54 Evolution News Articles
for July 2018
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7-15-18 The brain may clean out Alzheimer’s plaques during sleep
If sleep deprivation puts garbage removal on the fritz, the memory-robbing disease may develop. Neuroscientist Barbara Bendlin studies the brain as Alzheimer’s disease develops. When she goes home, she tries to leave her work in the lab. But one recent research project has crossed into her personal life: She now takes sleep much more seriously. Bendlin works at the University of Wisconsin–Madison, home to the Wisconsin Registry for Alzheimer’s Prevention, a study of more than 1,500 people who were ages 40 to 65 when they signed up. Members of the registry did not have symptoms of dementia when they volunteered, but more than 70 percent had a family history of Alzheimer’s disease. Since 2001, participants have been tested regularly for memory loss and other signs of the disease, such as the presence of amyloid-beta, a protein fragment that can clump into sticky plaques in the brain. Those plaques are a hallmark of Alzheimer’s, the most common form of dementia. Each person also fills out lengthy questionnaires about their lives in the hopes that one day the information will offer clues to the disease. Among the inquiries: How tired are you? Some answers to the sleep questions have been eye-opening. Bendlin and her colleagues identified 98 people from the registry who recorded their sleep quality and had brain scans. Those who slept badly — measured by such things as being tired during the day — tended to have more A-beta plaques visible on brain imaging, the researchers reported in 2015 in Neurobiology of Aging.
7-13-18 Pregnancy depression is on the rise, a survey suggests
Expectant women may be more anxious or depressed than their mothers were. Today’s young women are more likely to experience depression and anxiety during pregnancy than their mothers were, a generation-spanning survey finds. From 1990 to 1992, about 17 percent of young pregnant women in southwest England who participated in the study had signs of depressed mood. But the generation that followed, including these women’s daughters and sons’ partners, fared worse. Twenty-five percent of these young women, pregnant in 2012 to 2016, showed signs of depression, researchers report July 13 in JAMA Network Open. “We are talking about a lot of women,” says study coauthor Rebecca Pearson, a psychiatric epidemiologist at Bristol University in England. Earlier studies also had suggested that depression during and after pregnancy is relatively common (SN: 3/17/18, p. 16). But those studies are dated, Pearson says. “We know very little about the levels of depression and anxiety in new mums today,” she says. To measure symptoms of depression and anxiety, researchers used the Edinburgh Postnatal Depression Scale — 10 questions, each with a score of 0 to 3, written to reveal risk of depression during and after pregnancy. A combined score of 13 and above signals high levels of symptoms. From 1990 to 1992, 2,390 women between the ages of 19 and 24 took the survey while pregnant. Of these women, 408 — or 17 percent — scored 13 or higher, indicating worrisome levels of depression or anxiety. When researchers surveyed the second-generation women, including both daughters of the original participants and sons’ partners ages 19 to 24, the numbers were higher. Of 180 women pregnant in 2012 to 2016, 45 of them — or 25 percent — scored 13 or more. It’s not clear whether the findings would be similar for pregnant women who are older than 24 or younger than 19.
7-13-18 Artificial skin grown from spider silk could help heal wounds
Wounds and burns could one day be treated by the material spiders use to make their webs. Bandages made from spider silk could potentially heal wounds, or even replace damanged skin all together. Around 6.5 million people suffer from chronic wounds due to diabetic ulcers and pressure sores in the US alone, with annual treatment costs of $25 billion. So the hunt is on for new, low cost ways to treat these conditions, as well as new materials for skin grafts to replace tissue lost to burns or lacerations. The challenge is to create dressings that act as a scaffold to promote skin renewal, but without provoking an immune response or bacterial infections. And surprising as it might seem, spider silk is a good option. “Spider silk has an elasticity which matches that of skin,” says My Hedhammar of the KTH Royal Institute of Technology in Stockholm, Sweden. “Silk is made from protein, which is also the main component around the cells in skin. The silk kind of replaces the collagen found in skin.” Hedhammar’s team used spider silk protein produced by genetically engineered E. Coli bacteria. A key advantage of this production method is that chemicals found in the body which promote cell growth, such as binding agents and growth factors, can be genetically engineered onto to the silk protein, as well as antimicrobial proteins that are naturally found in skin. However, this modified spider silk is relatively costly, so the researchers put a thin layer on another type of silk, derived from the cocoons of silkworms. They used this combined material to make a mat for dressing wounds, and also made it into a porous sponge for use as artificial skin.
7-13-18 Scared of heights? This new VR therapy could help
Participants became less fearful after an avatar coached them through edge-of-ledge moments. Future therapy patients may spend a lot more time exploring virtual environments than sitting on sofas. In a clinical trial of a new virtual reality treatment for fear of heights, participants reported being much less afraid after using the program for just two weeks. Unlike other VR therapies, which required that a real-life therapist guide patients through treatment, the new system uses an animated avatar to coach patients through ascending a virtual high-rise. This kind of fully automated counseling system, described online July 11 in the Lancet Psychiatry, may make psychological treatments for phobias and other disorders far more accessible. This is “a huge step forward” for therapeutic VR, says Jennifer Hames, a clinical psychologist at the University of Notre Dame in Indiana, who wasn’t involved in the work. By bringing expert therapy out of the counselor’s office and into primary care clinics — or even people’s homes — the new system could help those who aren’t comfortable or don’t have the means to speak with a therapist face-to-face, she says. Users immerse themselves in this virtual reality program using a VR headset, handheld controllers and headphones. An animated counselor guides the user through a virtual 10-story office complex, where upper floors overlook a ground-level atrium. On every floor, the user performs tasks designed to test their fear responses and help them learn that they’re safer than they might think. The tasks start out relatively easy — like standing close to a drop-off where a safety barrier gradually lowers — and progress to more difficult challenges — like riding a moving platform out into the open space over the atrium.
7-13-18 Americans shirking exercise
A new government study has found that about 80 percent of Americans aren’t getting nearly enough exercise, potentially setting themselves up for health worries later in life, reports USA Today. The Department of Health and Human Services recommends that people ages 18 to 64 get at least 2½ hours of moderate-intensity aerobic exercise a week—walking at a brisk pace, for example—or 75 minutes of vigorous aerobic exercise, such as running or swimming. Adults should also do muscle-strengthening activities, such as weightlifting or push-ups, at least twice a week. But only 23 percent of adults are meeting those guidelines. Researchers found that a person’s sex, home state, and finances affected how much exercise they got. Nationally, some 19 percent of women and 27 percent of men hit the target. Residents of Mississippi were the least likely to work out, with about 14 percent meeting the guidelines, and Coloradans the most, at 33 percent. People in professional and management occupations were also more likely than factory workers to meet exercise recommendations. Where Americans live and work, the study notes, “can have very real consequences for their morbidity, disability, and mortality.”
7-13-18 No limit to longevity?
If there is an upper limit to the human life span, we might not have reached it yet. The average life expectancy around the world has more than doubled since 1900, thanks to improvements in sanitation, health care, and food supply. Still, past studies have suggested that because of biological limits, only a handful of genetic outliers will live beyond 115 years old, such as the oldest verified person ever, Jeanne Calment, who died at age 122, in 1997. But a new study of nearly 4,000 Italian centenarians indicates that human longevity may be slowly increasing. According to established demographic data, after age 65, the probability of death doubles each year. The mortality rate begins to decelerate at age 80 and, the researchers found, seems to plateau at age 105. At that point, the chances of dying in a given year are roughly 50-50. Study authors say this plateauing might be because of biological factors: For instance, cell division slows after age 100, making centenarians less likely to develop cancer. That means that as more people make it to 105, more will likely make it to 115 and beyond. If mortality “stays constant,” co-author Jim Vaupel tells TheGuardian.com, the old-age “record will be broken.”
7-13-18 US salmonella outbreak: 'Do not eat Honey Smacks,' shoppers told
US health officials have issued a blunt warning for people to avoid Honey Smacks, a popular breakfast cereal linked to a salmonella outbreak. The Centers for Disease Control and Prevention (CDC) urged consumers: "Do not eat this cereal." More than a million packets of the product were recalled by the manufacturer Kellogg's in June after 100 people were infected in 33 states. The cereal is the likely source of the salmonella outbreak, the CDC said. Salmonella infections can cause illness, or death in rare cases. No deaths have been reported in the latest outbreak. The warning not to eat Honey Smacks came in a post on social media by the CDC: "Even if some of the cereal has been eaten and no one got sick, throw the rest of it away or return it for a refund," the CDC said in a statement on its website. "Do not eat any Kellogg's Honey Smacks cereal, regardless of package size or best-by date," it said. The statement said salmonella strains had been found in both unopened and leftover samples of Honey Smacks at several locations.
7-13-18 Dopamine levels in our brains affect the risks we’re happy to take
The first brain-scanning study to track activity in the brain's decision-making centres during gambling shows fluctuations in dopamine levels affect risk-taking. Do you like a flutter? The levels of dopamine in your brain might be affecting how likely you are to gamble or take risks. Dopamine is a signalling molecule released by nerve cells known to be involved in predicting reward. While its role is often misunderstood – it has been blamed for everything from drug addiction to Facebook’s popularity – the compound plays an important role in the brain. Last year’s €1 million Brain Prize was given to three scientists who helped discover what it does. Now, for the first time, scientists have now been able to see how risk-taking is affected by the activity of dopamine-using nerve cells in the part of the brain that is involved in decision-making. People who had lower background levels of activity were slightly more likely to take a risky decision in a gambling task in the lab. Because the effect was small, this could only sometimes influence our decisions in real life, says Benjamin Chew of University College London, who did the work. He estimates that when facing the same choice we would make the same decision roughly eight times out of ten – but the other times it would be affected by dopamine fluctuations. To find out more, Chew’s team got 43 people to lie in a brain scanner while playing a gambling task, shown on a screen inside. In one version, for instance, they had to choose between definitely getting £2.70 or taking a 50-50 chance of a £6 pay-out, which over several rounds should result in less money.
7-13-18 Iceman's last meal was high-fat, high-calorie feast
Goat's fat and wild venison, plus sides of ancient wheat and bracken. It's not a menu likely to appear on Masterchef, but for some of our ancestors it was a nutritious feast. Scientists have revealed that the last supper of Oetzi the Iceman was well-balanced but also alarmingly high in fat. The man lived 5,300 years ago and met his death on a frozen glacier. His body was preserved in the ice for millennia until it was discovered in 1991. Scientists have been able to find out about many aspects of his life, including what he ate before he died. They say he filled his stomach with fat from wild goat, meat from red deer, an ancient grain known as einkorn and toxic fern. The fat content was 50%, which is much higher than the 10% in the average modern diet. "If you consider the altitude where the Iceman was hunting, you need this kind of energy supply," said Dr Frank Maixner of the Eurac Research Institute for Mummy Studies in Bolzano, Italy. "And the best way to do this is by eating fat; this gives you the necessary energy to survive in this harsh environment."
7-12-18 Otzi loaded up on fatty food before he died
New analysis fills in details of the famous Iceman mummy’s last meal. Around 5,300 years ago, the Iceman dined on wild meat and grains before meeting his end in the Italian Alps. His last meal was high in fat and optimal for a high-altitude trek, researchers report July 12 in Current Biology. Since his mummified remains were discovered in 1991, Ötzi’s life has undergone more scrutiny than many reality TV stars. His cause of death, his fashion, his tattoos, his ax, his cholesterol and his genetic instruction book, or genome, have all made headlines (SN 3/24/12, p.5). And in 2002, DNA analysis of samples from the Iceman’s lower intestine suggested that Ötzi ate red deer, goat and grains before he died. In 2011, radiological scans revealed that the mummy’s stomach contents were still intact (SN 9/24/11, p. 8). Now researchers are back with a more in-depth look inside the mummy’s gastrointestinal tract. Based on ancient DNA, proteins and other molecular data, the new analysis confirms the Iceman’s final menu: mountain goat (Capra ibex), red deer (Cervus elaphus), einkorn wheat (Triticum monococcum) and other domesticated grains. Traces of a toxic fern (Pteridium aquilinum) also turned up — possibly a home remedy for an upset stomach, but more likely either as part of the meal or as a wrapping for the food.
7-12-18 The right mix of gut microbes relieves autism symptoms in the long run
Impact on behavior lasts two years after getting fecal transplants. Giving children with autism a healthier mix of gut bacteria as a way to improve behavioral symptoms continued to work even two years after treatment ended. The finding may solidify the connection between tummy troubles and autism, and provide more evidence that the gut microbiome — the collection of bacteria and other microbes that live in the intestines — can influence behavior. “It’s a long way from saying there’s a cure for autism,” says Michael Hylin, a neuroscientist at Southern Illinois University in Carbondale who was not involved in the work. “But I think it’s a promising approach. It’s one that’s worthwhile.” Children with autism spectrum disorders often have gastrointestinal problems. In previous studies, environmental engineer Rosa Krajmalnik-Brown of Arizona State University in Tempe and colleagues discovered that children with autism had fewer types of bacteria living in their guts than typically developing children did. And many of the kids were missing Prevotella bacteria, which may help regulate immune system actions. The researchers wondered whether altering the children’s cocktail of gut microbes to get a more diverse and healthier mix might help fix both the digestive issues and the behavioral symptoms associated with autism.
7-12-18 How worried should you be about a new ‘superbug’ STI?
You’ve probably never heard of Mycoplasma genitalium, even though it’s one of the most prevalent. Here’s what you need to know . An emerging sexually transmitted infection that you’ve probably never heard of “could become the next superbug”, according to recent headlines. What exactly is Mycoplasma genitalium, and how worried should we be? M. genitalium is small bacteria that was first identified in 1981, and at that time it was unclear if it was a STI. Its true nature was only definitively confirmed in 2015 by a large UK survey of people aged 16-45 which found the infection was more common in those who had had more partners or unprotected sex. One reason it took so long to get the full picture of this infection is that it is very hard to detect. Commercial tests are only beginning to come on the market, so doctors haven’t been able to routinely screen for it. We now know that around 1 per cent of adults in the general population are infected with it, but the prevalence among people attending STI clinics can as high as to 38 per cent. It is actually one of the most common sexually transmitted bacterial infections in the UK and US, surpassed only by chlamydia. The majority of cases are symptomless and don’t seem to cause any harm, so the infection easily sails under the radar. But for some, the symptoms are similar to the STI chlamydia. Men might experience irritation in their penis or discharge, and painful urination. For women, the symptoms can include abdominal pain, pre-term birth and pelvic inflammatory disease (PID).
7-11-18 High blood pressure in older people linked to Alzheimer’s disease
For the first time, high blood pressure later in life has been linked to Alzheimer’s disease, a finding that might help us better understand the condition. A study of more than 1200 people around the age of 80 has suggested that high blood pressure in later life is associated with Alzheimer’s disease. Researchers tracked volunteers’ blood pressure for an average of eight years before their death, before performing autopsies to look for signs of Alzheimer’s disease in the brain. These included plaques of sticky amyloid protein between brain cells, and tangles of tau proteins inside them. The scientists observed that participants with a higher average systolic blood pressure – the pressure in the arteries when the heart beats – during these years had a larger number of tangles, but not plaques, in the brain. There is a longstanding debate about the relationship between blood pressure and Alzheimer’s disease – high blood pressure in middle age is thought to be one of many possible risk factors for the condition, but the evidence is not clear-cut. The team behind the new study say that theirs is the first to show a link between Alzheimer’s and blood pressure in older people. But researchers do not know yet how one might affect the other. One theory is that blood pressure changes could lead to impaired delivery of nutrients and clearance of toxic waste products from the brain, says Daniel Nation at the University of Southern California. “Another possibility is that these changes in arterial pulsation and perfusion may cause a mechanical injury to the blood–brain barrier, causing toxic blood products to enter the brain and exacerbate neurodegeneration,” says Nation.
7-11-18 How our bodies are rapidly colonised by bacteria when we’re born
We’ve had the best look yet at the microbes that make themselves at home in our bodies in the months following birth, including many mystery species. We’ve had the best look yet at the microbes that make themselves at home in our bodies in the months following birth. Many of these organisms are mystery species, and the study suggests that being born by C-section may have less of a long-lasting effect on the microbiome than previously thought. Our microbiome – the microbes that live in our gut and elsewhere on our body – plays a crucial role in our health. However, we don’t really know how the body’s microbial community becomes established once we’re born. To find out, Nicola Segata of the University of Trento, Italy, and colleagues recruited 25 mothers and their babies. They sampled bacteria from each mother’s gut, via faecal samples, as well as from their mouth, vagina, breast milk and skin. Genetic analysis enabled them to compare these bacteria with those present in the babies’ mouth and faeces during their first four months of life. The researchers found a very high diversity of microbes in the infant gut within 24 hours of birth. This diversity plummeted over the following week, then gradually recovered over the next four months. This suggests many different microbes initially move into the body, but only a few of these become established. At first, babies contain bacteria from many different sites from across their mother’s body, but microbes from their mother’s skin and vagina disappear soon after. “This doesn’t mean they’re not important. The organisms that are there in the first place are probably help shape the baby’s immune systems,” says Segata.
7-11-18 Cancer cells engineered with CRISPR slay their own kin
The technique reduced the size of tumors, a study in mice finds. Using gene editing, scientists have hoodwinked tumor cells into turning against their own kind. Cancer cells circulating in the bloodstream have something of a homing instinct, able to find and return to the tumor where they originated. To capitalize on that ability, researchers engineered these roving tumor cells to secrete a protein that triggers a death switch in resident tumor cells they encounter. The cancer-fighting cancer cells also have a built-in suicide switch — so the weaponized cells self-destruct before they can start tumors of their own, the team reports in the July 11 Science Translational Medicine. The new study isn’t the first attempt to fight cancer with cancer. Previous research has used circulating tumor cells to deliver cancer-killing viruses to noncirculating tumor cells, for example. But the new approach uses a gene-editing technology called CRISPR/Cas9 to manipulate the offensive-line cancer cells and give them more sophisticated properties, such as the ability to self-destruct once no longer needed. “The new twist here is the use of CRISPR-based technology to add resistance or sensitivity features to the parental cells,” says Renata Pasqualini, a cancer biologist at Rutgers Cancer Institute of New Jersey in Newark.
7-11-18 Autism can bring extra abilities and now we’re finding out why
Many strengths and difficulties associated with autism stem from the same thing, says Anna Remington, who researches questions autistic people are asking. WE HAVE been looking at autism all wrong, says Anna Remington. Our understanding of the condition has been skewed by an overly medical focus that classes any differences as impairments, she says, when in fact they could just represent diversity. Remington is head of the Centre for Research in Autism and Education at University College London, which tries to involve autistic people at every level in directing research and interpreting the results. “We ask autistic people ‘what should we be researching?'” she says. “Maybe surprisingly, it’s not the genetic research, it’s more about practical solutions like how do we improve employment rates?” Her own work focuses on autistic strengths, and her team is starting to uncover what underpins some of these abilities with a view to increasing employment opportunities for autistic people.
- What is autism?
- What kinds of abilities do autistic people have?
- Do we know what’s behind any of these abilities?
- What determines whether this extra capacity is a help or a hindrance?
- So we can’t choose how much of our capacity to use?
- Is there growing recognition of autistic advantages?
- Could the focus on advantages jeopardise support for autistic people who are not so able?
- We often think of autism as a spectrum, so sometimes people say, oh, so-and-so is a little bit autistic. Is there any truth in that?
7-11-18 Yoga and meditation work better if you have a brain zap too
Brain stimulation seems to offer a shortcut to unlocking the benefits of yoga and mindfulness sessions, but turbocharging meditation could have a dark side. FIRST came yoga, then hot yoga, beer yoga, even goat yoga. Now we have e-yoga, the combination of brain stimulation with meditation, mindfulness and downward dog. Paradoxical though it may seem to add modern technology to a spiritual practice, there are hints that passing a small electrical current through your brain enhances the hard-won effects of yoga and meditation, leading to greater feelings of well-being, more quickly. The first results of trials of the technology will be available next month, but that isn’t quick enough for some. Behind closed doors, the world’s first e-meditation classes have already started. The US defence agency is even investigating the concept as a way to enhance soldiers’ abilities. But don’t unroll your mat just yet: fast-tracking your zen could have a dark side. The yoga and meditation industry is booming, with more than 30 million people practising in the US alone and the global market worth £74 billion. It is no wonder: while practitioners have spoken about the transformative potential of meditation for centuries, science has only recently caught up. Mindfulness meditation – paying more attention to the present moment, to your thoughts, feelings and the world around you – can protect against depression, accelerate learning and alleviate pain and anxiety. It may even slow the ageing process. Yoga has also been found to offer numerous health benefits, such as helping with depression, anxiety and emotional eating. Both can switch off genes implicated in inflammation, which is linked to a number of diseases.
7-11-18 Ear implant lets deaf gerbils sense sound from light signals
A pioneering treatment has allowed deaf gerbils to perceive light as sound, raising hope for sophisticated optogenetic implants to relieve hearing loss. A special cochlear implant has used to light to enable deaf gerbils to sense sound. The results suggest that optical stimulation could one day be used to treat hearing loss in people. The method uses a technique called optogenetics, which involves manipulating nerve cells so they can be activated by light. The team used a virus to insert a gene for a protein that detects light into the cochlea, the snail-shaped organ in the inner ear that converts sound into electrical signals. They then implanted an optical fibre into the cochlea to deliver light signals. To test whether the animals could perceive these light signals as sound, the researchers trained gerbils with intact hearing before the treatment using a behavioural test called the shuttle box. The gerbils were placed in a box with two halves separated by a hurdle. When a sound was played, the animal had six seconds to jump over the hurdle to the opposite side. If they stayed on the same side, they got a gentle electric shock through the floor. Gerbils quickly learned to avoid this by jumping over the hurdle when they heard the sound. After having the treatment, the trained gerbils responded to light signals in the cochlea in the same way, suggesting they perceived the signal as a sound. “This tells you there is at least some resemblance of the percept that’s generated,” says team member Marcus Jeschke of University Medical Center Göttingen, Germany.
7-11-18 Texas toolmakers add to the debate over who the first Americans were
Unearthed spearpoints and other stone tools go back at least 16,000 years. People inhabited what’s now central Texas several thousand years before hunters from North America’s ancient Clovis culture showed up, researchers say. Excavations at the Gault site, about 64 kilometers north of Austin, produced a range of stone artifacts that date to between around 16,700 and 21,700 years ago, reports a team led by archaeologist Thomas Williams of Texas State University in San Marcos. An analysis of 184 of those finds identified 11 spearpoints unlike any others that have been found at ancient American sites, the scientists conclude July 11 in Science Advances. Researchers have long argued about whether people reached North America before the rise of Clovis culture 13,000 years ago. Evidence from the Gault site joins other recent reports of humans venturing deep into North America far earlier (SN: 6/11/16, p. 8), which would take Clovis people out of the running for the title of first New World settlers. Williams’ group estimated the age of the Gault pre-Clovis discoveries with a method that calculates the time since artifact-containing sediment has been exposed to sunlight.
7-11-18 Stone tools put early hominids in China 2.1 million years ago
The discovery suggests hominids left Africa 250,000 years earlier than thought. Members of the human genus, Homo, left Africa far earlier than thought, reaching what’s now central China by around 2.12 million years ago, a new study finds. Some stone tools unearthed at China’s Shangchen site date to roughly 250,000 years before what was previously the oldest Eurasian evidence of Homo, say geologist Zhaoyu Zhu of the Chinese Academy of Sciences in Guangzhou and his colleagues. Toolmakers visited the Chinese spot on and off until as late as 1.26 million years ago, the scientists report online July 12 in Nature. No hominid fossils have been found at Shangchen. Until now, the Dmanisi site, in the western Asia nation of Georgia, had yielded the oldest hominid remains outside Africa. Homo erectus fossils unearthed at Dmanisi date to between 1.85 million and 1.77 million years ago (SN: 11/16/13, p. 6). “An early form of Homo probably made the Shangchen artifacts, but it’s too early to say if that was H. erectus,” says coauthor Robin Dennell, an archaeologist at the University of Exeter in England.
7-11-18 Earliest evidence of humans outside Africa
Scientists say they've found the earliest known evidence of a human presence outside Africa. Stone tools discovered in China suggest primitive humans - or a close relative - were in the region as early as 2.12 million years ago. They are about 270,000 years older than the previous earliest evidence, which consists of bones and tools from Dmanisi in Georgia. The research, by a Chinese-British team, appears in the journal Nature. The stone artefacts were discovered at Shangchen on a plateau in northern China. They comprise different types of stone tools constructed for a variety of purposes. All show signs of having been used. Most were made of quartzite and quartz rock that probably came from the foothills of the Qinling Mountains, five to 10 km to the south of the dig site. But we don't know for sure which species of human relative made them. Humans left Africa at many times during their history. Living people outside Africa, for example, trace their origins to an exodus that occurred 60,000 years ago. But there had been no evidence of occupation by human relatives in Eurasia until the Dmanisi evidence at 1.8 million years ago. Writing in Nature, palaeoanthropologist John Kappelman, who was not involved with the new study, commented: "The roughly 14,000-kilometre trek from eastern Africa to eastern Asia represents a range expansion of dramatic proportions." Africa has traditionally been seen as the engine of human evolution - where key species arose before spreading out through the rest of the world. However, some scientists have proposed a more important role in this story for Asia. With these new finds, some researchers will wonder how much further back the human story goes in Asia.
7-11-18 Emerging sex disease MG 'could become next superbug'
A little known sexually transmitted infection could become the next superbug unless people become more vigilant, experts are warning. Mycoplasma genitalium (MG) often has no symptoms but can cause pelvic inflammatory disease, which can leave some women infertile. MG can be missed - and if it is not treated correctly, it can develop resistance to antibiotics. The British Association of Sexual Health and HIV is launching new advice. Its draft guidelines detail how best to spot and treat MG. Mycoplasma genitalium is a bacterium that can cause inflammation of the urethra in men, causing discharge from the penis and making it painful to urinate. In women, it can cause inflammation of the reproductive organs (womb and fallopian tubes) too, causing pain and possibly a fever and some bleeding. You can get it by having unprotected sex with someone who has it. Condoms can prevent this spread. It was first identified in the UK in the 1980s and is thought to affect 1-2% of the general population. MG does not always cause symptoms and will not always need treatment, but it can be missed or mistaken for a different sexually transmitted infection, such as Chlamydia. The BASHH says this is concerning. Tests for MG have recently been developed but are not available in all clinics yet although doctors can send samples to Public Health England's laboratory to get a diagnostic result. It can be treated with antibiotics - but the infection is developing resistance to some of these drugs.
7-10-18 Long-necked dinosaurs grew to be giants in more ways than one
Fossils suggest some early sauropod relatives grew massive using a previously unknown method. For sauropods — the largest animals known to have walked on Earth — there may have been more than one way to get gigantic. Most early relatives of the herbivorous dinosaurs have a suite of features once thought to be the essential blueprint for gigantism, such as sturdy pillarlike legs, elongated necks and forelimbs, and bones that grew continuously rather than in seasonal spurts. But an analysis of fossils of sauropodomorphs — a group that includes sauropods and some ancestors and similarly shaped relatives — suggests that some of the dinos may have had a different strategy for becoming behemoths, researchers report online July 9 in Nature Ecology and Evolution. Paleontologist Cecilia Apaldetti of the Universidad Nacional de San Juan in Argentina and colleagues examined four sauropodomorphs, including one newly identified species that the team dubbed Ingentia prima and three already known specimens of a sauropodomorph called Lessemsaurus sauropoides. Dating to the Late Triassic, between 237 million and 201 million years ago, these “Lessemsauridae” were far from puny: The animals weighed in at an estimated 7 to 10 metric tons, larger than an African elephant. All four specimens showed a combination of features that was distinct from sauropods as well as from other sauropodomorphs. Instead of upright, pillarlike legs, the dinos had crouched hind limbs and flexed front limbs, with elbows splayed slightly outward. Patterns of bone growth in the fossils also suggest that the animals grew in cyclical spurts rather than continuously. However, their bone growth was extremely rapid, a feature unique to this group, Apaldetti says. “They grew in a cyclical but extremely accelerated growth, at a speed even higher than that of the giants that grew continuously.”
7-10-18 Fossil of 'first giant' dinosaur discovered in Argentina
They are the biggest animals to have walked the Earth, with some weighing as much as a space shuttle. However, it is unclear how dinosaurs grew to such massive proportions. A new dinosaur discovery from Argentina gives fresh evidence on the rise of the giants. The animal used a novel strategy to become super-sized, involving very fast growth spurts and efficient bird-like lungs, say palaeontologists. The fossil was found in the northwest of Argentina during a field trip. The scientists found four skeletons in all, one of a new species and three of related dinosaurs. "We could see that it was a new species that we named Ingentia prima," said Dr Cecilia Apaldetti of Universidad Nacional de San Juan in Argentina. "That in Latin means the 'first giant'." The dinosaur dates back to the Triassic, about 30 million years before the iconic long-necked plant-eaters Diplodocus and Brachiosaurus appeared on the scene. It wasn't as large, weighing about 10 tonnes. But its discovery is a surprise, coming so early in dinosaur evolution. The new dinosaur species Ingentia prima and similar species are grouped together as "lessemsaurids". Dinosaur fans need to learn a new name, the lessemsaurids, because these were the first dinosaurs to grow to giant sizes of around 10 tonnes, back in the Triassic Period some 215 million years ago. The remarkable discovery of four lessemsaurid skeletons forces us to rethink when, and how, dinosaurs got so huge. We used to think that the first giant dinosaurs arose in the early part of the Jurassic Period, after supervolcanoes caused a global extinction at the end of the Triassic. But the lessemsaurids tell us that at least some dinosaurs were able to attain giant sizes during the latest part of the Triassic, before the extinction. What is really unexpected is that the lessemsaurids achieved their huge bodies independently of the gigantic sauropods like Brontosaurus and Diplodocus, which did indeed evolve later during the Jurassic. The development of huge size wasn't just a one-off event for the sauropods, but rather different types of dinosaurs were able to become colossal, which speaks to just how incredible these animals were.
7-9-18 Quantum dots in brain could treat Parkinson’s and Alzheimer’s diseases
Tiny particles seem to stop misfolded proteins from forming toxic clumps in the brains of mice, improving their performance on physical tests. Tiny particles called quantum dots reduce symptoms in mice primed to develop a type of Parkinson’s disease, and also block formation of the toxic protein clumps in Alzheimer’s. They could one day be a novel treatment for these brain disorders, although tests in people are some years away. Quantum dots are just a few nanometres in size – so small they become subject to some of the strange effects of quantum physics. They have useful electronic and fluorescent properties and are found in some TV screens and LED lights. Unlike most medicines, their tiny size means they can pass from bloodstream into the brain. Byung Hee Hong of Seoul National University in the South Korea and his colleagues wondered if they would affect the molecules involved in Parkinson’s or other brain disorders. Parkinson’s disease involves gradually worsening tremors and movement problems. It is thought to be caused by a protein called synuclein found in nerve cells folding into the wrong shape, which triggers a chain reaction of misfolding in nearby synuclein molecules. This leads to a build-up of long strands or “fibrils” of the protein, killing neurons. Hong’s team found that in a dish, quantum dots made from graphene – a form of carbon – bind to synuclein, and not only stop it from clumping into fibres, but also cause existing fibres to break up into individual molecules. “We didn’t expect the quantum dots to induce disaggregation of fibrils,” says Hong.
7-9-18 Apple peel drug makes mice live longer by targeting a cause of ageing
We’re beginning to understand the causes of ageing and how to reverse it – thanks to an extract from apple peel that helps improves strength in elderly mice. We’re beginning to understand the causes of ageing and how to reverse it – thanks to an extract from apple peel. A team has found that a combination of dasatinib – a leukaemia drug – and quercetin – an extract from apple peel – can make elderly mice live 36 per cent longer. These drugs were chosen for their ability to selectively kill so-called senescent cells. These abnormal cells are in the process of breaking down, but they resist dying. They usually start appearing in the human body in our 60s, although they can arise much earlier in people who are obese or experience a chronic disease. Some have suggested that these cells themselves catalyse the ageing process, kicking it into action. Now James Kirkland of the Mayo Clinic in Rochester, Minnesota, and his colleagues have shown that this does seem to be the case. When they injected small numbers of senescent cells into young, 6-month-old mice, the animals’ speed, endurance and strength fell by 20 to 50 per cent within a few weeks, sinking to the level of a typical elderly, 2-year-old mouse. “We wouldn’t believe it for a long time, so we did it again and again and again,” says Kirkland. “It was weird to get this result with so few cells.” To block the effect of senescent cells, the team looked for drugs that might destroy them – known as “senolytic” drugs. They selected a combination of dasatinib and quercetin because both interfere with the way that senescent cells avoid death.
7-9-18 Vaginal microbes in mice transfer stress to their pups
Transmitted signals alter the way offspring develop. Mouse mothers can transmit stress signals to offspring, changing the way the pups’ bodies and brains develop. Some of these stress messages get delivered during birth, scientists suggest July 9 in Nature Neuroscience. Researchers suspected that vaginal microbes from stressed-out moms could affect male pups in ways that leave them vulnerable to stress later in life (SN: 12/14/2013, p. 13). But earlier studies hadn’t demonstrated whether those microbes, picked up during birth, actually caused some of the changes seen in offspring, or if other aspects of life in utero were to blame. Tracy Bale of the University of Maryland School of Medicine in Baltimore and colleagues subjected pregnant mice to stressful trials that included smelling the scent of a fox for an hour, listening to unusual sounds overnight and being restrained in a tube for 15 minutes. Other pregnant mice didn’t experience these stressors. Then, researchers delivered pups by cesarean section, so that the pups weren’t exposed to their mothers’ community of vaginal microorganisms, or microbiome. After delivery, researchers dosed the pups with vaginal fluid taken from stressed or unstressed mothers. For male pups not exposed to stress in the womb, vaginal microbes from a stressed mother changed the amount of certain kinds of gut bacteria. (Just as in earlier studies, female pups didn’t show effects of their mothers’ stress.) When those male pups were older, being restrained led them to release more of the stress hormone corticosteroid than mice dosed with microbiota from unstressed moms. And in the brains of adult mice that had experienced chronic stress, genes involved in metabolism and the development of nerve cells behaved differently depending on whether early microbes came from stressed or unstressed mothers.
7-9-18 New dinosaur fossil explains how Diplodocus evolved to be so massive
A new fossil uncovered in Argentina shows a dinosaur adapting to life as a giant, rewriting our understanding of how giant sauropods like Diplodocus evolved. Diplodocus is the largest creature to have walked, but not much is known about how it evolved such proportions. A new fossil challenges current ideas about the path to giant dinosaurs. Cecilia Apaldetti and her colleagues at the National University of San Juan, Argentina, discovered a previously unknown dinosaur in north-west Argentina within a formation that dates to the late Triassic, around 220 million years ago. The researchers have christened it Ingentia prima, and placed it in a group of early sauropodomorphs called the lessemsaurids. The lessemsaurids are distant relatives of giant sauropods like Diplodocus, and developed into giants around 50 million years before Dipolodocus. Although nowhere near as big as the 50-tonne Dipolodocus, Ingentia, short-necked and walking on two legs, still weighed up to 10 tonnes. “Until now we thought that to acquire gigantic size, it was necessary to acquire adaptations in the structure of the skeleton to support this weight,” says Apaldetti’s colleague Ricardo Martínez. However, Ingentia lacks many of these – for example, it doesn’t have the stout, columnar legs of Diplodocus and modern-day giants like elephants. Also, while giant sauropods grew continuously, tree-ring like patterns in the bone show lessensaurids had growth spurts. Ingentia also developed bird-like air sacs that allowed it to breathe continuously – an important feature giant dinosaurs needed to get rid of their immense body heat.
7-6-18 Wearing a tie may be restricting blood flow to your brain
Tightly-worn ties have been found to impair the brain’s blood supply, prompting one scientist to suggest that it’s time to abandon them altogether. Time to say bye to your tie? The businesswear staple reduces blood flow to the brain by squashing veins in the neck, research suggests. Robin Lüddecke at University Hospital Schleswig-Holstein in Germany and his colleagues scanned the brains of 15 healthy young men before and after they put on a tie. Each participant was instructed to make a Windsor knot and tighten it to the point of slight discomfort. Just after the men tightened the ties, the blood flow in their brains dropped by an average of 7.5 per cent. In contrast, no changes in blood flow were observed when the experiment was repeated with 15 men who did not put on a tie. Wearing a tie compresses veins in the neck, pushing blood into the skull and creating pressure build-up, says Lüddecke. This extra pressure most likely crushes the brain’s blood vessels and reduces blood flow, he says. In healthy people, a 7.5 per cent drop in blood flow in the brain is unlikely to lead to noticeable symptoms, says Steve Kassem at Neuroscience Research Australia in Sydney. However, it could potentially create problems for smokers, older people or those with high blood pressure, who may already have sluggish blood flow due to blocked or damaged vessels in their brains, he says. In this high-risk group, an extra drop in blood flow due to tie-wearing might cause headaches, dizziness and nausea, Kassem suggests. Studies have found that long-term blood restriction to the brain is associated with the development of Alzheimer’s disease, although it’s unlikely that tie-wearing would have this severe an effect, he says.
7-6-18 No matter their size, newborn stomachs need frequent filling
Stomach size is just one of several factors that drive a newborn to feed. I’m making my way through my third round of breastfeeding a newborn and taking stock of how things are going. Some aspects are definitely easier: My milk came in really quickly (a perk of being a repeat lactator), the fancy breastfeeding baby holds are no longer mysterious to me and I already own all of the weird pillows I need to prop up my tiny baby. But one thing isn’t easier this time around: the bone-crushing, mind-numbing exhaustion. Just like my other two, this sweet baby seems to eat all the time. All day. All night. Sometimes multiple times an hour, especially in the witching hours of the evening. This frequency got me curious about the biology of newborns’ stomachs. Just how small are they? Are they so microscopic that one can hold only enough sustenance to keep my newborn satisfied for a thousandth of a second? Birth educators and medical professionals often use a marble to illustrate the size of a newborn’s stomach, a tiny orb that holds about 5 to 7 milliliters of liquid. But that small estimate has come into question. A 2008 review published in the Journal of Human Lactation points out that there aren’t many solid studies on the size of the infant stomach, and some of the ones that do exist come to different conclusions. Another review of existing studies concluded that the average newborn stomach is slightly smaller than a Ping-Pong ball and can hold about 20 milliliters, or about two-thirds of an ounce.
7-5-18 Tiny mitochondria may be controlling genes in heart of our cells
The nucleus is the mighty genetic control room of a human cell – but new research suggests that mitochondria can pull the levers of power there too. The nucleus has long been seen as the ruler of the cell, packed full of genes that run the show. But the idea it has complete control is questioned by a new study suggesting mitochondria may be able to influence the nucleus. Mitochondria are energy-generating structures found in the cells of complex organisms which possess their own much smaller genome. Changhan David Lee at the University of Southern California, Los Angeles, and his colleagues have found that in human cells this encodes an RNA that makes a peptide, a protein-like molecule, called MOTS-c. This peptide can move to the nucleus and influence genes there in response to cellular stress. The origins of this ability may lay in the idea that mitochondria are descended from bacteria that were ingested by our cells at some point in our evolutionary history, forming a symbiotic relationship that required communication. “We think these mitochondrial-derived peptides, such as MOTS-c, are part of an ancient communication system that is still in play today,” says Lee. The current mitochondrial genome is a relic of its bacterial origins because over time a lot of its genes transferred to the nucleus. This raises the intriguing question as to whether the mitochondrion is regulating its former genes – and Lee and his colleagues are now looking into this. They also hope that understanding the complex communication between mitochondria and the nucleus could shed light on the roles of both in aging and age-related diseases.
7-5-18 Young kids are surprisingly bad at using memory to plan ahead
We used to think children as young as four could plan for the future. But now it seems kids develop the type of memory needed to do this later than we thought. We used to think that planning for the future was a skill most children have by the age of four, but now it seems that we don’t develop the kind of memory needed to do this until we’re older. Episodic memory lets us reflect on our past, and imagine ourselves in the future. To find out when children develop this, Amanda Seed at the University of St Andrews in the UK and her colleagues devised a test for 212 children between the ages of three and seven. Each child was taught how to use a box that released a desirable sticker when the correct token was placed in it. An examiner showed them two boxes of different colours and told them that one would remain on a table while they left the room, and the other would be put away. The children were later offered three tokens to choose from, in a different room. Two matched the colours of the boxes they had previously seen, but the third was a new colour to distract them. Unknown to the children, only matching tokens would work – but thinking about the boxes they had used, and their colours, should enable them to predict that it might be best to pick a token that is the same colour as one of the boxes. The 3- and 4-year-old children didn’t choose the right token more often than they would by chance, suggesting they weren’t able to make this inference, but children aged 5 and older did.
7-5-18 Nerve cells that help control hunger have been ID’d in mice
Targeting similar cells in people could mark a new way to regulate appetites. Newly identified nerve cells deep in the brains of mice compel them to eat. Similar cells exist in people, too, and may ultimately represent a new way to target eating disorders and obesity. These neurons, described in the July 6 Science, are not the first discovered to control appetite. But because of the mysterious brain region where they are found and the potential relevance to people, the mouse results “are worth pursuing,” says neurobiologist and physiologist Sabrina Diano of Yale University School of Medicine. Certain nerve cells in the human brain region called the nucleus tuberalis lateralis, or NTL, are known to malfunction in neurodegenerative diseases such as Huntington’s and Alzheimer’s. But “almost nothing is known about [the region],” says study coauthor Yu Fu of the Singapore Bioimaging Consortium, Agency for Science, Technology and Research. In people, the NTL is a small bump along the bottom edge of the hypothalamus, a brain structure known to regulate eating behavior. But in mice, a similar structure wasn’t thought to exist at all, until Fu and colleagues discovered it by chance. The researchers were studying cells that produce a hormone called somatostatin — a molecular signpost of some NTL cells in people. In mice, that cluster of cells in the hypothalamus seemed to correspond to the human NTL.
7-5-18 Eight cups of coffee a day make you live longer? Don’t bet on it
Drinking coffee has once more been linked to a lower risk of early death but there are good reasons this could turn out to be froth, says Naveed Sattar. In medicine, a lot of what we know about how to cut the risk of an early death is rooted in high quality evidence from clinical trials or health policies. This is particularly true when it comes to the influence of smoking, obesity, diabetes, very high cholesterol and blood pressure. However, what is less certain is the impact of specific foods or drinks. Coffee is a prime example. On the one hand, multiple studies have suggested that those who drink it tend to develop heart disease, diabetes, cancer and other conditions less often, and live longer than those who do not. It also appears that the more cups of coffee you drink, the lower the risks. On the other hand, there is concern that too much coffee may cause some harms due to caffeine content. Caffeine stimulates the brain and generally causes alertness, but too much can lead to mild dependence and withdrawal symptoms, such as poor sleep, irritability and headaches. So, is coffee good or bad for us? The hunt for the answer goes on. The latest contribution is a study in the journal JAMA Internal Medicine, which looked at around half a million people in the UK. It reported that coffee drinking was linked to lower risk of early death, including in those drinking eight or more cups per day. It also showed that this finding was consistent irrespective of whether individuals were genetically fast or slow at metabolising caffeine, or whether the coffee was caffeinated or decaffeinated.
7-4-18 The brain’s secret powerhouse that makes us who we are
Once regarded as having only a bit-part role in mental operations, the cerebellum could actually be the crowning achievement of our brain's evolution. TUCKED away beneath the rest of the brain and only a tenth of its size, the cerebellum is typically seen as a trusty neural sidekick. Like Watson trailing behind Sherlock Holmes, it was useful enough, but not nearly as interesting. The cortex was where the good stuff happened, the stuff that makes us human. Recently, though, it has become clear that the cerebellum is far from a bit player in the story of humankind. Neuroscientists are starting to suspect that this little cauliflower-shaped orb at the back of our head, which is packed with more neurons than all the other brain regions put together and home to a superfast wiring system, is doing the kinds of complex calculations that allow for our most Sherlock-worthy feats. In fact, it could be the crowning achievement of our brain’s evolution. This upgrade in status has been a long time coming. In the 19th century, phrenologists, who looked at the shape of the skull to determine a person’s character, declared the cerebellum, with its wrinkly lobes that hang from the bottom of the brain, the root of sexual desire. The larger the cerebellum, the greater the likelihood of sexual deviance. The evidence soon began to suggest otherwise, however. During the first world war, the British neurologist Gordon Holmes noticed that the main problems for men whose cerebellums had been damaged by gunshot wounds had nothing to do with their sex lives and everything to do with the fine control of their movements, ranging from a lack of balance to difficulties with walking, speech and eye movements. From then on, the cerebellum became known as the mastermind of our smooth and effortless motions, with no role in thinking.
7-4-18 How to stop artificial intelligence being so racist and sexist
AI his frequently be biased, but a new technique may be able put fairness right at the heart of training algorithms. Something is rotten at the heart of artificial intelligence. Machine learning algorithms that spot patterns in huge datasets, hold promise for everything from recommending if someone should be released on bail to estimating the likelihood of a driver having a car crash, and thus the cost of their insurance. But these algorithms also risk being discriminatory by basing their recommendations on categories like someone’s sex, sexuality, or race. So far, all attempts to de-bias our algorithms have failed. But a new approach by Niki Kilbertus at the Max Planck Institute for Intelligent Systems in Germany and colleagues claims to offer a way to bake fairness right into the process of training algorithms. Machine learning systems improve with examples. The rough idea is that if you want to predict the likelihood of someone reoffending, you load up an AI with previous cases of people going through the criminal justice system. After viewing enough examples, the algorithm can then predict what will happen when presented with a fresh case. But there are certain things that, as a society, we don’t want an algorithm like this to take into consideration, such as someone’s race – bail shouldn’t be determined based on the colour of someone’s skin. “Loan decisions, risk assessments in criminal justice, insurance premiums, and more are being made in a way that disproportionately affects sex and race,” says Kilbertus. But unfortunately, the obvious quick fix of just removing sensitive categories from the data the algorithms are trained on doesn’t work.
7-4-18 The second great battle for the future of our food is underway
First it was GM food. Now battle lines are being drawn over whether crops and animals modified with CRISPR gene-editing can make it on to supermarket shelves. YOU have probably heard of CRISPR, the gene-editing technique set to cure diseases and modify our DNA. The real revolution, however, may be in its ability to transform our food. “The biggest impact is going to be in agriculture,” Jennifer Doudna, who helped develop the method, told New Scientist earlier this year. This is because older, cruder techniques make it expensive to develop genetically modified (GM) foods, so they are mostly the domain of big multinationals. In contrast, CRISPR has made genetic tinkering cheap and easy. “It takes a firm on average 13 years and costs $130 million to launch a GM crop” “Rather than just four or five large multinationals dominating the market, you’re going to have an explosion of companies all over the world innovating and coming up with improved crop varieties,” says Tony Moran of US biotech company Cibus. But just how far this revolution goes depends on how countries regulate CRISPR foods. The US and some others have decided that simple gene tweaks don’t require special regulation. But the world’s biggest market – the European Union – has yet to decide. A court decision due later this month could determine the technique’s fate in the EU, which is historically anti-GM, and perhaps the world. So why are people keen to CRISPR our food? For starters, genome-edited plants and animals could make what we eat safer by removing allergens and cancer-causing substances such as acrylamides. CRISPR could also make crops resistant to diseases and more nutritious.
7-4-18 It’s ok that the public rejected GM food – after all, we did ask
Many people see the public's rejection of genetically-modified food as a failure, but I would argue it was successful public engagement, says Lesley Paterson. The refusal of many people to accept genetically modified foods is often perceived as a failure to convince the public of the benefits of science. I would argue that, in terms of public engagement, the GM debate of 20 years ago was in some ways a success. The GM campaign should have gone further to facilitate a more thoughtful discourse, but at the end of the day, the response was “no thanks”. Genuine public engagement is, by its definition, a two-way process of asking questions and listening to the answers. Science has many consequences, so society must have a say. The focus was on convincing people that the technology was safe, but that wasn’t all the public wanted to talk about. When we ask people from all walks of life to discuss the implications of science innovations, four core questions typically arise: Who are the winners? Who are the losers? What are the benefits? What are the risks? More in-depth discussions around GM revealed that people did not just see themselves as consumers, but had wide-ranging concerns, including that big business could be the only real winner (see “The second great battle for the future of our food is underway”). It does not matter how many times we say “there is no evidence that GM foods are unsafe”, if the question is “who will benefit from the application of this technology?”.
7-4-18 Prehistoric two-year-old could grip tree branches with her feet
A young hominin who lived 3.3 million years ago had flexible feet that she could use to climb trees like a chimp, suggesting our ancestors kept this trait for a long time. A human-ape toddler who lived 3.3 million years ago had slightly ape-like feet that she could use to grasp the branches of trees. The finding suggests that young hominins spent more time climbing than adults did. It also indicates that, long after hominins started walking upright on two legs, they retained some ability to grasp with their feet. “They don’t have the grasping ability of chimpanzees,” says team member Jeremy DeSilva of Dartmouth College in Hanover, New Hampshire. “But it appears to us, based on the anatomy of the foot, that they’ve got more grasping ability than a modern human does.” DeSilva and his colleagues have described the almost complete foot of an Australopithecus afarensis, which lived 3.3 million years ago in what is now Ethiopia. That is at least 4 million years after our ancestors split from those of chimpanzees, but 3 million years before our own species appeared. The study is the latest development in a story that began in 2000, when Zeresenay Alemseged discovered a virtually complete A. afarensis skeleton in Dikika, Ethiopia. The skeleton belonged to a little girl, who was about two and a half years old when she died.
7-4-18 Foot fossil pegs hominid kids as upright walkers 3.3 million years ago
But a juvenile Australopithecus afarensis’ foot still had some apelike features. Walking was afoot long ago among toddler-aged members of a hominid species best known for Lucy’s partial skeleton. A largely complete, 3.3-million-year-old child’s foot from Australopithecus afarensis shows that the appendage would have aligned the ankle and knee under the body’s center of mass, a crucial design feature for upright walking, scientists report July 4 in Science Advances. “The overall anatomy of this child’s foot is strikingly humanlike,” says study director Jeremy DeSilva, a paleoanthropologist at Dartmouth College in Hanover. But the foot retains some hints of apelike traits. Compared with children today, for example, the A. afarensis child — only about 3 years old at the time of death — had toes more capable of holding onto objects or anyone who was carrying her, the team found. Those toes included a somewhat apelike, grasping big toe. “Young children having some ability to grasp mom could have made a big energetic difference for Australopithecus afarensis adults as they traveled,” DeSilva says.
7-4-18 Asia’s mysterious role in the early origins of humanity
Bizarre fossils from China are revealing our species' Asian origins and rewriting the story of human evolution. DECEMBER 1941. Japan has just entered the second world war. China, already fighting its neighbour, is in the firing line. At the Peking Union Medical College Hospital, Hu Chengzhi carefully packs two wooden crates with the world’s most precious anthropological artefacts. Peking Man – in reality some 200 fossilised teeth and bones, including six skulls – is to be shipped to the US for safekeeping. This is the last anyone ever sees of him. At the time, the Peking Man remains were the oldest known fossils belonging to human ancestors. Their discovery in the 1920s and 30s caused a sensation, triggering declarations that the cradle of humanity had been found. But just a few decades later, all eyes had turned to Africa. A slew of discoveries there left little doubt that it was our true ancestral home. As far as human evolution was concerned, Asia was out of the picture. Not any more. The last decade has seen the discovery of new Asian fossils, among others by Chinese palaeoanthropologists with a renewed interest in their heritage. As key moments in our past are rewritten, the spotlight is once more turning east. The first Peking Man remains were found in 1923, nearly 50 kilometres outside Beijing. Alongside the broad-nosed individuals with thick brows were burnt animal bones, suggesting an early human ancestor capable of controlling fire. Only four other ancestral human species had been discovered at that time, including Neanderthals in Germany and Australopithecus africanus, identified from the ape-like Taung Child remains in South Africa. Team leader Davidson Black believed the Chinese fossils represented a new species, which he called Sinanthropus pekinensis.
7-4-18 Cash and competition make doctors prescribe fewer antibiotics
Doctors in Australia and the UK are now prescribing fewer antibiotics thanks to financial incentives and a bit of competition among peers. Some family doctors in Australia and the UK are now prescribing fewer antibiotics following successful trials of measures intended to curb over-prescribing habits. Overuse of antibiotics is contributing to the rise of drug-resistant bacteria, which now kill at least 700,000 people globally each year. Research has found that many doctors still prescribe antibiotics for viral infections even though these drugs only work for bacterial infections. Australian GPs, for example, write around 5 million too many antibiotic scripts annually for viral respiratory infections like colds and flus. To address this problem, the Australian government last year sent letters to GPs whose antibiotic prescribing rates were in the top 30 per cent for their region. These letters were written in four different formats to see what worked best. The most effective letter declared in bold text: “You prescribe more antibiotics than x per cent of prescribers in your region” and displayed a large graph to illustrate this information visually. A government report released last week found that GPs who received this letter reduced their antibiotic prescribing by 12 per cent on average over the following year. The UK government has tried another approach: financial reward. In 2015, it began offering local health areas an extra £5 in health funding per capita if they improved a range of measures, including cutting antibiotic prescribing by GPs by 1 per cent or more.
7-4-18 Thai cave: How life in darkness could affect trapped boys
The 12 boys and their coach trapped in a cave in Thailand may be stuck there for a lengthy period – how will a lack of daylight affect them? Linda Geddes explores what scientists know. Aside from the psychological trauma of being trapped hundreds of metres underground, the absence of daylight may do strange things to the boys’ internal sense of time and their perception of it. These changes could put them at risk of depression, insomnia, and potentially create discord within the group. What do scientists know about how their bodies and minds will react to darkness – and are there measures that could help them? This isn’t the first time that people have been isolated in a cave system for months on end. In 1962, a French geologist called Michel Siffre holed himself up inside an underground glacier that he’d discovered near Nice for two months. With no access to clocks, calendars, or sunlight, and no visits from the world above, Siffre let his body dictate his behaviour. He kept a written record of his activities and telephoned his team on the outside each time he woke up, ate and just before he slept – although they didn’t reveal to him what time it was. When his colleagues eventually called to say the two months was up, Siffre didn’t believe them: he was convinced that only one month had passed. His psychological perception of time had become distorted by the constant darkness.
7-4-18 First commercial DNA data storage service set to launch in 2019
A start-up called Catalog claims it will be able to store a terabyte of data in a gram-sized DNA pellet, but questions remain over whether the technology is ready. BIG data could be about to get much smaller. Catalog, a start-up based at the Harvard Life Lab, has announced plans for the first commercial DNA data storage service. The company says it has developed a way to cheaply store a terabyte of data – the equivalent of 40 Blu-rays – in a DNA pellet. Using DNA as a data storage medium has long held appeal thanks to its durability and density. If kept cool and dry, DNA can reliably last for hundreds of years, so a vast data centre could be replaced by an ordinary refrigerator. But current technology makes this prohibitively expensive. For example, Twist Biosciences of San Francisco can create DNA strands that hold a mere 12 megabytes, enough for a handful of mp3s, at a cost of $100,000. Catalog’s chief science officer, Devin Leake, says the firm can do much better. From 2019, the firm says it will offer a terabyte worth of DNA-encoded data in a gram-sized pellet. “More significantly, compared to other DNA synthesis approaches, our cost is five orders of magnitude lower,” says Leake. But the company will need to bring costs down much further to compete with the price of cloud-storage on tape, which Amazon currently sells for less than a penny per gigabyte each month. Co-founder Hyunjun Park says that Catalog’s price hinges on a new approach. Rather than encoding a string of data onto a single DNA molecule, it produces a small core “alphabet” of DNA sequences that correspond to snippets of binary data and can be pooled together into much larger files.
7-3-18 Evidence grows that an HPV screen beats a Pap test at preventing cancer.
Switching to a human papillomavirus test may help reduce cases of the disease. Evidence continues to grow that screening for human papillomavirus infection bests a Pap test when it comes to catching early signs of cervical cancer. In a large clinical trial of Canadian women, pap tests more often missed warning signs of abnormal cell growth in the cervix than did HPV tests, researchers report July 3 in JAMA. As a result, at the end of a four-year period, researchers found 5.5 new cases of severely abnormal, precancerous cervical cells per 1,000 women who got Pap tests, compared with 2.3 cases per 1,000 women who got HPV tests. Pap tests are the standard way to screen for cervical cancer. “We should be moving away from screening with Pap tests toward screening with HPV tests,” says L. Stewart Massad, a gynecologic oncologist at Washington University School of Medicine in St. Louis, who wrote a commentary accompanying the study. Previous research has found HPV testing leads to increased detection of abnormal cervical cells before they become cancerous compared with a Pap test. For instance, a 2009 study reported fewer cases of advanced cervical cancers and fewer deaths among women in India tested for HPV (SN: 4/25/09, p. 11). The study supported HPV testing in poorer countries, where cervical cancer screenings aren’t widespread. Worldwide, cervical cancer ranks fourth deadliest for women.
7-3-18 DNA reveals Romans helped spread TB across three continents
The Romans gave us roads, public toilets and the modern calendar, but we may also have them to thank for spreading a deadly disease: tuberculosis. The Romans gave us roads, public toilets and the modern calendar, but we may also have them to thank for spreading a deadly disease: tuberculosis. A genetic analysis suggests that while TB first arose about 5000 years ago in Africa, the Roman Empire was behind its more recent, rapid spread around Europe and beyond. TB is a lung infection that, if left untreated, can cause a chronic cough, weight loss and a lingering death. By some estimates the bacteria that causes it, Mycobacterium tuberculosis, has killed more people than any other infectious disease in history. The strain of TB that affects humans can’t be carried by other animals, says Caitlin Pepperell at the University of Wisconsin-Madison. “So the evolution of the bacterium is inextricably tied to humans.” To find out its origins, Pepperell’s team looked at the genetic sequences of 552 samples of TB bacteria obtained from people across most of the world. They left out North and South America as people in these continents are mainly affected by TB bacteria that arrived with the first Europeans. Taking into account where the samples came from, and the known rate at which genetic mutations accrue in its DNA, they drew up the bacteria’s family tree. It was already known that TB bacteria can be divided into seven different families. Pepperell’s team found that the last common ancestor of all these lineages first arose in Africa, probably in West Africa, between around 4000 and 6000 years ago – roughly 3000 BC.
7-3-18 This ‘junk’ gene may be important in embryo development
Mice — and maybe humans — can’t get past the two-cell stage without it. A once-maligned genetic parasite may actually be essential for survival. Mouse embryos need that genetic freeloader — a type of jumping gene, or transposon, called LINE-1 — to continue developing past the two-cell stage, researchers report in the July 7 Cell. Many scientists “charge that these are nasty, selfish genetic elements” that jump around the genome, making mutations and wreaking havoc, says study coauthor Miguel Ramalho-Santos, a developmental and stem cell biologist at the University of California, San Francisco. But the new research suggests that the jumping gene is more helpful to development than previously thought. Transposons certainly can hop into and break genes, and cells deploy numerous tools to prevent the jumping genes from making RNA and protein copies of themselves. But, in early development, LINE-1 is turned on nearly full blast, packing RNA into embryonic cells as well as “germline” cells, which later give rise to eggs and sperm. Having active transposons potentially hopping around such vital cells could be dangerous. “The phrase ‘playing with fire’ comes to mind,” Ramalho-Santos says. If anything, embryos and germline cells should be among the cells most heavily guarded against transposons.
7-3-18 First attempt to get CRISPR gene editing working in sperm
Researchers say they have managed to get the CRISPR machinery into mature human sperm, but we don’t know yet whether it can successfully edit sperm genes. For the first time, biologists are trying to get the CRISPR gene-editing machinery directly into mature human sperm, rather than into fertilised embryos. The work is still at an early stage but could lead to a new way to prevent inherited diseases. Around half a dozen teams have used the CRISPR genome-editing method to alter the DNA of human embryos but it is still far from clear whether this approach is safe. One issue is that the embryo can start dividing before its DNA is corrected, meaning the faulty gene is fixed in some cells in the resulting embryo but not all cells – a phenomenon called mosaicism. So Diane Choi and her colleagues at the Center for Reproductive Medicine in New York are experimenting with delivering DNA coding for the CRISPR machinery to mature sperm cells rather than to embryos. At the European Society of Human Reproduction and Embryology conference in Barcelona today, they will announce that they may have found a way to do this that allows the sperm to remain relatively healthy, and potentially capable of fertilising eggs. “In theory all single-gene disorders transmittable by the male can be treated if we are able to successfully use CRISPR-Cas9 on sperm,” says Choi. Gene-editing could in theory be used to prevent fathers from passing on a wide range of genetic disorders. For example, it could enable two people who both have a disorder like cystic fibrosis or sickle cell aneamia to have a child together who doesn’t have their condition.
7-2-18 Injecting new heart cells improves recovery from heart attacks
Injecting brand new muscle cells directly into the heart helps it recover after a heart attack, a study in monkeys has found. Injecting brand new muscle cells directly into the heart helps it recover after a heart attack, a study in monkeys has found. Heart attacks cut off blood supply to the heart, causing some of the heart muscle cells to die. Survivors often develop chronic heart failure, in which their hearts struggle to pump blood to the rest of the body, leaving them feeling weak and tired. Charles Murry at the University of Washington and his colleagues wondered if injecting new heart muscle cells into the damaged heart could help. They injected new heart muscle cells into the hearts of six southern pig-tailed macaques – large monkeys with similar hearts to humans – two weeks after they had heart attacks. The heart muscle cells were grown from stem cells from human embryos. After three months, the monkeys given the new heart muscle cells had 23 per cent higher ejection fractions – a measure of heart pumping capacity – than those treated with a sham. “In humans, that would mean the difference from being unable to walk more than a few blocks or carry your own groceries to living a normal life,” says Murry.
7-2-18 Mongolians practiced horse dentistry as early as 3,200 years ago
Equine tooth extractions evolved to make way for a riding bit, making mounted warfare possible. Mongolian pastoralists were trying to remove troublesome teeth from horses’ mouths almost 3,200 years ago, making those mobile herders the earliest known practitioners of horse dentistry, a new study finds. Those initial, incomplete tooth removals led to procedures for extracting forward-positioned cheek teeth known as first premolars from young horses, say archaeologist William Taylor and his colleagues. That dental practice, which dates to as early as about 2,800 years ago, coincided with the appearance in Mongolia of metal bits that made it easier for riders to control horses, the researchers report the week of July 2 in the Proceedings of the National Academy of Sciences. Long-distance travel and mounted warfare with sedentary civilizations across Asia soon followed (SN: 11/25/17, p. 16). “Veterinary dentistry was instrumental in the rise of horse warfare on the Eurasian steppes, allowing herders to use metal bits while avoiding behavior and health complications for horses that may have accompanied bit use,” says Taylor, of the Max Planck Institute for the Science of Human History in Jena, Germany. In particular, first premolars could interfere with a bit’s movement and cause pain or damage to the tooth. Taylor’s group identified microscopic signs of cutting and sawing on frontal teeth from two of 10 Bronze Age Mongolian horses. These two teeth, which date to between around 3,200 and 2,900 years ago, apparently grew at odd angles that may have interfered with chewing. Horseback riding became widespread in Mongolia at that time (SN: 5/27/17, p. 10).
7-2-18 Simple steps that could help you live to 100
Naples in Florida is trying to help more of its residents live to 100 by adopting ways of life from parts of the world where people live the longest.
7-2-18 Artificial ovary could help women conceive after chemotherapy
Scientists have taken further steps in creating an artificial ovary that could one day be used to help women who have lost their fertility because of cancer treatment. Scientists have taken further steps in creating an artificial ovary that could one day used to help women who have been left infertile after cancer treatment. Researchers from the Rigshospitalet in Copenhagen, Denmark, took ovarian tissue from cancer patients and stripped it of cells. They then transplanted this structure into mice and found that it could support the survival and growth of the follicles. Twenty follicles were transplanted in and a quarter of them survived for at least three weeks. It is hoped that this artificial ovary could be implanted back into women and restore their fertility after cancer treatment. “This is the first time that isolated human follicles have survived in a decellularised human scaffold,” said Susanne Por, who presented the work at the European Society of Human Reproduction and Embryology (ESGRE) annual meeting in Barcelona today. Cancer treatments can often damage the ovaries, blocking the production of eggs and making pregnancy impossible. Women diagnosed with cancer can have their eggs frozen. Sometimes, doctors may offer to remove or freeze all or part of an ovary for re-transplantation after treatment. However, this runs the risk of reintroducing cancer cells, as some cancers can spread to the ovaries. An “artificial ovary” could reduce this risk.
7-2-18 Finally, there’s a way to keep syphilis growing in the lab
Inspiration for the breakthrough came from the bacterium that causes Lyme disease. For more than a century, scientists have tried to grow Treponema pallidum, the corkscrew-shaped bacterium that causes syphilis. But the stubborn spirochete has refused to thrive any place outside of a human or rabbit for more than 18 days. That doesn’t give researchers much time to study it. “I’ve basically spent my entire career watching these organisms die,” says microbiologist Steven Norris, of the University of Texas Health Science Center at Houston. Until now. Norris and colleagues have cooked up a new recipe that keeps the bacteria alive for months, they report June 26 in mBio. “We know very little about the organism,” Norris says. Being able to study it long-term in a dish could lead to better treatments for the millions infected worldwide and pave the way for the development of a vaccine to prevent the sexually transmitted disease (SN: 11/26/16, p.5). The first ingredient, rabbit epithelial cells, was adapted from a 1981 method that managed to grow the bacteria for about two weeks. But it needed a secret sauce, a medium that would encourage the bacteria to grow within the rabbit cells.
7-1-18 The study of human heredity got its start in insane asylums
‘Genetics in the Madhouse’ chronicles the early days of the science. England’s King George III descended into mental chaos, or what at the time was called madness, in 1789. Physicians could not say whether he would recover or if a replacement should assume the throne. That political crisis jump-started the study of human heredity. Using archival records, science historian Theodore M. Porter describes how the king’s deteriorating condition invigorated research at England’s insane asylums into the inheritance of madness. Well before DNA’s discovery, heredity started out as a science of record keeping and statistical calculations. In the 1800s, largely forgotten doctors in both Europe and North America meticulously collected family histories of madness, intellectual disability and crime among the growing numbers of people consigned to asylums, schools for “feebleminded” children and prisons. Some physicians who specialized in madness, known as alienists, saw severe mental deficits as a disease caused by modern life’s pressures. But most alienists regarded heredity, the transmission of a presumed biological factor among family members, as the true culprit. Asylum directors launched efforts to track down all sick relatives of patients. The increasing number of people institutionalized for mental deficits fueled the view that individuals from susceptible families should be discouraged from reproducing. Porter documents a mid-1800s push for standardized asylum statistics. Asylum directors turned to the correlation table, which drew statistical links between pairs of variables, such as disease type and percentage of people cured. In 1859, Norwegian researcher Ludvig Dahl published family pedigrees of mental illness, using detailed census records.
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54 Evolution News Articles
for July 2018
Evolution News Articles for June 2018