The science behind blowing bubbles

Soap bubbles

What exactly happens when you blow on a soap film to make a bubble? Behind this simple question about a favorite childhood activity is some real science, researchers at New York University have found.

In a series of experiments replicating bubble blowing, NYU's Applied Math Lab has discovered two ways in which bubbles can be made: one, by pushing with a steady but strong wind on a soap film through a circular wand, which causes it to grow into a bubble, and two, by pushing with a gentle wind on an already-inflated film in order to drive its further growth.

"This second method might explain how we often blow bubbles as kids: a quick puff bends the film outward and thereafter the film keeps growing even as the flow of air slows," says Leif Ristroph, an assistant professor at NYU's Courant Institute of Mathematical Sciences who led the study.

The first method is more intuitive, but less common.

"This is used by the bubble blowers we see in parks in the summertime," explains Ristroph. "They simply walk, sufficiently fast, it seems, with a soapy loop of rope, which provides the relative wind needed to stretch out the film."

The results, reported in the journal Physical Review Letters, point to potential applications in consumer products that contain bubbles or droplets, such as sprays, foams, and emulsions, which are combinations of unmixable liquids.

The paper's other researchers were Likhit Ganedi, an NYU undergraduate at the time of the work and now a graduate student at Carnegie Mellon University, Anand Oza, a postdoctoral fellow at the time of the research and now a professor at the New Jersey Institute of Technology, and Michael Shelley, a professor at the Courant Institute.

As a physics problem, blowing bubbles is a question of how a liquid film -- typically soapy water -- interacts with an imposed flow of an external fluid, which is air in the case of bubble blowing. This dynamic is crucial in understanding how to enhance industrial production of many chemical products.

To break down the science that explains this process -- i.e., what events precede the formation of bubbles -- the researchers created an experiment, replicating the blowing of bubbles, using oil films suspended in flowing water and pushed through a wire loop wand.

"Working with water instead of air has many advantages in terms of controlling, measuring, and seeing flows," Ristroph explains. "This is the trick that made these experiments possible."

Their experimental observations, combined with predictions drawn from mathematical models, allowed the researchers to understand the forces that produced the resulting film shapes.

Their findings give a precise recipe or set of instructions for how to blow bubbles -- and with it, related production processes.

Read more at Science Daily

Loch Ness Monster Hunter Hooked on Catfish Theory

A man who has spent 24 years scanning Scotland’s Loch Ness for its legendary mysterious monster reckons Nessie is most likely a giant catfish — although he is not prepared to give up looking just yet.

Steve Feltham, who holds a Guinness World Record for the longest continuous Nessie vigil, says it is the most probable explanation for the enigmatic beast that has captivated people’s imaginations the world over.

“The current frontrunner is the Wels catfish. It’s the most likely explanation,” the 52-year-old told AFP.

“I’m not saying it’s the final explanation. It ticks most of the boxes with sightings — but it doesn’t tick them all.”

Feltham left his home and girlfriend in 1991 to go looking for Nessie and has spent the years since in a caravan on the lake shore, scanning the waters.

Media reports this week suggested Feltham had given up his vigil after favouring the catfish theory, but he insisted he would keep searching for the definitive conclusion.

“We still have this world-class mystery and for the next several decades I hope to carry on trying to find the answer,” he said.

Catfish are native to central and eastern Europe but Feltham believes the Victorians might have introduced them to the deep freshwater lake so they could catch them for sport.

Wels catfish can group up to four meters (13 feet) long and weigh more than 400 kilogrammes (800 pounds) — though they are rarely more than half this size. The scaleless fish can live for at least 30 years.

Sightings dwindling

Feltham concedes there is no record of Wels catfish being released into Loch Ness, Scotland’s largest at 37 kilometers long and over 200 meters deep in some places.

But he said: “Given the number of hunting estates that there are around here, it’s plausible they (the Victorians) may have put a few in, giving themselves some good sport of catching one of the biggest freshwater fish in the world.

“If they did that here in the (late) Victorian era, they would have reached maturity in the 1930s” — the time when the Nessie craze took off.

He said in the early years of his vigil, there would be up to a dozen good sightings per year, but now there might only be one.

“Whatever Nessie turns out to be, it is dwindling. We are looking for the last one or two now,” he said.

Read more at Discovery News

If This Wasp Stings You, ‘Just Lie Down and Start Screaming’

This is the business end of the tarantula wasp, and by business end I mean the end that once made a guy crawl into a ditch and cry. True story.

Justin Schmidt is an entomologist, and has accordingly been stung by a lot of bugs. So he invented something called the Schmidt sting pain index (named after some guy called Schmidt, apparently), which ranks the pain of insect stings from one to four. Down at one is something like the fire ant, which is so named for a reason, while up at four is the bullet ant, which is so called for a very, very good reason.

Joining the bullet ant at four is a critter that lives right here in the southwestern US: the tarantula hawk. It’s actually a kind of solitary wasp with a sting whose resulting pain only lasts three seconds, but it’s so fiercely electric that could only be described as totally unacceptable. “There are some vivid descriptions of people getting stung by these things,” says invertebrate biologist Ben Hutchins of Texas Parks and Wildlife, “and their recommendation—and this was actually in a peer-reviewed journal—was to just lie down and start screaming, because few if any people could maintain verbal and physical coordination after getting stung by one of these things. You’re likely to just run off and hurt yourself. So just lie down and start yelling.”

Either this wasp is giant or this is a child holding it. Probably the former though, on account of child endangerment.

That paper, as it happens, was written by our friend Schmidt, and is probably the most unintentionally hilarious scientific paper I’ve ever read. He recounts one enterprising scientist who netted 10 tarantula hawks—and of course reached in to grab them: “Undeterred after the first sting, he continued, receiving several more stings, until the pain was so great he lost all of them and crawled into a ditch and just bawled his eyes out.”

Which is why folks in Texas have seemed a bit…worried over the past few weeks, as numbers of the things are on the rise. In reality, though, there’s nothing to be worried about here (trust me). The tarantula hawk is in fact a brilliant parasite that attacks tarantulas, not humans, paralyzing them with a sting before dragging them into a den. Here it lays an egg that hatches into a larva and devours the paralyzed spider alive—over the course of several weeks.

A tarantula wasp faces off against its namesake victim: the hawk.

So take heart, dear Texans. You’d have to try real hard to get stung by these things, like picking them up or stepping on them. Quite frankly, they don’t seem to pay people no mind, even if approached, probably because they know they could kick human asses all over the place. “The tarantula hawks are really bold in terms of wasps,” says Hutchins. “Researchers think that’s because they have very few natural predators. They have such an effective deterrent mechanism, and that’s their really painful sting.” Indeed, there are almost no reports of any animal dumb enough going after these things.

Accordingly, there’s not much to stop them when their numbers start climbing, like they are right now in Texas. Thanks to a strong rainy season, vegetation is doing quite well, and when vegetation does quite well, so do insects. The tarantula hawk is actually a nectar-feeder, not a carnivore, so it’s in fat city these days.

But not all of these wasps sting: The males can’t do it at all. This is because stingers in the insect world belong to the females (the structures evolved from ovipositors, which the females use to lay eggs). So in lovely conditions such as these, males will hang out on flowers and wait for the females to come around and mate. The female then flies off—and this is where the real fun begins.

Except for the tarantulas. They’re not going to like this one bit.

Sting Operation

Unlike a lot of insects, the fertilized female won’t just be depositing her eggs somewhere and flying off, hoping they’ll survive on their own. Nope, she finds an unwitting caretaker first: specifically, any number of tarantulas that are also good and active during these times of plenty.

The she-wasp has to be careful, because while she’s pretty darn big, the tarantula can be several times bigger than her. And although tarantulas may be harmless to humans, they have massive fangs that could do a number on the wasp. “The tarantula hawk will kind of approach the tarantula,” says Hutchins, “back away, approach, and then go in and actually get in underneath the tarantula and then flip it over, and then sting it. She’s usually looking for a chink in the tarantula’s armor, and that’s often at the joints in the legs.”

And she’s really good at it. One survey found that in 400 battles, only a single wasp perished. But that isn’t to say the tarantulas weren’t putting up a good fight. In his sneakily comic scientific paper, Schmidt notes that researchers have reported “violent encounters, often hearing loud crunching or snapping sounds as the spider has the wasp in its jaws, and with spiders frequently losing legs during the encounters.” It seems that the tarantula hawks’ hard, smooth exoskeletons may crunch a bit, but they still save their owners from death.

The wasp drags its victim to its doom. Not the wasp’s doom. The spider’s. Boy I’m on a roll this week.

As for the tarantulas, well, they almost never escape. The sting paralyzes the spider nearly instantly, allowing the wasp to drag it into a pre-dug burrow or back to the tarantula’s own den. Here it drops the victim and lays a single egg on it, then leaves and seals the chamber behind it. The egg hatches into a larva, which starts eating the still-paralyzed spider, focusing on non-essential tissues to keep it alive for as long as possible—perhaps weeks.

That there is one hell of a head start in life for the kiddo. It’s a striking contrast to the lives of social wasps, which collectively care for their young without encouraging them to devour paralyzed tarantulas. And indeed, this manifests in the wasps’ venom itself. Typically, the venom of social wasps tends to be both painful and damaging to tissue, whereas the tarantula hawk’s is all agony and no damage. This is likely because social wasps have a queen and young to protect from their enemies, so simply inflicting pain may not do the trick—the target may be down, but not out. In contrast, the tarantula hawk is a lone wolf, looking out only for itself. All it has to do is stun its attacker and make a getaway.

Read more at Wired Science

This Beetle Uses Its Poop as a Shield or Sword

A tortoise beetle and her poo-tipped brood doing the most disgusting impression of a Bloomin' Onion ever.

In one of greatest sketches from the show Upright Citizens Brigade, an enterprising redneck sells a poo stick—that’d be poo on the end of a stick—for $125. It’s the “latest in A1 protection,” and even comes with a few free replacement cartridges—that’d be extra turds. It’s so effective the redneck doesn’t even bother selling mace or tasers, and so dangerous one once killed his son.

Aside from being a bit overpriced, it’s hard to deny the effectiveness of a poo stick in warding off attackers. Which is exactly what the larvae of the tortoise beetles have been doing for millennia. Not content to just sit there and get eaten, using a highly elongated and mobile anus, they build a tower of poo on a special structure on their backs. It’s dextrous too: When threatened, the larvae can smack their foes with the so-called “fecal shield.”

Insects can opt to dump a whole lot of eggs into the ecosystem and just hope they make it on their own, but tortoise beetles are doting mothers, forming a system known as subsociality. A beetle mom begins by laying a cluster of eggs, typically on the underside of a leaf, at a very specific time of year: the rainy season. This ensures the young will have plenty of food when they hatch. When they do, she guards them fiercely, guiding them around as a herd to prime feeding locations.

Enjoy this image of an adult tortoise beetle, because it’s going to be all poo and anuses from here on out.

During all this time—from the moment she lays the eggs until the larvae have transformed into adults—she’s so preoccupied she doesn’t feed a bit. For as long as two months. “So they feed together, and she’s with them all the time making sure that none of the larvae walk away or get lost,” says Caroline Chaboo, a biologist at the University of Kansas. “She’s really a helicopter mom, constantly around them making sure that they stay together.” Of particular concern are predatory wasps that swoop in and nab the young. Mom is one hell of a scrapper, though, and if she’s knocked off a tree in a tussle she’ll inevitably make her way back to the larvae (unlike regular tortoises, tortoise beetles can indeed fly).

So, the shit shields. They’re all built on top of a structure called the anal fork that the larva can manipulate to reach any part of its body. Poke one on its left side, and it’ll give you a targeted smack right there. Or sometimes, the shield can be so big that the beetle is restricted to just flipping it up and down. Much of the structure is in fact old exoskeletons, which the beetle sheds and forces to the back of its body—exoskeletons that Chaboo suspects could sequester toxins, making the shield that much more effective.

That translucent tube is the larva’s highly mobile anus, which is a sentence I just wrote.

Waste Is a Terrible Thing to Waste

So how can the larva so deftly crap all over itself? “This part is quite hilarious because their anus—I’m talking to a man in California about the anus of a beetle larva—so the anus is this long tube that is extremely flexible and maneuverable,” Chaboo says. “So it can extend and deposit the feces exactly where they want to place it.”

What you end up with is a noxious weapon that the beetle can use either like a shield or a sword. And as a united brood, their effect is pretty damn intimidating. When threatened, even by something as simple as a scientist’s shadow passing over them, the larvae form up into a circle, pointing their butts and shields outward, as their mother charges around the perimeter. It’s just like buffalo circling around their babies with their business end facing out, only the beetles are wielding doo-doo instead of horns. How the young are communicating with their mother isn’t quite clear yet, though Chaboo suspects little squeaky noises they emit may have something to do with it.

En garde!

“This is just basic neurobiology,” says Chaboo. “It’s crazy. The investment is what stuns me, is that the female is there guarding this brood for two to three weeks and putting her life on the line. And the assault on the brood is never-ending, it’s just a constantly vigilant mother who can protect her brood to adulthood.”

An Ugly Duckling Becomes a Swan. Only With, Like, More Legs and Stuff

When the young make it to adulthood and finally part ways, they’ll ditch the shit shield in favor of more civilized garb. As an adult, the edges of their exoskeletons are actually clear, and their shape allows them to hunker down on a leaf or some such without exposing their legs to nippy predators. And they come in all manner of colors and iridescence, with males and females sometimes sporting entirely different shades.

Yet not all tortoise beetle males are like the others. Some fellas are shaped more like females, and Chaboo reckons these guys are sneakers. So instead of competing with larger rivals, as the big sluggers battle the sneakers slip past them and mate with the ladies undetected. (This brilliant little evolutionary trick actually happens elsewhere in the animal kingdom. Some smaller male cuttlefish, for instance, will change their color and posturing to mimic females, then sneak right under big males guarding a harem and have a romp.)

Some species of tortoise beetle can also change their color on the fly, though this probably doesn’t have to do with mating, since both sexes can pull it off (if it were just the males doing it to impress females, it’d be a different story). Their elytra, the wing covers that make a beetle a beetle, have a very special structure. “Think of a parking garage, with a roof and a floor and pillars that support the internal structure,” says Chaboo. “Fluid flows within that empty space. We suspect that by controlling the flow of fluid in that space these beetles can change their color.”

More research from Chaboo is forthcoming on the exact mechanisms involved, but these beetles go from a brilliant, shiny gold to a dull brown in milliseconds. That speed might suggest this is a matter of camouflage. While having all of those highfalutin colors may make you more attractive to mates, for instance, they also make you more attractive to predators (alternatively, vibrant hues may serve as a warning that the beetle is toxic). Being able to put on a new outfit on the fly may be good for protection—when you don’t have the option of slapping your enemies with your turds anymore.

Read more at Wired Science

Built-to-Last Beastie Gave Rise to Insects, Spiders and Shellfish

An otherworldly creature that lived a half billion years ago is helping scientists to recreate what the common ancestor of insects, spiders, scorpions and crustaceans looked like.

The bizarre animal, appropriately named Hallucigenia sparsa, suggests that the common ancestor of everything from black widow spiders to giant lobsters was far more complex than previously suspected. A common aspect of most of these animals, including spiders, is that they molt.

“It turns out that the ancestors of molting animals were much more anatomically advanced than we ever could have imagined,” co-author Jean-Bernard Caron, curator of invertebrate paleontology at the Royal Ontario Museum, said in a press release.

Caron added that Hallucigenia and its kind were “ring-like plate-bearing” species “with an armored throat and a mouth surrounded by spines.”

Hallucigenia was so bizarre that, for years, scientists couldn’t figure out which side of it was the front and which was the back. Some researchers even mistakenly drew the creature upside down.

“Prior to our study, there was still some uncertainty as to which end of the animal represented the head, and which the tail,” said co-author Martin Smith of Cambridge University’s Department of Earth Sciences.

He added, “A large balloon-like orb at one end of the specimen was originally thought to be the head, but we can now demonstrate that this actually wasn’t part of the body at all, but a dark stain representing decay fluids or gut contents that oozed out as the animal was flattened during burial.”

New fossils for its head, outlined in the latest issue of Nature, were unearthed in the Burgess Shale of Yoho National Park in western Canada. They reveal that Hallucigenia had a long head with a pair of simple eyes, which sat above a mouth that featured a ring of teeth-like needles. The latter were probably helped to generate suction, flexing in and out, like a valve or plunger, order to suck food into the organism’s throat.

The researchers speculate that the “needles” in the throat worked like a ratchet, keeping food from slipping out of the mouth each time it took another “suck” at its food. (Later animals, such as fish, evolved actual teeth as we know them, which permitted biting and chewing of food.)

Read more at Discovery News

Forget the Platypus. The Echidna Is the True Champ of Weird

This long-beaked echidna just can't even. Can't. Even.

Knuckles from the Sonic the Hedgehog games is supposed to be an echidna, one that flies around like Superman and runs so fast its legs become blurs. “Knuckles is a cool guy with a bad attitude,” claims Urban Dictionary in increasingly stilted English. “He does’nt [sic] like to be pushed around. Him and Sonic fight a lot, but I think their [sic] good buddies.”

Other than the being friends with hedgehogs bit, it’s not an inaccurate description of actual echidnas, the great misfits of the mammal family. There’s four species, including one in Australia called the short-beaked echidna. But it’s New Guinea’s three species of the little-studied long-beaked variety, which I’ll be focusing on here, that really amp up the weirdness—as you might have noticed from the photo above.

These nocturnal creatures lay eggs like reptiles and detect electrical fields like sharks. They’ve got the mug of an anteater and the spines of a porcupine. And of course the males have four-headed penises like … well, maybe something out of hentai?

Bowed Legs and Laid Eggs

It’s a good idea to start here by talking about mammals’ ancient ancestors the synapsids for a hot second. They superficially resembled modern reptiles (though reptiles are a distinct lineage), yet had many mammalian characteristics as well. Synapsids eventually gave rise to the three groups of mammals: monotremes, which include only the platypus and echidnas; placental mammals like humans; and marsupials. The monotremes split off from the mammalian lineage first, and did so very, very early on, some 200 million years ago, and today retain many “reptilian” features of their ancestors.

Perhaps the most conspicuous reptilian quality is the long-beaked echidna’s odd posture, which makes it look like a meathead that just got his pump on. “The legs are kind of splayed out to the side somewhat, like you might imagine a lizard whose legs kind of shoot out and then go down,” says Kristofer Helgen, a zoologist at the Smithsonian. “Whereas most of the mammals we’re familiar with, whether it’s us or a dog or a horse or a kangaroo, the legs go straight down under the body and support it. And so these things have more of a splayed reptilian posture.”

But where the echidna one-ups the reptiles is with its penis. Let me rephrase that. The echidna’s penis is far more fascinating than a reptile’s, specifically the fact that it has four heads, whereas reptiles have dual penises called hemipenes. However, the female echidna has only a paired vagina, so why the mismatch? Well, it seems the male will alternate, using two heads to inseminate the female before switching to the other two heads and inseminating again.

This is what the long-beaked echidna version of that beach scene from the movie 10 looks like.

Another reptilian characteristic is of course the fact the long-beaked echidna lays eggs. And while the female has a pouch like a marsupial, there’s one significant difference: this pouch isn’t permanent. “So what’s crazy about it is basically the muscles in the skin of the belly of the echidna temporarily form into a pouch that can house the baby or babies when they’re hatched out of the egg,” Helgen says. Here the young don’t suckle nipples, but instead lap up milk from glands that leak the stuff directly onto the mother’s fur.

But why would the platypus and echidna go the egg-laying route when every other mammal gives birth to live young? Well, the beauty of evolution is that different strategies suit different organisms perfectly fine, however ridiculous they may seem. Placental and marsupial mammals evolved to give birth to live young, while the monotremes held onto the egg-laying ways of their ancestors. Keep in mind that creatures are on Earth for one purpose only: to reproduce (the meaning of life is therefore nothing like what Monty Python says). If something is at all inefficient in that regard, that’s it for the species. Yet here, after hundreds of millions of years of evolution, is the echidna. It’s got a weird sex life, sure, but it works.

The Hunter and the Hunted

When the little long-beaked echidna eventually sets out on its own, it’s well-equipped to run down earthworms and millipedes and other invertebrates in the soft soils of New Guinea. Just like the platypus can pick up the electrical signals of its prey in the water using its bill, the long-beaked echidna uses its giant, electricity-detecting snout to probe for food in the darkness (the short-beaked echidna hunts social insects like ants, and therefore has no use for such a long schnoz). Strangely enough, though, the echidna has no teeth. Instead, it uses its tongue, which is studded with lots of tiny, sharp spines, to grind the prey against the roof of its mouth, which also has these spines.

And the echidnas share another extraordinary adaptation with their platypus relatives. “Platypuses are known to be venomous, and they have on their hind foot a spur that’s connected to a venom gland that’s situated just below the knee,” says Helgen. The long-beaked echidna has a similar structure, and “a lot of people have said it’s not poisonous, but studies are ongoing now that suggest that they may also be venomous at certain times of year.”

The less absurd though no less thorny short-beaked echidna crossing “conquer a log” off its bucket list.

As with the platypus, it may be a defensive adaptation, which Helgen experienced firsthand while doing fieldwork in New Guinea, where one long-beaked echidna put up a bit of a fight. “It was trying to dig and escape, but when I did manage to pick it up it was contorting its body. And it seems like it was trying to stick me with that thing.”

Sadly, such weapons—combined with its many spines—can’t protect the long-beaked echidna from humanity at large. Like much of Earth’s endangered wildlife, the three species of long-beaked echidna have the unfortunate distinction of being palatable to humans (luckily, the short-beaked variety in Australia seems to be doing OK). Also like much of Earth’s endangered wildlife, the echidnas find themselves ever more crowded out by human settlements.

That could all spell disaster for the species. “You can talk to people in areas where this animal lives,” says Helgen, “and even though older men—maybe they’re in their 50s, 60s, and 70s—they can usually count on two hands how many times they’ve hunted and killed these animals.” Part of the problem has been dogs. While a hunter will have a hard time tracking the nocturnal creatures, canines certainly won’t. By hunting with dogs, a party can rapidly clear entire areas of any long-beaked echidnas.

Read more at Wired Science

All Kangaroos Are Left-Handed

All kangaroos are left-handed, according to new research.

Previously it was thought that “true”-handedness, meaning predictably using one hand over the other, was a feature unique to primates. The new research, published in the journal Current Biology, not only negates that but also goes one step further: kangaroos are even more true-handed than we are.

“According to a special-assessment scale of handedness adopted for primates, kangaroos pulled down the highest grades,” said project leader Yegor Malashichev in a press release. “We observed a remarkable consistency in responses across bipedal species in that they all prefer to use the left, not the right, hand.”

Malashichev, a researcher from Saint Petersburg State University in Russia, and his team observed that wild kangaroos show a natural preference for their left hands when performing particular actions, such as grooming their noses, picking leaves, or bending tree branches. Left-handedness was particularly apparent in eastern grey and red kangaroos.

The kangaroos that they studied were at various locations in the wild at Tasmania and Australia. The term “hand” really does apply here, because kangaroos have five-fingered hands that somewhat resemble human hands, save for the kangaroos’ long claws in place of fingernails.

Not all marsupials were found to exhibit such handedness. The researchers determined that red-necked wallabies, for example, prefer their left hand for some tasks and their right for others. Generally speaking, these wallabies use their left forelimb for tasks that involve fine manipulation and the right for tasks that require more physical strength. The researchers also found less evidence for handedness in species that spend their days in the trees.

Read more at Discovery News

Spanish Gangs Use Voodoo to Traffic Girls

Earlier this week Spanish police arrested a half-dozen members of a human trafficking gang that lured four girls from Nigeria to Spain with the promise of jobs but instead forced them into prostitution and kept them there under threat of juju, or voodoo magic retribution.

“The Local,” an English-language Spanish news organization, reported that “Officers rescued four victims and arrested six members of the organization that used juju voodoo rituals to sexually exploit women… The traffickers had put the women through a juju voodoo ritual that used the victims’ fingernails or (hair) and involved animal sacrifice in front of idols in a temple in order to ‘guarantee that the women complied with everything they demanded, under threat of death to them and their families.’”

The women had been taken from Nigeria overland to the Moroccan coast, where they then went by boat to Lanzarote, the easternmost of the Canary Islands. The operation was conducted as part of Spain’s “National Police Plan Against Trafficking in Human Beings for Sexual Exploitation,” launched in 2013.

The girls’ belief in -- and fear of -- powerful magic prevented them from going to authorities. In many countries throughout the world belief in witches is common, and black magic is considered part of everyday life. A 2010 poll of 18 countries in sub-Saharan Africa found that over half of the population believe in magic. Witch doctors are consulted not only for healing diseases but also for placing or removing curses, and many Africans fear that witch doctors -- or those who hire them -- have power over their lives and health.

In her book “The AIDS Conspiracy: Science Fights Back,” Nicoli Nattrass, director of South Africa’s AIDS and Society Research Unit, notes that there “is a rich South African literature suggesting that many black people believe that HIV may have spiritual causes, notably witchcraft attacks.”

Those who subscribe to this belief system may sincerely fear that they could get AIDS simply by disobeying their pimps and traffickers or going to the police. Whether the traffickers believe in magic or curses is irrelevant; what’s important is that the victims do.

Read more at Discovery News

The Lowly Clam That Almost Sank Two of Columbus’ Boats

If your boat looks like this, you're up shit creek without a paddle, so...hopefully that thing has an engine?

It was the year 1731, and the Dutch economy was at the mercy of a clam. But not just any clam, mind you—give the Dutch some credit. This was a true oddity, or at the very least an eccentric. While your typical clam lives a life of security in its shell, the so-called shipworm has a tiny calciferous casing, from which erupts a skinny tube of flesh up to two feet long. Swarms of the things burrow into wood, be it ship hulls or piers or, unfortunately for the Dutch, wooden dikes.

The strange invertebrate had destroyed over 30 miles of Dutch dikes, and threatened another dozen miles. The Netherlands were in serious danger of flooding, and the economy was spooked. Peasants fled their farms and entered the cities, where they could find no jobs. Crews tried switching the wood out for tropical hardwood, to no effect. The only solution was to import stones and build dikes that way, at no small taxpayer expense.

It wasn’t the first time the shipworm had menaced humans, and it wouldn’t be the last. The things had already terrorized the ancient Greek and Roman navies, and ate away so badly at two of Columbus’ ships on his fourth voyage to the Caribbean that he had to abandon the vessels. Later on in the 1910s, a shipworm infestation hit the docks of San Francisco Bay, causing what would today be billions of dollars in damages.

But have shipworms ever actually sunk a boat out at sea? “More or less,” laughs molecular ecologist Luísa Borges of Germany’s Helmholtz Center for Material and Coastal Research. “If you believe in the historical reports, apparently they sunk quite a lot of ships, when they undertook these long voyages.” The loss of several vessels in the Spanish Armada, for instance, have been blamed on shipworms, which the Brits no doubt appreciated.

Barking Up the Wrong Tree

The first question to ask here isn’t how the shipworm manages to bore into wood—and in such numbers that it can threaten national economies, for that matter—but how the hell a marine creature could evolve to rely on a terrestrial material in the first place. Shipworms subsisting on trees that happen to wash out to sea is a bit like you trying to survive solely on dead things that wash ashore.

Shipworms are tireless advocates of recycling—as long as the material is wood, and they’re eating it. They’re somewhat meh about plastic.

But there are marine habitats where plenty of wood grows right in the saltwater: mangrove forests. Mangrove trees are incredible survivors. Saltwater would kill any other kind of tree, but the mangrove’s roots can filter out the salt, and some species have roots that grow vertically up out of the water to take in more oxygen. It was among these trees that the first shipworms likely evolved. But now, thanks to the global economy, the clams have hitched rides to coastal cities all over the world.

The shipworm’s life cycle begins as a larva that settles onto wood, be it a mangrove root or pier or ship. While the adult clam’s shell covers only a tiny fraction of its body, the larva looks like a regular bivalve. It begins drilling a tiny hole into the wood, either by releasing enzymes to break down the tissue or by rasping away with its shell, or a combination of the two methods. “So it’s mechanical, most of it,” says Borges. “But some people think there might be some enzymatic action there too. It’s not entirely known.”

“The animal has a very strong foot,” she adds, “as most bivalves and gastropods and so on have. And it uses it like a suck, and moves the shell sideways and uses it as a rasp and file device.”

Now, if you’re anything like me, you’ve gone your whole life without ever licking a two-by-four. But it’s safe to say that mucousy flesh does not get along well with the abrasiveness of wood, so this leaves the shipworm with a problem: As it grows and elongates and continues to bore deeper into the wood, the shipworm risks stripping its own delicate flesh away. To avoid this, it excretes a calcareous lining—the same calcium carbonate material that makes up its shell—along its worm-like body. Pull a shipworm out of some wood and it’ll leave the calcareous tube behind.

The business end of a shipworm. And business is booming.

Gut Instincts

Now, if you’re anything like me, you’ve also gone your whole life without eating mangrove trees. It’s safe to say that they’re indigestible for humans, but not for the shipworm. It can digest wood just fine with the help of some very special symbiotic bacteria. But here’s the strange thing: That bacteria doesn’t live in the shipworm’s gut. Instead, it lives in the gills and produces enzymes that make their way to the gut, where they break down the wood’s cellulose into sugars. Plenty of creatures use bacteria like this to digest weird foods, but the shipworm is alone in storing the microbes outside of its digestive system.

A diet of wood, though, leaves the shipworm wanting for protein. So out of that tiny hole it first bored when it was a larva, the shipworm extends fan-like structures that it uses to catch plankton floating by. “So imagine that you have a lot of shipworms in a piece of wood, and they don’t have much wood to eat,” says Borges. “They actually filter-feed more than they eat wood. Otherwise they destroy their own environment. So they can kind of adjust their diet to survive.”

Read more at Wired Science

Lamprey Eels Fall From Sky Over Alaska

Several foot-long lampreys have apparently fallen out the sky recently in Fairbanks, Alaska. They’ve been found in a shopping center parking lot and on lawns, and residents are unnerved by the creepy, toothed eel-like fish.

According to a story in the Alaska News-Miner, “Adult Arctic lampreys have fallen from the sky four times this week in Fairbanks, including at the Value Village parking lot, according to the Alaska Department of Fish and Game. That’s unusual for a fish that’s seldom seen in the water up here.”

While some news outlets had fun sensationalizing the story (a “New York” magazine headline blared that “Horrifying Fish Monsters Are Falling from the Sky” and another noted that “‘Vampire Fish’ Fall From the Sky in Alaska”) it’s a weird enough story on its own.

The phenomenon of small animals (such as worms, fish, or frogs) falling mysteriously from the sky has been reported for centuries. Waterspouts or tornadoes crossing over a lake or river can pick up debris, including lightweight aquatic animals, and carry them for miles before raining them down on a puzzled populace. There were no reported tornadoes or waterspouts in Fairbanks, however.

It could be a prank, but the most likely explanation for the falling lampreys was offered by the Alaska Department of Fish and Game: they’re dropped from the air by seagulls. Seagulls can often be seen feeding on lampreys and small fish in and over the water, but they don’t always eat their prey on the spot. Sometimes they fly away with their marine lunch in their beaks, and on occasion the birds will accidentally drop their meal before it’s consumed.

In those cases a lamprey may be found some distance from its aquatic home, and unless a person happens to be watching a seagull as the bird drops its meal, a lamprey would appear to fall from the sky (or be found on a sidewalk) without any apparent origin.

A grand total of four lampreys have been found over the past week—hardly a deluge—and the fact that dead lampreys are rarely seen up close by the general public (being difficult to catch and not sold commercially in the area) may have added to the unnerving effect.

Read more at Discovery News

Two Newfound Marsupials Do It to Death

Two chubby marsupial species that would literally die for sex (albeit 14-hour sessions) have been discovered Down Under, researchers now report.

The new species are types of antechinus, a bristly haired, mouselike marsupial that eats meaty meals such as spiders and insects. Every year, antechinus males fight each other tooth and claw so they can have sex with as many females as possible before dying.

After sex is complete, with some sprees lasting as long as 14 hours, stress hormones in males skyrocket, causing their immune systems to collapse, “and they all drop dead before the females give birth to a single baby,” lead study author Andrew Baker, a mammalogist at the Queensland University of Technology’s Science and Engineering department, said in a statement.

Until now, 10 species of this sex-crazed marsupial were known to science, with the first discovered in 1803. In the past three years, however, scientists have identified five new antechinus species, revealing the genus has more diversity than previously thought. Like the known antechinus species, the two most recently discovered species also spend two to three weeks a year in a testosterone-fueled mating marathon, the researchers said.

Scientists found one of the new species, the Tasman Peninsula dusky antechinus (Antechinus vandycki), in the remote areas of southeastern Tasmania. Researchers already knew about the other brown, furry marsupial, but didn’t realize it was its own species until now. Now named the mainland dusky antechinus (Antechinus swainsonii mimetes), the newbie lives in parts of New South Wales and Victoria in Australia.

However, A. vandycki faces challenges beyond surviving a mating frenzy: Loggers are tearing apart the animal’s habitat and may push the species into a threatened status, the researchers said. Moreover, three of the relatively new antechinus species, including A. vandycki,are also threatened by climate change; feral pests, such as cats and non-native foxes; and habitat loss, the researchers said.

“We discovered the Tasman Peninsula dusky antechinus not far from the old European settlement town of Port Arthur in Tasmania,” Baker said in the statement. “Most of its limited habitat falls within state forest, which is being logged.

“This species now apparently only lives in tiny, fragmented stands of intact forest that are under threat,” Baker added. “It’s a shame that mere moments after discovery, these little Tasmanian marsupials are threatened with extinction at human hands.”

In fact, Baker has already tried to place two of the other antechinus species he discovered — the black-tailed and silver-headed antechinus — on the state’s threatened species list.

“Both these species are found on remote mountaintops in southeast Queensland,” Baker said. “These species have already retreated to their misty mountain summits. In the face of ongoing climate warming, they have nowhere left to run.”

Read more at Discovery News

This Bug Is Big as a Gerbil. Fortunately It Loves Carrots

"What's up, Doc?" asked no giant weta ever. That noise is trademarked.

You know that scene in the newish King Kong where those folks get eaten alive in a pit of giant insects? It’s a damn character assassination, through and through. The huge cricket-like bugs among them are based on the giant weta, the heaviest reliably reported insect on Earth, at 2.5 ounces. And really, the movie bugs could have been even bigger for all I care—it’s that their crummy attitude is all wrong. Giant weta, for their monstrous size, are actually quite sweet. Not like cuddly sweet, though you’re welcome to try, but sweet nonetheless. They demand an apology. Or else…they’ll…just kinda just sit there and eat carrots.

Weta are New Zealand’s most iconic bugs, around 70 known species that range from the big ones like the giant weta to other smaller varieties: the “tree,” “tusked,” “ground,” and “cave” weta, all equally excellent in their own unique ways. They all differ in size and features, but all are products of the strange evolutionary history of New Zealand, an island that’s enjoyed relative isolation. That is, until humans arrived and started making a mess of things.

If the weta look to you like crickets addicted to protein shakes, you’re not far off. They are indeed in the same family, but in their long isolation in New Zealand, the weta have gotten weird. None can fly, for instance, because there have historically been no terrestrial mammals here. “That’s the critical part,” says biologist Priscilla Wehi of New Zealand’s Landcare Research, who you can see below calmly acting as a tree weta’s chew toy. “What that meant was that, as with a lot of our birds, being flighted wasn’t so important.”

You see, while flight may seem to be pretty legit, it’s energetically costly, and nature abhors a waste of energy. Without mammals chasing them around, weta have been able to stick to the ground to save energy. The same happened to New Zealand’s kakapo, the only flightless parrot in the world, a odd-looking bird that climbs trees to look for food and sort of just plummets out of them.

In part, it’s flightlessness that has allowed the giant weta to grow to such an extraordinary size. But there are limits to such growth, and the weta may well be pushing them. This is because insects don’t breathe like humans do. Instead of lungs, they have holes in their exoskeleton that open to tubes branching through the insect’s body, providing every cell with oxygen. This all works well and good, but it limits the insect’s size, since only so much oxygen can get deep in the critter as it dissolves into tissues.

But some 300 million to 400 million years ago, when oxygen levels were bonkers (35 percent of the atmosphere compared to 21 percent today), bugs grew huge—like dragonflies the size of seagulls and millipedes over 6 feet long—because more oxygen meant the gas could diffuse deeper into their huge bodies. Scientists think the oxygen plummeted to current levels when a giant space maid vacuumed it out (though it probably had more to do with a drop in sea level and drying out of land masses), so these days insects are a more reasonable size.

Not So Giant, But Definitely More Bitey

The other varieties of weta may be dwarfed by the giant type, but they’re no less extraordinary. The male tree weta, for instance, is equipped with gigantic mandibles, which it uses to battle other males for the right to mate, building harems of up to eight females. “They sometimes inflict damage on each other,” says Wehi, “which can even result in the loss of a leg or some other bit of their body, and they might try to throw the other male weta from the tree.”

The impressive jaws of the tree weta.

But there’s an alternative to battle. If the environment for whatever reason doesn’t produce enough food for all the tree weta, as some males molt they’ll stop growing, putting them at a severe disadvantage in battle. “So you might be more of what we call a sneaker, where because of your small size, you would wait until there’s a large male guarding a big harem of females and he was otherwise occupied fighting somebody else. And then you might be trying to mate with the females when he wasn’t looking.” (This clever little trick happens elsewhere in nature. Cuttlefish males change their body posture and coloration to mimic a female, then sneak right under the oblivious male’s belly. Thus he passes down genes not for brawn, but for smarts.)

There’s also the tusked weta, which like the tree weta fights for females, only its weapons do indeed look a bit like elephant tusks. And down in the undergrowth lives another type, the aptly named ground weta. This one digs burrows and waits there for other insects to traipse by, then pounces. Still another has adapted to life in caves, packing extra-long antennae it uses to feel around in the darkness.

All species have brilliantly adapted to life in island isolation. And accordingly, many are in trouble.

Mammalian Massacre

Humans arrived in New Zealand in the 13th century, but they didn’t arrive alone. Stowed away was the Pacific rat, which found a bounty of tasty creatures that had evolved there in total absence of mammals (save for bats). Fast forward to the 19th century, when Europeans brought the rest of the mammals that would lay waste to New Zealand’s endemic wildlife: cats, stoats, other types of rats. Now half of the island’s native bird species are gone.

A weta would never do the can-can, because that’s trademarked too. It would, however, lift up its spiny leg in order to ward off predators.

As for the weta, the tree variety seems to be doing alright. It takes shelter in small holes in trees, largely out of reach of marauding rats and such. But what’s really suffered is the lumbering giant weta. “They’ve been absolutely smashed by rats,” says Wehi. “So there have been huge conservation efforts in New Zealand, where we’ve used offshore islands as places where we can create habitats or place animals that are really badly affected by these introduced predators.”

A rather more ambitious approach is to build sanctuaries on the mainland. Crews have fenced off an entire mountain and trapped out all of its mammalian predators. Endemic species normally ravaged by mammals were then introduced to live with fewer hassles, just like they used to. Weirder still, a small population of giant weta has survived on a farm in a patch of a nasty prickly plant called gorse. The thicket, it seems, is impenetrable for rats—not to mention human researchers. “So you can probably imagine the poor people who have to go in and try to count their population,” Wehi says.

Read more at Science Daily

Prehistoric Bird Sported Feather 'Arrows' at Its Butt

Remains of a Dinosaur Age bird with two tail feathers shaped like arrows have been found in Northeast Brazil.

The hummingbird-sized specimen, described in the latest issue of the journal Nature Communications, reveals that early feathers were not just for flying, since the arrow-shaped feathers were not at all aerodynamically optimized.

Here, lead author Ismar de Souza Carvalho of the Universidade Federal do Rio de Janeiro describes the discovery:

As de Souza Carvalho mentions, his team found the “very impressive fossil” showing “a small flying bird with an exceptional preservation.”

They believe that the bird was a juvenile when it died of unknown causes.

The near-perfect fossil dates to the Early Cretaceous over 100 million years ago. It provides an unprecedented look at the tail feathers. Usually, these sorts of fragile appendages don’t preserve well, but they are in all of their 3D eye-catching drama in this fossil.

The scientists even found traces of color and pattern, suggesting that the bird would have been quite striking during its lifetime.

Since the feathers weren’t built for flying, the researchers write that they were likely “associated with sexual display, species recognition or visual communication” or all three.

Read more at Discovery News

'Purring' Wolf Spiders Softly Serenade Mates

Male wolf spiders use “purring” vibrations to serenade their sweethearts, but this wooing only works if the females can feel these vibrations, new research finds.

For the females to feel these vibrations, the courting couple must be standing on a suitable surface that can vibrate, like dry leaves, the researchers said in the new study.

Scientists had known that wolf spiders could make airborne sounds that are audible to humans. But this group of spiders doesn’t have typical ears, and it’s assumed that the critters can’t actually hear any airborne sounds, said Alexander Sweger, a doctoral student of biology at the University of Cincinnati, who presented the unpublished research at the Acoustical Society of America’s annual meeting in Pittsburgh on May 21.

“They’re quiet — nothing on the order of crickets,” Sweger told Live Science. “We think this airborne sound is primarily a byproduct. As far as we can tell, they may not deliberately be producing a sound.”

In fact, the “purring” wolf spider (Gladicosa gulosa) may help researchers learn how some animals use vibration, but not sound, to communicate, he said. Moreover, it’s possible that acoustic communication evolved from vibration, which is linked with sound, he said.

Sweger and his adviser, George Uetz, a professor of biological sciences at the University of Cincinnati, came across Gladicosa gulosa in the field one day. Intrigued, Sweger began reading literature on the species but found little research beyond the observational and anecdotal. So, he decided to study the spider, which has the unique ability to produce both vibrations and acoustic noises during courtship, he said.

The organ resembles a musical instrument: The wolf spider has two small, leglike appendages near its mouth called pedipalps. The lowest joint on the pedipalp has a rough surface (called a file) on one side and a scraper on the other. The spider can rub its pedipalps together so that the file and scraper cross each other, “and that creates the vibrations that then travel down the limb to the leaf,” Sweger said. Wolf spiders don’t spin webs, but are adept hunters with keen eyesight. Researchers have known about wolf spider vibrations since the 1970s, when they described their stridulatory organ, Sweger said.

“They’re courting on dead leaves,” he said. “And that leaf itself is what’s resulting in the airborne sound.”

Good vibrations

In an experiment, Sweger and his colleagues recorded the vibration made by a male G. gulosa with an instrument that can digitize the vibration and convert it into an audible sound. They also used a microphone to record the spider during courtship, “so it’s essentially the airborne sound you would hear in the room,” he said.

Then, they played the airborne sounds to both males and females that were stationed on either granite or paper.

Read more at Discovery News

Sawfish Have Virgin Births: First in the Wild

The first known virgin births in the wild have been documented among critically endangered smalltooth sawfish in Florida waters.

The discovery, reported in the journal Current Biology, marks the first time that living offspring from virgin births -- births where the mother did not mate with a male -- have been found in a normally sexually reproducing animal in nature.

Lead author Andrew Fields explained to Discovery News that “with fragmented habitat and low abundance,” it is likely that female smalltooth sawfish, known for their iconic tooth-studded rostrum or “saw,” are having trouble findings males. Lack of mating can then trigger the unusual births among certain adult females, he and his team suspect.

Fields, a researcher at the Stony Brook University’s School of Marine and Atmospheric Science, and his colleagues were conducting routine DNA fingerprinting of the sawfish (a type of ray related to sharks) in a Florida estuary when they determined that about 3 percent of those studied arose due to virgin birthing, a process technically known as parthenogenesis.

This phenomenon is thought to occur when an unfertilized egg absorbs a genetically identical sister cell. The resulting offspring have about half of the genetic diversity of their mothers and often die. In this case, however, the “parthogens” looked to be in perfect health, so the scientists just tagged and released them as part of an ongoing study that they are conducting on sawfish movements.

As for how those individuals might then reproduce later in life, Fields said, “They may give birth sexually or asexually.”

It is likely that virgin births are more common than previously thought among sharks and rays, both in captivity and in the wild. It is harder to detect and confirm the latter, given that DNA testing would be needed. Such births over the years, though, have surprised many aquarium staff members, who have found baby sharks suddenly appearing in tanks inhabited for lengthy periods by a lone female or multiple females and no males.

Senior author Demian Chapman, also from Stony Brook University, told Discovery News, “We know of parthenogenesis in blacktip, bonnethead, whitetip reef, whitespotted bamboo, and zebra sharks in captivity, so (there are) 5 species total.”

More species are expected to be added to that list. Some birds and reptiles have also undergone parthenogenesis in captivity.

For the smalltooth sawfish, the discovery is a dire warning about the species’ dwindling population. Fields said that it and other sawfish “are on the brink of extinction.”

He says that, for the smalltooth sawfish, “there is no accurate estimated population size, but it seems to be at 1–5 percent of historical levels based on the best evidence available. The primary threats are entanglement during fishing and habitat loss.”

Read more at Discovery News

This Isn’t a Spider, But It Does Have Genitals in Its Legs

This isn't slowmo. It's how a sea spider actually moves. The critter was spotted 8,675 feet deep off the coast of Vancouver by a submersible manned by Ocean Networks Canada. Clearly, it won't even give submersibles the time of day.

So, good news and bad news for those of you afraid of spiders. Good news is, this creature isn’t a spider because spiders can’t breathe underwater, so you’re safe from arachnids if you want to spend more time in the ocean. (Well, one species of spider actually can live underwater by trapping air around its abdomen—sorry, I’m really bad at good news.) The bad news is what while the sea spider may not be an actual spider, it looks like the ghost of a spider you once killed. Which might actually be worse and … totally scientific?

The 1,300 known species of sea spider are truly ancient animals that as far as scientists can tell aren’t closely related to any extant species, spiders or otherwise. At the moment, though, they’re lumped in the group that holds spiders and horseshoe crabs. They have such tiny abdomens that their guts extend into their legs. Their genitals are there in the limbs too, which makes mating … interesting. And like sea horses, it’s the males that carry the young.

Sea spiders live in both deep and shallow seas around the world, but all are carnivores, through and through. They have claw-like mouthparts known as chelicerae, which spiders also have, suggesting they may belong to the same group (appropriately enough called Chelicerata). The actual feeding happens through a proboscis, a sort of tube that can be longer than the rest of the sea spider’s abdomen in some species.

“They feed generally on things that don’t move, like sponges and corals, but also slow-moving things like worms or sea slugs,” says marine biologist Claudia Arango of the Queensland Museum in Australia. “What they do is they’ve got very sharp jaws at the tip of that tube, the proboscis, so they pierce the prey and start sucking out fluids.”

The deep and shallows are of course worlds apart as far as habitats go, so sea spider species have adapted accordingly. To find food in the blackness, the blind deep-sea varieties likely sniff out their prey’s chemical cues, while their shallow-water peers have four simple eyes. In the shallows, they also tend to be more colorful than in the deep sea, since in the darkness, flashy colors won’t do you no good nohow.

The sea spider Nymphon grossipes, which really got short-changed on the whole name thing.

Their body plans, too, are wonderfully adapted for their environments. The long-legged species are built like the tripods from The War of the Worlds—but with fewer legs and death rays—because sediment down in the deep can be soft and unstable, so lankier limbs keep it from sinking up to its abdomen. In the shallows, sea spiders tend to be stouter, with thicker, shorter legs that help them better hold on in rough waters, not to mention avoid shattering into a shower of limbs.

Leg Genitals and Other Adventures in Sea Spider Sex

What the many species of sea spider can agree on, though, is how to have sex: namely, very acrobatically. Both males and females have genital pores in their legs, males on just their last two pairs and females on every single limb. When a couple comes together the spindly male crawls on top of the spindly female. “So basically he climbs up and walks all over the female and then starts trying to go under the female so that both the pores come in contact,” says Arango. “The female would be standing totally normal while the male would be upside down, clinging on the female.”

Pseudopallene harrisi, from Australia. Note the claw-like chelicerae. It’s fashionably colorful not because it’s from Australia, but because that’s par for the course for shallow-water sea spiders.

When the female releases her eggs, the male combines them with his sperm and bundles them together in balls. These he holds with special appendages, known as baby björns ovigers, and “he carries the eggs all the way until they hatch, and sometimes even later you can see fathers carrying the babies,” says Arango. “It’s quite a heavy load sometimes.”

Inevitably, though, the larvae must set out on their own, and some species won’t just float at the mercy of the currents. They’ll invade the bodies of other creatures on the seafloor, including bivalves, burrowing into their flesh and feeding on them and eventually killing them. Others invade the bodies of coral, stealing the nutrients that algae produce for them.

A sea spider male carries eggs with specialized limbs called ovigers.

Still other species go after creatures called hydroids. One particular sea spider (.pdf) parasitizes the hydroid Tubularia larynx, a sort of small tube with frilly pink polyps, which grows en masse on rocks. The male sea spider will carry his young to fields of these hydroids and release them. Amid plenty of food, the young invade the hydroids’ tissues, feeding and feeding and growing and growing before erupting out of their dead hosts.

File Sea Spiders Under: It’s Complicated

It should be clear by now that sea spiders aren’t like any other creature on Earth—not by a long shot. I mean, the body plan alone is out of control. The daddy long legs is a lanky little thing, but the sea spider has so simplified its body plan that really its abdomen is little more than a joint for its legs, forcing its organs to flow into its limbs. Its heart is exceedingly simple, and because it lacks gills, it seems to absorb oxygen through its cuticle. And it has that bizarre proboscis, plus the males have those unique specialized arms used to hold eggs.

It all adds up to large-scale befuddlement for the folks studying them, and accordingly it’s a matter of controversy where exactly sea spiders fall in the tree of life. But Arango has an idea. “When you look at the morphology of the sea spiders, apart from a superficial resemblance to spiders, there’s lots of things that are unique,” says Arango. “In terms of giving them a place in the classification the best thing we can do, based on DNA mostly, is keep them at the base of the chelicerates.”

Anoplodactylus evansi may be Australian, but it looks a lot like a St. Louis Blues fan.

The problem is that sea spiders are a very, very old group of animals that likely diverged early on in the evolution of arthropods. I’m talking more than 500 million years ago, not all that long after the appearance of the first creatures we’d even recognize as animals. But for all that time on Earth, their fossils are scant, so tracing their lineage is a nightmare. And it doesn’t help that anatomically, they’re like nothing else living on this planet.

Read more at Wired Science

Genies Blamed For School Sickness, Possessions

Last week in Saudi Arabia nearly 200 elementary and middle school students “refused to attend classes after nine students claimed that genies — or jinn, as they are better known in the Arabic world — had made them sick” according to ArabNews.com, which added that “the students had fainted and experienced spasms at the start of the second semester, prompting many parents to believe jinns were present at the school.”

Jinn are described in the Koran, the Muslim holy book, as creatures made by Allah of smokeless fire. Belief in jinn is widespread throughout the Arabic and Muslim world. Just as many Christians readily accept the literal reality of angels, many Muslims accept the existence of genies as self-evident. Both religions share the belief that spirits such as demons and jinn can take possession of humans. Jinn are believed, like ghosts, to haunt buildings, homes and other locations.

It will often begin with one or two people exhibiting symptoms and as others in the same location see the behavior they unconsciously begin experiencing the same or similar symptoms. Episodes are most common in closed social units such as schools and factories, and among females — likely because they tend to have stronger social bonds than males. The symptoms are not serious and go away on their own, often within hours or days.

This is not the first time that jinn have been blamed for unexplained fits in Saudi schools. In his book “Legends of the Fire Spirits: Jinn and Genies from Arabia to Zanzibar” Robert Lebling notes that in 2000:

“Newspapers in Saudi Arabia reported the haunting of the al-Fikriyah Institute of Education, a functioning girls’ school in the Red Sea port of Jeddah, in an incident with unusual psycho-social overtones. A number of teachers at the school were reportedly subjected to fits and epileptic-like seizures, supposedly as a result of a (jinn) haunting.”

Though many doctors attributed that incident — like the one last week — to mass hysteria, some, including a cleric tasked with investigating the matter, insisted that jinn did in fact inhabit the school and were responsible for the symptoms.

As with many folk beliefs, the reality of jinn is less important than whether people believe in them; if a group of students or teachers believe that jinn can make them faint and there is no other ready explanation, then jinn will be blamed.

Though the school fits were harmless and soon passed, sometimes these beliefs can be dangerous; earlier this month a Moroccan woman who was believed to be possessed by a jinn died during an exorcism. According to a news story:

“To cast out the evil spirit from her body, the Fqih (exorcist) loudly recited incantations and passages from the Koran, the holy book of Islam. With the help of four of his assistants, the Fqih hit her with a stick all over her body in order to ‘force the evil spirit’ to leave her.”

In 2012 a Pakistani man and his family was convicted of killing his young wife during an exorcism who he believed was possessed by a jinn.

Read more at Discovery News

425-Million-Year-Old Parasite Fossilized Mid-Invasion

About 425 million years ago, a sneaky worm-like parasite invaded a crustacean before the two were fossilized together in the limestone of modern-day England, a new study finds.

The parasite, a newly identified species, is an ancient type of tongue worm, an arthropod that has a wormlike body with a head and two pairs of limbs, the researchers said. It is the first adult tongue worm to be found in the fossil record, they added.

“This is the most important fossil evidence yet discovered of the origins of this type of parasitism,” study co-author Derek Briggs, a professor of geology and geophysics at Yale University and curator of invertebrate paleontology at the Yale Peabody Museum of Natural History, both in New Haven, Connecticut, said in a statement.

The new species was dubbed Invavita piratica, meaning “ancient intruder,” as a nod to maritime piracy. It was discoveredin a crustacean host, called Nymphatelina gravida, a marine creature with two shells connected by a hinge. In fact, the researchers found several specimens of I. piratica in the fossil, which the scientists found in limestone rocks in Herefordshire, England.

The I. piratica specimens are “exceptionally preserved,” and range in size from about 0.04 to 0.16 inches (1 to 4 millimeters) long, the researchers wrote in the study.

“This discovery is important not only because examples of parasites are exceptionally rare in the fossil record, but also because the possible host of fossil tongue worms — and the origin of the lifestyle of tongue worms — has been the subject of much debate,” said the study’s lead author, David Siveter, a paleontologist at the University of Leicester, in the United Kingdom.

Researchers found several of the parasites inside the crustacean’s shell, near a bundle of eggs that may have belonged to the host, the researchers said. Other parasites were anchored to the outside of the shell, a position that is unique even among living tongue worms, the researchers said.

Nowadays, there are about 140 known species of parasitic tongue worms, known as pentastomids, which mostly prey on vertebrates, especially fish and reptiles.

Read more at Discovery News

Newly Created Fungus Is Part Human, Part Yeast

A living yeast that is part human and part fungus has been engineered by scientists in a feat that shows how, despite a billion years of evolution separating humans from yeast, the two species share hundreds of genes in common.

Those genes remain, in part, from the last common ancestor of humans and yeast.

“Cells use a common set of parts and those parts, even after a billion years of independent evolution, are swappable,” Edward Marcotte, a professor at The University of Texas at Austin, said in a press release.

“It’s a beautiful demonstration of the common heritage of all living things — to be able to take DNA from a human and replace the matching DNA in a yeast cell and have it successfully support the life of the cell.”

That’s just what Marcotte and his colleagues did, as they describe in their study published in the journal Science. Although yeast (such as the Baker’s yeast that might be in your refrigerator now) consists of a single cell and humans have trillions of cells organized into complex systems, multiple genes are shared between the two.

Of those, about 450 are critical for yeast’s survival, so the researchers removed the yeast version of each one and replaced it with the human version and waited to see whether the yeast would die.

They wound up creating hundreds of new strains of yeast, each with a single human gene. About half of these resulted in an organism that could survive and reproduce.

While this might sound like an eerie Frankenstein-like experiment, the goal is to produce a new way of researching human genetic diseases caused by mutations.

It’s actually cutting edge research, since the technique could help to reduce or even eliminate testing on live animals.

Another benefit is that the testing could lead to treatments designed for a particular individual. For example, researchers might insert precise versions of a human gene mutation into yeast and then expose the yeast to different drugs to test new therapies. As a result, the treatments could be tailored to a person’s precise genetic mutation.

Read more at Discovery News

Chance of Arachnids? 'Spider Rain' Explained

Millions of tiny spiders recently fell from the sky in Australia, alarming residents whose properties were suddenly covered with not only the creepy critters, but also mounds of their silky threads. But that’s not where the frightful news ends: Experts say that such arachnid rains aren’t as uncommon as you might think.

This month’s spider downpour in the country’s Southern Tablelands region is just the most recent example of a phenomenon commonly known as “spider rain” or, in some circles, “angel hair,” because of the silky, hairlike threads the spiders leave behind. Ian Watson, who lives in the region affected by the spooky shower, took to Facebook to describe what this strange “weather” looks like, according to the Goulburn Post.

“Anyone else experiencing this “Angel Hair” or maybe aka millions of spiders falling from the sky right now? I’m 10 minutes out of town, and you can clearly see hundreds of little spiders floating along with their webs and my home is covered in them. Someone call a scientist!” Watson wrote on the Goulburn Community Forum Facebook page.

So, here at Live Science, call a scientist (or two) is exactly what we did. Rick Vetter, a retired arachnologist at the University of California, Riverside, said Watson and his neighbors likely saw a form of spider transportation known as ballooning.

“Ballooning is a not-uncommon behavior of many spiders. They climb some high area and stick their butts up in the air and release silk. Then they just take off,” Vetter told Live Science. “This is going on all around us all the time. We just don’t notice it.”

The reason people don’t usually notice this ingenious spider behavior is that it’s not common for millions of spiders to do this at the same time, and then land in the same place, said Todd Blackledge, a biology professor at the University of Akron in Ohio.

“In these kinds of events [spider rains], what’s thought to be going on is that there’s a whole cohort of spiders that’s ready to do this ballooning dispersal behavior, but for whatever reason, the weather conditions haven’t been optimal and allowed them to do that. But then the weather changes, and they have the proper conditions to balloon, and they all start to do it,” Blackledge told Live Science.

This is likely what happened in New South Wales, where certain species of small spiders — as well as the tiny hatchlings of larger spider species— are known to balloon around the Outback during late autumn (May) and early spring (August). But, as Blackledge explained, an abrupt change in the weather or wind pattern may have carried these migrating spiders up and away and then back down to earth en mass — not the orderly dispersal that they (or the residents of the Southern Tablelands region) were expecting.

For the startled citizens of Goulburn and surrounding areas, however, the tiny spiders raining down from the sky probably pose no threat to humans, both Blackledge and Vetter said.

“There’s a tiny, tiny number of species that have venom that’s actually dangerous to people. And even then, if these are juvenile spiders, they’re going to be too small to even bite, in all likelihood,” Blackledge said.

Read more at Discovery News