Discover Living World

Fire-chasing beetles sense infrared radiation from fires hundreds of kilometres away | Not Exactly Rocket Science

Sun, 27 May 2012 13:00:29 +0000

In the 1940s, visitors watching football games at Berkeley’s Californian Memorial Stadium would often be plagued by beetles. The insects swarmed their clothes and bit them on the necks and hands. The cause: cigarettes. The crowds smoked so heavily that a cloud of smoke hung over the stadium. And where there’s smoke, there’s fire. And where there’s fire, there are fire-chaser beetles.

While most animals flee from fires, fire-chaser beetles (Melanophila) head towards a blaze. They can only lay their eggs in freshly burnt trees, whose defences have been scorched away. Fire is such an essential part of the beetles’ life cycle that they’ll travel over 60 kilometres to find it. They’re not fussy about the source, either. Forest fires will obviously do, but so will industrial plants, kilns, burning oil barrels, vats of hot sugar syrup, and even cigarette-puffing sports fans.

The beetles find fire with a pair of pits below their middle pair of legs. Each is only as wide as a few human hairs, and consists of 70 dome-shaped sensors. They look a bit like insect eyes. In the 1960s, scientists showed that the sensors detect the infrared ...

Alvin, the Deep Sea Research Sub, Has Spread Invasive Species in the Ocean | 80beats

Fri, 25 May 2012 15:31:27 +0000

Alvin during a deep sea mission.

As humans venture out to new corners of the world, so do invasive species. This story of old: mice hid out on Viking boats, plant seeds followed scientists to Antarctica, and, now, limpets have hitched a ride on the deep sea submersible Alvin. This last finding, published in Conservation Biology, surprised scientists, who didn’t think that limpets could survive drastic pressure changes as Alvin surfaced between dives.

Since 1964, Alvin the little sub that could has made thousands of scientific dives—from surveying the Titanic to exploring hydrothermal vents. The sub and its sampling gear are cleaned between each dive, but this new limpet discovery suggests a mistake happened somewhere down the line.

Scientists on a dive mission in 2004 collected 38 limpets hundreds of miles from their known range and far from the hydrothermal vents where they usually live. A closer look at the preserved specimens confirmed the scientists’ fears. The morphology, DNA sequence, sex ratios, bacterial colonies, and isotopes of this population exactly matched those of a previous sample taken by Alvin in a different part of the Pacific.

For researchers, disturbing the very ecosystems they’re trying to study is bad for both science ...

The Razor Clam’s Digging Superpower is Quicksand | 80beats

Thu, 24 May 2012 18:57:13 +0000

The digging motions of a razor clam.

The soft, pale foot of a six-inch long razor clam burrows through sand at an impressive rate of four body lengths per minute (video). When scientists put muscles in the razor clam to the strength test though, they found that its foot was only 1/10 as strong as it would need to be to dig so fast. What gives? The sand, literally.

Instead of relying on brute force, the burrowing razor clam turns the sediment around itself into quicksand, according to a study published in the Journal of Experimental Biology. And as Hollywood has taught us well, it’s easy to sink in quicksand.* The razor clam pulls its shell up, creating a vacuum that sucks water into the space surrounding its body. Quicksand is just sand with enough water between all its particles so that it no longer holds any weight, making it easy for the razor clam to tunnel down. Although most (big) pools of quicksand are created by earthquakes or flowing water, the razor clam’s small scale strategy is quite effective. In fact, the little buggers are so fast that recreational clam digging actually takes some practice.

*The human body ...

How a Descendant of Dinosaurs Became a Ubiquitous Dinner Dish | 80beats

Thu, 24 May 2012 17:32:36 +0000

Gallus gallus, the undomesticated ancestor of modern chickens

Chickens, the surviving descendants of once-mighty therapod dinosaurs, have come to dominate American dinner tables, where its meat is consumed at a rate of 80 pounds per person per year. How the wild grub-eating Gallus Gallus was tamed and commodified into frozen breaded cutlets is actually quite an epic story, one that involves (possibly) saving Greek civilization from Persians, the rise and fall of the Roman Empire, and continues today with KFC’s remarkable invasion of China.

Jerry Adler and Andrew Lawler have written a cover story for Smithsonian magazine on the taming of the chicken that delivers these tidbits and gives plenty more food for thought. It was the Egyptians, for example, who first figured out how to artificially incubate eggs, so they could be hatched without the presence of hens—a method so important that their methods were kept secret for centuries:

This was no easy matter. Most chicken eggs will hatch in three weeks, but only if the temperature is kept constant at around 99 to 105 degrees Fahrenheit and the relative humidity stays close to 55 percent, increasing in the last few days of incubation. The eggs must also ...

Virtual resurrection shows that early four-legged animal couldn’t walk very well | Not Exactly Rocket Science

Wed, 23 May 2012 18:00:38 +0000

In a small office north of London, Stephanie Pierce from the Royal Veterinary College is watching a movement that hasn’t been seen for 360 million years. On her computer, she has resurrected the long-extinct Ichthyostega – one of the earliest four-legged animals to creep about on land. By recreating this iconic beast as a virtual skeleton, Pierce has shown that while it looked like a giant salamander, it couldn’t possibly have walked like one. It had some of the planet’s earliest bony legs, but they weren’t very good at taking steps.

Ichthyostega hails from the Devonian period, a time in Earth’s history when swimming transformed into walking. Fish invaded the land and evolved into the first tetrapods—four-limbed animals that include amphibians, reptiles, birds and mammals. Muscular fins used for steering and balance evolved into legs for walking.

Since its discovery over 50 years ago, Ichthyostega has been an icon of this pivotal transition. Some 300 specimens have been found but many are incomplete, flattened or distorted. Pierce’s new model provides the best look yet at the animal’s skeleton. “It makes Ichthyostega a bit more tangible,” she says. “It’s not ...

In The Beginning Was the Mudskipper? | The Loom

Wed, 23 May 2012 17:00:05 +0000

In 1893, the Norwegian zoologist Fridtjof Nansen set off to find the North Pole. He would not use pack dogs to cross the Arctic Ice. Instead, he locked his fate into the ice itself. He sailed his ship The Fram directly into the congealing autumn Arctic, until it became locked in the frozen sea. Nansen was convinced that the ice itself would drift up to the pole, taking him and his crew along for the ride.

For two and a half years they drifted with the pack. It gradually became clear to Nansen that The Fram had stopped moving north and was now traveling east instead, back towards Europe. He leaped out of the ship and tried to sled up to the pole, only to discover that the ice he was now traveling on was moving south. Only four degrees away from true north, he decided to retreat. He bolted back for Franz Josef Land.

The Fram meanwhile continued to drift east. After several months, it broke free of the ice, and the crew sailed the ship south to the island of Spitzbergen. There on the bare flats they saw a giant ...

New sense organ helps giant whales to coordinate the world’s biggest mouthfuls | Not Exactly Rocket Science

Wed, 23 May 2012 17:00:03 +0000

The world’s largest animals have been hiding something. The bodies of the giant rorqual whales—including the blue, fin and humpback—have been regularly displayed in museums, filmed by documentary makers, and harpooned by hunters. Despite this attention, no one noticed the volleyball-sized sense organ at the tips of their lower jaws. Nicholas Pyenson from the Smithsonian Institution is the first, and he thinks that the whales use this structure to coordinate the planet’s biggest mouthfuls.

The rorquals sieve tiny prey from the water with a unique hunting technique called lunge feeding. They surge forwards, open their mouths and swallow everything in front of them. This seemingly simple tactic is one of the most extreme in the animal kingdom. In one move, a lunging fin whale can engulf a volume of water that’s bigger than its own body. Its bigger cousin – the blue whale – can swallow half a million calories in one gulp.

Here’s what happens in slow-motion prose. A hunting rorqual detects the movements of their prey with pressure-sensitive whiskers on the underside. It accelerates to high speed and opens its mouth to almost a right angle. The ...

Kiddie Pool-Sized Shell of Extinct Turtle Found in Colombian Mine | Discoblog

Tue, 22 May 2012 20:05:48 +0000

Don’t mess with this.

Folks, those turtle-shaped sandboxes are not just a consumerist fantasy: Carbonemys cofrinii is an extinct turtle with a 10-inch skull and, more impressively, a shell that rounds out to five feet, seven inches in length. That really is big enough to dig around in. That’s also the same height as the grad student who found the 60-million-year-old fossil in a Colombian mine.

The turtle was so big that it probably drove off other turtle competitors and dominated the lake by itself, scientists say. They think that C. cofrinni preyed on mollusks and small reptiles, like the one depicted in this artist’s interpretation. If we’re going to be spending time in the belly of a turtle, though, we’d personally prefer it to be full of sand and toys rather than chewed up food.

[via Wired]

Image via North Carolina State University, credit: Liz Bradford

Synthetic Biologists Turn DNA Into Rewritable, Digital Data Storage | 80beats

Tue, 22 May 2012 17:25:17 +0000

DNA is a great way to store information—just ask your cells. Its molecules are stable, and billions of base pairs coil neatly into a few microns in a cell nucleus. While it’s easy for a cell to read information from DNA, a cell can’t rewrite new data into its DNA sequence.

But now synthetic biologists at Stanford have managed to pull off that very trick. To do so, they had to abandon the genetic code of ATCG and get a DNA sequence to act like bits—pieces of binary information—in a computer. The memory system uses two enzymes that can cut out and reintegrate a sequence of DNA in a live cell. Crucially, the attachment sites are designed so that the DNA sequence can be flipped every time it is put back in. The sequence oriented one way would represent 1, and its inversion is 0.

This may sound unnecessarily convoluted and maybe even a little inefficient—this DNA “bit” took three years to engineer—but synthetic biologists have something bigger brewing on their hands. By working out the pieces of a biological circuit, they hope to get cells to perform computations. A DNA bit, for example, can be used as a counter for ...

Can Stuffing Germs up Ferrets Unleash a Human Pandemic? | DISCOVER

Fri, 18 May 2012 21:15:00 +0000

The Claim: A lab-concocted strain of ferret flu could become a doomsday weapon or bioterrorist threat.

The Contrarian: Wendy Orent, author of Plague, says the much-hyped fears are unfounded: The new strain presents no danger to humans but reveals a great deal about the transmission of flu.

Ferrets with the flu sneeze and cough like humans.

iStockphoto

Deadly H5N1 avian flu, long entrenched in Asian poultry, has terrified public health experts ever since it killed a Hong Kong boy in 1997. The disease has caused about 340 human deaths in all, raising concerns it might someday unleash a true pandemic. But that has never occurred. The virus is adept at killing chickens and can infect mammals, but it has never spread among them. Until recently no one knew why...

Up Close and Personal With the Mysterious “Placental Jellyfish” | 80beats

Fri, 18 May 2012 17:47:57 +0000

Last week, a video of this mysterious blob floating 5000 feet under the sea was all over the Internet. Was it a whale placenta? A jellyfish? After some collective ooing and aahing, folks on the interwebs put their thinking hats on. Craig McClain at Deep Sea News dug through the literature and found a 1988 paper describing just such a jellyfish, calling it Deepstaria reticulum.

Now the Monterey Bay Aquarium Research Institute has posted a stunning video of Deepstaria jellyfish. Watch it to learn more about Deepstaria—and to look at pretty images. Win win for a Friday afternoon.

[via Deep Sea News]

20 Things You Didn't Know About... Allergies | DISCOVER

Fri, 18 May 2012 14:15:00 +0000

1. Our immune system may be like those small bands of Japanese “holdout” soldiers after World War II. Not knowing that the war was over, they hid for years, launching guerrilla attacks on peaceful  villages.

2. With our living environment well scrubbed of germs, our body’s immune “soldiers” mistakenly fire on innocent peanuts and cat dander.

5. Most food allergies result from an immune response to a protein. In 2004 a team at Trinity College Dublin tried to counter that reaction by injecting mice with parasites, giving the animals’ immune systems the sort of threat they evolved to fight, thus distracting them from the food proteins.

6. The experiment worked.

7. Excited by such findings, in 2007 British-born entrepreneur Jasper Lawrence flew to Cameroon and walked barefoot near some latrines. His aim was to acquire hookworms, which he hoped would defeat his asthma and seasonal allergies.

8. That worked too.

9. Lawrence has since started a business shipping the parasites worldwide (but not here, where the FDA prohibits it). For $3,000, customers receive up to 35 hookworm larvae...

Deep-sea bacteria redefine life in the slow lane | Not Exactly Rocket Science

Thu, 17 May 2012 18:05:45 +0000

Your laziest days are positively frenetic compared to the lifestyle of some deep-sea bacteria, buried in the sediments of the Pacific Ocean. These microbes are pushing a slow-going lifestyle to an extreme. They subsist on vanishingly low levels of oxygen, in sediments that have not received any new food sources since the time of the dinosaurs. And yes, they survive.

Not only that, but these microbes could make up 90 per cent of those on the planet. “We’re looking at the most common forms of life on this planet, and we know almost nothing about them,” said Hans Røy, who has been studying them for many years. Now, Røy has finally measured just how slow their metabolism really is.

I’ve written about this discovery for The Scientist, so head over there for the full story.

Image by Shelly Carpenter, NOAA Ocean Explorer

Arrested Development Pays Off for Male Orangutans: Meek Ones Often Get the Girls | 80beats

Thu, 17 May 2012 16:00:32 +0000

A sexually mature male with cheek flanges, throat pouch, and very long fur.

Why would a sexually mature male orangutan want to look too young to father children? Just ask male dung beetles or goby fish. All these species have two types of males: big, aggressive ones that elaborately woo females and smaller sneaker males who, well, sneak behind the backs of the bigger ones. Both can end up successful fathers.

Male orangutans become sexually mature around age 10, but some will stay in arrested development for up to 20 years, even after fathering children of their own. These immature-looking males don’t have the broad cheek flanges, throat pouches, and long orange hair we normally associate with male orangutans. They also don’t produce the long calls that mature-looking males use to attract mates. Even with none of these secondary sex characteristics, male orangutans can get mates and have children. A previous study that tracked an orangutan population in Sumatra for 27 years found that 6 of 11 new babies were fathered by the immature-looking males.

A new paper in the American Journal of Physical Anthropology models how arrested development works in a population. The ...

As oxygen filled the world, life’s universal clock began to tick | Not Exactly Rocket Science

Wed, 16 May 2012 17:00:41 +0000

The Earth’s earliest days were largely free of oxygen. Then, around 2.5 billion years ago, primitive bacteria started to flood the atmosphere with this vital gas. They produced it in the process of harnessing the sun’s energy to make their own nutrients, just as plants do today. The building oxygen levels reddened the planet, as black iron minerals oxidised into rusty hues. They also killed off most of the world’s microbes, which were unable to cope with this new destructive gas. And in the survivors of this planetary upheaval, life’s first clock began to tick and tock.

Today, all life on Earth runs on internal clocks. These ‘circadian rhythms’ are the reason we feel sleepy at night, and why our hormones, temperature and hunger levels rise and fall with a 24-hour cycle. They’re molecular metronomes that keep the events inside our bodies ticking in time with the world around us.

Until now, it seemed that the major branches of the tree of life each had their own timekeeping systems, evolved independently of the others. But Akhilesh Reddy and John O’Neill from the University of Cambridge have disproved that ...

Trapped in Amber, the Oldest Evidence of Pollination | 80beats

Wed, 16 May 2012 14:54:49 +0000

Peering inside an ancient piece of amber, scientists have uncovered the oldest direct evidence of pollination: insects covered in pollen grains, likely from a gingko tree, from between 105 and 110 million years ago. These insects—a new genus of thrips, insects that still scuttle around today—had likely gathered pollen for food, trailing it from plant to plant along the way. To get an even closer look at the specimens (without cracking open the amber), the researchers took the lump to the European Synchrotron Radiation Facility. There, they used synchrotron X-ray tomography to generate a detailed 3-D image of the bugs, revealing tiny, specialized hairs they used to collect pollen grains (which are shown here in yellow).

Flowering plants first evolved about 130 million years ago, making them relative evolutionary newcomers; dinosaurs had already been around for 100 million years by then. Since early on, these plants have been aided in reproduction by insects that spread their pollen from one flower to the next, and in turn helped the insects by providing sustenance. “The co-evolution of flowering plants and insects, thanks to pollination, is a great evolutionary success story,” ...

Sleeper viruses explain why HIV evolves more slowly between people than within them | Not Exactly Rocket Science

Tue, 15 May 2012 23:00:50 +0000

HIV – the virus behind AIDS – is the most diverse of all viruses. Once it infects someone new, it mutates so rapidly that it can spawn a million genetically different strains in just a few months. This evolutionary onslaught overwhelms the host’s immune system, and creates big problems for any scientist trying to create a cure or a vaccine. By evolving so quickly, HIV turns itself into a million moving targets.

But when HIV jumps from one individual to another, something odd happens. The virus still mutates at a breakneck speed, but it does so 2 to 6 times more slowly than within any single person. Unexpectedly, the virus seems to evolve faster in a single host, than in a population.

There are three possible explanations for this puzzling trend, but Katrina Lythgoe and Christophe Fraser from Imperial College London think that only one is correct. They think that the ancestral strain – the one that kicked off someone’s infection – is more likely to spread to other people than its millions of descendants.

The progeny of the ancestral virus quickly evolve to avoid their host’s immune system and ...

Come For the Beautiful “Glass Gem” Corn; Stay for a Dose of Genetics | 80beats

Tue, 15 May 2012 17:57:51 +0000

No, this isn’t Photoshop or a gemstone-studded trinket—just an ear of corn. Seedsman Greg Schoen of the Seeds Trust got this “Glass Gems” corn from his “corn-teacher,” a part-Cherokee man in his 80s. He planted the seeds, had a gorgeous harvest last fall, and posted the posts on Seeds Trust’s Facebook page in October. Then last week, the photos of the gem-like corn got picked up on the internet and went viral. Good luck trying to get your hands on any seeds now…

But kernel color is a fascinating—dare we say, colorful—topic in the annals of genetics research. For one, why are there so many vibrant colors in a single ear of corn? You don’t usually see flowers of different colors on a single tree. Each kernel is actually a different corn plant (or the seed of one) with a unique mix of genes inherited from its parents. That’s why counting up kernels of different colors in the more familiar purple and yellow corn cobs is a common way of teaching how pigment genes are inherited in Mendelian genetics.

Kernel color has also been used to unravel an ...

Dogs Catch Yawns From Their Owners. Does That Mean They Empathize with Us? | 80beats

Tue, 15 May 2012 17:45:45 +0000

One sleepy person can start a bout of contagious yawning that quickly spreads through a room. But a new study suggests the effect may not be limited to the room’s human inhabitants: Dogs can “catch” yawns from people, the study found—especially their owners, hinting that pooches may empathize with familiar people.

When listening to recordings of people yawning, 12 of the 29 dogs in the study yawned themselves. It made a big difference, however, whom they heard: The dogs yawned more than four times as much when they heard their owner yawn as when they heard as a stranger.

Earlier work has suggested a link between contagious yawning and empathy. Humans and chimps both yawn more when friends and acquaintances yawn than when strangers yawn, and people who don’t have much insight into what others are feeling—such as very young children and people with autism—don’t seem to catch contagious yawns. This is some of the strongest evident yet that dogs—humans’ constant companions for 15,000 years—may be able to empathize with us. But a yawn alone can’t tell us what’s going on in a dog’s brain, or its heart of hearts. A similar ...

The Brain: Hidden Epidemic:  Tapeworms Living Inside People's Brains | DISCOVER

Tue, 15 May 2012 15:00:00 +0000

Theodore Nash sees only a few dozen patients a year in his clinic at the National Institutes of Health in Bethesda, Maryland. That’s pretty small as medical practices go, but what his patients lack in number they make up for in the intensity of their symptoms. Some fall into comas. Some are paralyzed down one side of their body. Others can’t walk a straight line. Still others come to Nash partially blind, or with so much fluid in their brain that they need shunts implanted to relieve the pressure. Some lose the ability to speak; many fall into violent seizures.

Underneath this panoply of symptoms is the same cause, captured in the MRI scans that Nash takes of his patients’ brains. Each brain contains one or more whitish blobs. You might guess that these are tumors. But Nash knows the blobs are not made of the patient’s own cells. They are tapeworms. Aliens.

A blob in the brain is not the image most people have when someone mentions tapeworms. These parasitic worms are best known in their adult stage, when they live in people’s intestines and their ribbon-shaped bodies can grow as long as 21 feet. But that’s just one stage in the animal’s life cycle. Before they become adults, tapeworms spend time as larvae in large cysts. And those cysts can end up in people’s brains, causing a disease known as neurocysticercosis.

“Nobody knows exactly how many people there are with it in the United States,” says Nash, who is the chief of the Gastrointestinal Parasites Section at NIH...

Image: A human brain overrun with cysts from Taenia solium, a tapeworm that normally inhabits the muscles of pigs. Courtesy of Theodore E. Nash , M.D.

Jurassic bends – the rise of fast predators bubbled the blood of prehistoric reptiles | Not Exactly Rocket Science

Tue, 15 May 2012 13:00:18 +0000

Experienced divers know that rising too quickly can be a fatal mistake. The changing pressure yanks previously dissolved gases out of one’s blood and forms tiny bubbles, like the fizz in a newly opened can of soda. Depending on where they emerge, the bubbles can cause everything from a rash (the skin) to seizures (the brain). To avoid this condition, known as decompression sickness or “the bends”, divers rise slowly.

Then again, if you’re being chased by a gigantic prehistoric shark, you may have no choice.

The bends were first described as a human ailment in 1841, but it has been afflicting diving animals for far longer. For decades, Bruce Rothschild has been studying bone diseases in prehistoric animals. He has found traces of the bends in the fossils of many ancient reptiles, which ruled the oceans while the dinosaurs walked the land. When the bubbles formed in bones, they blocked the local blood vessels, killed the surrounding tissue, and eventually caused the bone to collapse. The humerus – the bone of the upper arm – was particularly vulnerable.

Rothschild has found such signs among prehistoric turtles, dolphin-like ichthyosaurs, crocodile-like ...

Why Preserved Food is So Bad: “Retort Flavor” | 80beats

Mon, 14 May 2012 12:29:41 +0000

Autoclaves—would you cook a turkey in this?

At Popular Science is a profile of food scientists given an impossible task: make year-old mashed potatoes taste good. Food that lasts a year on the shelf needs to be sterilized, and that is a battle against extremophiles. Our most effective weapon is a very blunt one—heat. 252 degrees Fahrenheit to be exact.

Writer Paul Adams tours a food science lab and gets a taste of “retort flavor” in his sterilized mashed potatoes. The unappetizing term refers to the retort, a machine that obliterates microbes and flavor in one fell (and very hot) swoop:

The potatoes look right, once we’ve fluffed them up a bit, but the wholesome earthy taste and smell of fresh potatoes is almost gone from the dish. In its place there’s a tired, wet-paper flavor with notes of old steam pipe. This side effect of confined high-heat cooking is known in the trade as “retort flavor.” Stuckey’s theory is that it’s just underlying parts of the flavor coming through. Before food is retorted, she says, the dank base notes present in it are masked in part “by the beautiful aromatic volatile notes that we ...

Cancer evolution at TEDMED | The Loom

Fri, 11 May 2012 13:00:44 +0000

Earlier this year, TEDMED took place in Washington DC, showcasing people doing innovative research in medicine. This year’s talks are now being loaded online, and today I was happy to see that cancer and evolution got their due. Franziska Michor of Harvard explained how the threat of cancer is a legacy of our evolution into multicellular animals, and how every case of cancer is a miniature unfolding of evolution within our own bodies. What makes Michor’s work particular exciting is that she is bringing the mathematical precision of population genetics and other aspects of evolution to the treatment of cancer.

I wrote about some of Michor’s work in my 2007 Scientific American article, “Evolved for Cancer?” (carlzimmer.com, sciam.com) I’ve also explored cancer evolution here on the Loom: “Inside Darwin’s Tumor” and “The Mere Existence of Whales.” And you can find lots of Michor’s papers as free pdf’s on her publication page.

You ask for signed bookplates, you get signed bookplates | The Loom

Thu, 10 May 2012 23:27:45 +0000

At some of my recent talks, I’ve been running into people who’ve been annoyed that they forgot to bring a book of mine to get signed. You really couldn’t think of a better way to cheer up a writer, and so I feel the need to reciprocate.

So if you’ve gotten a book of mine and want to get it signed, I’ve printed up some bookplates that I can autograph and send to you.

Just to ensure I’m not signing bookplates for alien robots who will take these bookplates to their home planet to…do whatever evil thing alien robots do with bookplates from science writers…please follow these steps:

1. Take your picture with the book.

2. Email it to me, with your mailing address and any special signing request. As in, “To Ken Ham, so that someday he may appreciate transitional fossils….”

Optional step 3. For those on Twitter: instead of emailing me your photo, you can upload it to Twitter (mentioning my Twitter name @carlzimmer). Be sure to email me your address, too, so that I know where to send the bookplate.

So far, I’ve got three bookplates–one for Parasite Rex, one for Science Ink (in matching Goth type), and one for ...

The Hagfish's Special Trick for Warding Off Predators: Thick, Sticky Mucus | DISCOVER

Thu, 10 May 2012 21:30:00 +0000

Sharks are superb predators, but even they are no match for the animal kingdom’s most disgusting yet effective defense: the gag-inducing slime of the hagfish.

Hagfish are elusive deep-sea creatures that have mucus-secreting glands positioned all over their long, writhing bodies. Last fall marine ecologist Vincent Zintzen of the Museum of New Zealand Te Papa Tongarewa published a study describing the first-ever observations of hagfish exploiting those glands to ward off predators. He analyzed 500 hours of video from cameras placed in deep waters off the New Zealand coast and found 14 encounters between hagfish and fierce hunters like the seal shark and the conger eel. In every case the hagfish emerged unharmed while the predators fled the scene, gagging on the irritating slime that rapidly expands in seawater and clogs the gills. “It was striking how effective this defense mechanism was,” Zintzen says.

The videos also reveal that at least one species of hagfish can go on the attack...

Millions of Taxpayer Dollars are Used to Secretly Massacre Wildlife, Family Pets, Threatened Species | 80beats

Thu, 10 May 2012 17:10:11 +0000

Nearly a million coyotes have been killed by Wildlife Services since 2000.

In the western US, conflict between ranchers and wild animals who might harm their stock is an old, old story. But in 1915, the federal government started helping ranchers and farmers out by killing animals suspected of attacking livestock, eventually forming an agency known as Animal Damage Control. Today, though, the agency has morphed into something that appalled many of the readers who learned of its activities last week in the Sacramento Bee.

When Wildlife Services, as the group is now called, finds a bald eagle, a family’s beloved husky, or a young badger in a trap laid for coyotes or prairie dogs, its back broken or leg snapped, it is shot and its body buried. Its death at the hands of federal employees is rarely, if ever, reported as required. This happens thousands of times a year, on top of all the killings of wildlife that are the agency’s intended targets.

The Bee’s evidence against Wildlife Services’s claims of killing only when necessary, assembled in three investigative articles, is damning. The series is worth reading for yourself, along with the follow-up articles ...

Meat-eating plant digests insects using ants | Not Exactly Rocket Science

Wed, 09 May 2012 21:00:20 +0000

Many insects eat plants, but some plants can turn the tables on their would-be diners. The pitcher plants are among several groups that can capture insects and digest their flesh. And one species – the fanged pitcher plant – goes even further. It digests insects with insects.

There are around 120 species of pitcher plants and all of them have large leaves that fold to produce fluid-filled traps. The rims of the pitchers are usually extremely slippery, and insects that wander by lose their foothold and fall into the pool of fluid within. There, they drown and are digested by the plant.

The fanged pitcher is unusual. Its rim lacks the usual waxy layer and is less slippery than those of its cousins. And it’s the only species that recruits ants. The base of each pitcher contains a swollen tendril that houses ants of the species Camponotus shcmitzi. These insects are permanent residents; they’ve never been seen in any other plant.

People have assumed that this is yet another case of a plant-ant alliance. Aside from accommodation, the ants also get food from the nectar that exudes ...

Three nations divided by common gut bacteria | Not Exactly Rocket Science

Wed, 09 May 2012 17:00:52 +0000

A child from the village of Chamba in rural Malawi has very little in common with one living in the city of Philadelphia in the USA. They eat different food, speak different languages, and enjoy different lifestyles. But they are both united by the fact that they are vessels for teeming hordes of bacteria.

These children, like all of us, are home to trillions of bacteria and other microbes. These passengers outnumber our own cells by ten to one, and their genes outnumber ours by a hundred to one. Collectively, they’re known as the microbiome, and they are as much a part of us as any one of our own organs. They break down our food, safeguard our health, and affect our minds. And they have become intensely fashionable.

Microbiome research is booming, fuelled by the realisation that these microbes might provide a deeper understanding of our bodies, and new ways of diagnosing or treating diseases. But, with some exceptions, most microbiome studies have focused on wealthy populations from Europe, North America and Japan. There’s a risk that the bacteria of people from the developing ...

Insects that skate on the ocean benefit from plastic junk | Not Exactly Rocket Science

Tue, 08 May 2012 23:00:45 +0000

Imagine a world of two dimensions, a world with no up or down… just across. No climbing, falling, jumping, or ducking… just shimmying and sidling. Welcome to the world of the sea skater.

Sea skaters, or ocean striders, are small bugs. They’re relatives of the pond skaters or water striders that zip spread-eagled across the surface of ponds and lakes. Except they skate over the open ocean, eating plankton at the surface. “They skate through storms and wind and waves,” says Miriam Goldstein from the University of California San Diego and the Deep Sea News blog. “They even have a little ‘life jacket’ – the hairs on their body trap air so if they get sunk by a wave, they pop back up. They’re amazing!”

There are only five species of sea skaters, all belonging to the Halobates group. Of all the millions of insect species, these five are the only ones to live out at sea. Now, Goldstein has discovered that one sea skater Halobates sericeus actually benefits from what most people would regard as an ecological disaster – the circling mass of plastic and debris known as the ...

Rare Footage of Endangered Gorillas Includes Chest-Pounding Silverback | 80beats

Tue, 08 May 2012 21:53:01 +0000

The Cross River gorillas are an elusive bunch: there are fewer 250 individuals left of this western gorilla subspecies, and, understandably, they are afraid of humans. A few hours ago, though, the Wildlife Conservation Society announced that they’d managed to capture a tape of 8 gorillas—about 3% of the remaining population—in their native Cameroonian habitat, by using a motion-activated camera.

It’s a fascinating glimpse into the behavior of an animal that, given current trends, more than likely won’t exist in the near future. Lumbering on their knuckles through the crackling leaves, the gorillas occasionally plunk themselves down under a tree before continuing on their journey. About half-way through the edited clip, a large male gorilla charges past the camera, striking his chest with cupped hands, a motion that produces a high, distinctive, almost yodeling sound, and as he falls back on all fours, you can see the silver hair on his back. Shortly afterward, a gorilla missing its left hand moves across the scene; WCS thinks the hand could have been lost to a poacher’s snare.

It seems, though, that the ululating sound threw a few people off. CBS News’ coverage is studded with some choice work-arounds demonstrating that they’re not really sure ...

Do Unhatched Chicks Sleep and Wake In Their Eggs? | 80beats

Tue, 08 May 2012 14:07:24 +0000

You go to sleep at night, you wake up in the morning—the definition of sleep doesn’t seem so complicated. But start asking questions and things start getting thorny: Are dolphins that never stop swimming sleeping? Are migrating birds that “shut down” half their brains sleeping? Is someone under general anesthesia sleeping? And what about babies in the womb?

Unborn human babies in the womb are pretty difficult to monitor 24/7, so the researchers interested in that last question got ahold of unhatched chicken eggs. In a new Current Biology paper, they report that chicks show higher-brain activity patterns similar to sleep, and the cries of a hen could “wake up” the chick even when other loud but not chicken-salient sounds could not. These higher-brain activity patterns only appear in the last stage of incubation, presumably after their brains become well developed.

To monitor brain activity in the chicks, the scientists carefully made a small hole in the top of the egg and injected radioactive sugars onto the egg’s inner membrane. The developing embryo absorbed these sugars, which the team could then track with a PET scan. Active neurons need energy, which they get from sugar, so ...

How frogs climbed up into the Lost World: My story in tomorrow’s New York Times | The Loom

Tue, 08 May 2012 00:36:52 +0000

The tepuis of northern South America–tabletop mountains ringed by sheer cliffs rising up thousands of feet–inspired Sir Arthur Conan Doyle’s novel The Lost World. Doyle envisioned dinosaurs and other primordial creatures surviving on these remote islands in the sky.

It turns out that the tepuis are indeed ancient vestiges. The surrounding land eroded away 70 million years ago. Biologists have long been fascinated by the plants and animals that live on top of them today. In many cases, the species on a tepui are found nowhere else on Earth. Many have argued for the wonderfully-named “Lost World Hypothesis”–the unique species of the tepuis been stranded up there for 70 million years.

In tomorrow’s New York Times, I report on a team of scientists who tested that hypothesis by looking at the DNA of frogs that live on tepuis. And for them, at least, the hypothesis fails. Somehow, those tiny frogs managed to scale walls that strike fear in even the toughest rock climbers. For the full details, check out the story.

Image by Xyrenita on Flickr/via Creative Commons

Zombie Ant Parasite Has Its Own Parasite—a Fungus That Attacks Fungi | 80beats

Mon, 07 May 2012 19:19:15 +0000

Fruit body of a parasitic fungus, growing out of a dead ant.

The tale of the ant and the mind-controlling fungus Ophiocordyceps is straight out of a horror story.

An unlucky ant inhales a spore, the fungus begins to eat the ant from inside, and, in a particularly sinister twist, Ophiocordyceps hijacks the ant’s brain. The “zombie” ant is forced to leave its nest to climb up onto a tree, clamping its jaws into a leaf vein with abnormal force. A stalk sprouts from the now dead ant’s head. This stalk is fruiting body of the fungus, which will produce new spores that rain down onto the unlucky ants below.

Ophiocordyceps seems like a lean mean killing machine in that scenario, but the fungus itself is vulnerable—to another fungus it turns out. A new paper published in PloS ONE models the disease dynamics of Ophiocordyceps with respect to ants and a hyperparasitic fungi, which is the name for parasite whose host is also a parasite. Unfortunately, this hyperparasite is not of much help for the ant, as it only infects the Ophiocordyceps after the ant has died.

The researchers collected 432 fungus-infected ants from “graveyards” ...

In Memory of Lucy #scienceink | The Loom

Sun, 06 May 2012 15:13:11 +0000

Victoria McGowan writes,

Please find attached a photo of my Australopithecus tattoo. I’m a medical anthropologist researching the historical relationship between school meals and obesity in children as part of my PhD at Durham University. Obviously this has very little to do with Australopithecus but my interest in “Lucy” began when I started my UG degree in Anthropology here at Durham. One of my first lectures was on our Biological and Social Origins and we learnt about our evolutionary heritage. Lucy caught my eye because she was one of the most complete finds of this species at that time. Also as it was thought that she was more closely related to Homo genus than any other Australopithecus at that time.

I found it fascinating that from her remains we could postulate that she was bipedal and from her pelvis we could deduce that she would have gave birth to a larger brained infant than previous species. We can further postulate that her infant care practices would be more similar to our own, larger brained infant would have to complete their growth outside the womb and would require ...

The Mystery of the Melanesian Blondes | 80beats

Fri, 04 May 2012 20:28:17 +0000

A blond boy from the island of Vanatu

In many places, blond hair usually goes with white skin and European ancestry. But in the islands of Melanesia and among the Aborigines of Australia, blond hair crops up on dark-skinned people with no known European heritage. Scientists have long wondered, is it because they have some (very, very) long-lost European ancestors? Or did blond hair arise from a genetic mutation in the population there?

A paper published in Science this week lays that question to rest. The researchers found that blond Solomon Islanders in Melanesia have a single amino acid difference in the tyrosinase-related protein 1 (TYRP1) gene, which codes for an enzyme involved in the production of the pigment melanin. Other mutations in TYRP1 can give people albinism; this one gives them light-colored hair. The mutation is recessive, so only people who have two mutant copies of the TYRP1 gene are blond.

This mutation is not responsible for European blondness, which hammers home the fact that pale hair didn’t arrive on a boat with early European explorers—it’s definitely native to the islands.

For the full story and lots of tasty genetics, head over to Discover’s Gene ...

A duplicated gene shaped human brain evolution… and why the genome project missed it | Not Exactly Rocket Science

Fri, 04 May 2012 13:00:52 +0000

The Human Genome Project was officially completed in 2003, but our version of the genome is far from truly complete. Scientists are still finishing the last parts, correcting errors in the official sequence, and discovering new genes. These new genes did not go unnoticed because they are useless or insignificant. Some of them may be key players in our evolutionary story.

Two groups led by Evan Eichler and Franck Polleux have found that humans, alone among all animals, have three extra copies of a gene called SRGAP2, which is involved in brain development. The second of these copies, SRGAP2C, is particularly interesting because it affects the development of neurons, and produces features that are distinctively human. It also emerged between 2 and 3 million years ago, during the time when our brains became much bigger.

Genes are often duplicated by mistake when DNA is copied or shuffled around. These duplications provide raw fuel for fast evolution. Suddenly, genes get back-up copies. Either the original or the duplicate can mutate with impunity and take on new roles. But duplications ...

Case closed: blonde Melanesians understood | Gene Expression

Fri, 04 May 2012 06:21:26 +0000

As a small child perusing old physical anthropology books I would occasionally stumble upon images of people of Oceanian stock with light hair color. I would wonder: is this a biological or cultural feature? In other words, were people bleaching their hair? If it was biological, was it heritable, or was it simply malnutrition? Another aspect of the phenotype was also straightforward: it did not seem that light hair color resulted in any concomitant lightening of the skin. Granting that this was a heritable biological trait, the questions then were simple: was this trait an independent occurrence of de-pigmentation in Oceania, or was it due to introgression of European alleles?

First, one must note that this is not an isolated feature in Oceania. Rather, blondism crops up in the Solomon Islands, in New Guinea, as well as among some Australian desert groups. This in itself should make us skeptical of the model of European admixture. Additionally, blue eyes, which exhibits a higher frequency in Europeans than blonde hair, is not similarly common in these populations. But all this speculation is now a historical curiosity. The results are widely known from conference ...

Cockroaches Get Lonely, Kind of (But a Little Feather-Poking Can Help) | 80beats

Thu, 03 May 2012 20:07:40 +0000

When people think of cockroaches, some may think of the much-smarter-than-a-bug Gregor Samsa, but it takes a special kind of person—a social biologist, really—to think of them as “gregarious.” Yes, these unloved (by humans), trash-eating creatures have social lives too. A recent review in the journal Insectes Sociaux highlights the social behavior of two so-called gregarious cockroach species: Blattella germanica and Periplaneta americana. Although not as sophisticated as eusocial insects like ants or bees, these cockroaches can communicate, recognize kin, and even get “lonely” in isolation. Now we’re getting Kafka-esque.

To talk to and recognize one another, cockroaches use hydrocarbons, molecules that are made of only hydrogen and carbon atoms. These chemical markings help them identify group shelter spots, where they hang out together during the day between nightly foraging runs. (When they are out looking for new shelter or food, they tend to follow the crowd too.) The hydrocarbon signature is unique to each cockroach. Siblings can recognize each other and avoid incest, which is not so great for genetic diversity.

When forced into isolation by lab researchers, these gregarious cockroaches get “isolation syndrome,” taking longer to molt and reach sexual maturity. Isolated cockroaches also have problems ...

Male water striders evolved antennae to grab females by the eyes | Not Exactly Rocket Science

Thu, 03 May 2012 18:00:26 +0000

The worst sex you have ever had pales in comparison to what female water striders have to put up with. Put it this way: you have never been held down by your eyes.

As the female skates over the surface of ponds and lakes, males will try to force themselves upon her. She resists by struggling vigorously. But in some species, males can avoid being thrown off with antennae that have evolved into antler-shaped restraints. They bend in on themselves and are loaded with an array of prongs and spikes that perfectly fit to the shape of a female’s head.

Locke Rowe from the University of Toronto has been studying water striders for almost 20 years. In many species, males have evolved structures that give them an edge in their indelicate liaisons with females. “But the traits I studied before were rather simple – a spine here or there,” says Rowe. The subject of his latest study, a species called Rheumatobates rileyi – is… well, the opposite of simple.

The females have normal antennae. The males however, have “spectacularly modified grasping devices”, says Rowe. “They’re large, muscular, and fitted with spines and ...

Mutant flu paper is finally published, reveals pandemic potential of wild viruses | Not Exactly Rocket Science

Wed, 02 May 2012 17:00:59 +0000

It’s finally out. After months of will-they-won’t they and should-they-shouldn’t-they deliberations, Nature has finally published a paper about a mutant strain of bird flu that can spread between mammals.

The strain was produced by Yoshihiro Kawaoka from the University of Wisconsin-Madison, who was trying to understand whether wild bird flu viruses have the potential to start a pandemic. These viruses can occasionally infect humans, but so far, they’ve been contained by their inability to efficiently jump from human to human. Kawaoka’s work makes it clear that they can evolve that ability.

Kawaoka’s study, along with a similar one from Ron Fouchier, has been the subject of intense debate for the last several months (catch up on the backstory here). What are the benefits of the research, and do they outweigh the risks? Now that the paper is finally out, we can start to answer those questions.

I’ve written about the paper for Nature News, focusing very heavily on the science rather than the politics. Head over there for a tighter version of this story. In this post, I’m going to highlight four important themes from the paper.

One: H5N1 can evolve to spread ...

How Our Circadian Cycle Helps Us Not Need to Pee Overnight | Discoblog

Wed, 02 May 2012 16:48:31 +0000

How to keep track of mouse urine

Eight hours is a long time without a trip to the bathroom when awake, yet most of us can sleep through the night without peeing. And no, it’s not just because you (presumably) stop drinking coffee in your sleep: even when food and drink are factored out, you both make less urine and have better bladder capacity during the night. As with most behaviors that change from day to night, it does indeed have everything to do with the circadian rhythm.

In a new study published in Nature Communications, researchers compared normal mice with mice whose circadian rhythms were disrupted by genetic mutations. To keep track of mice urination over time, they used a rather charming contraption that slowly unspooled urine paper under the cages (see image). Urine spots on the paper were counted up and, sure enough, urination in the normal mice showed 24-hour patterns while the mutant mice did not.

The study also identified a molecular mechanism that lets bladders hold more urine during sleep. Concentrations of the bladder protein Cx43 goes up and down over the course of 24 hours. It makes bladder muscles more sensitize to ...

Dolphins that help humans to catch fish form tighter social networks | Not Exactly Rocket Science

Tue, 01 May 2012 23:00:30 +0000

In the coastal waters of Laguna, Brazil, a shoal of mullet is in serious trouble. Two of the most intelligent species on the planet – humans and bottlenose dolphins – are conspiring to kill them. The dolphins drive the mullet towards the fishermen, who stand waist-deep in water holding nets. The humans cannot see the fish through the turbid water. They must wait for their accomplices.

As the fish approach, the dolphins signal to the humans by rolling at the surface, or slapping the water with their heads or tails. The nets are cast, and the mullet are snared. Some manage to escape, but in breaking formation, they are easy prey for the dolphins.

http://youtu.be/sVinWYmu5lQ

According to town records, this alliance began in 1847, and involves at least three generations of both humans and dolphins. Today, there are around 55 dolphins in the neighbourhood, and around 45 per cent of them interact with the fishermen.

Now, Fabio Daura-Jorge from the Federal University of Santa Catarina, Brazil studied Laguna’s dolphins to learn how their unusual collaboration has shaped their social networks. He spent two years taking photographs of the local dolphins, and ...

Bees That Drink Sweat From People’s Skin and Tears From People’s Eyes | 80beats

Tue, 01 May 2012 16:12:29 +0000

Drink up!

Have you ever thought about how nutritious your bodily fluids are? Full of goodies like salts and proteins…Wild bees know all about it, feeding human sweat and tears as a source of nutrition.

Urban sweat bees, for example, use humans like a salt lick. “These bees prefer sweaty people—over most animals—because the human diet usually is so salty that their perspiration is saturated with the essential nutrient,” according to a recent feature in the Wall Street Journal on sweat bees. A new species (Lasioglossum gotham) of these bees was recently identified from a specimen netted in the heart of Brooklyn. Although they are as a group fairly common, they’re tiny and they don’t sting, which is why you probably haven’t heard New Yorkers complaining about them. “[M]ost people never notice when the tiny bees alight on a bare arm or leg,” says the WSJ.

But what about a bee in your eye, you’d probably notice that right? Scientists have investigated different families of bees in Thailand that drink tears, both human and animal. Eyes wide open, the researchers used themselves as bee bait. (They also used meat, Ovaltine, cheese, and ...

Top tip: do not steal food from ant traps | Not Exactly Rocket Science

Tue, 01 May 2012 13:00:16 +0000

The Amazonian tree known Hirtella physophora looks rather unassuming, but it is the site of several grisly spectacles. Amid its leaves and branches, an animal, a plant and a fungus conspire to create a nightmarish trap where trespassers become meals, robbers get the death penalty, and assassins are assassinated.

The tree is home to ants called Allomerus decemarticulatus, which defend it from hungry insects. In return, the tree provides the ants with leaf pouches and swollen thorns as shelter, and feeds them with nectar and sugary nodules. These food sources are rich in carbohydrates but low in proteins. To supplement their diets, the ants need flesh, and they get it by shaping the tree into traps.

The ants cut hairs from the plant and weave them together into a hollow gallery, which extends down the side of the tree’s branches. Within the gallery, the ants hide inside small holes, jaws agape. From the outside, nothing can see them. If an insect lands on the trap, hundreds of lurking jaws seize its legs and pull it spread-eagled, as if on a medieval ‘torture rack’. The victim is overpowered and dismembered.

http://www.youtube.com/watch?v=zrL5BYRqrTI

This ...

Her identity by descent made flesh | Gene Expression

Sun, 29 Apr 2012 21:49:10 +0000

As I have indicated before, my daughter has a family tree where everyone out to 0.25 coefficient of relatedness has been genotyped by 23andMe. This is convenient in many ways. Before, relatedness was a theory. Now relatedness can be ascertained on the genomic level. Sometimes this can lead to peculiar consequences. “On paper” my daughter is 1/8 Scandinavian. Or 12.5%. But truly the expected value is 13.5%! (weighting by contributions from each maternal grandparent). Still, this remains an expected value. I would need a large sample of Scandinavians from that locale to make a truly precise guess as to the genetic contribution. Similarly, though I come in at about ~15 percent East Asian, my daughter looks to be a bit more East Asian than you’d expect based on that value (i.e., closer to 8-8.5 percent; I run her genotype more than a dozen times now). This may be a bias in the methodology, or, more likely it is simply the sampling error from my genome (I contributed more East Asian segments in the chromosomes passed down).

In any case, 23andMe has a “family inheritance” feature which is very convenient. ...

Dogs Are Manipulable, Cats Are Manipulative, and Both Act Like Babies | Discoblog

Sat, 28 Apr 2012 14:54:57 +0000

How you doin’?

After thousands of years living in our homes, cats and dogs have gotten pretty good at tuning into human social cues—as good as human babies anyways.

Dogs, with their adorable puppy faces, are easily swayed by the actions of humans. A new study in PLoS ONE shows that dogs will prefer a plate of food preferred by a person, even if that plate has less food on it. Cats, on the other hand, have an especially annoying “solicitation” purr that they deploy when they want something from their owners, much like (though quieter than) a hungry baby that will not stop screaming. Pet owners who fancy themselves parents may actually be onto something.

Although babies can’t understand words, they are good at following body language and the gazes of their parents—what are called “ostensive cues.” Dogs do the same thing; when they see you looking in a particular direction, for example, they look there too. Researchers in this new study show that dogs made their decisions based on these ostensive cues as well. They began by presenting the dogs with two plates with unequal amounts of food. Then an experimenter would look at and ...

This Scientist Endures 15,000 Mosquito Bites a Year | Discoblog

Fri, 27 Apr 2012 17:35:34 +0000

The things we do for science.

Researchers who study mosquitoes and other blood-sucking insects sometimes use themselves as skeeter chow. In some cases, it’s because certain species of mosquitoes seem to prefer human blood to animal blood. In others, though, it’s a cheap, convenient alternative to keeping animals around for the insects to feed on or buying blood. And as it turns out, once you’ve been bitten a certain number of times you develop a tolerance to mosquito saliva.

Entomologist Steve Schutz, seen above paging through a magazine while the bloodsuckers go to work on his arm, feeds his mosquito colony once a week. He has welts for about an hour, but after that the bites fade, occasionally leaving a few red spots. That’s good, because at 300 bites a week, he averages about 15,000 a year. That’s dedication.

A Multitude of Hands: My new essay for National Geographic | The Loom

Fri, 27 Apr 2012 15:26:38 +0000

In the May issue of National Geographic, I contemplate the hand. Human hands are unique and versatile–and yet we are far from the only animals with them. By looking at the variety of hands in nature, we can see some of the most striking evidence of how evolution tinkers in all sorts of unexpected way. Check it out.

The print version is accompanied by lovely sketches of a wide range of hands. If you read the story online, you can see an animation of the human hand. And if you have the National Geographic iPad app, you can see videos of other hands, from frogs to aye-ayes.

[Image: White -handed gibbon by Ingo Arndt, on Arkive.]

Scientists brave ‘world’s worst water’ to watch wild bacteria evolving | Not Exactly Rocket Science

Thu, 26 Apr 2012 20:00:15 +0000

For almost a decade, Jillian Banfield has been travelling to a place that “pushes the limits of human endurance” – Richmond Mine in Northern California. Its abandoned caverns can reach 48 degrees Celsius and 100 per cent humidity. They are low in oxygen. They contain possibly the most acidic naturally occurring water on Earth, with a pH value of -3.6.

But even in these conditions, there is life. Bacteria grow within the cave, floating in thin films on top of its hot, acidic water. They are the lords of their extreme world, and they provide an unrivalled opportunity to study how wild microbes evolve.

The mine ecosystem is extremely simple. The dominant species is a bacterium called Leptospirillum that lives in sulphuric acid and eats iron. Only a handful of other microbes share the mine, and most migrants would simply die. This is an ideal community for keen scientists – it’s small, well-defined, not very diverse, and self-contained. “The fact that it’s a simple, closed community makes it feasible to observe the evolution of the main players, without worrying about genotypes coming in from outside,” says Richard ...

Neurons in a pigeon’s brain respond to magnetic fields | Not Exactly Rocket Science

Thu, 26 Apr 2012 18:00:47 +0000

In retrospect, the helmet should have been a clue…

Of all the super-senses that animals possess, the ability to sense the Earth’s magnetic field must be the most puzzling. We’ve known that birds can do it since the 1960s, but every new attempt to understand this ability – known as magnetoreception – just seems to complicate matters even further.

Take the latest discovery. Le-Qing Wu and David Dickman from the Baylor College of Medicine have found neurons in a pigeon’s brain that encode the properties of a magnetic field. They buzz in different ways depending on how strong the field is, and which direction it’s pointing in.

This is a big step. Scientists have identified parts of the brain that are important for magnetoreception, but no one has managed to nail down the actual neurons responsible for the sense. Miriam Liedvogel, who studies magnetic senses, calls it “a milestone in the field”. It’s a key puzzle piece that has been unavailable for a very long time.

But Wu and Dickman’s discovery doesn’t solve the magnetoreception puzzle. If anything, it makes it more complex. Until recently, scientists thought that ...