Father's age influences rate of evolution: 90% of new mutations from father, chimpanzee study shows

The offspring of chimpanzees inherit 90% of new mutations from their father, and just 10% from their mother, a finding which demonstrates how mutation differs between humans and our closest living relatives, and emphasises the importance of father's age on evolution.

Published today in Science, researchers from the Wellcome Trust Centre for Human Genetics and the Biomedical Primate research Centre in the Netherlands looked at whether, in chimpanzees, there was a heightened risk of fathers passing on mutations to their children compared to humans.

In humans, each individual inherits, on average, about 70 new mutations from their parents. However, this number is influenced by paternal age such that older fathers tend to result in more mutations -- in humans each extra year of age results in two extra mutations.

Mutation risk is linked to father's age because the sperm lineage in males keeps dividing, while females have all the eggs they are ever going to produce present at birth. Paternal age is an established risk factor in a number of disorders including schizophrenia and autism.

The study found that the number of new mutations inherited by chimpanzees from their parents is, on average, very similar to that in humans, but that the effect of the father's age is much stronger -- each additional year of father's age results in three extra mutations.

The results suggest that sexual selection can influence the rate of evolution through its effect on the male mutation rate.

Professor Gil McVean, from the Wellcome Trust Centre for Human Genetics at the University of Oxford said: "In humans, a father's age is known to affect how many new mutations he passes on to his children, and is also an established risk factor in a number of mental health disorders.

"This study finds that in chimpanzees the father's age has a much stronger effect on mutation rate -- about one and a half times that in humans. As a consequence, a greater fraction of new mutations enter the population through males, around 90 per cent, compared to humans, where fathers account for 75 per cent of new mutations."

In the study, Wellcome Trust-funded researchers sequenced the genomes of nine western chimpanzees from a three generation family living at the biomedical primate research centre in the Netherlands.

To establish the number of new mutations a child inherits researchers sequence children and their parents and compare the genetic sequence -- any change in the sequence that doesn't exist in either parent genome is a new mutation. To find out which parent the mutation comes from you need to sequence members of the next generation of the family.

Read more at Science Daily

Fly Found With Da Vinci Princess Spurs Mystery

A fly larva discovered among the remains of an Italian Renaissance princess -- often credited to be the true Mona Lisa -- has a produced a zoological puzzle, raising questions about the origins of the insect.

Widely believed to be a native of the Americas, the black soldier fly (Hermetia illucens) thrives on decaying organic material. It was thought to have first reached Europe in the early 1900s.

“We can now prove the insect was present in Europe several centuries before,” Gino Fornaciari, professor of history of medicine and professor of paleopathology and funerary archaeology at the University of Pisa, told Discovery News.

“Indeed we found a larva in the sarcophagus of the Italian princess Isabella of Aragon, who died in 1524,” he added.

Isabella, the daughter of King Alfonso II of Naples, married her first cousin, the Duke of Milan Gian Galeazzo Sforza, in 1489.

For the occasion, Leonardo Da Vinci, who had been working in Milan as the court artist since 1482, orchestrated a magnificent party with plays, robots and fountains. Some art historians now argue that Isabella, and not Lisa Gherardini Del Giocondo, was the sitter for the Mona Lisa.

Her husband was never able to rule, because his uncle, Ludovico, confined Gian Galeazzo and Isabella in a castle-prison in Pavia. Isabella, who complained that her marriage was historically bad, remained there until her husband died suddenly at 25, possibly poisoned by Ludovico.

She then returned to Naples and finally died there at the age of 54, likely poisoned by her own medicine to treat syphilis.

According to Fornaciari, who exhumed her body, Isabella’s teeth were covered by a black patina which was intensively and intentionally abraded.

The black color was produced by mercury, the drug she was given in massive doses to treat -- ineffectively -- her syphilis.

Among her remains, near the skull, the researcher found two body parts belonging to a fly larva, which was identified as a black soldier fly.

Often confused with a wasp, this insect is well known in forensic entomology as it dominates decaying bodies.

“It is highly unlikely the black soldier fly reached Isabella’s body centuries after her death,” wrote Fornaciari, along with Giovanni Benelli, an entomologist at Pisa University, and colleagues in the Journal of Archaeological Sciences.

The sarcophagus was previously opened by thieves when the body was already skeletonized, making it unsuitable for the black soldier fly.

The finding raises new questions about the origin of this insect. According to the researchers, there are three possible scenarios.

Read more at Discovery News

Dinosaur Blood Ran Just Right: Not Warm, Not Cold

Dinosaurs were neither warm-blooded like mammals, nor cold-blooded like reptiles, instead they were somewhere in between, suggests a new study.

Exploiting the middle ground as a strategy may have helped dinosaurs rule the Earth for more than 100 million years, scientists report today in the journal Science .

The question of whether dinosaurs were lumbering cold-blooded or active warm-blooded animals has been debated for decades, but finding a definitive answer has proven difficult.

Now, biologist John Grady from the University of New Mexico and colleagues, have developed a new method for analysing dinosaurs' metabolic rates.

Building on previous work by palaeontologists and physiologists, they created a large database on growth and energy in both living and extinct groups of vertebrates including 21 species of dinosaurs.

They then used statistical analyses and energetic models to determine the relationship between growth rate and energy use.

Annual growth rings in fossils were used to determine growth rates, while metabolic rates were estimated by using changes in body size as an animal grows from birth to adult (known as ontogenetic growth).

"We found that growth rate is a good indicator of energy use in living animals. Warm-blooded (endothermic) mammals grow 10 times faster than cold-blooded (ectothermic) reptiles, and metabolise 10 times faster; in general doubling one's metabolic rate leads to a doubling in growth rate," Grady explains.

However, when they examined the growth rates of dinosaurs, although there was some variation in the rate they grew, they had neither the high metabolic rate of mammals and birds, nor the low metabolic rate of reptiles.

"Surprisingly we found that, instead, they occupied the middle energetic ground."

Today, mesothermic animals are uncommon, but living species come from across the evolutionary spectrum, and include leatherback turtles, tuna, great white sharks and the echidna.

These animals at times rely on internally-generated metabolic heat to maintain body temperatures, while being subject to external temperatures in others.

"They generate enough heat to warm their blood above ambient temperature, but don't do anything to maintain it, such as shivering which humans do when they are cold," says Grady.

"Meanwhile, echidna body temperatures can fluctuate by up to 10 degrees when they are active."

Dinosaurs evolved around 200 million years ago, and competed for resources with ectothermic animals like lizards.

Their higher metabolic rate meant they could move faster making them a more dangerous predator, or more elusive prey, says Grady.

"A higher metabolic rate gave them other competitive advantages as well: they could grow faster and reproduce faster.

"But being completely warm-blooded like a mammal limits the maximum size an animal can reach — it is doubtful that a lion the size of T. rex would be able to eat enough wildebeasts (or elephants) without starving to death.

"With their lower food demands, however, the real T. rex was able to get really big while still maintaining their advantage over their competition."

As well as helping us understand how warm-blooded animals evolved, understanding dinosaurs' energy use challenges our understanding of how life operates, Grady explains.

Read more at Discovery News

9/11 Conspiracies: Social Media And Their Enduring Appeal

Over the past week, a video claiming to prove that no planes actually hit the Twin Towers on September 11, 2001, circulated widely on Facebook and other social media. Despite a self-evidently absurd premise (thousands of people saw the event, both on television and in real life above them in Manhattan), the video now has been seen almost 3 million times.

The video was soon definitively debunked; it was not a hoax nor faked, but nor was it what it was claimed to be. A 9/11 conspiracy theorist "truther" had reviewed the footage and while slowing down and manipulating the video, decided that there was something suspicious about that footage: part of a plane seemed to disappear before impact.

Researcher Mike Hall analyzed the video "proof" and discussed the results on a podcast called Skeptics with a K (as distinguished, for example, by "sceptics" who populate countries who use the Queen's English). As Slate writer Scott Huler explained, Hall found that the hijacked plane "disappeared exactly the way you disappear when you step behind a tree: The building came between the camera and the airplane. The building is a good six blocks south of the tower—in front of it, not behind it. The single supposed fact on which the video based its 2 million–hit paranoid parade was provably wrong, in minutes."

Interestingly, it did not occur to the conspiracy theorist that the video he was analyzing might have been faked or inaccurate in some way; in classic conspiracy thinking, one video that seems to show something different than dozens of others (not to mention thousands of eyewitness accounts) is hailed as the one true and accurate evidence.

Sharing the Conspiracy

So what explains the wild popularity of the video? Part of the answer lies in the unquenchable thirst for conspiracy theories, and the fact that they are impervious to debunking. 9/11 conspiracies, in part because they trade on politics and what was arguably America's greatest tragedy, are not going away any time soon.

While certain specific claims central to conspiracy theories can be, and have been, disproven (ranging from Barack Obama's "faked" birth certificate to Osama bin Laden's "faked" death to the appearance of supposedly dead Sandy Hook school shooting victims), conspiracy theories themselves, for the most part, are immune to debunking. True believers will dismiss any information that proves them wrong as simply a part of the cover-up. It's a closed information system, a self-reinforcing echo chamber that insulates beliefs from skeptical analysis.

Though the casual ambivalence with which this patently false conspiracy misinformation video spread through social media is concerning, it's important not to overstate its influence. Though the video was made by a conspiracy theorist, just because nearly 3 million people saw and/or shared the video does not mean that they endorsed it; most just passed it along as another "interesting" video, which for all they cared might as well have been of a kitten astonished by a mirror.

In fact many—perhaps most—people probably didn't get past the headline. Research has found that most people don't actually bother to read what they share on Facebook or Twitter. As a Time magazine piece (that I didn't read every single word of) notes, "Just because a story gets a lot of tweets doesn’t mean people are reading it.

"Chartbeat, a company that measures real-time traffic for websites, says its data indicate that many people only spend a few seconds on an article page before tweeting it out. Chartbeat measures things like how far people scroll down, amount of time spent on a page and where they click next in order to determine whether people are actually reading content. 'We've found effectively no correlation between social shares and people actually reading,' Chartbeat CEO Tony Hailie tweeted."

Thus it's easy to overestimate the influence of these conspiracy videos when the psychology of social media plays a bigger role. In fact, the public ambivalence seen in the social sharing of the video (reflected in accompanying messages such as "I don't know if it's real, but check this out..." or "Something to think about...") is typical of conspiracy theory propaganda, which often includes disingenuous disclaimers along the lines of "I'm not saying it's true, just asking questions!"

In both cases the effect is the same: the "disclaimers" allow both conspiracy theorists and non-conspiracy theorists to spread misinformation and speculation under the guise of sharing an outrageous claim without having to formally and personally vouch for its validity.

Slate's Huler reminds readers "to think-- and above all check -- before you share. If it's a lie, by perpetuating it you claim at least a portion of the responsibility."

Read more at Discovery News

Oceans of Water Locked 400 Miles Inside Earth

Deep within the Earth's rocky mantle lies oceans' worth of water locked up in a type of mineral called ringwoodite, new research shows.

The results of the study will help scientists understand Earth's water cycle, and how plate tectonics moves water between the surface of the planet and interior reservoirs, researchers say.

The Earth's mantle is the hot, rocky layer between the planet's core and crust. Scientists have long suspected that the mantle's so-called transition zone, which sits between the upper and lower mantle layers 255 to 410 miles (410 to 660 kilometers) below Earth's surface, could contain water trapped in rare minerals. However, direct evidence for this water has been lacking, until now.

To see if the transition zone really is a deep reservoir for water, researchers conducted experiments on water-rich ringwoodite, analyzed seismic waves travelling through the mantle beneath the United States, and studied numerical models. They discovered that downward-flowing mantle material is melting as it crosses the boundary between the transition zone and the lower mantle layer.

"If we are seeing this melting, then there has to be this water in the transition zone," said Brandon Schmandt, a seismologist at the University of New Mexico and co-author of the new study published today (June 12) in the journal Science. "The transition zone can hold a lot of water, and could potentially have the same amount of H2O as all the world's oceans." (Melting is a way of getting rid of water, which is unstable under conditions in Earth's lower mantle, the researchers said.)

A water-rich mineral

Ringwoodite is a rare type of mineral that forms from olivine under very high pressures and temperatures, such as those present in the mantle's transition zone. Laboratory studies have shown that the mineral can contain water, which isn't present as liquid, ice or vapor; instead, it is trapped in the ringwoodite's molecular structure as hydroxide ions (bonded oxygen and hydrogen atoms).

In March, another research group discovered an unusual diamond from the mantle that encased hydrous ringwoodite. Though the find suggested the transition zone could contain a lot of water, it was the first and only ringwoodite specimen from the mantle scientists have ever analyzed (all other samples were produced in the lab or found in meteorites), and may not be representative of other mantle ringwoodite.

"Right now, we're one-for-one, because that ringwoodite had some H2O in it, but we didn't know if it was normal," Schmandt told Live Science. So Schmandt and geophysicist Steven Jacobsen of Northwestern University in Illinois set out to observationally test if other mantle ringwoodite also contains water.

The researchers knew the crystal structure of ringwoodite allows the transition zone to hold water, but that structure changes if the material moves across the boundary to the lower mantle (due to increasing pressures and temperatures). Because the structure of minerals in the lower mantle can't trap water the way ringwoodite can, Schmandt and Jacobsen reasoned the rocks would melt as they flowed from the transition zone to the lower mantle. "Melting is just a mechanism of getting rid of the water," Schmandt said.

To test this hypothesis, Jacobsen and his colleagues conducted lab experiments to simulate what would happen to transition zone ringwoodite as it travels deeper into the Earth. They synthesized hydrous ringwoodite and recreated the temperatures and pressures it would experience in the transition zone by heating it with lasers and compressing it between hard, anvil-like diamonds.

Using their setup, they then slowly increased the temperature and pressure to mimic the conditions in the lower mantle. The ringwoodite transformed into another mineral called silicate perovskite, and transmission electron microscopy showed that the mineral contained silicate melt around single crystals of perovskite.

"What that tells us is if there is similarly hydrated ringwoodite in the transition zone that's dragged down, we would expect it to produce melt," Schmandt said. "Because melt changes how seismic waves propagate, that's a target I can hunt for [with seismometers]."

Finding the melt

Using the Earthscope USArray, a network of portable seismometers across the United States, Schmandt analyzed seismic waves as they passed from the transition zone to the lower mantle. He found the waves slowed as they crossed into the lower mantle, suggesting that melt was present in the boundary. Importantly, the decrease in seismic velocity didn't happen everywhere — models showed the wave velocity decreased only where material was flowing downward from the transition zone to the lower mantle, as the researchers predicted. [Infographic: Earth's Tallest Mountain to Its Deepest Ocean Trench]

The melt produced in the boundary likely then flows back upward, returning to minerals that can hold the water, Schmandt said, adding that this mechanism allows the transition zone to be a stable water reservoir.

"[The study] provides critical experimental support for the important role that the transition zone plays in controlling the melting behavior and flux of hydrogen in the deep Earth," Graham Pearson, a mantle geochemist at the University of Alberta, who wasn't involved in the work, told Live Science in an email.

Anna Kelbert, a geophysicist at Oregon State University who also wasn't involved in the study, notes that scientists have previously used numerous approaches to look for evidence of Earth's interior water reservoir, but this is the first time researchers have searched for clues of the reservoir by focusing on the potential water-induced melting at the bottom of the transition zone. "It provides an important multidisciplinary perspective on this problem," Kelbert said. "It has important implications on our understanding of the behavior of subducting slabs deep in the mantle, and on our understanding of overall water budget/distribution in the Earth."

Read more at Discovery News

The 120-Foot-Long Jellyfish That’s Loving Global Warming

The lion’s mane jellyfish only looks like a lion’s mane if you squint really hard and pretend that lions have tentacles and live in the ocean. And have translucent heads.

In the Sherlock Holmes story “The Adventure of the Lion’s Mane,” our hero is strolling along a beach when he comes across a man in his death throes, staggering and screaming before shouting his last words: “The lion’s mane!” His name is Fitzroy McPherson, and all over his back are thin red lines—which Sherlock notices because he’s a detective and all—as though the man “had been terribly flogged by a thin wire scourge.”

McPherson’s colleague, a mercurial fellow named Ian Murdoch, becomes a person of interest. He had, after all, once thrown McPherson’s dog through a plate glass window. But that suspicion falls to pieces when the dog-hurler himself staggers into Sherlock’s home in comparable agony, all marked up with the same red lines.

And then the answer hits the great detective. With a police inspector and a guy named Stackhurst he hurries to the beach and finds the culprit: “Cyanea!” he cries. “Cyanea! Behold the Lion’s Mane!” It’s a great jellyfish among the rocks. Shouts Sherlock: “It has done mischief enough. Its day is over! Help me, Stackhurst! Let us end the murderer forever.” And with that they push a boulder into the water, crushing the critter.

That’s a whole lot of animal cruelty in a single short story, and the severity of a sting from a lion’s mane jellyfish, known scientifically as Cyanea capillata, is highly exaggerated here. But this critter is actually far more remarkable than its fanciful villainization. What Sherlock failed to mention is that this is the world’s largest jellyfish, with a bell that reaches a staggering 8 feet wide and tentacles that grow to 120 feet long, far longer than a blue whale. And this monster is really, really loving the whole global warming thing, conquering more and more of Earth’s oceans in massive blooms. So please, if you will, welcome our new giant gelatinous overlords.

“Hey, kids? Do me a solid and keep your hands off of me.”

It’s those seemingly endless tentacles, hundreds and hundreds of them, that make this incredible growth possible, according to Lisa-Ann Gershwin, a marine biologist with Australia’s Commonwealth Scientific and Industrial Research Organisation. “They’ve got all of these fishing lures out there at the same time,” she said. “Every single tentacle is out there to catch something. They can find so much food simply by multitasking, really.”

Lion’s manes will take just about anything, from the tiniest zooplankton—little critters and fish larvae and such that drift in the open ocean—to smaller jelly species and even their own kind. Their mighty weapons are stinging cells known as nematocysts, which on contact fire poisonous barbs into the prey (think Scorpion from Mortal Kombat, only nematocysts didn’t used to get me in trouble for spending so much money in arcades).

Though nowhere near as powerful of the notoriously deadly box jellyfish, the sting of the lion’s mane is more than enough to incapacitate small critters—and dish out searing pain to humans. (Gershwin herself once had a lion’s mane sting her foot, which “went all red and puffy” and felt like it was being stabbed with “thousands of needles.”) Thoroughly ensnared by the tentacle’s innumerable spines and none too healthy on account of the poison, the prey is reeled in. The lion’s mane can do this a single tentacle at a time, contracting the muscles in each until the prey reaches its curtain-like “oral arms,” folds of tissue in its bell.

The photographer likely suffered greatly to take this picture, but rest easy knowing that we paid for the rights to republish it, so at least he’s getting compensated for his efforts.

From here the prey passes into the jelly’s mouth, which is really just a hole in its body that also functions as its anus, and finally moves into the stomach. “And then they have a circulatory system of canals where the nutrients from the stomach are just dispersed out to the rest of the body through this network,” said Gershwin. “It’s really, really simple, but it works really well. I mean, they’ve been doing exactly that for 600 million years, and it works so well they haven’t needed to change it.”

That’s quite an evolutionary sweet spot. Such a sweet spot, in fact, that the lion’s mane never bothered to evolve true eyes. Instead, these jellies have extremely rudimentary eyespots and can do nothing more than detect light and dark—no shapes and certainly no colors (interestingly, box jellyfish have eyes more like our own, complete with lenses and such, presumably so they can observe the terror they strike in humans). And a brain? Not really necessary, as it turns out. They do have nerve bundles that essentially automate all of their processes, but these are nothing like a brain as we would recognize it.

“A brain is kinda overrated, really,” said Gershwin. “We find it kind of entertaining, and a little bit important, but they do all the stuff they need to do without a brain. But so do venus fly traps. Lots of things can actually do kind of sophisticated behaviors without a brain.”









 Reproduction for the lion’s mane, though, is quite sophisticated. Males release sperm threads into the water, and females hoover them up with their mouth-anus thing, a totally unscientific term that I just made up. Her eggs are fertilized internally, and when they hatch, the larvae roam around a bit inside her, then drift off to settle on the seafloor.

But these larvae don’t turn right into what we would identify as jellies, in what is known as the medusa stage, named after the mythical lady with snakes for hair. Instead, they become little white tubes with frilly ends called polyps, which wait until conditions are just right to actually clone themselves hundreds of times over, releasing baby jellies into the water column. Though scientists have yet to do genetic testing on this, Gershwin suspects that huge blooms of lion’s mane jellies could in fact all be clones from a single tiny polyp. It’s a bit like Attack of the Clones, only interesting.

Sting Operation

And boy have they been blooming. Populations of jellyfish like the lion’s mane seem to be exploding in the world’s oceans—because, bluntly put, we’ve goofed. Global warming, overfishing, pollution, basically anything terrible we’ve done to the seas have been an absolute boon to jellyfish, according to Gershwin. Data on jellyfish populations is scarce, so nothing is yet definitive, but as Gershwin puts it, “we now find ourselves in the unexpected position of knowing that we have serious problems with stings to tourists and cloggings of power plants and salmon kills and whatnot, but really having little idea about the speed and trajectory in terms of long-term view.”

As humans, it’s clear we need to tackle the direness that is global warming, but the lion’s mane and its jelly comrades would really prefer that we didn’t. Not only do jellies grow faster in warmer waters, temperature is a pivotal factor in their reproduction. In some species, polyps will only develop as days grow longer in summer, but others instead wait until the water climbs to a certain temperature. Thus ever-hotter oceans in these times of global warming could make for more blooms.

Yeah, we didn’t have to pay for this one, so hopefully the photographer is OK.

 In addition, global warming is monkeying with oxygen concentration in our seas, which is also great news for jellies. “Colder water holds more dissolved oxygen than warmer water,” said Gershwin. “So even a really slight warming—a degree, a half a degree, a quarter of a degree—we may not feel it, but it changes the amount of oxygen that the water can hold.”

And jellyfish are really good at living in oxygen-deprived water. Pretty much everything else in the sea? Not so much. “High-rate breathers,” such as beefy fish that need lots of oxygen to power their muscles, die off when jellyfish lazily cruise around, not the slightest bit fazed.

Then there’s the inflow of our sewage and fertilizers, nutrients that microscopic plants called phytoplankton go ga-ga for. Their populations explode, and are then eaten by their animal counterparts, zooplankton, which are in turn eaten by jellies. But when blooming phytoplankton die and decompose, the bacteria that feed on them suck still more oxygen out of the water.

Read more at Wired Science

Tiny Plants Travel Around the World via Bird Wings

Bird wings harbor tiny plants that, with their avian transportation, can travel at least half way around the world, a new study finds.

The plants likely fall off here and there, colonizing regions far away from where each of the plant’s journeys began, according to the study, which is published in the journal PeerJ.

For the study, a team of 10 biologists, including three undergraduate students, collected American golden plover feathers in the field and used microscopes to closely examine the feathers.

The researchers found a total of 23 plant fragments that were trapped in the feathers of long-distance migratory birds that were about to leave for South America.

“We really had no idea what we might find,” one of the undergrads, Emily Behling, was quoted as saying in a press release.

The University of Connecticut senior added, “Each feather was like a lottery ticket, and as we got further into the project I was ecstatic about how many times we won.”

Clinging to the feathers were mosses, spores, plant pieces and more. Most are thought to be able to grow into new plants if they fall off, or if the bird knocks them off, in a suitable environment.

For example, about half of all known moss species can self-fertilize to produce offspring. Many can grow as clones. It only takes a single successful dispersal event to establish a new population. This helps to explain why moss might suddenly appear here and there in home gardens.

Co-author and PhD candidate Lily Lewis, also from the University of Connecticut, said, “Mosses are especially abundant and diverse in the far Northern and Southern reaches of the Americas, and relative to other types of plants, they commonly occur in both of these regions, yet they have been largely overlooked by scientists studying this extreme distribution. Mosses can help to illuminate the processes that shape global biodiversity.”

Read more at Discovery News

Frogs' Tongues Can Lift Three Times Their Weight

Could you bench press three times your weight — with your tongue? An experiment with horned frogs shows these amphibians’ tongues are just that strong.

O.K., they weren’t exactly doing bench presses, but an experiment with horned frogs measured the power of their tongues by placing a tasty cricket behind a glass slide. When the frogs’ tongues shot out at lightning speed to grab the crickets, a transducer attached to the slide recorded the forces exerted by the frog’s tongue.

The South American horned frog is known for its incredible snatching power — it has been observed slurping up whole mice in the wild. A study published in the journal Scientific Reports, suggests the tongue functions similar to sticky tape.

Thomas Kleinteich at the University of Kiel in Germany used four horned frogs purchased from local pet shops. Even these domesticated versions displayed incredible tongue power and speed. The forces measured from their tongues were on average larger than the weight of the frog itself, and more than three times bigger in the case of one of the younger frogs.

“The thing that’s interesting about frog tongues is that they’re really fast,” he told BBC News. “It only takes milliseconds.”

Of course, force, alone, can’t capture a cricket or mouse. That also requires some stick, which, in the case of the frog, comes in the form of mucus. Interestingly, the researchers found that less may be more when it comes to mucus and grabbing power.

“The common belief is… that the mucus acts as some sort of superglue,” Dr Kleinteich told the BBC. “But what we found was actually that we got higher adhesive forces in trials where we found less mucus. That was quite interesting.”

Read more at Discovery News

Did Super-Sized Animals Live Long Before Dinosaurs?

It's generally believed that Earth's earliest animals were not very big, but discovery of a huge new fish that lived around 423 million years ago has scientists rethinking what life was like close to 200 million years before the first dinosaurs emerged.

The fish, named Big Mouth Blunt Tooth (Megamastax amblyodus), is described in the latest issue of Scientific Reports. For its time, the toothy and lobe-finned fish was in the number one spot on the food chain.

"At 1 meter (3.3 feet) in length or greater, it was vastly larger than any other animal," lead author Brian Choo told Discovery News, adding that Big Mouth was "likely the earliest vertebrate (backboned) apex predator in the fossil record."

Choo, a paleontologist at the Chinese Academy of Sciences and Flinders University, and his colleagues analyzed Big Mouth's remains, which were unearthed at the Kuanti Formation in Yunnan, southwestern China. During the fish's lifetime, a period known as the Silurian, this region was part of the South China Sea. It is where the marine ancestors of all jawed animals, including humans, first evolved.

Equipped with both piercing and crushing teeth, Big Mouth likely preyed upon hard-shelled moving species, such as mollusks and armored fishes. The second largest animal at the time, Guiyu onerios -- aka Ghost Fish, was a mere one-third of Big Mouth's size.

Why then was Big Mouth so big?

One reason, according to the researchers, is that competition among fish appears to have been fierce.

Co-author Min Zhu explained, "During the Silurian period, the South China Sea, then at the equator, was the cradle of early jawed vertebrates, thus the ecological competition among these creatures was very intense."

Another reason is that Big Mouth probably had plenty of oxygen. Modern fish are generally worse off in low oxygen conditions, and big fish require more oxygen than small ones, Choo said. Big Mouth therefore could not have existed unless sufficient oxygen was present.

This has major implications because, as it stands, there are two major theories about what Earth's oxygen level was like during the Silurian. One holds that near-modern oxygen levels occurred around 420 million years ago, while another holds that they did not occur until 20 million years later.

Big Mouth provides strong evidence that near-modern oxygen levels occurred at least 420 million years ago, which Choo said was "a likely byproduct of the spread of plants on land."

"There was life on land during the Silurian, but it certainly wasn't nearly as diverse as today," he continued. "There would have been a variety of low-growing primitive plants growing in moist areas. While there were no trees, there was a towering organism called Prototaxites, possibly a giant fungus, which grew up to 8 meters (26.3 feet) tall."

The only animals on land were backbone-less ones, such as huge sea scorpions that scuttled along the beaches and swamps. There were no flying animals at this time, and sharks weren't around yet either. If additional Big Mouth-sized (or larger) animals did exist, they were probably other fish.

Paleontologist Per Ahlberg is a professor of evolutionary organism biology at Uppsala University. He recently saw the fossils for Big Mouth, and was impressed.

Read more at Discovery News

Oldest Handmade Skull Attributed to Leonardo da Vinci

Researchers believe they have found Leonardo Da Vinci’s “sorrow stone” — a creepy, miniature skull crafted in great anatomical detail.

Missing a lower jaw, the early 16th century artifact was found by a German couple in 1987 in an antique shop.

“It is a small, naturalistic looking, deformed skull of a more than 50-year-old-male and it is made of a partially hollowed stone like material,” wrote independent Belgian researcher Stefaan Missinne in the Wiener Medizinische Wochensschrift, a medical journal published in Vienna.

Milky white with small, brownish-yellow stains, the tiny artifact features remarkable detail. “Detailed eye sockets lead to the inside of the cranium and allow for a ‘view’ of the inside, which is anatomically abnormal,” Missinne said.

According to French skull expert Roger Saban, the object resembles an anatomic drawing known as RL 19057. Housed in the Royal Collection in Windsor Castle, the unpublished drawing shows a similar deformed skull missing a lower jaw.

Despite the extraordinary level of detail, the drawing and the skull both feature the same small anatomical errors, further strengthening the link with Leonardo.

Chemical analysis showed the artifact was made from an agate-based mixture of quartz and gypsum. Leonardo invented this mixture, which he called “mistioni,” between 1503 and 1509. No one else is known to have experimented with this material, which was likely sourced in a mine near Volterra in Tuscany.

The size of the artifact match Florentine measurement units that were used in the Renaissance. “The origin of the skull, leads, therefore, to Florence,” Missinne said.

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