105 Evolution News Articles
for July 2016
Click on the links below to get the full story from its source
7-31-16 Gibraltar caves reveal Neanderthals' secrets
Gibraltar caves reveal Neanderthals' secrets
The cave systems at the base of the rock of Gibraltar have just received Unesco world heritage status, in recognition of the rich insights they bring to the study of Neanderthals. They reveal that modern humans share a little more than you might expect with the extinct species.
7-29-16 Parasitic worm eggs found on Silk Road latrine artifacts
Parasitic worm eggs found on Silk Road latrine artifacts
Find is first firm evidence disease carried along ancient trade route. Microscopic evidence that long-distance travelers carried infectious diseases along Asia’s ancient Silk Road comes from cloth-capped sticks, excavated at a 2,000-year-old latrine in north central China. Rare evidence has emerged that humanborne infectious diseases moved across Asia around 2,000 years ago via the famous Silk Road. Clues to this ancient illness spread come from cloth wrapped around the ends of sticks once used by travelers as the equivalent of toilet paper. Preserved feces on cloth caps of sticks previously excavated from a latrine at a Silk Road way station in north central China contain microscopic eggs of intestinal worms, including a species found only far to China’s south and east. A traveler or government official must have carried the infectious parasite to the desert-bordering pit stop from at least 1,500 kilometers away, says a team led by archaeologists Hui-Yuan Yeh and Piers Mitchell of the University of Cambridge. The scientists report their findings online July 22 in the Journal of Archaeological Science: Reports.
7-29-16 Autoimmune diseases may be side effect of a strong immune system
Autoimmune diseases may be side effect of a strong immune system
We finally have evidence from human studies that disorders like lupus could be a by-product of being well protected against other diseases. Evolution could be to blame for our autoimmune diseases, such as lupus, multiple sclerosis and rheumatoid arthritis. For the first time, we have evidence that people who are more susceptible to disorders of this kind are that way because their immune system is better equipped to combat dangerous infections, enabling them to live longer. “There are so many autoimmune diseases affecting all sorts of tissues,” said Andrea Graham, an evolutionary biologist at Princeton University, at the annual meeting of the International Society for Evolution, Medicine and Public Health in Durham, North Carolina, last month. So what could explain the existence of these conditions? “One potential answer is that vulnerability to immune-mediated disease is simply the price we must pay for potent and rapid defence against infection.”
7-29-16 Gift-giving brain cells are lifeline to injured nerve cells
Gift-giving brain cells are lifeline to injured nerve cells
Astrocytes share energy-making mitochondria with neural neighbors. Star-shaped astrocytes may donate mitochondria to nerve cells in distress, helping the brain escape damage from stroke and possibly other maladies, a new study suggests. Under duress, nerve cells get a little help from their friends. Brain cells called astrocytes send their own energy-producing mitochondria to struggling nerve cells. Those gifts may help the neurons rebound after injuries such as strokes, scientists propose in the July 28 Nature. It was known that astrocytes — star-shaped glial cells that, among other jobs, support neurons — take in and dispose of neurons’ discarded mitochondria. Now it turns out that mitochondria can move the other way, too. This astrocyte-to-neuron transfer is surprising, says neuroscientist Jarek Aronowski of the University of Texas Health Science Center at Houston. “Bottom line: It’s sort of shocking.”
7-29-16 Inbreeding has destroyed the English bulldog’s genetic diversity
Inbreeding has destroyed the English bulldog’s genetic diversity
Decades of extreme selection and inbreeding mean there is little genetic variation left to save the English bulldog from its many severe health problems. The future looks dire for the English bulldog, one of the most popular – and illness-prone – dog breeds in the UK and US. Among other problems, English bulldogs have difficulty breathing, moving and mating. These traits are a result of how we have selectively bred the dogs to promote characteristics like its shortened muzzle and stature. Decades of heavy inbreeding have caused further problems, including autoimmune diseases and allergies. To see if these problems could be remedied in future generations by careful breeding, Niels Pedersen at University of California, Davis, and his team analysed the DNA of more than 100 English bulldogs to get a measure of how much genetic diversity still exists in the breed. “I have been concerned for some time about the increasing incidence of heritable disorders in many pure breeds of dog,” says Pederson. “The bulldog is unarguably one of the most egregious examples of that trend.” (Webmaster's comment: Same seems to be true of Persian cats.)
7-29-16 English Bulldog health problems prompt cross-breeding call
English Bulldog health problems prompt cross-breeding call
Crossing the English Bulldog with another breed is the best way to ensure its survival, scientists have argued. Due to centuries of selective breeding for physical traits, the Bulldog has become so inbred it cannot be returned to health without an infusion of new bloodlines, a genetic study suggests. The US researchers say the Olde English Bulldogge, a related breed from America, is a viable candidate. (Webmaster's comment: Many pure-breed dogs and cats suffer from the inbreeding problem. They are often not in good health and their intellgence often has suffered.)
7-28-16 Fossil tumour is oldest evidence of human cancer discovered yet
Fossil tumour is oldest evidence of human cancer discovered yet
A 1.7 million year-old ancient human foot bone found in South Africa shows signs of osteosarcoma, an aggressive form of bone cancer. A fossilised foot bone carries the oldest evidence of malignant cancer we’ve ever seen. Dating back 1.7 million years, the fossil from South Africa shows signs of osteosarcoma, an aggressive form of bone cancer. The fossil metatarsal bone appears to have belonged to an ancient human, although the researchers who discovered it are not sure which species. “Modern medicine tends to assume cancers and tumours in humans are diseases caused by modern lifestyles and environments,” said Edward Odes, at the University of Witwatersrand, South Africa. Finds like this show that the origins of cancer occurred in our ancient relatives, millions of years before modern societies existed, he said.
7-28-16 Why a parasitic vine can’t take a bite out of tomatoes
Why a parasitic vine can’t take a bite out of tomatoes
Tomatoes sense the attacks of parasitic vines by the proteins they secrete. Like botanical vampires, dodder plants (Cuscuta sp.) suck the life out of crops around the world. But tomatoes are mysteriously immune to the parasitic vine’s attacks. To figure out how they do it, a research team from England and Germany hit tomatoes and three other plant species with C. reflexa extract in the lab. Tomatoes totally overreacted, producing stress hormones to protect itself from the parasite, while the other plants failed to mount a defense.
7-28-16 Human eye spots single photons
Human eye spots single photons
Ability to detect smallest unit of light focuses debate on vision sensitivity. People were able to detect single photons in a recent study, indicating that human eyes are sensitive to individual particles of light. Human eyes are capable of detecting a single photon — the tiniest possible speck of light — new research suggests. The result, published July 19 in Nature Communications, may settle the debate on the ultimate limit of the sensitivity of the human visual system, a puzzle scientists have pondered for decades. Scientists are now anticipating possibilities for using the human eye to test quantum mechanics with single photons. Researchers also found that the human eye is more sensitive to single photons shortly after it has seen another photon. This was “an unexpected phenomenon that we just discovered when we analyzed the data,” says physicist Alipasha Vaziri of Rockefeller University in New York City.
7-28-16 Antibiotic resistance: 'Snot wars' study yields new class of drugs
Antibiotic resistance: 'Snot wars' study yields new class of drugs
Antibiotic resistance: 'Snot wars' study yields new class of drugs
A new class of antibiotics has been discovered by analysing the bacterial warfare taking place up people's noses, scientists report. Tests reported in the journal Nature found the resulting drug, lugdunin, could treat superbug infections. The researchers, at the University of Tubingen in Germany, say the human body is an untapped source of new drugs. The last new class of the drugs to reach patients was discovered in the 1980s. Nearly all antibiotics were discovered in soil bacteria, but the University of Tubingen research team turned to the human body.
7-28-16 How Houdini tadpoles escape certain death
How Houdini tadpoles escape certain death
Chemicals probably trigger a three-stage emergency early hatching process. When predatory snakes take a bite out of clusters of unhatched red-eyed tree frog embryos, some manage to escape the slaughter by wriggling out of their eggs to safety.Tree frog tadpoles are the ultimate escape artists. To avoid becoming breakfast, the embryos of red-eyed tree frogs prematurely hatch and wriggle away from a snake’s jaws in mere seconds, as seen at left. Embryos also use this maneuver to flee from flooding, deadly fungi, egg-eating wasps and other threats. Adding to the drama, red-eyed tree frogs lay their eggs on the undersides of leaves that hang a few inches to several feet above ponds. So the swimmers perform this feat suspended on a leaf, breaking free in midair and cannonballing into the water below.
7-27-16 Old planets always get too hot or cold for life in the end
Old planets always get too hot or cold for life in the end
Searching for alien life on planets orbiting older stars may be fruitless - they nearly always lose their liquid water with time. Age matters. Searching for alien life on planets orbiting older stars may be fruitless because they always become prohibitively hot or cold. The search for life on other worlds has focused on planets in what’s known as the habitable zone – the ring around stars where it’s the right temperature for liquid water. That has led some to target planets orbiting red dwarf stars, as their smaller size and cooler temperatures mean planets in the habitable zone are closer in, and so easier to spot. But we should also look for planets whose stars are the right age, regardless of their size, say Shintaro Kadoya and Eiichi Tajika at the University of Tokyo, Japan.
7-27-16 Teen brain upgrade
Teen brain upgrade
MRI scans have revealed the final “edit” of the brain before adulthood for the first time. Scans of 300 young people show how the brain’s cortex layer thins down – probably as a result of pruning out unwanted connections between neurons. At the same time, important neurons gain a sheath that helps them transmit signals more quickly.
7-27-16 You are junk: Why it’s not your genes that make you human
You are junk: Why it’s not your genes that make you human
Genes make proteins make us – that was the received wisdom. But from big brains to opposable thumbs, some of our signature traits could come from elsewhere. IT WAS a discovery that threatened to overturn everything we thought about what makes us human. At the dawn of the new millennium, two rival teams were vying to be the first to sequence the human genome. Their findings, published in February 2001, made headlines around the world. Back-of-the-envelope calculations had suggested that to account for the sheer complexity of human biology, our genome should contain roughly 100,000 genes. The estimate was wildly off. Both groups put the actual figure at around 30,000. We now think it is even fewer – just 20,000 or so. “It was a massive shock,” says geneticist John Mattick. “That number is tiny. It’s effectively the same as a microscopic worm that has just 1000 cells.” We’ve only gradually come to grasp the full implications of this discovery. The blueprint for building a human, or indeed any complex creature, lies not only in our genes but in other, neglected parts of our genome. This long-overlooked DNA could have shaped iconic traits such as our upright stance, opposable thumbs, big brains, capacity for language, even our tendency to form monogamous relationships. We might like to think of ourselves as pinnacles of evolution, but actually we are mostly made of junk.
7-27-16 CRISPR genome editing could save sight by tweaking DNA
CRISPR genome editing could save sight by tweaking DNA
A test of the CRISPR technique in mice shows that it has real promise for treating hereditary eye diseases, although several hurdles remain. The genome editing technique has now been tested in animals as a possible therapy for saving the sight of people with inherited eye diseases, and the results are looking good. “We are certainly very excited by the potential,” says Alex Hewitt at the University of Tasmania, Australia, whose team has shown that it is possible to use CRISPR to disable genes in the eyes of mice. The first trials of CRISPR treatments in people could start soon. In August, a group in China plans to treat lung cancer with the technique (see “First human trial“). But the team will simply remove immune cells from the body, edit their DNA to make them better at killing cancer cells, and put them back. For many other diseases, though, we need to find ways to use CRISPR to alter cells while they are still inside the body – a much greater challenge. The appeal of using genome editing to treat eye diseases is that it is easier to get new DNA into the cells of the eye than other tissues. Several teams are exploring the possibility – the firm Editas Medicine in Cambridge, Massachusetts, has said it hopes to start testing a CRISPR treatment for a form of blindness in people next year.
7-27-16 Red wolf may lose endangered status because it’s just a hybrid
Red wolf may lose endangered status because it’s just a hybrid
Not being a recognisable species could lose the red wolf its conservation status, despite being the only carrier of genes from extinct southern grey wolves. The red wolf, a critically endangered species living in the south-eastern US, may be nothing more than a hybrid between coyotes and the grey wolf, a new study suggests. If so, it may lose its conservation status and protection, given that US legislation does not protect hybrids. This could lead to loss of an important evolutionary lineage, because the red wolf is the only living repository of genes from the grey wolves that were driven near extinction in the south-eastern states by trapping and agricultural development. Zoologists have struggled for many years to decide how many species of wolves live in North America. Everyone agrees on the coyote and the grey wolf, which is found all round the northern hemisphere. The US government also recognises two others, the eastern wolf, now found in Ontario, and the red wolf, which has been bred in captivity from 12 individuals and reintroduced to the eastern US.
7-27-16 Distinctions blur between wolf species
Distinctions blur between wolf species
Blending of coyotes, grays leads to muddled canine identities. Eastern wolves and red wolves might be better described as mixtures between gray wolves and coyotes rather than distinct species, a new genetic analysis suggests. Wolves are having something of an identity crisis. Gray wolves and coyotes might be the only pure wild canine species in North America, a new genetic analysis suggests. Other wolves — like red wolves and eastern wolves — appear to be blends of gray wolf and coyote ancestry instead of their own distinct lineages. Red wolves contain about 75 percent coyote genes and 25 percent wolf genes, an international team of scientists reports online July 27 in Science Advances. Eastern wolves have about 25 to 50 percent coyote ancestry.
7-27-16 X-rays reveal complete dino skeleton
X-rays reveal complete dino skeleton
Scientists have used high-power X-rays to "see inside" an exquisite and complete dinosaur specimen. Scanning the specimen might allow the scientists to reconstruct the dinosaur's brain. The skeleton belongs to a small, plant-eating dinosaur which lived 200 million years ago - at the beginning of the Jurassic Period. Although this species was widespread at the time, scientists have largely had to rely on incomplete fossils. The skeleton is too small and fragile, and the rocks around it too hard, to allow it to be studied by conventional means. In addition, the rock matrix in which the fossil is preserved contains trapped minerals which prevented it from being scanned in a standard CT scanner.
7-27-16 Giant 1.2 metre wide dinosaur footprint discovered in Bolivia
Giant 1.2 metre wide dinosaur footprint discovered in Bolivia
A giant dinosaur footprint measuring over a metre wide has been discovered in Bolivia in South America. It's thought to have been made by an Abelisaurus, a predator that lived around 80 million years ago. These massive creatures once roamed South America, according to palaeontologist Sebastian Apesteguia. The print was found by a tourist guide in Maragua, a place well known for dinosaur tracks. Other dino remains have also been found in the area.
7-27-16 Ice Bucket Challenge funds gene discovery in ALS (MND) research
Ice Bucket Challenge funds gene discovery in ALS (MND) research
The Ice Bucket Challenge that went viral in 2014 has funded an important scientific gene discovery in the progressive neurodegenerative disease ALS, the ALS Association says. Scientists have identified a new gene contributing to the disease, NEK1. The Ice Bucket Challenge has raised $115m (£87.7m) from people pouring cold water over themselves and posting the video on social media. It was criticised as a stunt, but has funded six research projects.
7-27-16 Hammerhead sharks roll over and swim sideways to save energy
Hammerhead sharks roll over and swim sideways to save energy
Uniquely among sharks, the great hammerhead has an unusually long dorsal fin that appears to make it more efficient for it to swim rolled over. Hammerhead sharks spend much of their time tilted to one side in what looks an awkward swimming posture, a tagging study has revealed. But the weird habit actually makes sense: it seems to be the most energy-efficient way for them to swim. But data from accelerometers and video cameras that Payne and his colleagues attached to five great hammerhead sharks in Australia, Belize and the Bahamas showed otherwise. The tracked sharks spent up to 90 per cent of time swimming at roll angles between 50 and 75 degrees. Unlike other sharks, the great hammerhead’s dorsal fin is longer than its pectoral fins. When a great hammerhead tilts to the side, its long dorsal fin increases its “wingspan”, allowing it to swim more efficiently. Wind tunnel experiments with an anatomically accurate model of a great hammerhead suggest the sharks use about 10 per cent less energy when they swim this way instead of upright.
7-27-16 Unprecedented Alzheimer’s drug slows disease by 80 per cent
Unprecedented Alzheimer’s drug slows disease by 80 per cent
A drug that targets tau tangles in the brain has produced strong results in a large clinical trial, slowing the progression of the disease in hundreds of people. At last, there’s a drug that seems to have a big effect on the progression of Alzheimer’s disease. It took 30 years to develop, but the treatment has proven successful in a large trial of people with mild to moderate symptoms of the disorder. “It is a significant event in the history of Alzheimer’s and dementia research,” Maria Carrillo at US charity the Alzheimer’s Association, says of the results, announced today. The drug, called LMTX, is the first to produce really promising results in a large phase III trial, in which potential therapies are pitted against a placebo in hundreds of recipients. Drugs do already exist for Alzheimer’s, but these generally have only a modest effect. “Our results are unprecendented, compared with anyone else’s,” says Claude Wischik at the University of Aberdeen, UK, and co-founder of the firm TauRx Pharmaceuticals, which developed LMTX.
7-26-16 Science News reporters answer your questions about aging
Science News reporters answer your questions about aging
How can aging be delayed? How does the brain age? And what does aging look like in animals, plants or the rest of the natural world? The July 23 issue of Science News tackles these questions and more in a special report called "Aging's Future." Read their in-depth features on aging:
- A healthy old age may trump immortality: Despite disagreements about what aging is and isn't, scientists have reached a radical consensus: It can be delayed. By Tina Hesman Saey
- The brain's blueprint for aging is set early in life: The brain's decline may mirror its beginning, offering clues to aging. By Laura Sanders
- Organisms age in myriad ways — and some might not even bother: There is great variety in how animals and plants deteriorate (or don’t) over time. By Susan Milius
7-26-16 Dutch men revealed as world's tallest
Dutch men revealed as world's tallest
When it comes to height, Dutch men and Latvian women tower over all other nationalities, a study reveals. The average Dutchman is now 183cm (6ft) tall, while the average Latvian woman reaches 170cm (5ft 7in). The research, published in the journal eLife, has tracked growth trends in 187 countries since 1914. It finds Iranian men and South Korean women have had the biggest spurts, increasing their height by an average of more than 16cm (6in) and 20cm (8in).
7-25-16 Universal ancestor of all life on Earth was only half alive
Universal ancestor of all life on Earth was only half alive
The identification of genes likely to belong to the common ancestor of life suggests its biochemistry was incomplete, forcing it to cling to undersea vents. Many of the genes in our cells evolved billions of years ago and a few of them can be traced back to the last common ancestor of all life. Now we have the best picture yet of what that ancestor was like and where it lived, thanks to a study that identified 355 genes that it probably possessed. “It was flabbergasting to us that we found as many as we did,” says William Martin of the University of Dusseldorf in Germany, who led the study. The findings support the idea that the last universal common ancestor (LUCA) lurked in hydrothermal vents where hot water rich in hydrogen, carbon dioxide and minerals emerged from the sea floor. “It’s spot on with regard to the hydrothermal vent theory,” Martin says. He describes LUCA as half-living, because it may have depended on abiotic reactions in the vents to produce many of the chemicals it needed.(Webmaster's comment: Zeroing in on where life began.)
7-25-16 Mystery ancient human ancestor found in Australasian family tree
Mystery ancient human ancestor found in Australasian family tree
A genome analysis suggests that Asian and Pacific human populations share a single origin and their ancestors might have bred with Homo erectus. An unknown hominin species that bred with early human ancestors when they migrated from Africa to Australasia has been identified through genome mapping of living humans. The genome analysis also questions previous findings that modern humans populated Asia in two waves from their origin in Africa, finding instead a common origin for all populations in the Asia-Pacific region, dating back to a single out-of-Africa migration event. Modern humans first left Africa about 60,000 years ago, with some heading west towards Europe, and others flowing east into the Asia-Pacific region. Previous research looking at the genomes of people living today has revealed that the Asia-Pacific arrivals mated with two hominin species they found there – the Neanderthals and the Denisovans.
7-25-16 Neanderthal skulls and brains may have developed just like ours
Neanderthal skulls and brains may have developed just like ours
The way that skull shape changed as Neanderthals grew up suggests that they were just as smart as us, although it's still a contentious finding. Evidence from Neanderthals’ skulls suggests that their large brains grew in the same way as ours do. That in turn suggests that Neanderthals were perhaps not so cognitively different from us – although not everyone agrees with this interpretation. We know that Neanderthal brains were roughly the same size as ours, making them the largest among all known extinct human species. To get a sense for how they grew over an individual’s life, Christoph Zollikofer at the University of Zurich, Switzerland, and his colleagues looked at 15 Neanderthal skulls. Six belonged to adults and nine to children; the youngest was an individual who died just weeks after birth, the oldest a child who died aged roughly 12. The team found evidence that at birth, Neanderthal brains were subtly but significantly longer, wider and flatter than modern human brains. Subsequently, though, the Neanderthal brain developed rather like ours: certain regions, including the cerebellum, expanded quickly during childhood and then became some of the slowest-growing areas in early adulthood. This conclusion fits with archaeological evidence that Neanderthals were just as capable of sophisticated behaviour as modern humans. Both species used similar symbolism and independently made similar advances in technology, for instance, and Neanderthals may have shared our skill with language.
7-25-16 Revealed: the teenage brain upgrades that occur before adulthood
Revealed: the teenage brain upgrades that occur before adulthood
Editing, pruning and strengthening of neuron connections in adolescent brains makes for sleeker performance – but errors may cause schizophrenia. The final brain edit before adulthood has been observed for the first time. MRI scans of 300 adolescents and young adults have shown how the teenage brain upgrades itself to become quicker – but that errors in this process may lead to schizophrenia in later life. The editing process that takes place in teen years seems to select the brain’s best connections and networks, says Kirstie Whitaker at the University of Cambridge. “The result is a brain that’s sleeker and more efficient.” When Whitaker and her team scanned brains from people between the ages of 14 and 24, they found that two major changes take place in the outer layer of the brain – the cortex – at this time. As adolescence progresses, this layer of grey matter gets thinner – probably because unwanted or unused connections between neurons – called synapses – are pruned back. At the same time, important neurons are upgraded. The parts of these cells that carry signals down towards synapses are given a sheath tha
7-25-16 Scans reveal how teenage brain develops
Scans reveal how teenage brain develops
A University of Cambridge team has identified the areas of the brain that change the most during the teenage years. Brain scans showed that they are the areas associated with complex thought processes. The scientists also discovered a link between teenage brain development and mental illness, such as schizophrenia. While the areas associated with the basic functioning of the body such as vision, hearing and movement are fully developed by adolescence, the areas associated with complex thought and decision making are still changing. These areas are nerve centres with lots of connections to and from other key areas.
7-25-16 Most powerful obesity gene yet boosts risk by 40 per cent
Most powerful obesity gene yet boosts risk by 40 per cent
A genetic variant common among people in Samoa may have evolved to support their ancestors on long island voyages in the South Pacific. A gene variant that increases a person’s obesity risk by 30 to 40 per cent is the strongest genetic predictor of body weight discovered in humans so far. Having just one copy of a particular variant of a gene called CREBRF is associated with a 1.5 increase in BMI. For a person weighing 83 kilograms who is 1.75 metres tall, this is the equivalent of putting on 4.6 further kilograms. The genetic variant was uncovered during a genomic analysis of more than 5000 people in Samoa, where obesity rates are among the highest in the world. Ryan Minster at the University of Pittsburgh, Pennsylvania, and his team found that a quarter of Samoans carry this variant, which may have evolved during their history of colonising the South Pacific. “They had to endure voyages between islands and subsequently survive on those islands,” says Minster.
7-25-16 US and UK fall behind in largest ever global study of height
US and UK fall behind in largest ever global study of height
While English-speaking countries have high rates of obesity, their citizens are nowhere near as tall as the average heights of the Netherlands and Latvia. The height of men and women in the UK has increased by around 11 centimetres over the last century. But the nation with the tallest average height for men is the Netherlands, while the tallest average height for women is found in Latvia. The largest ever study of global height found that in 2014, men in the Netherlands had an average height of 182.5 centimetres (5 feet, 11 inches). The average female height in Latvia was 170 centimetres (5 feet, 7 inches). The tallest nations worldwide are all found in Europe, and also include Estonia, Denmark, Serbia and the Czech Republic. While the US had the third-tallest men and fourth-tallest women in the world back in 1914, the US has now slipped to 37th and 42nd place, respectively. British men are the 31st tallest worldwide, while British women are 38th. “Our study shows the English-speaking world, especially the US, is falling behind other high-income nations in Europe and Asia Pacific,” said Majid Ezzati, a global health researcher at Imperial College London. “Together with the poor performance of these countries in terms of obesity, this emphasises the need for more effective policies towards healthy nutrition throughout life.” The greatest height increases over the past century were seen in women in South Korea – who are now an average of 20.2 centimetres taller – and men in Iran, where the average male height has increased by 16.5 centimetres. Iran has also seen large improvements in life expectancy in recent decades, in part due to new rural health programmes.
7-25-16 Ancient air bubbles could revise history of Earth’s oxygen
Ancient air bubbles could revise history of Earth’s oxygen
If new findings are correct, rise in gas preceded earliest animals. Ancient air embedded inside rock salt for 815 million years suggests that oxygen was already abundant when the first animals appeared. The microscopic air bubbles were trapped inside rectangular inclusions in the rock. Whiffs of ancient air trapped in rock salt for hundreds of millions of years are shaking up the history of oxygen and life on Earth. By carefully crushing rock salt, researchers have measured the chemical makeup of air pockets embedded inside the rock. This new technique reveals that oxygen made up 10.9 percent of Earth’s atmosphere around 815 million years ago. Scientists have thought that oxygen levels would not be that high until 100 million to 200 million years later. The measurements place elevated oxygen levels well before the appearance of animals in the fossil record around 650 million years ago, the researchers report in the August issue of Geology. “I think our results will take people by surprise,” says study coauthor Nigel Blamey, a geochemist at Brock University in St. Catharines, Canada. “We came out of left field, and I think some people are going to embrace it, and other people are going to be very skeptical. But the data is what the data is.” (Webmaster's comment: And that's what I report here, whether or not anyone likes it, including myself.)
7-22-16 How dinosaurs hopped across an ocean
How dinosaurs hopped across an ocean
Ancient land bridges may explain how animals navigated breakup of continents. Land crossings may have allowed dinosaurs, lizards and early mammals to migrate across the Atlantic Ocean around 150 million years ago, one researcher proposes. Two land bridges may have allowed dinosaurs to saunter between Europe and North America around 150 million years ago. The bridges would explain how dinosaurs, mammals and other animals were able to hop from one continent to the other after the Atlantic Ocean formed during the breakup of the Pangaea supercontinent. Some species of Stegosaurus, for instance, appear in the fossil record on both sides of the Atlantic. Leonidas Brikiatis, an independent biogeographer in Palaio Faliro, Greece, proposes that two strips of land bridged North America and Europe during the late Jurassic and early Cretaceous periods. One bridge spanned from eastern Canada to the Iberian Peninsula, where Spain is today, and lasted from around 154 million to 151 million years ago. The other linked North America and Scandinavia from around 131 million to 129 million years ago, Brikiatis reports in the August Earth-Science Reviews.
7-22-16 23andMe’s tools for scientists
23andMe’s tools for scientists
23andMe is bringing its direct-to-consumer genetic-testing kits to the scientific community, said Alessandra Potenza in TheVerge.com. The biotech company’s new service allows researchers to use 23andMe’s saliva collection kits and DNA testing services for their own studies. In return, research subjects can choose to receive 23andMe’s genetic reports, which provide information on ancestry, a person’s risk of passing on certain inherited diseases, and other health traits. Normally, these reports cost $199 per DNA sample. Researchers, however, will be eligible for a discounted rate, while their participants get the report for free. The new service “is meant to make life easier for researchers,” who often handle DNA collection themselves, as well as provide a reward or incentive for study participants.
7-22-16 Alcohol linked to at least seven cancers – not just liver cancer
Alcohol linked to at least seven cancers – not just liver cancer
The more alcohol you drink, the higher your risk of cancers like breast and colon cancer. But research suggests that there is no "safe" level of consumption. There is strong evidence that alcohol causes at least seven types of cancer, a review has concluded. Writing in the journal Addiction, Jennie Connor at the University of Otago in New Zealand says alcohol is estimated to have caused about half a million deaths from cancer in 2012 alone – 5.8 per cent of cancer deaths worldwide. She found evidence of a link between drinking and cancer of the mouth and throat, larynx, oesophagus, liver, colon, bowel and breast. “We see the risk increasing as the amount of alcohol consumed increases, and we agree that there is solid evidence to conclude that alcohol consumption directly causes cancer,” says Susannah Brown, science programme manager for the World Cancer Research Fund. Although the highest risks are from heavy drinking, people who drink at low levels are still at risk. According to Connor, there is no safe level of drinking when it comes to cancer.
7-22-16 The surprising benefits of thumb sucking
The surprising benefits of thumb sucking
Kids are often urged to stop biting their nails or sucking their thumbs because their fingers are teeming with germs. But new research suggests these “bad” habits could actually reduce children’s risk of developing allergies, reports The Washington Post. The findings support the “hygiene hypothesis” of allergies, which contends that exposure to microbes early in life educates and strengthens the immune system; when kids aren’t exposed to enough germs, that “priming” process doesn’t occur and their immune systems overreact to new substances. Researchers in New Zealand put this theory to the test by monitoring the oral habits of more than 1,000 children from birth to adulthood and conducting skin-prick tests to identify those who suffered from allergies. They found that 49 percent of those who weren’t thumb-suckers or nail-biters as kids eventually developed allergies to things like pets, grass, and dust mites. But allergies were found in only 31 percent of those who both bit their fingernails and sucked their thumbs when they were younger, and in 38 percent of those who did one or the other. The study’s author, Malcolm Sears, says that doesn’t mean parents should encourage kids to bite their nails or suck their thumbs. “What we are saying is don’t be quite so afraid of a little bit of dirt.”
7-22-16 Red hair raises cancer risk
Red hair raises cancer risk
Everyone knows that pale-skinned people with red hair get sunburned more easily, but a new study has found that the risk of skin cancer for gingers is so elevated, it’s as if they’ve spent 21 additional years in the sun. A genetic analysis of more than 400 people with melanoma revealed those carrying a particular variant of the MC1R gene associated with red hair had 42 percent more cancer-causing genetic mutations after sun exposure than those without the variant. Redheads, who account for less than 2 percent of the global population, have two copies of the gene, making them highly prone to skin cancer.
7-21-16 Evolution of gut bacteria tracks splits in primate species
Evolution of gut bacteria tracks splits in primate species
Microbes may have played role in shaping ape, human evolution. Gut bacteria have been passed down from the ancestors of humans and African apes for millennia, evolving alongside their hosts, says a new study that looked at bacteria from gorillas, bonobos, chimpanzees and humans. Microbes may have played a role in making us, us. A new study shows similar patterns in the evolution of gut bacteria and the primates they live in, suggesting that germs and apes could have helped shaped one another. For at least 10 million years, bacteria have been handed down from the common ancestor of humans and African apes. As apes split into separate species, so did the microbes inside them, researchers report July 22 in Science. Now, relationships between gut bacterial species mirror the family tree of gorillas, humans, bonobos and chimpanzees. Germs are a piece of our history, says evolutionary biologist Andrew Moeller who led the study while at both the University of Texas at Austin and the University of California, Berkeley. “Just like genes we’ve inherited from our ancestors,” he says, “we've inherited some of our bacteria from our ancestors as well.” (Webmaster's comment: Without the bacteria in our bodies we'd all be dead. They are an essential part of us.)
7-21-16 Yeasts hide in many lichen partnerships
Yeasts hide in many lichen partnerships
Fungus discovery challenges textbook idea of organisms’ symbiosis. A wolf lichen is one of the species making scientists rethink more than a century of assumptions about what’s in a lichen. The discovery of unknown yeasts hiding in lichens from six continents could shake up a basic idea of what makes up a lichen partnership. For more than a century, biologists have described a lichen as a fungus growing intimately with some microbes (algae and/or cyanobacteria) that harvest solar energy. The fungus is treated as so important that its name serves as the name for the whole lichen. Biologists have recognized that more than one fungus can show up in lichen close-ups, but their role hasn’t been clear. Now that may be on the brink of changing. Fifty-two genera of lichens collected from around the world include a second fungus — single cells, called yeasts, of a previously unknown order now christened Cyphobasidiales. Toby Spribille of the University of Graz in Austria and colleagues report the finding online July 21 in Science.
7-21-16 Brain map carves cortex into twice as many areas
Brain map carves cortex into twice as many areas
A new brain map, based on multiple scans of more than 400 individuals, has carved the "cortex" into 180 different compartments - 97 of which are new. This crumpled outer layer of the brain is home to our advanced cognition, perception and movement. It has been mapped in various ways for centuries, but this new effort is a landmark attempt at a definitive, modern atlas for neuroscientists. The work is reported in Nature and the data is available to scientists online. It the most significant result to date from the Human Connectome Project, a US-led collaboration aimed at unravelling the wiring of the human brain and how it affects behaviour.
7-21-16 Eating each other’s faeces helps earwig young survive famine
Eating each other’s faeces helps earwig young survive famine
The odd feeding behaviour may even help keep the young insects together in a primitive form of social living. Desperate times call for desperate measures. As food shortages hit, European earwig babies resort to eating each other’s faeces in their underground homes, helping to keep hunger and death at bay. In times of plentiful food, the earwig offspring, or ‘nymphs’, feast on scraps of plant and insect material that their mother brings back from her trips above ground, and on food she regurgitates. But when faced with limited supplies, the nymphs have to make do with what’s around them to survive. Unlike many other insects that live in groups, European earwigs don’t clear their nest of faeces. Availability of faeces in hard times keeps the nymphs alive for about two more days on average than without them, researchers have now found. (Webmaster's comment: Survival is the ultimate criteria and nothing else.)
7-20-16 Boozy primates seek out nectar with the highest alcohol content
Boozy primates seek out nectar with the highest alcohol content
Aye-ayes and a slow loris preferred artificial nectar with more booze in lab tests, suggesting that tippling is an ancient strategy for primates. Aye-ayes, a tiny crazed-looking lemur species, prefer fake nectar with higher concentrations of alcohol – as does the slow loris, a small primate with huge eyes from Southeast Asia. Chimps have been caught gulping fermented sap in the wild before, but it wasn’t clear if primates just tolerated the alcohol or actively sought it out, says Robert Dudley at the University of California in Berkeley. “This is the first study – albeit using captive primates – to show that there is a preference for higher levels of alcohol,” says Dudley, who wasn’t involved in the study. (Webmaster's comment: Our love of alcohol and our inclination for getting drunk is from our genetic past.)
7-20-16 Tiny ants move a ton of soil
Tiny ants move a ton of soil
Fungus-gardening ants build warrens of tunnels underground. A new study quantifies how much soil they can move — and it’s a lot. Those little piles of dirt that ant colonies leave on the ground are an indication that ants are busy underground. And they’re moving more soil and sediment than you might think. A new study finds that, over a hectare, colonies of Trachymyrmex septentrionalis fungus-gardening ants in Florida can move some 800 kilograms aboveground and another 200 kilograms below in a year. The question of how much soil and sand ants can move originated not with entomologists but with geologists and archaeologists. These scientists use a technique called optically stimulated luminescence, or OSL, to date layers of sediment. When minerals such as quartz are exposed to the sun, they suck up and store energy. Scientists can use the amount of energy in buried minerals to determine when they last sat on the surface, taking in the sun. (Webmaster's comment: There are no such things as magic bullets, but there such things as ants. Changing the world one grain of sand at a time.)
7-19-16 Swapping analogous genes no problem among species
Swapping analogous genes no problem among species
Yeast survives with bacteria, plant, human versions of shared genetic material. Yeast, bacteria and plants are very different organisms, but have many genes that look alike. New research shows about half of those analogous genes can substitute for each other. Organisms as different as plants, bacteria, yeast and humans could hold genetic swap meets and come away with fully functional genes, new research suggests. Researchers have known for decades that organisms on all parts of the evolutionary tree have many of the same genes. “How many of these shared genes are truly functionally the same thing?” wondered Aashiq Kachroo, a geneticist at the University of Texas at Austin, and colleagues. The answer, Kachroo revealed July 15 at the Allied Genetics Conference, is that about half of shared genes are interchangeable across species.
7-19-16 Herbicide no match for fruit flies’ gut microbes
Herbicide no match for fruit flies’ gut microbes
Bacteria team up to protect insects from toxic chemical atrazine. Fruit flies can break down a popular herbicide with help from friendly microbes, new research suggests. Drosophila melanogaster fruit flies have no genes needed to process an herbicide called atrazine, statistical biologist James “Ben” Brown of Lawrence Berkeley National Lab in California said July 16 at the Allied Genetics Conference. Researchers expected that the inability to break down the herbicide might make the chemical, which is often sprayed on cornfields, toxic to the flies. But after feeding atrazine to fruit flies for 72 hours, Brown and colleagues detected very little response to the chemical.
7-19-16 Ancient barley DNA gives insight into crop development
Ancient barley DNA gives insight into crop development
An international group of scientists have analysed the DNA of 6,000 year old barley finding that it is remarkably similar to modern day varieties. They say it could also hold the key to introducing successful genetic variation. Due to the speed at which plants decompose, finding intact ancient plant DNA is extremely rare. The preserved ancient barley was excavated near the Dead Sea, the journal Nature Genetics reports. The arid environment conserved the biological integrity of the grains, the paper says.
7-18-16 DNA sequencer sent to space station
DNA sequencer sent to space station
Nasa has sent a DNA sequencer to the International Space Station in an effort to help astronauts monitor their own health. The device is designed to show whether DNA sequencing is possible in microgravity. Nasa hopes DNA sequencers could enable the environmental monitoring of microbes to identify potential causes of illness and understand the health of astronauts. Last year, Nasa microbiologist Dr Sarah Castro said of the project: "Currently aboard the space station there is not a real-time method for identifying microbes, diagnosing infectious disease, and collecting any form of genomic and genetic data concerning crew health. "Meeting these needs relies on returning samples from space to Earth and subsequent ground-based analysis, which takes time." The sequencer, which is just 9.5cm long and weighs 120g, is tiny compared to the microwave-sized devices used on Earth. (Webmaster's comment: 40 years ago DNA sequencing use to take a whole laboratory of equipment. Eventually all that was reduced to an instrument the size of a microwave, and now it can be done with an instrument that fits in your hand. Science and Technology is truly amazing.)
7-18-16 Obese grandfathers pass on their susceptibility to junk food
Obese grandfathers pass on their susceptibility to junk food
Having an obese grandfather can make mice more likely to develop diabetes and other weight-related disorders, an effect that may be down to sperm epigenetics. A study in mice shows that the grandsons of obese males are more susceptible to the detrimental health effects of junk food, even if their fathers are lean and healthy. The finding adds to evidence that new traits can be passed down the family line without being permanently recorded in a family’s genes – a phenomenon called transgenerational epigenetics. Last year, a study found that the DNA in the sperm of obese men is modified in thousands of places, and that these sperm also contain short pieces of RNA. These are epigenetic modifications – they don’t affect the precise code of genes, but instead may affect how active particular genes are.
7-18-16 No one-fits-all healthy diet exists
No one-fits-all healthy diet exists
Search on for genes to explain why weight, cholesterol, insulin vary in mice on same food plan. Different genetic strains of mice had varying reactions to eating a ketogenic diet, a high-fat, low-carb diet. The results back up recent evidence that people’s responses to foods may differ widely. Weight gain may depend on how an individual’s genes react to certain diets, a new study in mice suggests. Four strains of mice fared differently on four different diets, William Barrington of North Carolina State University in Raleigh reported July 15 at the Allied Genetics Conference. One strain, the A/J mouse, was nearly impervious to dietary changes. Those mice didn’t gain much weight or have changes in insulin or cholesterol no matter what they ate: a fat-and-carbohydrate-laden Western diet, traditional Mediterranean or Japanese diet (usually considered healthy) or very low-carbohydrate, fat-rich fare known as the ketogenic diet.
7-18-16 ‘Junk DNA’ has value for roundworms
‘Junk DNA’ has value for roundworms
Roundworms have to fight off foreign DNA while protecting its own genes that will be passed to the next generation. Some bits of “junk DNA” — called PATCs — may help. PATCs help keep the worms’ own genes active while alien genes are turned off. “Junk DNA” may be an essential part of a worm’s inheritance. Parts of this not-so-disposable DNA serves as a “watermark” to authenticate a Caenorhabditis elegans roundworm’s own genes and distinguish them from foreign genes that need to be shut down, researchers report in the July 14 Cell.
7-15-16 First evidence that GM mosquitoes reduce disease
First evidence that GM mosquitoes reduce disease
A trial in Brazil suggests that the approach not only reduces the number of mosquitoes, it also reduces the number of people who get dengue. Releasing genetically modified mosquitoes appears to have helped reduce cases of dengue in a town in Brazil. The news comes as the US is considering whether to approve the use of the same mosquitoes. The trial involved Aedes mosquitoes that had been modified to kill off wild mosquitoes of the same species, and was carried out in the town of Piracicaba. Just by eliminating the standing water where the mosquitoes that carry dengue and other diseases like Zika breed, Piracicaba was able to halve the number of dengue cases during the 2015-16 dengue season, compared with last year. But in the areas where the GM mosquitoes were released too, cases of dengue fell by more than 90 per cent.
7-15-16 First farmers had diverse origins, DNA shows
First farmers had diverse origins, DNA shows
The new study analysed the genomes of early farmers from Iran's Zagros mountains. Analysis of DNA from some of the world's first farmers shows that they had surprisingly diverse origins. Researchers sequenced genomes from ancient Neolithic skeletons uncovered in Iran. The results shed light on a debate over whether farming spread out from a single source in the region, or whether multiple farmer groups spread their technology across Eurasia.
7-15-16 Outdoor learning 'boosts children's development'
Outdoor learning 'boosts children's development'
Pressures on teaching time and resources often means the benefits of outdoor learning are overlooked, a report says. Outdoor learning can have a positive impact on children's development but it needs to be formally adopted, a report suggests. Childhoods were dramatically changing, with fewer opportunities to spend time outdoors, researchers observed. The loss of exposure to the natural environment would have negative long-term consequences, they warned. Establishing an "outdoor learning hub" would help teachers, and help shape policies and strategy, they suggested.
7-15-16 Seeing the upside in gene drives’ fatal flaw
Seeing the upside in gene drives’ fatal flaw
Inevitable destructive mutations could be used to prevent genetic-engineering tool from running amok. Gene drives cut DNA and paste themselves into an organisms’ genes. This ability enables them to be inherited by a majority of offspring, instead of the 50 percent chance a regular gene has of being passed on to the next generation. Mutations may stop gene drives’ spread, and that might be a good thing, some researchers say. What some people view as a flaw in a new genetic-engineering tool might actually be a safety feature, a study suggests. CRISPR/Cas9 gene drives, as the new tools are called, are molecular cut-and-paste machines that can break regular rules of inheritance and get passed to more than 50 percent of offspring. The rapid spread of engineered genes through a population may allow researchers to make mosquitoes unable to spread malaria or other diseases, to sterilize the insects, or to clear pests or invasive species out of places where they are not wanted. Gene drives have worked in the lab, but have many ethical, technical and other hurdles to overcome before they could be released in the wild. For instance, many scientists, environmentalists and policy makers are concerned that gene drives could wipe out entire species or have unintended consequences for ecosystems.
7-15-16 Kiss of death marks young ant rivals for worker kill squad
Kiss of death marks young ant rivals for worker kill squad
Rather than killing youthful competitors themselves, some male ants get their nest-mates to do it for them. Paint a target on his back. Instead of dispatching their young competitors directly, adult male ants smear them with bodily fluids, leaving the youths with a bulls-eye marking them for assassination by worker ants. “They let the workers do the dirty job of finishing off all the rivals,” says Jürgen Heinze at the University of Regensburg in Germany. Insects that live in colonies – such as ants, bees and wasps – generally operate as a superorganism. The entire group benefits when each member supports and safeguards their collective society. “To some extent, they all have the same interest,” says Sara Helms Cahan at the University of Vermont in Burlington. “But not completely.” That’s because some resources are in short supply. Unlike most ants, which seek out mates in swarms of eligible insects from many colonies, ants in the genus Cardiocondyla breed within their nests. By staying home, those males pit themselves against one another in order to reproduce with their nest’s queen or queens.
7-15-16 Are human still evolving? Growing evidence suggests we are
Are human still evolving? Growing evidence suggests we are
Natural selection was long thought over for humans, but new work relating education and reproductive success indicates it is still at work, says John Hawks. It wasn’t so long ago that there was something of a consensus on recent human evolution, or the lack of it. The belief was that culture had elevated our species above Darwin’s “hostile forces of nature”, stopping natural selection in its tracks 50,000 years ago. But that view has increasingly been questioned over the past 10 years. Those who say selection stopped long ago point to vast improvements in life expectancy. To be sure, life expectancy has increased and many dread diseases have receded. But to pass on their genes to the next generation, people must not only survive, but reproduce. Differences in reproduction are differences in fitness, in the biological evolutionary sense. This idea underpins a new study by Jonathan Beauchamp at Harvard University, which looked at associated with traits including educational attainment. It suggests that natural selection has been at work on people in the US in the 20th century.
7-15-16 Scientists warn of 'unsafe' decline in biodiversity
Scientists warn of 'unsafe' decline in biodiversity
Scientists warn that, if left unchecked, biodiversity loss could have devastating consequences. An international team of scientists has issued a warning that biodiversity is dropping below safe levels for the support and wellbeing of human societies. As a species we are inextricably connected with the processes of our local ecosystems, such as crop pollination, waste decomposition and regulation of the carbon cycle. These ecosystems depend on the biological diversity within them to function. The planetary boundaries framework updated in 2015 states that losing more than 10% of the biodiversity in an area places the local ecosystem at risk. A report in Science this week states that 58% of the world's land coverage already falls below this safe level. They find that the global average of biodiversity has dropped to 85% of that of unaffected ecosystems.
7-14-16 Why do islands give rise to such unusual creatures?
Why do islands give rise to such unusual creatures?
Land of opportunity: Islands make up a sixth of all land on Earth. Some are formed from lava expelled by volcanoes under the sea, such as the Hawaiian Islands. Others, like Madagascar, are created when landmasses break apart over hundreds of millions of years. Isolated from the mainland, a new island often provides a unique habitat. With its own set of conditions, life can evolve differently. Some creatures develop the most unusual traits to survive – and thrive – in their new home. In many cases, separated from their mainland ancestors, they eventually transform into new species altogether.
7-14-16 Two groups spread early agriculture
Two groups spread early agriculture
Fertile Crescent cultures diverged to take farming east and west. A bone fragment from a 7,000-year-old farmer was discovered in a cave in the Zagros region of Iran. His DNA and the DNA of three other individuals from a second Iranian site revealed that two different groups were involved in early farming. The cradle of agricultural civilization was culturally diverse. Two societies lived side-by-side 10,000 years ago in the rich Near Eastern valleys of the Fertile Crescent, where humans first learned to farm, a new study finds. Over time, one group expanded west, carrying agriculture into Europe. The other spread east, taking their traditions into South Asia, researchers report online July 14 in Science.
7-14-16 Too much light weakens bones and changes immune system
Too much light weakens bones and changes immune system
Research in mice suggests that continuous exposure to light has wide-ranging effects on health, a worrying finding for people who do shift work. Too much light is bad for your health. So suggests research in mice, which found that six months of continuous lighting led to a loss of strength and bone mass, and signs of increased inflammation. The findings are worrying for people who experience prolonged light exposure – such as shift-workers and hospital patients – but some of the effects seem to be reversible. The experiment involved 134 mice, which experienced no dark for half a year. By the end, the mice had lost about half their strength compared with controls, as measured by grip endurance tests and their ability to cling to bars, while the signals of their internal body clocks were weakened. Their bones were affected too. The bulbous, spongy parts of their bones that are responsible for bearing most weight lost a third of their volume, and became 10 per cent thinner – just as in the early stages of osteoporosis. There were also signs of increased inflammation, such as a rise in the number of neutrophil white blood cells – usually associated with stress or infection.
7-14-16 Why the turtle got its shell
Why the turtle got its shell
Burrowing power, not protection may have triggered carapace evolution. An ancient reptile (Eunotosaurus africanus), a precursor to today’s turtles, had a body well-suited to burrowing. Turtle shells didn’t get their start as natural armor, it seems. The reptiles’ ancestors might have evolved partial shells to help them burrow instead, new research suggests. Only later did the hard body covering become useful for protection. The findings might also help explain how turtles’ ancestors survived a mass extinction 250 million years ago that wiped out most plants and animals on earth, scientists report online July 14 in Current Biology.
7-14-16 Darwin’s discovery: The remarkable history of evolution
Darwin’s discovery: The remarkable history of evolution
Not long ago, it was thought that god created all species. That changed in 1858, but the story of evolution is riddled with myths, says Darwin expert John van Wyhe. Evolution is the most revolutionary concept in the history of science. Nothing else has more radically changed our understanding of the natural world and ourselves. The work of Charles Darwin showed, irrefutably, that humans are just another animal occupying a small branch on a vast tree of life. No divine spark is needed to explain our existence and traits. But how exactly did Darwin devise his theory of evolution? What ideas did he build on? Where does the naturalist Alfred Russel Wallace, who proposed a similar theory, fit in? And how shocking was the idea to the Christian society of the time? The story of the uncovering of this great revelation has been retold countless times since the publication of Darwin’s On the Origin of Species in 1859. In the process, the assumptions and guesses of one generation became accepted as fact by the next – with some spawning widespread myths. Perhaps the most fundamental of these is that thinkers had been striving for centuries to solve the mystery of the origin of species. They hadn’t, and indeed they couldn’t have – just as ancient Greek philosophers could not have been searching for dark matter. (Webmaster's comment: An Absolute Must Read!)
7-14-16 The last Neanderthal
The last Neanderthal
A special video series telling the real story of how our extinct relative lived and died.For decades, we've thought of our Neanderthal cousins as brutish, primitive beings. Second-class humans driven extinct by their own fallibility and stupidity. But as we are fast learning, the truth about who they were and how they died is far more intriguingIn a special series, BBC Earth has recreated the last days of the last Neanderthal.
7-14-16 Predatory dinosaur had tiny arms like Tyrannosaurus rex
Predatory dinosaur had tiny arms like Tyrannosaurus rex
A new meat-eating dinosaur has been discovered in Argentina that possessed stubby arms like Tyrannosaurus rex. But the new creature, named Gualicho shinyae, was not closely related to T.rex, suggesting the unusual limbs evolved independently. The 90 million-year-old animal from northern Patagonia measured about 7.6m long and would have weighed about a tonne - about the same as a polar bear.
7-13-16 'Three centuries' to catalogue all Amazon tree species
'Three centuries' to catalogue all Amazon tree species
Tree species in the Amazon rainforest are so many and varied that it would take three centuries to catalogue them, a major study has estimated. In research published in the journal Scientific Reports, more than 500,000 museum specimens dating back 300 years were audited. They say nearly 12,000 tree species have been discovered so far. Based on this figure, they predicted that about 4,000 rare types remained to be discovered and described.
7-13-16 T. rex lookalike suggests that tiny arms developed for a purpose
T. rex lookalike suggests that tiny arms developed for a purpose
A new species of dinosaur, Gualicho shinya, had tiny arms like T. rex despite coming from a separate continent, suggesting this feature evolved for a reason. While Tyrannosaurus rex was stalking prey some 68 million years ago in what is now North America, down south an unrelated predator was trying out a similar look. A new dinosaur species, Gualicho shinyae, unearthed in Argentina’s Huincul formation bears a mosaic of features and looks a bit like an Allosaurus, a subgroup of two-legged, bird-like theropods. Its most striking feature, however, is its tiny arms that look like those of a T. rex — even though the two species lived on separate continents. The Huincul formation is renowned for remarkable dinosaur fossils, including Argentinosaurus – perhaps the largest dinosaur ever. But nothing quite like Gualicho had ever been found here. “Gualicho has anatomical traits that you see in very disparate groups of theropod dinosaurs,” says Pete Makovicky of The Field Museum in Chicago, who described this “mosaic” dinosaur. “It appears to be closest to Allosaurus, but it doesn’t quite fit comfortably.”
7-13-16 What animals’ life spans can tell us about how people age
What animals’ life spans can tell us about how people age
To understand human longevity, look to the animal world, says James Carey, a biodemography specialist at the University of California, Davis. Studying other species, from insects to elephants, “provides important information for why we age and why we live as long as we do,” Carey says. By looking at how long other organisms can live, Carey and other researchers have found some guiding principles for why some species flash in and out in days and others live for more than a century. For example, most groups of related organisms have similar maximum known life spans, Carey notes. Songbirds, such as the Eastern bluebird, generally live a maximum of eight to 10 years, for instance, while parrots (African gray parrot shown above) or raptors can survive for decades. Species can evolve so that they live a bit less or more than closely related species, but you probably won’t find a species of mouse that lives 100 years or a tortoise that dashes through life in a month. The graph below shows the longest-lived individuals for a selection of species — including many that make great fodder for cocktail party conversation (goldfish, anyone?).
7-13-16 The brain’s blueprint for aging is set early in life
The brain’s blueprint for aging is set early in life
An elderly brain has some telling similarities to a developing brain. If you’ve ever watched a baby purse her lips to hoot for the first time, or flash a big, gummy grin when she sees you, or surprise herself by rolling over, you’ve glimpsed the developing brain in action. A baby’s brain constructs itself into something that controls the body, learns and connects socially. Spending time with an older person, you may notice signs of slippage. An elderly man might forget why he went into the kitchen, or fail to anticipate the cyclist crossing the road, or muddle medications with awkward and unfamiliar names. These are the signs of the gentle yet unrelenting neural erosion that comes with normal aging. These two seemingly distinct processes — development and aging — may actually be linked. Hidden in the brain-building process, some scientists now suspect, are the blueprints for the brain’s demise. The way the brain is built, recent research suggests, informs how it will decline in old age.
7-13-16 Still mysterious, aging may prove malleable
Still mysterious, aging may prove malleable
Aging happens to each of us, everywhere, all the time. It is so ever-present and slow that we tend to take little notice of it. Until we do. Those small losses in function and health eventually accumulate into life-changers. Despite its constancy in our lives, aging remains mysterious on a fundamental level. Scientists still struggle to fully explain its root causes and its myriad effects. Even as discoveries pile up a clear picture has yet to emerge. Debates continue about whether individual life spans and the problems associated with aging are programmed into our bodies, like ticking time bombs we carry from birth. Others see the process as a buildup of tiny failures, a chaotic and runaway deterioration that steals vim and vigor, if not health and life itself. There is no unified theory of aging. That means that there is no one way to stop it. As longtime aging researcher Caleb Finch put it in an interview with Science News: Aging is still a black box.
7-13-16 A healthy old age may trump immortality
A healthy old age may trump immortality
There may be ways to stay vibrant for much longer than we do today. It’s unlikely that scientists will ever find a way to avoid death. And taxes are completely out of their hands. But aging, recent research suggests, is a problem that science just might be able to fix. As biological scientists see it, aging isn’t just accumulating more candles on your birthday cake. It’s the gradual deterioration of proteins and cells over time until they no longer function and can’t replenish themselves. In humans, aging manifests itself outwardly as gray hair, wrinkles and frail, stooped bodies. Inside, the breakdown can lead to diabetes, heart disease, cancer, Alzheimer’s disease and a host of other problems. Scientists have long passionately debated why cells don’t stay vigorous forever. Research in mice, fruit flies, worms and other lab organisms has turned up many potential causes of aging. Some experts blame aging on the corrosive capability of chemically reactive oxygen molecules or “oxidants” churned out by mitochondria inside cells. DNA damage, including the shortening of chromosome endcaps (called telomeres) is also a prime suspect. Chronic, low-grade inflammation, which tends to get worse the older people get, wreaks so much havoc on tissues that some researchers believe it is aging’s prime cause, referring to aging as “inflammaging.” All these things and more have been proposed to be at the root of aging.
7-13-16 Organisms age in myriad ways — and some might not even bother
Organisms age in myriad ways — and some might not even bother
Escape artists and suicidal reproducers offer clues to how senescence evolved. Biologists have long tracked aging in fruit flies and lab mice, but a bloom of recent data from more diverse organisms is stirring up discussion about how aging could have evolved — and if it’s inevitable. The ongoing studies of Martínez’s pampered pond invertebrates and a massive effort to study aging in a roadside weed are good examples of these provocative approaches. They’re shaking up basic assumptions of a long-standing theory and inspiring new thinking to explain why there’s so much crazy variety in how life deteriorates — or maybe doesn’t.
7-13-16 Gorillas may have evolved a way to beat a cheating berry plant
Gorillas may have evolved a way to beat a cheating berry plant
A "deceitful" West African plant makes super-sweet, but low-calorie berries to attract animals that disperse their seeds. Gorillas can see through the ploy – at least, that’s the theory. Fool me once, perhaps… it looks like gorillas don’t get fooled twice, at least not by a cheating plant. If true, that makes them smarter than humans and almost 50 other primate species all of whom can be tricked by a West African plant that grows super-sweet but low-calorie berries. Pentadiplandra brazzeana’s fruit is packed with a protein called brazzein, which mimics the taste of high-energy sugary fruits, but costs the plant less to make. So sweet is brazzein that it’s even been suggested as a new artificial sweetener for human consumption. The problem for hungry primates is that it’s mostly a waste of time eating the plant’s fruit. Brenda Bradley, an anthropologist at George Washington University, thinks the plant is probably producing cheap, sweet proteins to “trick” African primates into eating the low-calorie berries and dispersing their seeds.
7-13-16 The musical harmonies you like depend on where you’re from
The musical harmonies you like depend on where you’re from
There’s no such thing as a nasty-sounding chord: it all depends on what you’re used to. That’s the suggestion from a study of more than 160 people from the US and Bolivia, which found that people may have no innate preference for particular chords or harmonies. Some think that certain elements of music transcend culture and are universal. The ancient Greeks discovered that musical harmony seems rooted in mathematics, while many cultures worldwide base their musical scales around the octave and use mathematically neat chords like the perfect fifth. But Josh McDermott at the Massachusetts Institute of Technology and his team have found evidence that our biology does not innately prefer such mathematically simple harmonies.
7-12-16 Hidden red hair gene a skin cancer risk
Hidden red hair gene a skin cancer risk
People can carry a "silent" red hair gene that raises their risk of sun-related skin cancer, experts warn. The Sanger Institute team estimate one in every four UK people is a carrier. The gene's effect is comparable to two decades of sun exposure in terms of cancerous changes, they say. While people with two copies of the gene will have ginger hair, freckles and pale skin and probably know to take extra care in the sun, those with one copy may not realise they are at risk. These carriers may not always look like "easy burners", say the researchers - but they are.
7-12-16 When bird populations shrink, females fly away
When bird populations shrink, females fly away
Skewed sex ratios of willow warblers might result from females choosing to join bigger and better populations, leaving small ones dominated by males, a new study suggests. In some populations of birds, males may wonder why they can’t find a mate. It’s not that they’re unattractive or can’t sing the right song. It’s that females are in short supply. This phenomenon is a common one in birds, particularly in threatened species and among populations that are small or fragmented. And scientists weren’t sure why this inequality crops up. Perhaps females are more likely to die, researchers speculated, or there are differences in when and where males and females move. (Webmaster's comment: Female birds are going to go when they can find the largest selection or the best selection of mates, just like human females do. Finding the most and best options for breeding is just evolution at work.)
7-12-16 Post-stroke shifts in gut bacteria could cause additional brain injury
Post-stroke shifts in gut bacteria could cause additional brain injury
Mouse study suggests fecal transplants as therapy. After a brain injury, the guts become temporarily paralyzed. That alters gut microbe populations, triggering the activity of pro-inflammatory T cells, which cause further damage in the brain, mouse studies show. A series of new experiments reveals a surprising back-and-forth between the brain and the gut in the aftermath of a stroke. In mice, this dickering includes changes to the gut microbial population that ultimately lead to even more inflammation in the brain. There is much work to be done to determine whether the results apply to humans. But the research, published in the July 13 Journal of Neuroscience, hints that poop pills laden with healthy microbes could one day be part of post-stroke therapy.
7-12-16 What if we could find the 'off-switch' for pain?
What if we could find the 'off-switch' for pain?
oy in Pakistan became a local legend as a street performer in recent years by traversing hot coals and lancing his arms with knives without so much as a wince. A thousand miles away, in China, lived a family wracked by excruciating bouts of inexplicable pain, passed down generation after generation. Scientists eventually determined what the boy and the family had in common: mutations in a gene that functions like an on-off switch for agony. Now, a bevy of biotech companies, including Genentech and Biogen, are staking big money on the idea that they can develop drugs that toggle that switch to relieve pain without the risk of addiction. The gene in question is SCN9A, which is responsible for producing a pain-related protein called Nav1.7. In patients who feel nothing, SCN9A is pretty much broken. In those who feel searing random pain, the gene is cranking out far too much Nav1.7. That discovery raises an obvious question: Can blocking Nav1.7 provide relief for many types of pain — and someday, perhaps, replace dangerous opioid therapies? "That's the dream," said David Hackos, a senior scientist at Genentech, which has two Nav1.7 treatments in the first stage of clinical development.
7-12-16 Why do we sleep? Naps might free up space for learning more
Why do we sleep? Naps might free up space for learning more
The purpose of sleep may be to weaken the new brain connections we form during the day, ensuring we have enough capacity to form more memories when we wake up. It is one of life’s great enigmas: why do we sleep? Now we have the best evidence yet of what sleep is for – allowing housekeeping processes to take place that stop our brains becoming overloaded with new memories. All animals studied so far have been found to sleep, but the reason for their slumber has eluded us. When lab rats are deprived of sleep, they die within a month, and when people go for a few days without sleeping, they start to hallucinate and may have epileptic seizures. One idea is that sleep helps us consolidate new memories, as people do better in tests if they get a chance to sleep after learning. We know that, while awake, fresh memories are recorded by reinforcing connections between brain cells, but the memory processes that take place while we sleep have remained unclear. Support is growing for a theory that sleep evolved so that connections in the brain can be pruned down during slumber, making room for fresh memories to form the next day. “Sleep is the price we pay for learning,” says Giulio Tononi of the University of Wisconsin-Madison, who developed the idea.
7-12-16 Silencing ‘Spider-Man gene’ makes flies stick to walls and die
Silencing ‘Spider-Man gene’ makes flies stick to walls and die
Scientists have discovered a gene called spidey that regulates flies’ protective shield, without which they get stuck to walls. Scientists have discovered a gene that, when inactivated, can give flies super sticky powers. The gene, found in vinegar flies and named spidey, after Spider-Man, is responsible for producing their protective waxy coating – switching it off makes flies extra sticky. The lipids that make up this waxy layer normally act as a raincoat and protect flies against various exterior elements, including microbes and environmental stress. They also carry information about the age, sex and social status of the carrier. “Loss of the lipids allows substances like food to accumulate on the surfaces of their legs,” says Chiang. “The flies eventually get completely stuck to surfaces.” Without the lipid shield, gunk builds up on the flies. The insects then get caught up in this sticky mess as it aggregates and creates a force that sucks them down onto surfaces.
7-11-16 Soil organisms alone can determine which plants grow where
Soil organisms alone can determine which plants grow where
The living communities under the land can determine what kinds of plants thrive about the ground – and giving “soil shots” to land can shape its restoration. Change the organisms that live in soil and you can change the kinds of plants that grow in it. A field trial in the Netherlands has found that adding a thin layer of soil from a healthy ecosystem to degraded land greatly speeds up restoration. What’s really surprising, though, is that this “inoculation” can determine in what direction the ecosystem develops. “Soil organisms are the helmsmen that determine where the ecosystem goes,” says Jasper Wubs of the Netherlands Institute of Ecology in Wageningen.
7-11-16 When mouth microbes pal up, infection ensues
When mouth microbes pal up, infection ensues
Benign oral bacteria provides energy boost for pathogen. Normally harmless mouth bacteria can be a bad influence. When they pal around with tooth- and gum-attacking microbes, they can help those pathogens kick into high gear. This teamwork lets infections spread more easily — but also could offer a target for new treatments, scientists report online June 28 in mBio.
7-11-16 ‘Cracking the Aging Code’ tackles aging from evolutionary perspective
‘Cracking the Aging Code’ tackles aging from evolutionary perspective
Book offers some advice on getting older that’s not yet tested. A new book on aging starts with what sounds like a promise: “It is a common belief that aging is inevitable and universal. Nothing could be further from the truth.” From this, you might expect the final pages to offer a list of options for fending off the ravages of time. But this is less a how-to guide and more of a dive into why aging happens. The authors, theoretical biologist Josh Mitteldorf and writer Dorion Sagan, take an extensive stroll through evolutionary theory and aging research in support of an off-center view. After pointing out problems with several theories of why aging evolved, the authors present the controversial premise that aging is a programmed march toward oblivion that evolved as a form of population control. “Aging in animals enforces a common, predictable life span, helping to prevent the dominance of any one individual or one gene type. Diversity is preserved for the health of the community.” Other researchers have been skeptical of that idea.
7-9-16 Mystery of 101-year-old master pianist who has dementia
Mystery of 101-year-old master pianist who has dementia
Somehow an elderly woman who struggles to recognise people or where she is can tap in to the musical training of her youth to play nearly 400 songs by ear. At first glance, she was elderly and delicate – a woman in her 90s with a declining memory. But then she sat down at the piano to play. “Everybody in the room was totally startled,” says Eleanor Selfridge-Field, who researches music and symbols at Stanford University. “She looked so frail. Once she sat down at the piano, she just wasn’t frail at all. She was full of verve.” Selfridge-Field met this woman, referred to as ME to preserve her privacy, at a Christmas party around eight years ago. ME, who is now aged 101, has vascular dementia: she rarely knows where she is, and doesn’t recognise people she has met in the last few decades. But she can play nearly 400 songs by ear – a trick that depends on tapping into a memory of previously stored musical imprints – and continues to learn new songs just by listening to them. She has even composed an original piece of her own. ME’s musical talent, despite her cognitive impairments, inspired Selfridge-Field to spend the last six years observing her, and she presented her observations today at the International Conference on Music Perception and Cognition in San Francisco, California.
7-8-16 Why granny's only robot will be a sex robot
Why granny's only robot will be a sex robot
We need home care bots far more than we need sex robots, but guess which one we're more likely to get. In the early 2000s, the former Bell Labs engineer was busy caring for his elderly father and building his own technology business. That’s when he first came up with the idea for a companion robot: a machine that could look after his dad and keep him in touch with the outside world via webcam. Hines started working on a prototype, but ran into trouble finding financial and legal support for the project. So he gave up, and instead turned his attentions to Roxxxy, a life-size sexbot dressed in filmy black lingerie (“always turned on and ready to talk or play!”). That gambit was far more successful. As Hines deadpanned in an interview with IEEE Spectrum in 2010, adult entertainment is “recession-proof”. On the surface, the fates of sexbots and carebots should not be so divergent. Both are mechanised stand-ins for roles that are typically undervalued and ill-treated in society, with neither ethically straightforward to replace. Neither will work without a robot that can move around on its own and do some heavy lifting. Both would work even better with some level of social or emotional intelligence built in, to better respond to human needs. (Webmaster's comment: It's all about surviving and breeding. Those are our number one drives. That why army killer robots and sex bots will be the number one robots to be developed. Caring for the elderly does little for surviving so one can breed.
7-8-16 Evolutionary forces are causing a boom in bad science
Evolutionary forces are causing a boom in bad science
Evolutionary analysis suggests that the way researchers are rewarded, and the competitive environment they work in, are pushing them to do worse research. Call it a crisis. Researchers are finding it harder to replicate each other’s findings, while the rate of retractions of published studies is rapidly rising. But why is this happening? It’s difficult to determine to what extent the retraction trend is caused by more studies reporting false findings, and how much is down to the fact false findings are now more likely to be identified. Some speculate that the internet has made it far easier for scientists to scrutinise each other’s work, and plagiarism can now be detected automatically. However, new research supports the idea that, in fact, we are encouraging poor scientific practices by accident. Paul Smaldino and Richard McElreath at the University of California Davis used an evolutionary theory-based computational model to analyse the problem of bad science. They found that “the most powerful incentives in contemporary science actively encourage, reward and propagate poor research methods and abuse of statistical procedures”. In short, it’s natural selection for shoddy science.
7-8-16 Underwater city was built by microbes, not people
Underwater city was built by microbes, not people
The structures in Greek waters reveal geologic rather than archaeological past. When snorkelers discovered what appeared to be ancient stonework off the coast of the Greek island of Zakynthos in 2013, archaeologists sent to the site thought the odd rocks might be the ruins of an ancient city. But among the columns, bagel-shaped rings and paving stone?like rocks, they found no telltale pottery shards or other artifacts. Soon after, geochemist Julian Andrews of England’s University of East Anglia and colleagues dove down to the supposed ruins and collected samples. Turns out, the so-called Lost City of Zakynthos was built by microbes, not by ancient Greeks. What appear to be submerged Greek ruins are actually the fossilized remains of sediments laid down by methane-chomping microbes millions of years ago, the researchers report in the September Marine and Petroleum Geology.
7-8-16 Editing human genes
Editing human genes
The first human trial of an experimental gene-editing technology designed to fight cancer will likely begin later this year, Science reports. Known as CRISPR-Cas9, the new therapy involves inserting and altering genes within patients’ disease-fighting T cells to improve the cells’ ability to seek out and destroy tumors. A National Institutes of Health (NIH) ethics panel has greenlighted tests of the breakthrough technique, to be conducted by the University of Pennsylvania, the University of Texas, and the University of California at San Francisco. Funded by tech billionaire Sean Parker, the trials will include 18 people with one of three types of cancer: melanoma, sarcoma, and myeloma. The main goal of the study is to assess the safety of CRISPR-Cas9, which still needs approval from the Food and Drug Administration. “It’s an important new approach,” says oncologist Michael Atkins, an NIH panel member. “We’re going to learn a lot from this. And hopefully it will form the basis of new types of therapy.”
7-8-16 Antibiotic resistance discovered in the guts of ancient mummies
Antibiotic resistance discovered in the guts of ancient mummies
The presence of antimicrobial resistance genes in 1000-year-old Incan remains suggest resistance was common hundreds of years before we discovered penicillin. The gut bacteria inside 1000-year-old mummies from the Inca Empire are resistant to most of today’s antibiotics, even though we only discovered these drugs within the last 100 years. These ancient genes were largely in microbes whose resistance is problematic today, including Enteroccocus bacteria that can infect wounds and cause urinary tract infections. But they found that many other species, including some harmless ones, carried some of these resistant genes too.
7-8-16 Mutant mice become 'super sniffers'
Mutant mice become 'super sniffers'
US scientists have mutated mice to turn them into "super sniffers". The aim is to create a new generation of rodents that can sniff out drugs or explosives, with the scientists saying the experiment is a proof of concept. In the future, rats, mice, and perhaps dogs, could be genetically altered to track down certain scents, they report in the scientific journal Cell Reports. "What we think we can do is make 'super sniffers' for particular odours," said co-researcher Dr Paul Feinstein. The scientists used genetic modification to make mice better at detecting certain scents.
7-7-16 Hightailing it out of the water, mudskipper style
Hightailing it out of the water, mudskipper style
Land-walking fish and a robot show value of an additional appendage in crawling up sandy slopes. Nothing conquers a slippery slope like a good twitch of the tail, say researchers exploring how vertebrates could have taken the first treacherous steps on land. When early vertebrates invaded land 360 million years or more ago, their tails might have been critical in helping them climb sloping sand or mud, suggests physicist Daniel Goldman of Georgia Tech in Atlanta. These surfaces can suddenly shift from a solid heap to a flowing slide that sends climbers slipping and flailing. Using a tail the right way in a hop-swing kind of gait, however, lets little fish called mudskippers and a dune-invader robot get going on slippery slopes, Goldman and an interdisciplinary team report in the July 8 Science. It’s the latest in research on how animals and robots can cope with treacherous surfaces.
7-7-16 Sea worm fossil gives clues to 'common ancestor'
Sea worm fossil gives clues to 'common ancestor'
Fossils of a sea worm that lived on the ocean floor about 500 million years ago are giving new insights into how early creatures evolved. Tube-like structures once thought to be a type of seaweed were made by a worm that lived a solitary life on the sea bed, say scientists. Prof Simon Conway Morris, from St John's College, University of Cambridge and a co-researcher on the study, said: "Oesia fossils are pretty enigmatic - they are very rare and until now we could not prove which group they belonged to. "Now we know that they were primitive hemichordates - perhaps the most primitive of all."
7-7-16 Memories of favourite locations have a special place in brain
Memories of favourite locations have a special place in brain
The hippocampus is a brain area important for general navigation, and now it seems that mice use a specific part of it to store significant locations. t could be that romantic restaurant, or your favourite park bench. A specific part of the brain seems to be responsible for learning and remembering the precise locations of places that are special to us, research in mice has shown for the first time. Place cells are neurons that help us map our surroundings, and both mice and humans have such cells in the hippocampus – a brain region vital for learning, memory and navigation. Nathan Danielson at Columbia University in New York and his colleagues focused on a part of the hippocampus that feeds signals to the rest of the brain, called CA1. They found that in mice, the CA1 layer where general environment maps are learned and stored is different to the one for locations that have an important meaning.
7-7-16 Three-parent-babies might have health problems in later life
Three-parent-babies might have health problems in later life
A study in mice suggests that mitochondrial replacement can adversely affect ageing and metabolism, but it is not clear if this would happen in people too. Mitochondrial replacement therapy was approved by the UK Parliament last year and will allow women with genetic faults in their mitochondria – the cell’s energy generators – to have children without passing on their faulty mitochondrial DNA. The therapy involves transferring the nucleus of the mother’s egg or fertilized embryo into an egg from an unrelated donor. The resulting child will inherit nuclear DNA from both their parents, and mitochondrial DNA from the donor. But now a study in mice has suggested that a mismatch between mitochondrial and nuclear DNA can cause accelerated ageing and affect metabolism and obesity.
7-6-16 To zip through water, swordfish reduce drag
To zip through water, swordfish reduce drag
Newly found organ excretes oil that may increase swimming efficiency. Olympic swimmers shave their bodies before a big race to break records. Swordfish use a different trick, a new study suggests: They grease their heads. The fish (Xiphias gladius) are among the fastest in the ocean — their streamlined bodies can cut through the water at about 90 kilometers per hour. A newly discovered oil-producing organ in the fish’s head gives it slick skin that could boost its speed, scientists report in the July 6 Journal of Experimental Biology. MRI scans show that the organ links to tiny pores on the head that ooze the oil, creating a thin layer of lubrication on the skin’s surface.
7-6-16 DNA sequencing turns rivers into ecosystem surveillance systems
DNA sequencing turns rivers into ecosystem surveillance systems
Rather than counting species by eye, some ecologists sample the DNA they shed to quickly get a roll call of an entire ecosystem. THE Mekong river teems with life as it flows to the South China Sea. But the unique species found here are under threat from plans to build hydropower dams along the river. A new environmental monitoring technique may help limit the damage, by quickly counting all the species upstream using only DNA pulled out of the river. That information could be used to influence dam locations at the planning stage. Traditional surveying methods would take years to identify ecological hotspots that dams should avoid – time developers don’t want to waste. “There’s no way you’re going to sample that [large an area] with the traditional methods,” says Douglas Yu at the Kunming Institute of Zoology in China. Yu hopes to speed up surveying by gathering the fragments of DNA littered throughout the environment and identifying the species they belong to with DNA sequencing. He wants to work with Chinese ecologists to carry out “eDNA surveys” in the Mekong, building up a picture of where rare and vulnerable species live. The idea is based on recent research that suggests every river acts as a conveyor belt for genetic material released from cells shed from the species living there – what’s called environmental DNA (eDNA). Identifying species like this – in much the same way that microbiologists use DNA sequencing to identify bacteria in a sample – could revolutionise wildlife surveys. This would allow biologists to quickly detect many of the species in an ecosystem.
7-6-16 Donor mitochondria could influence metabolism, aging
Donor mitochondria could influence metabolism, aging
Mouse study has implications for 3-parent babies. For a “three-parent baby,” getting disease-free mitochondrial DNA from a surrogate may do more than just avert disease: For better or for worse, a donor’s mitochondria could also affect the course of aging, new research shows. Two strains of mice – genetically identical except for the source of their mitochondria, the energy centers of cells – aged very differently, researchers report online July 6 in Nature. Even though both mouse strains had healthy mitochondrial DNA, the mice with mitochondria that did not come from the same source as the rest of their DNA fared better later in life: After two years, these mice showed fewer signs of aging and had a lower incidence of tumors.
7-5-16 Put the butter knife down and step away from the ‘sat fat’
Put the butter knife down and step away from the ‘sat fat’
A major US study has undermined the increasingly vocal claims that saturated fat in food poses no risk to health, says Ian Johnson. Confusion reigns. Is a diet rich in saturated fat risky for health or not? One of the oldest and most widely understood dogmas of human nutrition is that too much of this fat from meat, dairy and other animal sources is potentially harmful. Given the strength of the consensus on this for decades, it has been unsettling to see this advice comprehensively challenged recently by a loose confederation of doctors, nutritionists and popular writers. These detractors say that saturated fat has no adverse effect on human health, and that overconsumption of carbohydrates and highly processed plant oils is instead fuelling an increase in obesity and metabolic disease. Much of this is based on high-quality systematic reviews of epidemiological studies published in recent years that found no statistically significant relationship between intakes of saturated fats and heart disease across Western populations. They may have to think again. A major epidemiological study led by researchers at Harvard University sheds new light on this perplexing state of affairs.
7-5-16 Rafting allowed this sea slug to conquer the world’s oceans
Rafting allowed this sea slug to conquer the world’s oceans
Unlike most other nudibranchs, which are restricted to the sea floor, Fiona pinnata travels the oceans by hitching a ride on anything that passes. Unlike most sea slugs that crawl on coral reefs, the nudibranch Fiona pinnata lives on the go. These seafaring sea slugs live on floating islands of debris, eating gooseneck barnacles and drifting with the currents. As a result, they span the globe – yet a genetic analysis shows they are still closely related. It seems rafting helps sea slugs find each other. They travel on anything that floats: uprooted mats of kelp, plastic – even loggerhead sea turtles. Although many of these vessels wash up on shore or sink, the species survives as larvae jump to a new home. “It’s like it’s juggling, the ball is always in the air,” says co-author Jonathan Waters at the University of Otago in Dunedin, New Zealand. “There’s always stuff out there for them to live on. They never need the shore.”
7-5-16 New dating suggests younger age for Homo naledi
New dating suggests younger age for Homo naledi
South African hominid may have lived only 900,000 years ago. A new statistical analysis of skulls and teeth suggests that a recently discovered South African hominid dubbed Homo naledi lived around 900,000 years ago. That’s roughly 1 million years later than estimated by other researchers. H. naledi skulls shown here were included in the new study. Homo naledi, currently the best-known and most mysterious fossil species in the human genus, may be considerably younger than previously thought, a new investigation suggests. Evolutionary trees of ancient hominids statistically reconstructed from skull and tooth measurements indicate that H. naledi lived around 912,000 years ago, say paleoanthropologist Mana Dembo of Simon Fraser University in Burnaby, Canada, and her colleagues. That’s a provisional estimate, since researchers have yet to date either H. naledi’s bones or the sediment in which some of its remains were excavated.
7-5-16 It’s safe to prescribe fewer antibiotics for coughs and colds
It’s safe to prescribe fewer antibiotics for coughs and colds
A study of 610 general practices has found that efforts to curb the spread of antibiotic resistance do not lead to more complications like meningitis. People do not experience more serious health problems when family doctors are stricter about prescribing antibiotics for conditions like coughs, colds and sore throats – a finding that should help stop the spread of antibiotic resistance. A study of 610 general practices in the UK found that surgeries that have lower antibiotic prescribing rates do not see significantly more complications in patients with respiratory infections. The finding is encouraging for family doctors, who have to decide whether or not to prescribe antibiotics many times a day, without knowing if a person’s condition is caused by bacteria or a virus. Prescribing antibiotics for viral infections helps spread antimicrobial resistance, but the fear has been that failing to catch a bacterial infection in its early stages might lead to complications.
7-4-16 Rewarding stimulation boosts immune system
Rewarding stimulation boosts immune system
Experiment in mice may help explain placebos’ power. Feeling good may help the body fight germs, experiments on mice suggest. When activated, nerve cells that help signal reward also boost the mice’s immune systems, scientists report July 4 in Nature Medicine. The study links positive feelings to a supercharged immune system, results that may partially explain the placebo effect.
7-1-16 Bacteria 'gardeners' farm algae to harvest when food runs out
Bacteria 'gardeners' farm algae to harvest when food runs out
A common type of marine microbe uses clever chemistry to nurture algae as well as break them down for food. They’re possibly the tiniest, most ancient gardeners in the world. A type of marine bacteria tends algae, using pesticides to keep other microbes away. Understanding how Roseobacter does this could help us better understand nutrient circulation in the world’s oceans, where the bacteria and their microalgae “crops” are abundant. “They’re key players in global nutrient recycling,” says Eva Sonnenschein of the Technical University of Denmark in Lyngby, who reported her team’s latest results last month at the annual meeting of the American Society for Microbiology in Boston. On average Roseobacter account for 3 per cent of bacterial diversity globally, and as much as 20 per cent in places.
7-1-16 First evidence that synaesthesia gives colour to sign language
First evidence that synaesthesia gives colour to sign language
People with synaesthesia can associate colours and tastes with written words. Now, for the first time, we’ve discovered this can also happen for sign language. Imagine if each of the words in this article had their own taste, or the music you’re listening to played out as visual scene in your mind. For synaesthetes – a small proportion of people whose senses intertwine – this is the stuff of the every day. “Most people describe it as a gift,” says Jamie Ward, a neuroscientist at the University of Sussex in the UK. Now, he and his colleagues have found a new form of synaesthesia – one that moves beyond written language to sign language. It is the first time the phenomenon has been observed. “People with synaesthesia experience the ordinary world in extraordinary ways,” says Ward. In theory, any two senses can overlap. Some synaesthetes connect textures with words, while others can taste them. More commonly, written letters seem to have corresponding colours. An individual synaesthete may always associate the letter A with the colour pink, for instance. This type of synaesthesia has been found across many written languages, prompting Ward’s team to wonder if it can also apply to sign language.
7-1-16 Gut bacteria spotted eating brain chemicals for the first time
Gut bacteria spotted eating brain chemicals for the first time
The discovery of gut bacteria that need the calming chemical GABA to survive could explain why bacteria seem to influence our mood. Bacteria have been discovered in our guts that depend on one of our brain chemicals for survival. These bacteria consume GABA, a molecule crucial for calming the brain, and the fact that they gobble it up could help explain why the gut microbiome seems to affect mood. Philip Strandwitz and his colleagues at Northeastern University in Boston discovered that they could only grow a species of recently discovered gut bacteria, called KLE1738, if they provide it with GABA molecules. “Nothing made it grow, except GABA,” Strandwitz said while announcing his findings at the annual meeting of the American Society for Microbiology in Boston last month. GABA acts by inhibiting signals from nerve cells, calming down the activity of the brain, so it’s surprising to learn that a gut bacterium needs it to grow and reproduce. Having abnormally low levels of GABA is linked to depression and mood disorders, and this finding adds to growing evidence that our gut bacteria may affect our brains.
7-1-16 Letting parasites fight could help battle drug resistance, too
Letting parasites fight could help battle drug resistance, too
Mouse malaria study suggests way to keep pathogens from evading medicines. Taking advantage of malaria strains battling each other could let doctors treat patients without encouraging more drug resistance, a lab test in mice suggests. Without drugs, malaria parasites with no resistance to a medicine often can outcompete any pockets of drug-resistant parasites among them, Nina Wale of the University of Michigan pointed out June 18 at the Evolution 2016 conference. The drug-susceptible forms can hog resources and suppress the resistant ones. As drug treatments kill off the susceptible pathogens, however, the once-struggling drug-resistant minority can take over, creating a case of drug-resistant malaria. As a new strategy for treating diseases without fostering drug resistance, Wale proposed intervening in the competition between parasite forms by weakening the resistant minority. Depleting resources needed more by resistant pathogens could let the susceptible ones wipe out the resistant ones. The result: Drugs can clear a malaria infection without a surge of resistance.