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…]
Sheherzad Preisler writes: The environmental artist Ned Kahn, a MacArthur Foundation “genius grant” awardee, gravitates toward phenomena that lie on the edges of what science can grasp — “things,” he tells me over the phone, “that are inherently complex and difficult to predict, yet at the same time beautiful.” The weather, for example, has, because of its chaotic yet orderly nature, “fascinated me for my whole career,” he says. For almost the last 30 years in particular, he’s been creating dynamic installations that he thinks of as “observatories”: Since they frequently incorporate wind, water, fog, sand, and light, he states on his website, “they frame and enhance our perception of natural phenomena.”
Take his most recent project, the “Shimmer Wall”. Composed of over 30,000 tiles, it will be a 1,100-foot long façade of a new building, home to the “Ocean Wonders: Sharks!” exhibit, set to open this year at the New York Aquarium (over $80,000, toward a $100,000 goal, has been donated for its construction). It will house over 100 species of animals, including but not limited to a variety of crustaceans, sharks, fish, rays, and turtles. “They were struggling with the façade and someone on the design committee knew about my work and approached me,” says Kahn. “That led to the idea that we’re doing a skin for the aquarium inspired by fish skin, shark skin, scales. I’ve been doing a number of faceted, fragmented, kinetic artworks influenced by scales — that move with the wind and, when you step back, you get an idea of how the wind affects it.”
Kahn tells me that, before Hurricane Sandy hit, on October 29th 2012, there was a six-foot square experimental piece of the Wall outside the aquarium, to test if it could stand extreme weather. It held up perfectly, he says. In his conversation with Nautilus, Kahn also spoke with enthusiasm about how nature both inspires and interacts with his work, as well as what people make of it. [Continue reading…]
(Note: The sound in this video has no connection with the shimmering wall — it is the sound of waves on a shore on the Canary Islands.)
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…]
Brian Gallagher writes: It’s always a mistake to read,” Philip Marcus, a computational physicist and a professor in the mechanical engineering department at the University of California, Berkeley, tells me in a coffee shop near campus. “You learn too many things. That’s how I got really fascinated by fluid dynamics.”
It was 1978, and Marcus was in his first year of a post-doctoral position at Cornell focused on numerical simulations of solar convection and laboratory flows using spectral methods. But he had wanted to study cosmic evolution and general relativity; the problem, as Marcus told me, was that there was talk of no one seeing results of general relativity within their lifetime. As a result, “the field kind of collapsed on itself a little bit, and so everybody from general relativity was going to other fields.”
It was also in 1978 that Voyager 1 began to send up-close images of Jupiter back to Earth. When Marcus needed to, as he put it, “unwind, relax, whatever,” he would walk over to a special library, next to the astrophysics building, and marvel at Voyager’s images of the Great Red Spot. The storm had raged hundreds of millions of miles away since at least 1665, when it was first observed by Robert Hooke. “I realized that almost nobody in astronomy was trained in fluid dynamics, and I was,” he told me. “And I said, well, I’m in as good a position as anybody to start studying this.”
And he never stopped. Today, he is something of an expert on the solar system’s most famous storm. Sporting a mountain-biker’s build, he answered my questions with animation, often waving his hands around to clarify his concepts. He admitted this energy of his could encourage clumsiness. “People are leery of me,” he said. “If I walked into a laboratory, I would immediately break everything.” Thankfully, he explained, “I have the great fortune of having some wonderful friends who are experimentalists.” [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…]
Alex Riley writes: As they drove on featureless dirt roads on the first Tuesday of 2010, John Dabiri, professor of aeronautics and bioengineering at the California Institute of Technology, and his then-student Robert Whittlesey, were inspecting a remote area of land that they hoped to purchase to test new concepts in wind power. They named their site FLOWE for Field Laboratory for Optimized Wind Energy. Situated between gentle knolls covered in sere vegetation, the four-acre parcel in Antelope Valley, California, was once destined to become a mall, but those plans fell through. The land was cheap. And, more importantly, it was windy.
Estimated at 250 trillion Watts, the amount of wind on Earth has the potential to provide more than 20 times our current global energy consumption. Yet, only four countries — Spain, Portugal, Ireland, and Denmark — generate more than 10 percent of their electricity this way. The United States, one of the largest, wealthiest, and windiest of countries, comes in at about 4 percent. There are reasons for that. Wind farm expansion brings with it huge engineering costs, unsightly countryside, loud noises, disruption to military radar, and death of wildlife. Recent estimates blamed turbines for killing 600,000 bats and up to 440,000 birds a year. On June 19, 2014, the American Bird Conservancy filed a lawsuit against the federal government asking it to curtail the impact of wind farms on the dwindling eagle populations. And while standalone horizontal-axis turbines harvest wind energy well, in a group they’re highly profligate. As their propeller-like blades spin, the turbines facing into the wind disrupt free-flowing air, creating a wake of slow-moving, infertile air behind them. [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…]
Claudia Geib writes: On a damp, foggy January morning in 1793, Louis XVI, besieged monarch of France, stood before a guillotine. To some 20,000 of his angry subjects, Louis declared: “I die innocent of all the pretended crimes laid to my charge. I forgive all those who have had any hand in my misfortunes, and I pray that my blood may be of use in restoring happiness to France — and you, unhappy people!” The rest of his speech was cut short. The king was strapped to a plank, slid through the “widow’s window,” and decapitated.
What Louis could not have known was that one root of his “misfortunes” was not any one of his subjects. It was El Niño, the climatic fluctuation that has sown misfortune for humankind for millennia. Today, as global temperatures rise, El Niño events will likely become more dramatic — causing longer, drier droughts, extreme floods, and more unpredictable weather. Stories of how El Niño shaped history are thus more than mere curiosities, says Brian Fagan, author of Floods, Famines, and Emperors: El Niño and the Fate of Civilizations.
“You cannot study climate change without looking at human experience of climate in the past,” he says. We might live in a world of billions more people, but past El Niños can still offer insights into human behavior. “They won’t tell you how to do something,” Fagan says, “but they can give you precedents for how you might.” [Continue reading…]
The Guardian reports: Physicists have detected ripples in the fabric of spacetime that were set in motion by the collision of two black holes far across the universe more than a billion years ago.
The event marks only the second time that scientists have spotted gravitational waves, the tenuous stretching and squeezing of spacetime predicted by Einstein more a century ago.
The faint signal received by the twin instruments of the Laser Interferometer Gravitational Wave Observatory (LIGO) in the US revealed two black holes circling one another 27 times before finally smashing together at half the speed of light. [Continue reading…]
Discover Magazine reports: A peculiar new molecule hovering within a star-forming dust cloud in deep in space could help explain why life on Earth is the way it is.
The cloud, called Sagittarius B2, resides near the center of the Milky Way, and it’s there that researchers from the California Institute of Technology discovered an organic element that displays a key property shared by all life. Propylene oxide is the first element discovered outside of our solar system to exhibit chirality, or the presence of two distinct, mirror-image forms. Many complex molecules have this property, including myriad organic molecules necessary for life. The chemical formula of these two versions is exactly the same, but the structure is flipped.
All life on Earth is composed of chiral molecules, and the versions organisms use, either right- or left-handed, determines fundamental properties of their biology. For example, all living things only use the right-handed form of the sugar ribose to form the backbone of DNA, giving it that the signature twist. You can think of molecular handedness by picturing gloves — hence the “handed terminology”. The gloves, or molecules, may look similar, but you could never put a left-handed glove on your right hand. [Continue reading…]