30 Evolution News Articles
For January 2016
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1-28-16 Bed bugs develop resistance to widely used insecticides
Bed bugs develop resistance to widely used insecticides
A new study indicates that bed bugs in the US have developed resistance to neonicotinoids, the most widely used insecticide in the world. Researchers found the blood sucking insects in Cincinnati and Michigan had "dramatic levels" of immunity to regular doses of the chemicals. To kill these bugs required concentrations 1,000 larger than needed to eliminate non-resistant creatures. The scientists say non-chemical methods of control now need to be considered.
1-27-16 Overactive brain pruning in teens could cause schizophrenia
Overactive brain pruning in teens could cause schizophrenia
The gene most strongly associated with schizophrenia seems to ramp up pruning, the loss of brain-cell connections that normally happens during adolescence. During his PhD, Steven McCarroll was surprised to receive a phone call from an old classmate – and startled to find the call came from prison. His friend had been walking down the street when he was gripped by the conviction that people were chasing him, and broke into an apartment to hide. McCarroll’s friend was in the throes of schizophrenia. Symptoms of the condition include hallucinations, such as hearing voices, and paranoid delusions. The event set the stage for McCarroll’s career. Now a molecular biologist at Harvard Medical School in Boston, his latest work offers tantalising clues about the cause of the condition, which is poorly understood and can affect people for life. It suggests that schizophrenia can result from a normal stage of teenage brain maturation gone wrong. “It’s really exciting because it could lead to new ways of treating the disorder,” says Oliver Howes, who studies psychosis at King’s College London. The work builds on a recent landmark study that pointed to 108 regions of our DNA in which certain variants raise the risk of schizophrenia. The most strongly implicated area is a large region of the genome that encodes proteins involved in the immune system – on the face of it, a puzzling find for a brain disorder.
1-27-16 Death Valley fish a 'recent arrival'
Death Valley fish a 'recent arrival'
One of the most extraordinary fish species in world may not be as old as once thought. The Devils Hole pupfish survive in 32-degree Celsius water in a rock shaft in Death Valley in the US. Previous studies suggested they could have become separated as a distinct population more than 10,000 years ago. But the latest genetic analysis points to the pupfish being resident in their unique habitat for perhaps only a few hundred years at most. Christopher Martin and colleagues tell a Royal Society journal that the revelation raises interesting questions as to how the animals got into their present location. There are other pupfish populations in Death Valley but for any of those to have colonised Devils Hole they would somehow have had to cross one of the driest, hottest deserts on Earth.
1-27-16 Conserving the world’s rarest fish may mean letting it die out
Conserving the world’s rarest fish may mean letting it die out
The famous pupfish from Devil's Hole in California may be just the latest in the long cycle of birth – and extinction – of unique fish species in this cave. This pupfish, Cyprinodon diabolis, lives in a single pool in the middle of Death Valley, the hottest place on Earth. We had assumed it had been clinging to isolated existence at that site since the glaciers receded and the valley dried up 10,000 years ago. But its genes tell a different story. The species is actually a newcomer, having colonised the hole from nearby springs – and then diverged from its ancestors – within the past few hundred years. It has also been exchanging genes with related species of pupfish in nearby springs, despite the hot, dry desert separating them.
1-25-16 Did Zika’s recent mutations let it explode as a global threat?
Did Zika’s recent mutations let it explode as a global threat?
As the virus continues to spread, scientists are trying to understand how it went from causing sporadic, contained outbreaks to threatening almost an entire hemisphere. Don’t get pregnant, at least for now. That is the chilling warning from governments battling the Zika pandemic, as evidence mounts that the mosquito-borne virus can cause severe birth defects. As the scale of the impact starts to emerge, scientists are scrambling to learn more about the little-known virus. Is it evolving to be more severe and contagious in humans? Or has it taken off so aggressively simply because someone carried it to a new place with the right mosquitoes? Zika virus got a foothold in the Americas, via Brazil, early last year. Since then it is estimated to have infected up to 1.3 million people there, and to have broken out in 27 countries where it was previously unknown, across Asia, Africa and the Pacific. This includes 12 countries in the Americas that have been infected since mid-December. (Webmaster's comment: There are over 7 billion humans, more than most other animals. We are a huge and easy target for disease.)
1-25-16 Lanky bird's killer kick quantified
Lanky bird's killer kick quantified
When the lanky leg of a secretary bird kicks a snake in the head, the killer blow can transfer five times the bird's own weight in a hundredth of a second.
1-23-16 Your ancestors' poor diet may have 'scarred' your gut microbes
Your ancestors' poor diet may have 'scarred' your gut microbes
The lack of fiber in our modern-day Western diets has been much bemoaned — it correlates with lower diversity of gut microbes, higher risk of heart disease, and heavier body weight. But a study in mice adds a new layer: That lack of fiber may not just be hurting our health, but that of our children and great-grandchildren, by way of their gut bacteria. Researchers found that mice's depleted bacterial diversity as a result of low-fiber diets gets passed on to offspring, and that loss of diversity cannot be easily reversed in future generations. When those mice were bred while on the low-fiber diets, their offspring had even lower bacterial diversity than their parents. This got worse with every generation the scientists studied, producing what the authors called a "diet-induced ratcheting effect" in the paper published recently in Nature.
1-22-16 First warm-blooded lizards switch on mystery heat source at will
First warm-blooded lizards switch on mystery heat source at will
Tegus are unique among lizards in being able to control their body temperature during reproduction – hinting at how warm-bloodedness first evolved. The first known warm-blooded lizard, the tegu, can heat itself to as much as 10 °C above its surroundings – making it unique among reptiles. But bizarrely, it only switches on its heating system at certain times of the year. The discovery may add to the debate about whether dinosaurs were warm- or cold-blooded, or something in between – a bit like these lizards. It may also provide a clue to how warm-bloodedness, or endothermy, first evolved, says Glenn Tattersall of Brock University, Canada, who co-led the research with Cleo Leite at the Federal University of São Carlos in Brazil. Unlike mammals and birds – which can heat themselves – reptiles, amphibians and fish generally depend on absorbing heat from their surroundings.
1-22-16 Humanity’s profound impact on the Earth
Humanity’s profound impact on the Earth
The pervasive and profound influence of human activity on the Earth and its atmosphere may have ushered in a new geological epoch—a feat historically reserved for asteroid impacts and other cataclysmic natural events. An international team of scientists is arguing in a new study that the world has entered the Anthropocene, or human epoch, marking the end of the Holocene, or present epoch, which began some 12,000 years ago as the planet thawed from the ice age.
1-21-16 Why humans need less sleep than other primates
Why humans need less sleep than other primates
Most of us feel like we need more sleep, but as a species we have actually evolved to sleep less than our ape and monkey relatives. Could that be the key to our success?
1-21-16 Ancient 'massacre' unearthed near Lake Turkana, Kenya
Ancient 'massacre' unearthed near Lake Turkana, Kenya
Archaeologists say they have unearthed the earliest evidence of warfare between hunter-gatherers, at a site in northern Kenya. The 10,000-year-old remains of 27 people found at a remote site west of Lake Turkana show that they met violent deaths. They were left to die there rather than being buried. Many experts have argued that conflict only came about as humans became more settled. These people, by contrast, were apparently nomadic hunter-gatherers.
1-20-16 Grisly massacre site in Africa reveals one of the earliest wars
Grisly massacre site in Africa reveals one of the earliest wars
Ten skeletons found near Lake Turkana in Kenya show signs of violent death in the oldest known incident of hunter-gatherer warfare, 10,000 years ago. Remains of a grisly massacre discovered in Nataruk, Kenya, show that violent conflict was a fact of life even for our hunter-gatherer ancestors. Ten skeletons excavated at the site show signs of a violent death, including blows and cuts to the head. Two of the bodies have obsidian projectile tips embedded in them, probably from arrows. The body positions of another two suggest that their hands might have been tied when they died. The site, dated to around 10,000 years ago, is the only known evidence of a prehistoric massacre of hunter-gatherer people, says Marta Mirazón Lahr at the University of Cambridge, whose team analysed the skeletons. “It was an intentional conflict between two groups, and it involved a large number of people, so it qualifies in my mind as small-scale warfare,” she says. The motivation for the attack could have been a raid for resources, such as territory or fish in the nearby lake, the team suggests. Alternatively, aggression might have been a standard response when groups of humans met each other, as it is for chimpanzees.
1-20-16 Crisis in antibiotic resistance could be slowed by blood test
Crisis in antibiotic resistance could be slowed by blood test
A test that can distinguish between bacterial and viral infections could prevent unnecessary use of antibiotics that speeds the rise of drug resistance. “At the moment it’s basically down to looking at the evidence and then having a gut feeling about whether the patient needs antibiotics or not,” says Peter Openshaw at Imperial College London. Now researchers have developed a test that could help. It measures changes in gene expression to deduce whether a person’s immune system is trying to fight off bacteria or a virus.
1-19-16 English DNA 'one-third' Anglo-Saxon
English DNA 'one-third' Anglo-Saxon
The present-day English owe about a third of their ancestry to the Anglo-Saxons, according to a new study. Scientists sequenced genomes from 10 skeletons unearthed in eastern England and dating from the Iron Age through to the Anglo-Saxon period. Many of the Anglo-Saxon samples appeared closer to modern Dutch and Danish people than the Iron Age Britons did.
1-19-16 Your face is mapped on the surface of other people’s brains
Your face is mapped on the surface of other people’s brains
The spatial layout of your body parts is reflected in the way the neurons that control each bit are organised - now it seems other people's faces are too. A map for other people’s faces has been discovered in the brain. It could help explain why some of us are better at recognising faces than others. Every part of your body that you can move or feel is represented in the outer layer of your brain. These “maps”, found in the motor and sensory cortices (see diagram, below), tend to preserve the basic spatial layout of the body – neurons that represent our fingers are closer to neurons that represent our arms than our feet, for example. The same goes for other people’s faces, says Linda Henriksson at Aalto University in Helsinki, Finland. Her team scanned 12 people’s brains while they looked at hundreds of images of noses, eyes, mouths and other facial features and recorded which bits of the brain became active. This revealed a region in the occipital face area in which features that are next to each other on a real face are organised together in the brain’s representation of that face. The team have called this map the “faciotopy”. The occipital face area is a region of the brain known to be involved in general facial processing. “Facial recognition is so fundamental to human behaviour that it makes sense that there would be a specialised area of the brain that maps features of the face,” she says.
1-19-16 Your home is a jungle inhabited by 100 different species
Your home is a jungle inhabited by 100 different species
Our homes are complex ecosystems, supporting on average 100 different kinds of creepy-crawly, finds the first census of arthropods in houses. If only they paid rent. There are on average 100 species of creepy-crawly in every house, according to the first comprehensive census of house-dwelling arthropods. Some are part of an intricate ecosystem that relies on crumbs and nail clippings for food. Others are accidental visitors trapped in this strange and dangerous world, unbeknownst to most homeowners. The survey found 579 species, mainly insects, spiders, beetles, mites, flies and ants, in 50 detached houses in the leafy suburbs of Raleigh, North Carolina. “The residents were really surprised and often horrified that we found so much, so we had to calm them down by saying it was normal,” says Matt Bertone of North Carolina State University in Raleigh, who led the survey. He says the results dispel ideas that modern homes are sterile deserts, showing instead that they teem with unseen life. “The biggest surprise was finding at least one species in almost every room, with only five of the 554 rooms drawing a blank,” says Bertone. Some have adapted to live in human homes permanently, such as cobweb spiders and booklice.
1-15-16 Shape-shifting worm creates five different versions of itself
Shape-shifting worm creates five different versions of itself
The unusual strategy means worms of the same species in the same environment can look – and behave - very differently to one another. Their shapes are so different that they look like five different species. But genetic studies have shown single species of nematode worm, newly discovered inside figs, can develop into five distinct forms. It is a striking example of physical divergence without genetic divergence.
1-15-16 Editing the human race
Editing the human race
A new genetic technology called CRISPR may enable scientists to make permanent changes in a person’s DNA. What is CRISPR? It’s a revolutionary gene-editing technique that enables scientists to snip out a piece of any organism’s DNA cheaply, quickly, and precisely—cutting and editing the code of life the way a film editor would splice an old film reel.
1-14-16 Humans adapted to Arctic life 10,000 years earlier than thought
Humans adapted to Arctic life 10,000 years earlier than thought
Evidence of a mammoth and wolf attacked by weapons suggests humans were on America's doorstep as early as 45,000 years ago. Now we’ve discovered a particular carcass – apparently killed and butchered with weapons – that is special. It was found in north-western Siberia and is 45,000 years old, which means that our species seems to have adapted to Arctic life 10,000 years earlier than we thought. Together with a similarly ancient wolf bone with signs of weapon damage unearthed in eastern Siberia, this suggests humans were widespread in the region at the time. They may have therefore had the opportunity to move even further east – into North America – long before 20,000 years ago, which is when we had thought people first reached the Americas.
1-14-16 These baboons and lemurs have left the trees to live in caves
These baboons and lemurs have left the trees to live in caves
Our ancestors are not the only ones to figure out the benefits of sheltering in caves. But this lifestyle offers unique challenges as well as advantages. They’re not afraid of the dark. A group of chacma baboons in South Africa’s De Hoop Nature Reserve and a group of ring-tailed lemurs in Madagascar have been spotted taking shelter and even sleeping in caves – much as early humans used to do. For the baboons, it started when the group lost their leader. The charismatic alpha male from a neighbouring territory took over – and brought with him a revolutionary idea.
1-13-16 Kathy Niakan: Scientist makes case to edit embryos
Kathy Niakan: Scientist makes case to edit embryos
DA scientist has been making her case to be the first in the UK to be allowed to genetically modify human embryos. Dr Kathy Niakan said the experiments would provide a deeper understanding of the earliest moments of human life and could reduce miscarriages. The regulator, the Human Fertilisation and Embryology Authority (HFEA), will consider her application on Thursday. If Dr Niakan is given approval then the first such embryos could be created by the summer. Every person has gone through a remarkable transformation from a single fertilised egg into a fully fledged human being made of trillions of precisely organised cells. (Webmaster's comment: I wouldn't exactly use the word "precisely." The total variability in the human structure is quite extreme. Look at the details in any X-ray. The general shape is there, but it's not "precise.")
1-13-16 Dinosaurs took part in building competitions to attract females
Dinosaurs took part in building competitions to attract females
Physical evidence that dinosaurs put on showy displays to attract mates has been discovered for the first time. For some male dinosaurs, the way to a female’s heart may have been a shovelling contest. Raised earth ridges flanked by parallel troughs, discovered in Colorado, are the first physical evidence that dinosaurs competed in attention-grabbing displays to woo mates. Dating back around 100 million years, the structures are sometimes accompanied by three-toed footprints, suggesting that they were made by a species of theropod – the group that included velociraptors and the ancestors of birds. “These discoveries provide a unique glimpse into dinosaur social behaviour,” says Brent Breithaupt of the Wyoming State Office, part of the team that discovered these tracks from the Cretaceous.
1-13-16 Shark virgin births seen in two generations for the first time
Shark virgin births seen in two generations for the first time
Two surprising new findings are overturning everything we knew about parthenogenesis, suggesting virgin births could be far more common than we thought. IT WASN’T a one-off. Virgin births are far more common than we thought, and can continue for multiple generations. These two surprising findings are overturning everything we knew about parthenogenesis. Some animals, including Komodo dragons and domestic chickens, can sometimes produce offspring without copulating with a male. Females do this by using one of two methods to add an extra set of chromosomes to their eggs, producing either full- or half-clones of themselves. It had only been seen in captivity – until two virgin births were recently recorded in a wild sawfish and pit viper. The process was also thought to be a dead end, producing infertile offspring. Now, for the first time, researchers have seen an individual born through parthenogenesis go on to have its own virgin birth. (Webmaster's comment: So what do we need men for? Increase in genetic variability seems to be the only answer and a healthier gene pole.)
1-12-16 First children diagnosed in DNA project
First children diagnosed in DNA project
The first children with debilitating "mystery" diseases have finally been given a diagnosis as part of a huge scheme to analyse people's DNA. Four-year-old Georgia Walburn-Green's damaged eyes and kidneys and her inability to talk had baffled doctors. She is one of the first to have her precise genetic abnormality identified through the 100,000 Genomes Project. Her parents said the day Georgia was finally diagnosed was one of the biggest of their lives.
1-12-16 Male spiders lure aggressive females with peek-a-boo paddle game
Male spiders lure aggressive females with peek-a-boo paddle game
A newly discovered species of jumping spider has evolved bizarre paddle-shaped limbs that can be used to calm females for safer mating. Males of a newly discovered species of jumping spider spend hours waving special paddle-shaped legs at prospective mates, in an effort to copulate without being attacked – or even eaten. Mating can potentially cost you your life if you are a male spider. To avoid becoming lunch, Jotus remus plays a game first to tire out hungry females.
1-8-16 'Case is made' for Anthropocene Epoch
'Case is made' for Anthropocene Epoch
There is little doubt now that we have entered a new geological age, believes an international scientific panel. The team, which has been tasked with defining the so-called Anthropocene, says humanity's impacts on Earth will be visible in sediments and rocks millions of years into the future. The researchers are working towards a formal classification of the new epoch. An open question is the formal start date, which some panel members think could be the 1950s. This decade marks the beginning of the "Great Acceleration", when the human population and its consumption patterns suddenly speeded up. It coincides with the spread of ubiquitous "techno materials", such as aluminium, concrete and plastic. It also covers the years when thermonuclear weapons tests dispersed radioactive elements across the globe. Their long-lived activity will still be apparent to anyone who cares to look for it hundreds of millennia from now.
1-7-16 Marks of the Anthropocene: 7 signs we have made our own epoch
Marks of the Anthropocene: 7 signs we have made our own epoch
From nuclear weapons to intensive farming, there is overwhelming evidence that our activities will leave a lasting impact on the geological record. There is now overwhelming evidence that our impact on Earth constitutes its own distinct geological epoch, dating from the middle of the 20th century. Here are the seven signs that will clearly identify the Anthropocene epoch for future geologists. 1. Nuclear weapons, 2. Fossil fuels, 3. New materials, 4. Changed geology, 5. Fertilisers, 6. Global warming, 7. Mass extinction.
1-7-16 Neanderthal genes 'boosted our immunity'
Neanderthal genes 'boosted our immunity'
We may owe our ability to fight disease to our extinct relatives - the Neanderthals and Denisovans. According to a pair of scientific studies, key genes in the immune system come from our ancient "cousins". The findings, which appear in The American Journal of Human Genetics, suggest we have Neanderthals to thank for being able to fight off pathogens. But interbreeding may have had a downside, as the same genes may have made us more prone to allergies. Modern-day people can trace their ancestry to a small population that emerged from Africa about 60,000 years ago. As the African humans spread out across the world, they came into contact with other ancient humans based in Europe and Western Asia. Genetic evidence suggests that these different "tribes" interbred, with part of the genome of Neanderthals still present in humans alive today.
1-7-16 Dinosaurs took part in building competitions to attract females
Dinosaurs took part in building competitions to attract females
Physical evidence that dinosaurs put on showy displays to attract mates has been discovered for the first time. For some dinosaurs, the way to a female’s heart may have been a soil-digging contest. Researchers working in Colorado have discovered the first physical evidence that some dinosaurs competed in attention-grabbing displays to woo mates. The structures, which date back to the Cretaceous, are comprised of raised earth ridges flanked by parallel troughs, and a type of dinosaur is thought to have dug them in order to catch the attention of females. Three-toed footprints in some of the troughs suggest that a species of theropod – the group that included velociraptors and the ancestors of birds – were their architects. (Webmaster's comment: Competition for mates is a obvious outcome of evolution which improves the survival of the species. Dinosaurs evolved for 160 million years and all the same advantages of mating selection would have evolved in their species just as they have for all other animals.)
1-1-16 The composer discovering the secrets of birdsong
The composer discovering the secrets of birdsong
Birdsong is the inspiration for composer Peter Cowdrey's music. As a child he tried to transcribe birdsong but was frustrated by the speed and complexity of the songs of everyday garden birds. Now, using a spectrograph to visualise and slow down birdsong, he not only uses it in his music but also works with school children developing lessons that combine music and science. (Webmaster's comment: These songs have evolved over Millions of Years. That bird songs are highly complex is not surprising.)