Jul 28, 2014

How Texas Man Survived 1,000 Killer Bees

A municipal worker who got stung by an estimated 1,000 bees while mowing a park lawn on Thursday (July 24) was in stable condition. So how did he survive the buzzing attack?

Turns out, the man's attackers — probably Africanized honeybees, according to the local fire department — are not as deadly as their name may suggest. To be lethal, the bees would likely have had to sting the man several hundred more times, experts say. In addition, the victim seems not to have been allergic to the bees. (The bees also stung two other workers who tried to help the man, according to Wichita Falls' News Channel 6.)

Not-so-killer bees

Africanized honeybees, or "killer bees," have been in the United States since about 1990, according to May Berenbaum, head of the department of entomology at the University of Illinois. But despite their dramatic nickname, these insects aren't that deadly.

An estimated 40 people in the United States die every year from stings by hymenoptera species. That group of insects includes some 150,000 species of bees (and killer bees), wasps, ants and other bugs, Berenbaum said.

It's hard to pin down specific data on the number of people attacked annually in the United States by Africanized honeybees: As Berenbaum explained, this is partly because not all attacks are reported and partly because, oftentimes, people aren't quite sure what stung them.

Furthermore, it's difficult to pin the blame on a particular species of bee in instances of injuries or deaths caused by insects, because some species don’t leave any telltale evidence. While honeybee stingers stay behind in the body of the victim, many species take their stingers with them after attacking, Berenbaum explained.

Fierce defenders

Though Africanized honeybees don't always attack, when they do, the results can be devastating. While the victim of Thursday's attack in Wichita Falls, Texas, survived the incident, not all killer bee victims have been as lucky.

Last year in Waco, Texas, about three hours south of Wichita Falls, an estimated 40,000 Africanized honeybees attacked a local farmer who was mowing a neighbor's pasture with tractor, ABC News reported. Larry Goodwin, 62, sustained more than 3,000 stings before collapsing to the ground. He was pronounced dead at the scene.

The number of stings that Goodwin sustained likely caused his unfortunate death, Berenbaum explained. The average person can sustain 10 bee stings per pound of body weight, both Berenbaum and the U.S. Department of Agriculture note. As such, 500 stings might be enough to kill a child, but the 1,000 stings suffered by the man in Wichita Falls did not deliver a lethal dose of venom, given his body weight.

"With honeybees, in particular, the venom isn't really designed to kill. It's designed to educate — basically, to drive away an enemy and make sure the enemy doesn't repeat the threat," Berenbaum told Live Science.

Unfortunately for the victims of killer bee attacks, the insects aren't very good at distinguishing between a true threat and an accidental nudge from a noisy mower. Africanized honeybees are extremely protective of their hive and brood, much more so than European honeybees. And their "home turf" is much larger than that of their calmer cousins. About 100 yards (91 meters), or the length of a four-lane highway, is usually a safe distance from these insects, according to the U.S. Department of Agriculture.

In addition to number of stings, other factors also play roles in determining a person's chances of surviving a killer bee attack. These include the general health of the victims, and their weight and sensitivity to bee venom.

Furthermore, people who are allergic to bee stings can experience a severe physiological reaction after just one sting, Berenbaum said.

Called anaphylactic shock, this severe allergic reaction can prove lethal for some people attacked by bees. Berenbaum describes anaphylaxis as an "immune response running amuck," and while she said that everyone is likely to experience some kind of allergic reaction to bee venom, only some individuals experience anaphylactic shock.

Allergic to bees or not, anyone who encounters a swarm of these defensive insects should "run away," she said. "And don't zigzag. That serpentine move you see in movies all the time just slows you down."

Read more at Discovery News

Colossal Bad Luck Caused Dinosaurs To Go Extinct

Dinosaurs would likely still be around today if the 6.2-mile-wide Chicxulub asteroid had crashed into Earth just a little while before or after it did, concludes an international team of some of the world's leading paleontologists.

In short, dinosaurs were victims of colossal bad luck, according to University of Edinburgh vertebrate paleontologist and evolutionary biologist Stephen Brusatte, who led the study that is published in the latest issue of Biological Reviews.

"The asteroid almost certainly did it," meaning wiped out the dinosaurs, he told Discovery News, "but it just so happened to hit at a bad time when dinosaur ecosystems had been weakened by a loss of diversity."

"If the asteroid hit a few million years earlier, when dinosaurs were more diverse, or a few million years later, when they had a chance to recover as they often had done before after diversity losses, then dinosaurs probably wouldn't have gone extinct," he said.

Brusatte and his team came to this conclusion after studying an updated catalog of dinosaur fossils to create a picture of how dinosaurs, and the environment, changed over the few million years before the asteroid struck what is now Mexico.

The researchers found that during the years prior to the asteroid hit, Earth was undergoing huge volcanic eruptions and extreme changes in temperature and sea level. The changes were, at least in some respects, interconnected. For example, major volcanic eruptions, especially in what is now India, likely affected global temperatures.

Tectonic events, such as mountain formation, also led to the disappearance of a large seaway that had covered much of the interior of North America during most of the Cretaceous.

All of these changes impacted dinosaur populations, with large plant-eating dinosaurs that were at the base of the food chain particularly experiencing a dramatic drop in number. This, in turn, would have weakened the entire dino ecosystem.

"I think there is a perception that when the asteroid smashed into the Yucatan Peninsula 66 million years ago, it hit a static world, something of a paradise in which dinosaurs had been thriving for millions of years," Brusatte said. "But the asteroid actually hit a planet that was experiencing a lot of turmoil."

Paleontologists may be coming to a consensus on how non-avian dinosaurs--which flourished for over 150 million years--bit the dust, but they still don't know why certain birds survived the end of the Cretaceous onslaught.

"A lot of dinosaurs really looked and behaved like birds," he said. "If we were standing around in the Cretaceous, I don't think we would have made a distinction between a Velociraptor-type dinosaur and a true bird, and that is true of these feathered dinosaurs: these things were basically birds, and the line between them and birds is an arbitrary one."

Many species of birds did go extinct around 66 million years ago--just not all of them--reminded Richard Butler of the University of Birmingham's School of Geography, Earth and Environmental Sciences. Butler was not a co-author of the new paper.

Some birds might have survived because they were small, had more offspring, or possessed certain other characteristics and behaviors that permitted their survival, Butler and Brusatte theorize.

They both think that, without the asteroid impact and all of the other climatic and environmental upheaval, dinosaurs would still be roaming the planet today.

Read more at Discovery News

River in China Turns Red in an Hour

A river in China that's normally considered quite clean turned blood red in just an hour last week.

Residents were shocked at the turn of events, in part because there are no factories or chemical plants in the area and it was considered unpolluted.

The water looked fine, residents said, early in the morning last Thursday. But then about 200-300 meters of the river began turning red and had a strange smell.

"The really weird thing is that we have always been able to catch fish and you can even drink the water because it's just normally so good," local Na Wan told NBC News. "Nobody has any idea how it could have ended up being polluted because there are no factories that dump anything in the water here."

NBC reported that experts were on the scene taking samples and one suggested that the cause was likely some sort of dye that had been dumped in the river.

From Discovery News

'Family on All Fours' Not an Evolutionary Throwback

When Turkish evolutionary biologist Uner Tan introduced the world to a Turkish family with some members who could walk only on all fours, in a "bear crawl," he and other scientists speculated this odd gait was the resurgence of a trait lost during human evolution.

Not so, a new study finds.

The family and other people with Uner Tan syndrome do not represent "a backward stage in human evolution," as Tan wrote in a 2006 paper in the International Journal of Neuroscience, said Liza Shapiro, a professor of anthropology at the University of Texas at Austin. In new research, Shapiro and her colleagues compared videos of the family's gait with the gaits of nonhuman primates, such as chimpanzees or gorillas. They found the gait patterns did not match. Instead of recreating ape walks, people with Uner Tan are simply adapting to their disorder, Shapiro and her colleagues reported July 16 in the journal PLOS ONE.

Tan first noticed the syndrome that now bears his name in a family of 19 living in rural southern Turkey. Five of the family members walk using their feet and hands, and also have cognitive disabilities. The family was the subject of the 2006 BBC2 documentary, "The Family That Walks on All Fours."

Research has since revealed that the disorder is caused by a genetic mutation on chromosome 17, which affects the cerebellum, part of the brain responsible for movement and balance. From the beginning, Tan's statements about the evolutionary nature of the affected family's walking patterns were controversial. The affected children never had physical therapy or adaptive technology such as wheelchairs, making their gait a necessity.

But no one ever challenged the primary claim: that the affected children walked like nonhuman primates. Primates that walk on all fours do so differently than most other mammals, Shapiro told Live Science. Primates walk in a diagonal sequence, putting down a hind limb and then the opposite front limb: left foot, right hand, right foot, left hand.

Most other mammals walk in a lateral sequence, with the same-side limbs following each other: left foot, left hand, right foot, right hand. Human babies and adults asked to "bear crawl" on hands and feet typically walk in a lateral sequence, too, Shapiro said.

Shapiro said she became interested in studying the gait of people with Uner Tan Syndrome in 2006 after seeing the documentary on the Turkish family.

"It was all about whether or not it was evolutionary reversal, which kind of horrified me," she said. Immediately, though, she could see that the family was not using the primate diagonal gait.

Shapiro did not have access to good video of the family's walking patterns until recently, when one of her co-authors told her he had footage from the BBC. From that video, she and her colleagues were able to analyze more than 500 strides made by the five family members with the disorder.

About 99 percent of the strides were lateral, not diagonal — a blow against the notion that the family members had "rediscovered" an ancestral primate way of walking. Instead, they were walking like any typical adult would if asked to move on hands and feet.

A lateral gait is handy for long-limbed animals (such as humans) when walking on all fours, she said, because it helps keep the limbs from bumping into one another.

Read more at Discovery News

Monster Hawaii Telescope Construction Begins

The construction phase of the world’s biggest optical telescope has begun atop Mauna Kea, Hawaii.

Final approval by the Hawaii Board of Land and Natural Resources for a sublease on July 25 has green-lighted building work for the Thirty Meter Telescope (TMT) to begin in October.

With a primary mirror spanning 30 meters, the TMT will dwarf all optical telescopes on Earth and in space. The twin-telescope Keck Observatory is the next biggest telescope on Mauna Kea with mirrors measuring 10 meters across. Not only will the TMT dwarf Keck, it will also be able to acquire observations 12-times sharper than the Hubble Space Telescope.

Initiated ten years ago by the Association of Canadian Universities for Research in Astronomy (ACURA), the California Institute of Technology (Caltech) and the University of California, the TMT’s international scope has expanded to include partners around the globe. Chinese and Japanese institutions are working to build components for the TNT and India is also expected to join the collaboration.

“Design of the fully articulated main science steering mirror system in the telescope, as well as development of the lasers, laser guide star systems and other high-tech components, is proceeding in China,” said Yan Jun, Director General of the National Astronomical Observatories of China, in a TNT press release.

“Japan has seen to the production of over 60 mirror blanks made out of special zero-expansion glass that does not alter its shape with temperature changes,” said Masanori Iye, TMT International Observatory Board Vice Chair and TMT Japan Representative for the National Astronomical Observatory of Japan. “The blanks will be highly polished for use in the telescope’s 30-meter diameter primary mirror. The final design of the telescope structure itself is nearing completion.”

The TMT’s 492-segment mirror will observe the Cosmos in wavelengths from near-infrared, through optical to ultraviolet, allowing us an unprecedented view of objects in our galaxy and the first stars that were forming after the Big Bang. Like Keck, the TMT will use adaptive optics (AO) to compensate for atmospheric turbulence.

AO utilizes a powerful laser that cuts through the upper atmosphere, creating an artificial star from the telescope’s perspective, detecting turbulence. It is this turbulence that is responsible for twinkling stars — interference that can blur celestial targets for telescopes on the ground. Atmospheric aberrations can then be compensated for by rapid adjustments by each telescope segment.

Read more at Discovery News

Jul 27, 2014

Downy Beast Suggests All Dinos Sported Feathers

Steven Spielberg's "Jurassic Park" might need a little more revising -- a newly discovered dinosaur species offers hints that feathers were much more common among the ancient beasts than once thought.

Researchers unearthed hundreds of fossils of a new genus and species of plant-eating dinosaur called Kulindadromeus zabaikalicus in Siberia that sports both feathers and scales. The finding suggests that most dinosaurs had feathers, which they used for insulation or attracting mates, only later relying on the fringes for flight, according to a study detailed today (July 24) in the journal Science.

"Here, for the first time, we have found featherlike structures in a dinosaur is far from the lineage leading to birds," said study co-author Pascal Godefroit, a paleontologist at the Royal Belgian Institute of Natural Sciences in Belgium.

Scientists have long known that birds descended from dinosaurs. Since the mid-1990s, paleontologists in China have been finding feathered dinosaur skeletons from about 20 different groups, but they all belonged to a single lineage, theropods, which includes Tyrannosaurus rex and velociraptors. In fact, some scientists believe T. rexmay have sported some feathers itself.

Godefroit and his colleagues found hundreds of skeletons of the same species, from a lineage of plant-eating dinosaurs known as ornithischians, which lived about 160 million years ago during the middle to late Jurassic period. Researchers found the fossils buried in the bottom of what appears to have been a large lake.

"It was a small animal, not very impressive," Godefroit said. It was about 4.9 feet (1.5 meters) long; walked on two long, slender legs; and sported very short arms, he said.

The little dinosaur skeleton was equipped with preserved long filaments resembling downy feathers around its arms and legs. Because the animal couldn't fly, the scientists think these filaments may have served as insulation. The specimen also had more-complex feathers that it may have used to entice mates, Godefroit said. The animal had a long tail, covered in large, thin scales.

The preservation of soft tissues such as feathers and scales is extremely rare, the researchers said, which explains why relatively few feathered dinosaur fossils have surfaced before. "The conditions for preserving feathers are really exceptional," Godefroit said.

"This is the first time birdlike feathers have been found in dinosaurs that are not closely related to birds," said Darla Zelenitsky, a paleontologist at the University of Calgary in Canada, who was not involved in the research. "This unexpectedly reveals that such feathers would likely have been present in most groups of dinosaurs," Zelenitsky told Live Science in an email.

Steve Brusatte, a paleontologist at the University of Edinburgh in Scotland, agreed that feathers probably existed in the common ancestor of all dinosaurs. The idea is not a new one, he said; two other fossils of plant-eating dinosaurs found in China had simple, filamentlike feathers, but it was debatable whether these were related to bird feathers, or evolved independently. Now, this new evidence "seals the deal that feathers were also present in plant-eating dinosaurs," Brusatte told Live Science.

As for the fossil scales, they resemble modern birds' scales, which are actually aborted feathers, the researchers said. In chickens, for example, genes in the skin control the development of feathers. If these genes are modified, the chicken will sprout feathers on its legs, like that of an English chicken. Perhaps primitive dinosaurs had already developed this genetic mechanism of preventing feathers from developing in certain parts of their bodies, Godefroit said.

Read more at Discovery News

Tonga May Have Been a Vast Seafaring Empire

The seafaring empire of Tonga in the South Pacific Ocean once spanned more than a thousand miles, serving as the hub through which distant settlements exchanged artifacts and ideas, researchers say.

This finding could help explain the rise of monumental structures throughout the Pacific starting about 700 years ago, scientists added.

Tonga is an archipelago of about 160 Polynesian islands, with the core of the kingdom covering an area of about 195,000 square miles (500,000 square kilometers). The islands, located about two-thirds of the way from Hawaii to New Zealand, were first settled about 2,800 years ago by the Lapita people.

Beginning about 800 years ago, a powerful chiefdom arose in Tonga, unique in Oceania — that is, the islands of the South Pacific — in how it successfully united an entire archipelago of islands. However, much remained unknown about how far Tonga's influence actually reached.

"How much voyaging and interaction occurred in the prehistoric Pacific has been debated for centuries," said lead study author Geoffrey Clark, an archaeologist at the Australian National University in Canberra.

To learn more about the extent of Tonga's empire, scientists chemically analyzed nearly 200 stone tools excavated from the centers of its leaders, especially artifacts from the royal tombs on Tongatapu, the main island of Tonga. They also chemically analyzed more than 300 stone artifacts and rock samples taken from other Pacific islands, such as Samoa.

"All of the work has been done with a large Tongan workforce from the community who are now being funded to conserve many of the monumental tombs," Clark said.

They found that stone artifacts in Tonga often matched rock samples from Samoa and Fiji — in fact, 66 percent of stone tools analyzed from Tonga were long-distance imports. One tool apparently was made from rock that came from as far away as Tahiti, about 1,550 miles (2,500 km) east of Tongatapu. In contrast, stone tools from a monumental stone mound in Samoa were made from local sources of rock.

These findings revealed that Tonga was the center of a maritime empire that goods flowed toward as tribute from distant locales. The researchers suggest these exotic artifacts may have served as status symbols among Tongan elites.

"Complex societies like the Tongan maritime chiefdom had extensive contacts with other island groups," Clark told Live Science. "The chiefdom was an important interaction hub through which ideas, goods and people could move over large distances."

In addition, these findings could help explain puzzling discoveries seen elsewhere in Oceania.

"It has been observed that many of the significant chiefdoms in the Pacific began to build monumental architecture around the same time as one another — 1300 to 1500 A.D. — and it's been unclear why this should be, as the societies are often separated by thousands of kilometers of ocean," Clark said. This new work suggests the formation of the Tongan state may have stimulated these widespread changes in the Pacific.

In the future, the researchers want to find and examine stone tools from before the rise of the Tongan state to understand how interactions between Tonga and other islands changed over time.

Read more at Discovery News

Carving Defaced by King Tut's Possible Father Found

A newly discovered Egyptian carving, which dates back more than 3,300 years, bears the scars of a religious revolution that upended the ancient civilization.

The panel, carved in Nubian Sandstone, was found recently in a tomb at the site of Sedeinga, in modern-day Sudan. It is about 5.8 feet (1.8 meters) tall by 1.3 feet (0.4 m) wide, and was found in two pieces.

Originally, it adorned the walls of a temple at Sedeinga that was dedicated to Queen Tiye (also spelled Tiyi), who died around 1340 B.C. Several centuries after Tiye's death — and after her temple had fallen into ruin — this panel was reused in a tomb as a bench that held a coffin above the floor.

Archaeologists found that the god depicted in the carving, Amun, had his face and hieroglyphs hacked out from the panel. The order to deface the carving came from Akhenaten (reign 1353-1336 B.C.), a pharaoh who tried to focus Egyptian religion around the worship of the "Aten," the sun disk. In his fervor, Akhenaten had the name and images of Amun, a key Egyptian god, obliterated throughout all Egypt-controlled territory. This included the ancient land of Nubia, a territory that is now partly in Sudan.

"All the major inscriptions with the name of Amun in Egypt were erased during his reign," archaeology team member Vincent Francigny, a research associate at the American Museum of Natural History in New York, told Live Science in an interview.

The carving was originally created for the temple of Queen Tiye — Akhenaten's mother — who may have been alive when the defacement occurred. Even so, Francigny stressed that the desecration of the carving wasn't targeted against Akhenaten's own mom.

Today, only one column and a plethora of blocks survive from Queen Tiye's temple, which has not been excavated, Francigny said.

The archaeologists also found that, after Akhenaten's death, the god's face and hieroglyphs on this carving were restored. This restoration may have been done during the reign of the boy king Tutankhamun (reign 1336-1327 B.C.), who is famous for his rich tomb.

"The name of Amun as well as his face were first hammered out and later carved anew, proving that the persecution of this god extended to this remote province during the reign of Akhenaton and that his images were restored during the following reigns," Francigny and Claude Rilly, director of the French archaeological mission in Sedeinga, wrote in the most recent edition of the journal Sudan and Nubia.

Akhenaten's religious revolution did not last. Shortly after his death, Tutankhamun, who may have been Akhenaten's son, assumed the throne and returned Egypt to its former polytheistic religion.

This particular carving would have been restored either during King Tut's reign or one of his successors'.

An ancient record tells of Tutankhamun's efforts to try to undo the revolution Akhenaten had unleashed. The account blasts Akhenaten, claiming that his revolution led the gods to abandon Egypt.

Read more at Discovery News

Satanic Leaf-Tailed Gecko Wears the World’s Most Unbelievable Camo

The incredible satanic leaf-tailed gecko does a spot-on impression of a leaf. "Thank you, thank you," the gecko says. "I'll be here for the three to five years of my expected lifespan."
“What’s in a name?” Shakespeare once asked, apparently in Romeo and Juliet, which I just learned from Google because I did not pay attention in that class in college. “That which we call a rose by any other name would smell as sweet.” I think this means that a name doesn’t matter for much, because it’s just, like, words or something.

But don’t tell that to Madagascar’s most excellently named, not to mention most beautiful, critter: the satanic leaf-tailed gecko (sorry, aye-aye, but you’re a close second on both the name and the beauty). That’s its actual name, and you can be damn sure the gecko is proud of it. But monikers aside, this masterfully camouflaged little lizard, with a leafy tail complete with missing chunks that look to have rotted away, is a testament to natural selection.

Known to scientists as Uroplatus (meaning “flat tail”) phantasticus (meaning “good lord what is this thing and why is it looking at me like that?”), the satanic leaf-tailed gecko is one of 14 species in its genus, including the mossy leaf-tailed gecko, which long ago renounced Satan in favor of Mosses. These geckos are found only in Madagascar, and emerge only at night to hunt.

Satanic leaf-tailed geckos come in all manner of colors, including orange and stick.
It’s thought that they’re after mostly insects, yet little is known about their diet in the wild. In captivity, though, “satanic leaf-tailed geckos feed on almost everything they can overwhelm, including crickets, flies, spiders, cockroaches, and snails,” said herpetologist Frank Glaw of the Bavarian State Collection of Zoology. “Large species like Uroplatus fimbriatus and Uroplatus giganteus even accept young mice.”

And the satanic leaf-tailed gecko has its own predators aplenty, including birds and snakes and rats. If they decide to stand their ground, they stare down their foes, and “suddenly widely open their mouths, emit loud cries, show the reddish tongue and mucosa and try to bite,” said Graw (it’s no wonder locals are very much afraid of the gecko—as they are of the aye-aye, as it happens). They’ll also flash their tails to confuse the potential predator, but should that fail, they can leap deftly from branch to branch or straight down to the leaf litter.

But, really, it’s best to just avoid being seen in the first place. And that, of course, is where their amazing camouflage really comes into play. Not only does the gecko’s tail look like a dead leaf, so too does its body.

“A light line along the back together with leaf-vein-like lines and skin structures on the body can complete the perfect imitation of a dead leaf,” said Graw. And their coloration is incredibly varied, as you can see in the gallery above, coming “in all shades of beige, grey and brown, often with a mixture of lichen-like or even greenish spots which look very much like moss. This variability ensures that they have an adapted outfit for the different structures in their habitat.”

To avoid detection, leaf-tailed geckos will hang from branches, much like leaves.
Reinforcing this camouflage for the satanic leaf-tailed geckos is their behavior: They’ll spend the day hanging motionless off of branches or snuggling among dead leaves, often twisting their leafy tails around their bodies. Other larger species in the satanic’s genus have still another strategy for sleeping safely during the day, flattening their bodies against tree trunks and limbs, making good use of those famously grippy feet (a magic power derived, by the way, from countless hair-like structures that allow some geckos to even stick to inverted glass panes, not that nature would ever ask them to). Fringes and flaps along the edges of their bodies help erase their outlines and shadows, dissolving the geckos into the bark.

“Both strategies, to mimic dead leaves or tree bark, are obviously very successful to bluff diurnal predators that rely on their vision, especially birds,” said Graw. “A similar strategy has evolved in the Australian leaf-tailed geckos that resemble Uroplatus, although they are not closely related. However, it remains remarkable that these strategies have not evolved more often among geckos from other parts of the world.”

Dance Dance Evolution

But how on Earth could such ridiculously and perfectly complex camouflage evolve in the first place? Surely, some guiding hand in the sky must have said, “Yes, that’s a lovely outfit, let’s go with that one.” In reality, the satanic leaf-tailed gecko and its related species are some of the most striking manifestations of Darwin’s principle of natural selection.

Some species of leaf-tailed gecko shun leaves to blend instead into bark. Can you find the gecko in this picture? If so, great job. You just made a gecko question its worth.
First of all, it’s a harsh fact of life that some animals produce more offspring than can possibly survive. (It’s particularly harsh when you consider something like Australia’s mouse-like marsupial antechinus, whose males have so much sex that they go blind and die. They’re lucky to even make it that far, though: Females give birth to more young than they have teats. The strongest make it to a teat and survive, the others perish and tumble off of their mother.) Even if the organism can manage to not get picked off by the predator, the environment isn’t necessarily suited to nurture every single individual. There’s a certain capacity.

Offspring are born with variations, just as you and your siblings look and behave differently. And these variations either end up suiting the organism better or worse to its environment. Critters with the magic variations—say, looking a bit like the leaves they live in—have a better chance of surviving (by being more likely to escape a predator’s notice) to pass these genes along. Thus does a species adapt ever so slowly to its environment over evolutionary time. It’s been happening on Earth for billions of years. The satanic leaf-tailed gecko just happens to be one of its more fantastically molded triumphs.

Read more at Wired Science

Jul 24, 2014

Humans Caused 322 Animal Extinctions in Past 500 Years

Our species caused 322 animal extinctions over the past 500 years, with two-thirds of those occurring in the last two centuries, according to a paper published in a special issue of the journal Science this week.

Many animals are threatened with human-caused extinction now, with researchers expressing particular concern over amphibian and invertebrate (creatures without a backbone) losses. Numbers of the latter group have nearly halved as our population doubled in size over the past 35 years.

Ecologists, zoologists and other scientists believe that, without urgent steps to stem the losses, we are facing global scale tipping points from which we may never look back or recover.

"Indeed, if current rates (of human population growth) were to continue unchecked, population size would be, by 2100, about 27 billion persons -- clearly an unthinkable and unsustainable option," co-author Rodolfo Dirzo, professor of environmental sciences at Stanford University, told Discovery News.

Dirzo and his colleagues call for "decreasing the per capita human footprint," by developing and implementing carbon-neutral technologies, producing food and goods more efficiently, consuming less and wasting less.

They also say it is essential that we ensure lower human population growth projections are the "ones that prevail."

Haldre Rogers and Josh Tewksbury, authors of another paper in the same issue, believe that, "animals do matter to people, but on balance, they matter less than food, jobs, energy, money, and development."

They continued, "As long as we continue to view animals in ecosystems as irrelevant to these basic demands, animals will lose."

Keeping animals alive and ecosystems healthy translate to big bucks on a global scale. Tewksbury, director of the Luc Hoffmann Institute of the World Wide Fund for Nature, pointed out that Southeast Asia's Mekong River Basin, through its fisheries, supports 60 million people. Rogers, a researcher in Rice University's Department of Ecology & Evolutionary Biology, added that 73 percent of visitors to Namibia are nature-based tourists, with their money accounting for 14.2 percent of that nation's economic growth.

"Whale watching in Latin America alone generates over 275 million dollars a year," Tewksbury said. "Multiple studies have demonstrated how turtles are worth more alive than dead."

In the United States, he added, shark-watching results in $314 million per year, directly supporting 10,000 jobs.

He and the other researchers point out that human health, pollination, pest control, water quality, food availability and other critical factors are also dependent on ecosystem stability.

In the United States, he added, shark-watching results in $314 million per year, directly supporting 10,000 jobs.

He and the other researchers say that human health, pollination, pest control, water quality, food availability and other critical factors are also dependent upon ecosystem stability.

Yet another paper in the latest issue of Science outlines controversial measures, beyond basic conservation efforts, to improve the current situation. These include re-wilding, meaning placement of underrepresented species back into the wild; human removal of invasive species; and, perhaps most controversial of all, de-extinction: bringing already extinct species back to life.

"People are currently grappling with the implications of de-extinction, including how to select the best candidate species," co-author Philip Seddon, a zoologist at the University of Otago, told Discovery News.

Rogers said that restoration and re-introduction have shown progress.

"The return of the bald eagle and the California condor to the skies and the wild turkey to the lands of the U.S. are great success stories," she said.

She and Tewksbury are also working on the island of Guam, where the invasive brown tree snake has rid the island of birds, causing the forests there to be without seed dispersers for 30 years. This, in turn, has contributed to financial challenges for locals.

Read more at Discovery News