40 Evolution News Articles
For February 2016
Click on the links below to get the full story from its source
2-29-16 Exquisite fossils reveal oldest nervous system ever preserved
Exquisite fossils reveal oldest nervous system ever preserved
A set of 520-million year old fossils has a nervous system more complex than that evolved by their modern successors. It’s the most ancient nervous system we’ve ever seen, preserved inside 520 million-year-old fossils. What’s more, the nervous systems of these creatures’ modern-day descendants are less intricate, proving that evolution isn’t a one-way street to complexity. Found in South China, the five Cambrian fossils belonged to a group of organisms that gave rise to the arthropods, including insects, spiders and crustaceans. The fossils are of Chengjiangocaris kunmingensis, a creature around 10 centimetres long, with a segmented body, multiple pairs of legs and a heart-shaped head. But most interesting of all is its nerve cord and associated neurons. Together, the fossils show the entire nervous system of the organism, apart from its brain – making this the oldest preserved nervous system that has ever been found. “The detail of this fossil is exquisite,” says Rob DeSalle of the American Museum of Natural History in New York, who was not involved in the work. “The information from this specimen unravels transitions in how the nervous systems of arthropods evolved.” (Webmaster's comment: Another blow to the Creationists "it was too complex to evolve, it must have been designed" theory.)
2-29-16 Super-fast evolving fish splitting into two species in same lake
Super-fast evolving fish splitting into two species in same lake
After just 150 years, stickleback fish in Switzerland have started to split into two different species, despite living in the same lake and interbreeding. Some thought it was impossible. But a population of stickleback fish that breed in the same streams is splitting into two separate species before our eyes, and at rapid speeds. Three-spine sticklebacks were introduced to Lake Constance in Switzerland around 150 years ago – a blink of an eye in evolutionary terms. But since then, the fish have begun splitting into two separate types: one that lives in the main lake (pictured above left, female top, male in breeding colours below), and another that lives in the streams that flow into it (above right). The main lake dwellers are bigger, with longer spines and tougher armour. In theory, these differences could be due to lifestyle rather than evolution – perhaps lake fish survive longer and grow larger. But David Marques of the University of Bern and colleagues have found that there are already clear genetic differences between the two types. “We could be glimpsing the beginnings of two species,” he says. What makes this finding extraordinary is that both types of fish breed in the same streams at the same time of year. They have been interbreeding all along, and still do, yet they are splitting into two genetically and physically different types.
2-28-16 Neuroscience reveals 4 rituals that will make you happy
Neuroscience reveals 4 rituals that will make you happy
You get all kinds of happiness advice on the internet from people who don't know what they're talking about. Don't trust them. Actually, don't trust me either. Trust neuroscientists. They study that gray blob in your head all day and have learned a lot about what truly will make you happy. UCLA neuroscience researcher Alex Korb has some insights that can create an upward spiral of happiness in your life. Here's what you and I can learn from the people who really have answers:
2-27-16 The eyes of the animal kingdom
The eyes of the animal kingdom
The eyes of the animal kingdom are endlessly diverse. Why so much variety? you ask people what animal eyes are used for, they'll say: same thing as human eyes. But that's not true at all. In his lab at Lund University in Sweden, Dan-Eric Nilsson is contemplating the eyes of a box jellyfish. Nilsson's eyes, of which he has two, are ice blue and forward facing. In contrast, the box jelly boasts 24 eyes, which are dark brown and grouped into four clusters, called rhopalia. Nilsson shows me a model of one in his office: It looks like a golf ball that has sprouted tumors. A flexible stalk anchors it to the jellyfish. "When I first saw them, I didn't believe my own eyes," says Nilsson. "They just look weird." Four of the six eyes in each rhopalium are simple light-detecting slits and pits. But the other two are surprisingly sophisticated; like Nilsson's eyes, they have light-focusing lenses and can see low-resolution images. Nilsson uses his eyes to, among other things, gather information about the diversity of animal vision. But what about the box jelly? It is one of the simplest animals, just a gelatinous, pulsating blob with trailing bundles of stinging tentacles. It doesn't even have a proper brain — merely a ring of neurons running around its bell. What information could it possibly need? (Webmaster's comment: The Creationists are incredibly ignorant. Their claim that eyes are too complex to evolve completely ignores the 100's of variations of eyes that have evolved over time from simple light sensors to those more complex than ours.)
2-26-16 First life may have been forged in icy seas on a freezing Earth
First life may have been forged in icy seas on a freezing Earth
Life may have originated in cold conditions on an early incarnation of snowball Earth, according to new evidence from 3.5-billion-year-old rocks. Did life begin in the freezer? Early Earth may not have been as hot and hellish as we thought. In fact, it may have become a snowball around the time life first emerged. This is according to a fresh analysis of rocks from South Africa that formed about 3.5 billion years ago, during the Archaean period. Previous research suggested that the ocean in which these rocks formed was warm – perhaps around 85°C. But Maarten de Wit at the Nelson Mandela Metropolitan University in Port Elizabeth, South Africa, now says the ocean temperature was similar to today’s – and that there is even evidence that ice was present. Because South Africa’s Barberton Greenstone Belt, where these rocks are now found, formed at a latitude of 20° to 40°, this implies that Earth may have become engulfed in ice at least once during the Archaean, he says.
2-25-16 Artificial tail-less sperm is the best test-tube sex cell yet
Artificial tail-less sperm is the best test-tube sex cell yet
A lab in China has taken the lead in the race to make artificial sperm, developing fertile spermatids that meet the gold standard for the first time.They can’t swim. But artificial mouse cells that resemble nearly mature sperm are the best test-tube sperm cells yet, meeting the elusive gold standard set in 2014. The cells resemble spermatids, the round cells that mature to form the familiar tailed sperm. Generated from embryonic stem cells, Jiahao Sha of Nanjing Medical University in China and his team have shown that, when injected using a method used in some forms of IVF, these cells can fertilise mouse eggs, and go on to produce pups that themselves grow up to be fertile. These artificial spermatids are the first in vitro sex cells to meet a set of criteria defined by three fertility and reproduction researchers in 2014. The guidelines were intended to add rigour to the race to artificially generate sperm-like cells, an endeavour that is heating up worldwide. Unlike many other efforts, Sha’s cells successfully undergo the meiotic cell divisions that are crucial for making genetically correct sex cells. Until now, researchers have struggled to prove that they have pushed cells through an important but complicated dividing process that leaves cells with only half of the father’s chromosomes. “We think our work is the first to monitor and examine all requirements for successful meiosis,” says Sha. (Webmaster's comment: Move over America, a new science research powerhouse is emerging.)
2-25-16 Lab-grown sperm makes healthy offspring
Lab-grown sperm makes healthy offspring
Sperm have been made in the laboratory and used to father healthy baby mice in a pioneering move that could lead to infertility treatments. The Chinese research took a stem cell, converted it into primitive sperm and fertilised an egg to produce healthy pups. The study, in the Journal Cell Stem Cell, showed they were all healthy and grew up to have offspring of their own. Experts said it was a step towards human therapies. It could ultimately help boys whose fertility is damaged by cancer treatment, infections such as mumps or those with defects that leave them unable to produce sperm.
2-25-16 Male sand martin birds filmed having sex with a dead male
Male sand martin birds filmed having sex with a dead male
Observation of homosexual necrophilia in birds will ruffle the feathers of those who cling to outdated views of “natural” sexual behaviour. Leave a good-looking corpse, and your mates may mate with it. That at least is what recently happened with sand martins in Japan, which were filmed engaging in homosexual necrophilia. In 2014, Naoki Tomita and Yasuko Iwami from the Yamashina Institute for Ornithology in Abiko saw a dead sand martin by the roadside. As they watched, three males repeatedly mounted it. After 15 minutes, the researchers collected the body and later found it was a male. They have now published an article describing the incident – only the second paper describing such behaviour in birds. Homosexual behaviour is common in birds, but in this case it was probably due to mistaken identity, as male and female sand martins look the same. (Webmaster's comment: No surprise here. Human males have been known to mate with dead people. We humans evolved from other animals and all creatures have the same basic drives.)
2-24-16 Sea butterflies fly underwater just like insects do in the air
Sea butterflies fly underwater just like insects do in the air
The mystery of how a sea snail moves through water has been resolved: they move their wings just like flies do, generating lift to keep afloat. THESE graceful winged sea snails are so admired for their looks that they are known as sea butterflies. It turns out that they share more with insects than just a name – they flap their wings under water just like flies. The tiny snails, Limacina helicina, are one species of zooplankton in the cold waters of the Arctic and Antarctic. Their heavy shell makes them sink like a rock when stationary – unless they secrete a mucous web that keeps them afloat. They have also evolved wing-like appendages for swimming. But exactly how they beat their “wings” and how that propels them was unknown. Now David Murphy at Johns Hopkins University in Baltimore, Maryland, and his team have captured those details for the first time, using four high-speed cameras in a tank with free-swimming snails.
2-23-16 Just the fear of big predators can alter an entire ecosystem
Just the fear of big predators can alter an entire ecosystem
In the first experiment of its kind, raccoons exposed to the sound of dogs spent much less time foraging and so populations of their prey got a boost. The fear of large carnivores, such as dogs, can have knock-on effects throughout an ecosystem. Predators don’t control populations of their prey just by killing them. They also paint what is termed a landscape of fear, inhibiting prey from feeding and turning parts of their habitat into no-go zones. Now it appears that this has far-reaching effects throughout the food web.
2-19-16 Plants have evolved forgetfulness to wipe out memory of stress
Plants have evolved forgetfulness to wipe out memory of stress
The ability to forget may be a coping strategy used by plants to deal with unpredictable environments. Plants can teach us a thing or two about dealing with the ups and downs of life. They may have evolved the ability to forget stressful situations, as a way of dealing with highly unpredictable environments. Some plants have “long-term memory”. For instance, Arrhenatherum elatius, a perennial grass species common in Europe, seems to remember drought and is better able to defend against damage from excessive sunlight than plants that haven’t been through an earlier drought. Such experience helps prime plants to produce the necessary proteins and chemicals at short notice should stressful conditions recur. Plants can preserve such memories across generations, at times via epigenetic mechanisms, which influence whether or not genes are expressed.
2-19-16 New underground plant hides from the sun and parasitises fungi
New underground plant hides from the sun and parasitises fungi
A purple-flowered plant that needs no sunshine and lives underground stealing nutrients from fungi has been discovered in Japan. A newly discovered Japanese plant spends most of its life hidden underground and steals nutrients from fungi rather than getting its energy from the sun. The plant can’t photosynthesise and, like other mycoheterotrophs, steals the carbon it needs from a fungal host. The parasitic plant attracts strands of mycorrhizal fungus into its many hairy roots and then feeds off fungus growing inside the roots.
2-18-16 Tiny sea snail 'swims like a bee'
Tiny sea snail 'swims like a bee'
A tiny species of sea snail "flies" underwater using movements just like winged insects, according to a study. US scientists observed the so-called sea butterfly - actually an aquatic snail - using high-speed video and flow-tracking systems. The 3mm critter flaps its wing structures, which grow where a snail's foot would normally be, in a characteristic figure-of-eight pattern. It also uses some of the vortex-making tricks that keep insects in the air.
2-17-16 Neanderthals and humans interbred '100,000 years ago'
Neanderthals and humans interbred '100,000 years ago'
Neanderthals and modern humans were interbreeding much earlier than was previously thought, scientists say. Traces of human DNA found in a Neanderthal genome suggest that we started mixing with our now-extinct relatives 100,000 years ago. Previously it had been thought that the two species first encountered each other when modern humans left Africa, about 60,000 years ago.
2-17-16 Sea butterflies fly underwater just like insects do in the air
Sea butterflies fly underwater just like insects do in the air
The mystery of how a sea snail moves through water has been resolved: they move their wings just like flies do, generating lift to keep afloat. These beautiful winged sea snails are so admired for their graceful looks they are known as sea butterflies. Now it turns out they share more with insects than just a name – they flap their wings underwater just like flies or thrips. The tiny snails, Limacina helicina, are found in the cold waters of the Arctic and Antarctic. Their heavy shell makes them sink like a rock when stationary – unless they secrete a mucous web that keeps them afloat. They are also equipped with wing-like appendages that allow them to swim. But exactly how they beat their wings and how that allows them to move was unknown.
2-16-16 Why the brain is a marvel of evolution
Why the brain is a marvel of evolution
As part of the BBC #In the Mind series Fergus Walsh visits the Bristol Brain Bank, one of a network of ten brain banks managed by the Medical Research Council. Here he shares some facts and figures about what makes the human brain one of the most complex structures in the world. The report contains detailed shots of the human brain from the start.
2-17-16 Invasive species blamed as second biggest cause of extinctions
Invasive species blamed as second biggest cause of extinctions
A new analysis of IUCN Red List data says alien species are driving native ones extinct, but that may only be true for islands, not continents, critics say. Alien invaders are the second biggest cause of species extinctions, according to a new study, but not everyone is convinced. The role invaders play in wiping out native species has long been a bone of contention for conservationists. The new study looks at the Red List, a catalogue of extinct and threatened species drawn up by the International Union for Conservation of Nature (IUCN). For species that are completely extinct or extinct in the wild, those who draw up the list identify one or more contributing factors. Tim Blackburn at University College London and his colleagues compiled data from the Red List on 247 species of plant, amphibian, reptile, bird and mammal that have disappeared since 1500. They found that invasive species are the second most common threat associated with the losses, behind hunting, fishing or harvesting. For amphibians, mammals and reptiles, invasive species were the number one threat.
2-15-16 Take exams early in the morning to get a higher score
Take exams early in the morning to get a higher score
A Danish study has found that children's exam results get worse for every hour later in the day that they sit a standardised test. Hans Henrik Sievertsen from the Danish National Centre for Social Research in Copenhagen and his team have looked at 2 million standardised test scores from Danish children aged between 8 and 15. Starting from 8 am, for every hour later that a test was taken, scores declined by an amount equivalent to the effect of missing 10 days of school. Children who were performing worse at school seemed most affected by the time they sat the exam. The team thinks the difference is down to cognitive fatigue. If a test was taken just after a 20 or 30 minute break, scores improved by as much as if the children had taken it 2 hours earlier.
2-15-16 Your immune system becomes like your partner’s when you cohabit
Your immune system becomes like your partner’s when you cohabit
If you’re healthy, your immune systems won’t change that much throughout your lifetime. The biggest upheaval? Moving in with a partner and having kids. Share and share alike. When you’re in a relationship, you might well share sleeping habits, diets and exercise schedules with your partner. Now it seems your immune systems also converge when you live together. Everyone’s immune system is unique, varying in the number and type of immune cells and their activation states. This diversity is why the same flu virus can make one person ill for an afternoon, but can leave someone else bedridden for days. But Liston spotted an interesting pattern – the immune systems of people who live together seem to be remarkably similar. “There is a 50 per cent reduction in variation, which is an extremely profound effect,” says Liston. “It’s a larger effect than you see over 40 years of ageing.”
2-15-16 The sinister reason why people fall in love
The sinister reason why people fall in love
Romance may have existed in some form long before the origin of humanity, and some believe it was born out of death and violence. Your heart beats a little faster, glands open to secret tiny dribbles of sweat, and your body starts producing hormones, which make you feel a bit giddy and warm inside. These are some of the biological processes that occur as you are thrust into the early throes of love – or infatuation, it can be hard to tell which it is. It seems Shakespeare was more correct than he could have known. Peer into the evolution of love in the animal kingdom and it becomes apparent that love had its beginnings long before the advent of humanity. What's more, it could have been born out of something quite sinister.
2-13-16 The fascinating sleep habits of 7 animals
The fascinating sleep habits of 7 animals
Scientists suspect that bullfrogs do not sleep — at all. Humans spend one-third of their lives catching some zzzzzz. That may seem like a lot of time, but a koala requires more than double the daily amount of sleep we do. Domestic cats commonly spend half of each day asleep, which is about as obvious as scientific facts come. This visual comparison of the number of hours certain animals sleep and how they do so offers a small insight into some of the complex questions scientists are asking about sleep.
2-12-16 Should biologists stop grouping us by race?
Should biologists stop grouping us by race?
More than a decade after leading geneticists argued that race is not a true biological category, many studies continue to use it, harming scientific understanding and possibly patients, researchers argued in a provocative essay in Science on Thursday. "We thought that after the Human Genome Project, with [its leaders] saying it's time to move beyond race as a biological marker, we would have done that," said Michael Yudell, a professor in the Dornsife School of Public Health at Drexel University and coauthor of the Science paper calling on journals and researchers to stop using race as a category in genetics studies. "Yet here we are, and there is evidence things have actually gotten worse in the genomic age."
2-12-16 Mice watching movies on iPods prefer action to mouse erotica
Mice watching movies on iPods prefer action to mouse erotica
If you play them mouse movies, mice spend more time watching the ones showing fights than the videos of mouse sex. A study that presented mice with multiple movies, played on iPods, has found that the animals spent longer watching other mice fighting than watching them copulating. Shigeru Watanabe of Keio University in Japan and his team tested mice to see if they could distinguish between video clips of different social behaviours. They used three scenes – one of mice sniffing each other, another of two mice fighting, and the third of a copulating pair – and played them on a loop on iPods, without sound. They placed an iPod in each of two side compartments of an enclosure, each playing a different video, and recorded the time spent in each compartment by 40 male mice with no sexual experience. (Webmaster's comment: Are we men or are we mice? Hard to tell since we like the same things.)
2-12-16 Inside a wasp’s head: Here’s what it sees to find its way home
Inside a wasp’s head: Here’s what it sees to find its way home
Video reconstructions of what wasps look at when flying are helping us to understand how they navigate and learn about their habitat. Step behind the eyes of a wasp. These reconstructions of how the insects see the world are revealing how they find their way home. Wasps have low-resolution vision, so they rely on visual cues and a photographic memory for navigation. Every morning, they embark on information-gathering missions when they first leave their nests to help guide them home later, but what they learn about their environment has been a mystery. To try and figure this out, Jochen Zeil of the Australian National University in Canberra and his team used high-speed cameras to track the head movements of ground-nesting wasps (Cerceris australis) during these flights.
2-12-16 'Health risk' legacy from Neanderthals
'Health risk' legacy from Neanderthals
Some instances of depression, among other ailments, may be influenced by our Neanderthal heritage. Scientists say a range of conditions, including skin disease and even a tendency towards tobacco addiction, have strong links to the DNA we retain from our ancient evolutionary cousins. A US-led team found the associations when searching for Neanderthal genetic variations in 28,000 modern-day people.
2-11-16 Our Neanderthal genes linked to risk of depression and addiction
Our Neanderthal genes linked to risk of depression and addiction
Having sex with Neanderthals meant some of us still carry their DNA, and with it, a higher risk of depression and nicotine addiction. Ever since we learned, in 2010, that humans and Neanderthals once interbred one question stood out: what, if any, consequences have those Stone Age liaisons had on us? A new study now provides the clearest evidence yet that they did affect us, changing our risk to a range of health-related issues. Tony Capra at Vanderbilt University in Nashville, Tennessee, and his colleagues studied an anonymised database containing medical records and genetic data from more than 28,000 people of European descent. Europeans retain some Neanderthal DNA, though the amount and the exact parts they have vary between individuals. They used information from the Neanderthal genome to identify segments of Neanderthal DNA in each person’s genetic data. Then they explored whether particular chunks of Neanderthal DNA in their genomes were associated with a variety of specific medical conditions.
2-9-16 Bacteria 'see' like tiny eyeballs
Bacteria 'see' like tiny eyeballs
Biologists say they have solved the riddle of how a tiny bacterium senses light and moves towards it: the entire organism acts like an eyeball. In a single-celled pond slime, they observed how incoming rays are bent by the bug's spherical surface and focused in a spot on the far side of the cell. By shuffling along in the opposite direction to that bright spot, the microbe then moves towards the light. Despite being just three micrometres (0.003mm) in diameter, the bacteria in the study use the same physical principles as the eye of a camera or a human. (Webmaster's comment: So much for the "Intelligent Design" idea that the eye is too complex to have evolved. The basic structures and principles of an eye as part of a creature have probably been around for billions of years.)
2-9-16 Mutant sperm-factories spread in testes
Mutant sperm-factories spread in testes
Mutant sperm-factories spread in men's testicles as they age to increase the risk of children with genetic diseases, researchers have shown. Millions of spermatogonia produce a constant supply of sperm in the testes. But the University of Oxford study showed mutant spermatogonia gain a "tumour-like" competitive edge, leading to a greater proportion of sperm becoming defective. Experts said couples should consider having children earlier in life. A range of diseases including autism and schizophrenia are more likely with older dads due to mutations in their sperm.
2-8-16 Inside the cloning factory that creates 500 new animals a day
Inside the cloning factory that creates 500 new animals a day
A controversial Korean lab led by Woosuk Hwang is moving from cloning pets to endangered animals. For the past few years, the lab has worked on cloning domestic dogs. Now the researchers plan move on to saving their wild relatives. They want to rescue some of the world’s most endangered canids, including the Ethiopian wolf and the dhole, or Asiatic wild dog. But will cloning help or hurt these species? This has raised concerns among conservationists, not least because they fear cloning will be little more than a shiny distraction from wider efforts to preserve habitats and biodiversity.
2-8-16 Homebrew biology kit brings synthetic biology to the masses
Homebrew biology kit brings synthetic biology to the masses
A desktop bioreactor that lets you hack DNA to create glow-in-the-dark paint, and soon bread and beer, hits the market. Ever wanted to create your own organism? It’s now easier than ever. Just take a dash of E. coli, a pinch of jellyfish DNA, stir well and heat gently. As it bubbles away in a vial mounted on top of the stylish wooden box, the mixture slowly turns red. When done, this bioluminescent paint made by your customised bacteria will glow like a firefly. At an event for synthetic biology start-ups in San Francisco on 4 February, Amino Labs showed off the Amino One, a tabletop bioreactor aimed at the consumer market. The kit shrinks several lab components on to a device the size of a briefcase. Beginners will be able to modify and grow bacterial cells to create paint, medicinal compounds, scents and even foodstuffs such as yogurt, beer and bread. The Amino One comes with a couple of basic recipes that walk users through the steps needed to create their first custom bacteria. To make red bioluminescent paint, for example, you simply insert the kit’s K-12 strain of E. coli and jellyfish DNA into the bioreactor. The Amino One then raises the temperature inside the chamber, prompting the bacterial cells to open their membranes and allow the DNA in. (Webmaster's comment: Shades of the movie "Blade Runner." How will this play out over the next 100 years? Scary!)
2-5-16 Declaring genetic war on mosquitoes
Declaring genetic war on mosquitoes
“It’s time to kill all the mosquitoes,” said Daniel Engber. The Zika virus is now spreading around the world, apparently causing birth defects wherever mosquitoes carry it, and those same “flying hypodermic needles” are also injecting people with the viruses that cause chikungunya and dengue and the parasite that causes malaria. “Mosquito-borne diseases kill hundreds of thousands of people every year” and cause widespread human misery, especially among children and the poor. It’s time to step up the fight, with a weapon far more effective than mass spraying of cancer-causing pesticides: releasing genetically modified mosquitoes into the wild. Researchers have engineered a modified strain of Aedes aegypti—the mosquito carrying most of the diseases—that breeds with wild females, impregnating them with offspring that are sterile. In tests in Brazil, these genetically modified bloodsuckers reduced the mosquito population by 90 percent. Naturally, eco-activists are resisting using GMO techniques to wipe out the species, but most scientists say that eliminating mosquitoes would have little or no impact on the food chain or natural ecosystems. Mosquitoes are disgusting, parasitic critters that are at war with humanity. “It’s time to give them hell.”
2-5-16 Gut microbes 'help bears to hibernate'
Gut microbes 'help bears to hibernate'
Researchers have discovered seasonal changes in the gut microbes of brown bears, which apparently help the beasts cope with the demands of hibernation. Bears feast and gain weight in the warm months, ready for the big winter doze. In faecal samples from 16 wild bears, scientists found a bug population that was more suited to depositing fat in summer, and burning it in winter. And when transplanted into lab mice, the "summer" bacteria caused greater fat gain than the "winter" ones.
2-4-16 Mystery invaders conquered Europe at the end of last ice age
Mystery invaders conquered Europe at the end of last ice age
Ancient DNA suggests that 14,500 years ago populations that had thrived in Europe’s heartlands were replaced by mysterious new arrivals. Europe went through a major population upheaval about 14,500 years ago, at the end of the last ice age, according to DNA from the bones of hunter-gatherers. Ancient DNA studies published in the last five years have transformed what we know about the early peopling of Europe. The picture they paint is one in which successive waves of immigration wash over the continent, bringing in new people, new genes and new technologies. These studies helped confirm that Europe’s early hunter-gatherers – who arrived about 40,000 years ago – were largely replaced by farmers arriving from the Middle East about 8000 years ago. These farmers then saw an influx of pastoralists from the Eurasian steppe about 4500 years ago, meaning modern Europe was shaped by three major population turnover events.
2-4-16 Chins are a bit useless so why do we have them?
Chins are a bit useless so why do we have them?
There are plenty of theories to explain why we have chins, but none of them stands up to scrutiny. Will we ever solve the mystery? It becomes even stranger when you consider that among the all primates – including our extinct relatives – only we have chins. Nobody seems to know why – although over the last century several theories as to its purpose have been offered.
2-3-16 Speargun-toting superbugs end up shooting each other
Speargun-toting superbugs end up shooting each other
The curious speargun duels bacteria engage in seem to be a waste of time and resources– so why do they do it? Gun owners are more likely to get shot than people who don’t own weapons – and something similar seems to be true for bacteria. Some superbugs kill rivals with powerful poison-tipped spearguns. But in crowded conditions they often end up brawling with the nearest family member. No superbugs actually die in kin combat, because they are immune to their own spears. So the fights, which seem to continue indefinitely, appear to be futile and a waste of energy. Why they happen at all puzzled many of the bacteriologists at a Royal Society meeting in London last week.
2-2-16 Are humans driving evolution in animals?
Are humans driving evolution in animals?
Are humans inadvertently driving evolution in other species? Mounting evidence suggests activities such as commercial fishing, angling and hunting, along with the use of pesticides and antibiotics, are leading to dramatic evolutionary changes. Sitting down to a roast chicken dinner doesn't seem like an obvious opportunity to consider evolution. But it is. Think about it: those big tasty carrots, that plump, tender chicken and those handsome potatoes all differ markedly from their natural ancestors. A wild carrot is barely more than a slightly enlarged purple tap-root and red jungle fowl certainly don't have the extravagant cleavages found on modern broiler chickens. The intentional selection of the qualities we like (such as flavour and size) in domesticated livestock and cultivated crops has led to descendent animals and plants that differ genetically from their ancestors. This change in gene frequency is evolution, and in this case has come about by a process called artificial selection. Natural selection is basically the same process. The difference is that instead of humans selecting individuals to breed, natural selection pressures such as predation, or the reluctance of females to mate with lower quality males, cause some individuals in a population to prosper and produce offspring while others fare poorly, leaving fewer offspring. If the trait that caused the parents to prosper has a genetic basis, then the offspring will inherit that trait and likewise prosper, changing the frequency of genes in the population.
2-2-16 Asian stone tools hint humans left Africa earlier than thought
Asian stone tools hint humans left Africa earlier than thought
Cut marks on bones and simple stone tools found in the outer Himalayas have been dated to 2.6 million years ago, but not everyone is convinced. The first early humans to leave Africa did so half a million years earlier than we thought, according to an analysis of simple stone tools and three cow bones with cut marks found in Asia. But not everyone is convinced yet. A joint Indian-French team found the artefacts on the Siwalik hills about 300 kilometres north of New Delhi, India, where tectonic activity has exposed an outcrop of bedrock dating back at least 2.6 million years. The bones and tools were found lying on the surface, which made their dating tricky. But given that artefacts are rare in the younger rocks surrounding the outcrop, and the latest finds were preserved in the same way as those previously uncovered in the ancient bedrock, they probably eroded out of the bedrock on which they sit, the team says.The team’s examination of the cut marks on bones (shown above) suggests that they were made with a stone tool. “We are absolutely confident,” says Singh. “Hominins lived in sub-Himalayan floodplains 2.6 million years ago.”
2-1-16 Our body adapts to intense exercise to burn fewer calories
Our body adapts to intense exercise to burn fewer calories
People who do vigorous exercise are more efficient at using energy, reducing the calories burned for the rest of the day - which may be why weight loss plateaus. Sorry exercise addicts – all those intense workouts might not be helping you lose as much weight as you thought. People who are the most physically active seem to become more efficient at using energy, and so burn fewer calories when not exercising than the rest of us. As expected, those who were moderately active burned more energy per day than those who were couch potatoes. But this relationship then plateaued, with those who were most active using the same energy as those who were moderately active.
2-1-16 Scientists get 'gene editing' go-ahead
Scientists get 'gene editing' go-ahead
DUK scientists have been given the go-ahead by the fertility regulator to genetically modify human embryos. It is the first time a country has considered the DNA-altering technique in embryos and approved it. The research will take place at the Francis Crick Institute in London and aims to provide a deeper understanding of the earliest moments of human life. It will be illegal for the scientists to implant the modified embryos into a woman. But the field is attracting controversy over concerns it is opening the door to designer - or GM - babies. DNA is the blueprint of life - the instructions for building the human body. Gene editing allows the precise manipulation of DNA.
2-1-16 Scientists discover zebra stripes are not for camouflage
Scientists discover zebra stripes are not for camouflage
Remember hearing that zebra stripes are for camouflage? It never made any sense. How were those distinctive stripes somehow supposed to make zebras invisible in the savannah, where there's ankle-high grass, scores of hungry lions and not a lot of cover. Now, in a new study published in PLoS One, the scientists finally conclude these stripes serve a very different purpose. But since 1930, scientists have quietly peddled the theory — far out of reach of your elementary school text books — that zebra stripes may have evolved to ward off disease-carrying flies. Studies have shown that flies prefer to land on all black or all white surfaces, but that stripes freak them out. And it would make solid evolutionary sense for zebras to evolve to protect themselves from parasitic flies, because they often carry fatal diseases.
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