense that language is charged with power, almost magic: the idea that words, when spoken, can bring about new states of affairs in the world. They do not so much describe, as invoke.
As a consequence of the development of writing, first in the ancient Near East and soon after in Greece, old habits of thought began to die out, and certain other, previously latent, mental faculties began to express themselves. Words were now anchored and, though spellings could change from one generation to another, or one region to another, there were now physical traces that endured, which could be transmitted, consulted and pointed to in settling questions about the use or authority of spoken language.
Writing rapidly turned customs into laws, agreements into contracts, genealogical lore into history. In each case, what had once been fundamentally temporal and singular was transformed into something eternal (as in, ‘outside of time’) and general. Even the simple act of making everyday lists of common objects – an act impossible in a primary oral culture – was already a triumph of abstraction and systematisation. From here it was just one small step to what we now call ‘philosophy’. [Continue reading…]
Discover reports: Circular structures discovered in a French cave continue to build the case that Neanderthals were more intelligent than we give them credit for.
Deep inside the Bruniquel Cave, researchers discovered two rings of stalactites and stalagmites that appeared to have been deliberately stacked and arranged to form a structure. The site also contained charred animal bones, which may have served as torches to illuminate the dark depths of the cave or keep bears at bay. The thing is, a new dating analysis suggests these structures were built more than 170,000 years ago, long before Homo sapiens arrived in the area. That means Neanderthals were the likely architects, and we didn’t expect them to be such adept builders and cave explorers.
The structures in Bruniquel were first discovered in 1990 and dated at the time to roughly 50,000 years ago based on carbon dating techniques. However, in 2013, Sophie Verheyden of the Royal Belgian Institute of Natural Sciences conducted a new study, drilling into the stalactites and stalagmites to measure differences between layers of rock that accumulated before and after they were felled. Her analysis, published Wednesday in Nature, revealed an astounding age of roughly 176,500 years, more than three times the previous estimate. By contrast, the oldest known human cave art is only around 42,000 years old. [Continue reading…]
Katherine Hirschfeld writes: In March 2013, a drug cartel staged a grisly tableau near a central plaza in Uruapan, Mexico. Seven dead and mutilated bodies were left sitting upright in plastic chairs. Two had crudely lettered signs pinned to their chests with ice picks that read, “Warning, this is going to happen to all muggers, pickpockets, thieves of cars, homes, and walkers — as well as kidnappers, rapists, and extortionists.” Photos found their way to CNN and other media outlets in the United States and Europe. (You may view them here if you are brave.)
Those who inhabit the upper world — law-abiding citizens who enjoy the rights and protections of government — instinctively turn away from such images of horrific violence. Not only are the photos disturbing to look at, they don’t make sense. Why would a drug cartel go to such lengths to issue a proclamation against thievery? Drug cartels are not law-abiding organizations, so why arrange a display of dead bodies with ice picks and cardboard signs in order to declare rules?
The scene at Uruapan contains a message from the underworld — the subterranean organized crime groups that control much of the world’s traffic in illicit commodities. Criminal organizations often communicate through the bodies of the dead, and we should not look away just yet, because their message contains a warning for all of us.
What the bodies in Uruapan tell us is that underworld groups are law-and-order organizations, but their laws and their order are not the same as those of the upper world. We know this because the intrepid journalists, human rights activists, and forensic anthropologists who have crossed over to explore specific examples of the global underworld have brought back stories that reveal common themes. Criminal groups may be culturally or geographically distinct, but they operate with similar rules.
The primary rule of the underworld is that the cartel (or the mafia or the warlord) makes the rules, and disobedience is a capital crime. Public displays of death convey the cartel’s power to impose the kind of lethal punishment typically reserved for the state. The public setting in Uruapan symbolizes that the Mexican government no longer has jurisdiction over matters of criminal justice in this municipality. Through these practices, the cartel reanimates the dead and compels them to speak to the living one last time: “Obey, or you will end up like us.” [Continue reading…]
Phys.org reports: The discovery of stone tools found in a Florida river show that humans settled the southeastern United States far earlier than previously believed — perhaps by as much as 1,500 years, according to a team of scientists that includes a University of Michigan paleontologist.
Michael Waters of Texas A&M University and Jessi Halligan of Florida State University led a research team that also included U-M’s Daniel Fisher and scientists from the University of Minnesota, University of Texas, University of Arizona, Stafford Research Laboratories in Colorado, Aucilla Research Institute in Florida, and Exeter and Cambridge universities in the United Kingdom.