10 Bogus -- And Widely Believed -- Statistics

Numbers are all around us, especially in the news: A new drug has a 72 percent success rate in treating a disease (but only in patients under 35), while the president enjoys a 48 percent approval rating, even though according to a 2010 poll, almost one in five of the estimated 314 million Americans believe he is Muslim.

We hear statistics all the time, and science studies are often based on them. While some cynics dismiss all statistics as easily manipulated (the famous “there are lies, damned lies and statistics” quote), the truth is that statistics are important and indeed essential to understanding the world around us.

Numbers can be wrong for many reasons, including mistakes, miscalculations, different studies using different definitions, bias in promoting political or social agendas, and, of course, outright fraud. Often, the statistics themselves are correct; it’s how those numbers are interpreted. After all, a glass can be both half full and half empty, depending on how you look at it.

Here are 10 examples of spectacularly flawed statistics that are (or have been) influential and widely believed.

"The teen pregnancy rate has been high for years, and is on the rise."

Worrying about “kids today” is a time-honored tradition. Every generation wrings their hands and laments the wild, immoral and reckless ways of today’s wayward youth. The sky-high rate of teen pregnancy is often cited as a prominent example, along with a list of suspected corrupting influences such as sex-saturated TV shows and music lyrics.

It’s also wrong; the fact is that teen pregnancy is low and has been dropping. Data from the Centers for Disease Control and Prevention’s National Center for Health Statistics found that the birth rate for U.S. teenagers (ages 15 to 19) fell 6 percent in 2009, the lowest level ever recorded in nearly seven decades of tracking teenage childbearing.

The report, “Births: Preliminary Data for 2009” found that the rate for the youngest teenagers, 10-14 years, fell from 0.6 to 0.5 per 1,000, also the lowest level ever reported. The birth rate for teenagers 15-17 years declined 7 percent to 20.1 per 1,000. This rate dropped 9 percent from 2007 (22.1) to 2009, and was 48 percent lower than the rate reported in 1991. In fact, teen pregnancy has dropped 39 percent since its peak in 1990, partly because the most recent studies report that 87 percent of boys and 79 percent of girls use birth control.

"There are XX number of gays in America."

How many homosexual men and women are there in the United States? It’s hard to say. Accurately counting the number of gays is fraught with difficulty for many reasons, including that different researchers use different definitions (Who do we count as gay? Anyone who has sex with someone of the same gender? Only those who self-identify as gay? Bisexuals?), and because sexual activity is private and surveys must rely on often-biased self reports.

Estimates of the percentage of gays by Alfred Kinsey from the 1930s and 1940s concluded that about one in ten American men were more or less exclusively homosexual. This 10 percent estimate, though controversial in some quarters, was widely quoted and circulated for decades.

In his book, “Damned Lies and Statistics,” Joel Best, professor and chair of sociology and criminal justice at the University of Delaware, noted that, “Later surveys, based on more representative samples, have concluded that the one-in-ten estimate exaggerated the amount of homosexuality; typically, they find the 3 to 6 percent of males (and a lower percentage of females) have had significant homosexual experience at some point.... and that the incidence of homosexuality among adults is lower—between 1 and 3 percent.”

A 2011 study by UCLA demographer Gary Gates of the Williams Institute on Sexual Orientation Law and Public Policy concluded that America has approximately 4 million homosexual adults, representing about 1.7 percent of the population.

"Up until recently in human history, our forefathers usually died by age 40."

Most of us have, at one time or another, heard someone talk about how our forefathers died so much younger than we do today. Sometimes, for example, it’s used to help explain why many women got married in their teens centuries ago; after all, they had to get started with families early since they’d be dead by 40! According to the National Center for Health Statistics, life expectancy for American men in 1907 was only 45 years, though by 1957 it rose to 66. However, this does not mean that our great-grandfathers rarely lived into their fifties.

In fact maximum human lifespan -- which is not the same as life expectancy -- has remained more or less the same for thousands of years. The inclusion of high infant mortality rates in calculating life expectancy creates the mistaken impression that earlier generations died at a young age. For those with a shaky understanding of statistics, the problem is that giving an average age at which people died tells us almost nothing about the age at which an individual person living at the time might expect to die. The idea that our forefathers routinely died young (say, at age 40) has no basis in historical fact.

Speaking of dying by 40...

"A woman over 40 is more likely to be killed by a terrorist than get married."

This statistic, in wide circulation since the 1980s, is really, really bogus. As the ever-reliable folks at the rumor-debunking website Snopes.com noted, this little nugget first appeared in a June 1986 article in “Newsweek” magazine titled “Too Late for Prince Charming?” which melodramatically (and inaccurately) claimed that women over forty with university degrees are more “likely to be killed by a terrorist: they have a minuscule 2.6 percent probability of tying the knot.”

The 2.6 percent statistic came from a badly flawed 1985 study which, according to Barbara Mikkelson of Snopes.com, “was contradicted by a U.S. Census Bureau report from about that same time which found... that women at age 40 had a 23 percent chance (at marriage), not 2.6%” The original reference to being killed by a terrorist was, of course, a bit of creative hyperbole not meant to be taken literally.

It’s difficult to calculate a precise percentage chance of women over 40 marrying because there are so many factors involved. Women (and career-minded women in particular) are waiting until later in their lives to get married and have children -- to mention that many of them are either happy being single or are in long-term committed relationships and don’t feel the need to legally “legitimize” their relationships with marriage. In any event, women over 40 (college educated or not) are far more likely to marry than be killed by a terrorist.

Read more at Discovery News

Detecting Exoplanets: NOW WITH X-RAY VISION!

Superman’s x-ray vision has nothing on space-based super ‘scopes Chandra and XMM Newton, which have detected a distant exoplanet passing in front of its star for the very first time in high-energy x-rays.

The planet that’s been spotted doesn’t resemble the fictional Krypton, though, nor is it anything like Earth: exoplanet HD 189733b is a hot Jupiter — a bloated, broiling gas giant racing through the searing glow of its parent star, locked in a 2-day-long orbit 30 times closer than we are from our sun.

The overheated exoplanet orbits HD 189733, a sun-like star located 63 light-years away in the northern constellation Vulpecula.

Of course, exoplanets have been observed many times before using various methods, such as detecting the faint reduction in a star’s apparent brightness caused by a passing planet and identifying the slight wobble in a star’s position resulting from the gravitational tug of orbiting worlds. But this is the first time that an exoplanet’s transit has been observed in x-ray wavelengths.

“Thousands of planet candidates have been seen to transit in only optical light,” said Katja Poppenhaeger of the Harvard-Smithsonian Center for Astrophysics (CfA), leader of a new study to be published in the Aug. 10 edition of The Astrophysical Journal. “Finally being able to study one in X-rays is important because it reveals new information about the properties of an exoplanet.”

Located so close to its star, HD 189733b is literally being blown away by the powerful solar wind. As it turns out, its large size is working against it; HD 189733b’s extended atmosphere makes a big target for all that stellar outpouring. It’s estimated that the planet is losing 100 million to 600 million kilograms of mass per second, evaporated by high-energy particles.

Then again, if it wasn’t for its size it may not have been detected by Chandra. As HD 189733b passes in front of its star from our viewpoint much more x-ray light gets blocked than visible light — three times more, in fact.

“The X-ray data suggest there are extended layers of the planet’s atmosphere that are transparent to optical light but opaque to X-rays,” said co-author Jurgen Schmitt of Hamburger Sternwarte in Hamburg, Germany. “However, we need more data to confirm this idea.”

The rendering above shows HD 189733b as it passes its star, surrounded by a vast, hazy atmosphere. Its blue color has been confirmed with optical observations with Spitzer and Hubble — a result of silicate particles in its atmosphere.

The faint red star in the bottom right corner is a smaller companion. It’s also visible in the x-ray image at lower right (the bright point directly underneath HD 189733 is a more distant source).

Read more at Discovery News

Cockatoos Know What's Going On Behind Barriers

How do you know that the cookies are still there even though they have been placed out of your sight into the drawer? How do you know when and where a car that has driven into a tunnel will reappear? The ability to represent and to track the trajectory of objects, which are temporally out of sight, is highly important in many aspects but is also cognitively demanding. Alice Auersperg and her team from the University of Vienna and Oxford show that "object permanence" abilities in a cockatoo rivals that of apes and four-year-old humans.

The researchers published their findings in the journal Journal of Comparative Psychology.

For investigating spatial memory and tracking in animals and human infants a number of setups have been habitually used. These can roughly be subdivided depending on what is being moved: a desired object (food reward), the hiding places for this object or the test animal itself: In the original invisible displacement tasks, designed by French psychologist Jean Piaget in the 50s, the reward is moved underneath a small cup behind one or more bigger screens and its contents is shown in between visits: if the cup is empty we know that the reward must be behind the last screen visited. Humans solve this task after about two years of age, whereas in primates only the great apes show convincing results.

Likely to be even more challenging in terms of attention, are "Transposition" tasks: the reward is hidden underneath one of several equal cups, which are interchanged one or more times. Human children struggle with this task type more than with the previous and do not solve it reliably before the age of three to four years whereas adult apes solve it but have more trouble with double than single swaps.

In "Rotation" tasks several equal cups, one bearing a reward are aligned in parallel on a rotatable platform, which is rotated at different angles. "Translocation" tasks are similar except that the cups are not rotated but the test animal is carried around the arrangement and released at different angles to the cup alignment. Children find Translocation tasks easier than Rotation tasks and solve them at two to three years of age.

A team of international Scientists tested eight Goffin cockatoos (Cacatua goffini), a conspicuously inquisitive and playful species on visible as well as invisible Piagetian object displacements and derivations of spatial transposition, rotation and translocation tasks. Birgit Szabo, one of the experimenters from the University of Vienna, says: "The majority of our eight birds readily and spontaneously solved Transposition, Rotation and Translocation tasks whereas only two out of eight choose immediately and reliably the correct location in the original Piagetian invisible displacement task in which a smaller cup is visiting two of three bigger screens." Alice Auersperg, the manager of the Goffin Lab who was also one of the experimenters, explains: "Interestingly and just opposite to human toddlers our cockatoos had more problems solving the Piagetian invisible displacements than the transposition task with which children struggle until the age of four. Transpositions are highly demanding in terms of attention since two occluding objects are moved simultaneously. Nevertheless, in contrast to apes, which find single swaps easier than double the cockatoos perform equally in both conditions."

Similarly, Goffins had little complications with Rotations and Translocation tasks and some of them solved them at four different angles. Again, in contrast to children, which find Translocations easier than Rotations, the cockatoos showed no significant differences between the two tasks. Auguste von Bayern from the University of Oxford adds: " We assume that the ability to fly and prey upon or being preyed upon from the air is likely to require pronounced spatial rotation abilities and may be a candidate trait influencing the animals' performance in rotation and translocation tasks."

Read more at Science Daily

Damselfish Eye Confuses Would-Be Predators

Young damselfish grow large fake eyes and bulk up their body to confuse predators and avoid being eaten, Australian researchers have found.

Marine biologist Oona Lönnstedt from James Cook University and colleagues published their research in the Nature journal Scientific Reports.

"Juvenile damselfish have lightly colored bodies and a conspicuous eyespot on the rear dorsal fin that fades away as individuals approach maturation," said Lönnstedt.

Their study shows that false eyespots grow and real eyes shrink in response to the presence of predator. It is also the first to demonstrate that the presence of predators can affect both growth and color patterns in their prey.

Like some species of insects and fish, damselfish are highly vulnerable to predation when they are juveniles, and eyespots are thought to have evolved to deter predators.

A Taste of the Enemy

To explore what impact the presence of predators have on the development juvenile Ambon damselfish, (Pomacentrus amboinensis), young damselfish were caught at the end of their larval phase, before they had been exposed to predators.

One group was placed in a tank back in the lab and conditioned to dusky dottybacks (Pseudochromis fuscus). These were placed in the tank inside a transparent plastic bag for 30 minutes at a time, while skin extracts and other odor cues were simultaneously injected into the tank.

Another group was similarly exposed to the herbivorous goby (Amblygobius phalanea), while a third group was not exposed to any other fish.

The researchers found significant differences in both the behavior and morphology between the groups of study fish.

"Prey exposed to predators for six weeks grew deeper bodies, developed larger eyespots and exhibited stunted eye growth compared to prey exposed to herbivores or those that were isolated from other fish," said Lönnstedt.

Increased body depth is a common prey response to gape limited predators, she adds. Not only do deeper bodies deter attacks, they also improve speed, acceleration and maneuverability.

"But what is intriguing is the finding that the juvenile prey grow larger eyespots and display smaller eyes when continuously exposed to predators."

Lönnstedt believes the large eyespot tail area of the damselfish, along with smaller eyes, gives the impression that the fish is pointing in the other direction, "potentially confusing predators about the orientation of the prey."

She adds that it could also lure predator to attack the tail rather than the head.

"An attack on the head would damage vital parts allowing almost no chance of survival."

Experience Counts

The researchers also found that damselfish exposed to predators were more cautious in their behavior: they foraged significantly less, were less active, and spent more time sheltering than the control fish, especially in the early stages of the experiment.

"Reduced activity levels increase prey survival by making the prey less conspicuous to the predator," said Lönnstedt. "(It) also saves energy, allowing individuals to allocate more into growth and/or development."

Read more at Discovery News

Wolves Help Grizzly Bears Get Berries

Wolves and grizzly bears would seem to be archenemies, but a new study shows how wolves are actually helping grizzly bears to obtain tasty, nutritious berries in Yellowstone National Park.

The discovery shows just how tightly woven ecosystems are, and how the domino effect can both hurt and benefit members.

The situation began to unfold back in the early 1900s, when officials had the short-sighted idea of moving wolves out of Yellowstone. It was called “predator control.” By the 1970’s, scientists found no evidence of a wolf population in Yellowstone, a verdant place that had previously been home to wolves for ages.

In October 1991, Congress provided funds to the U.S. Fish & Wildlife Service to start wolf restoration efforts at Yellowstone. (A central Idaho restoration was also funded then.)

The new study, published in the Journal of Animal Ecology, examined how the re-introduction of wolves is affecting other wildlife in the park.

Lead author William Ripple, an Oregon State University professor in the Department of Forest Ecosystems and Society, and his team found that, during the period with few or no wolves, elk herds expanded and over-browsed berry bushes. This was bad news for grizzly bears.

“Wild fruit is typically an important part of grizzly bear diet, especially in late summer when they are trying to gain weight as rapidly as possible before winter hibernation,” Ripple said in a press release. “Berries are one part of a diverse food source that aids bear survival and reproduction, and at certain times of the year can be more than half their diet in many places in North America.”

Now, however, with wolves hunting elk again, there are more berries. Yellowstone is berry central for bears, with numerous types that they love: serviceberry, chokecherry, buffaloberry, twinberry, huckleberry and others. Since the reintroduction of wolves, the percentage of berry waste in bear poo has nearly doubled.

“Studies like this also point to the need for an ecologically effective number of wolves,” co-author Robert Beschta, an OSU professor emeritus, said. “As we learn more about the cascading effects they have on ecosystems, the issue may be more than having just enough individual wolves so they can survive as a species. In some situations, we may wish to consider the numbers necessary to help control over-browsing, allow tree and shrub recovery, and restore ecosystem health.”

Read more at Discovery News

Coffin at King Richard III Site Holds...Another Coffin

King Richard III's rediscovered resting place is turning out more mysteries this summer. Excavators finally lifted the heavy lid of a medieval stone coffin found at the site in Leicester, England, only to reveal another lead coffin inside.

The "coffin-within-a-coffin" is thought to have been sealed in the 13th or 14th century — more than 100 years before Richard, an infamous English king slain in battle, received his hasty burial in 1485.

The team of archaeologists from the University of Leicester thinks this grave in the Grey Friars monastery might contain one of the friary's founders or a medieval knight.

"The inner coffin is likely to contain a high-status burial — though we don't currently know who it contains," reads a statement from the university.

The outer stone coffin measures about 7 feet (2.1 meters) long and 2 feet (0.6 meters) wide at the head and 1 foot (0.3 meters) at the feet. Eight people were needed to remove its lid.

The lead funerary box inside has been carried off to the university, where researchers will conduct tests to determine the safest way to open it without damaging the remains. But so far, they've been able to get a look at the feet through a hole in the bottom of the inner coffin.

The archaeologists suspect the grave may belong to one of Grey Friar's founders: Peter Swynsfeld, who died in 1272, or William of Nottingham, who died in 1330. Records also suggest "a knight called Mutton, sometime mayor of Leicester," was buried at the site. This name may refer to the 14th-century knight Sir William de Moton of Peckleton, who died between 1356 and 1362, the researchers say.

"None of us in the team have ever seen a lead coffin within a stone coffin before," archaeologist Mathew Morris, the Grey Friars site director, said in a statement. "We will now need to work out how to open it safely, as we don't want to damage the contents when we are opening the lid."

Richard III, the last king of the House of York, reigned from 1483 until 1485, when he was killed in battle during the War of Roses. He received a quick burial at the Grey Friars monastery in Leicester as his defeater, Henry Tudor, ascended to the throne.

Richard's rise to power was controversial. His two young nephews, who had a claim to the throne, vanished from the Tower of London shortly before Richard became king, leading to rumors that he had them killed. After his death, Richard was demonized by the Tudor dynasty and his reputation as a power-hungry, murderous hunchback was cemented in William Shakespeare's play "Richard III." Meanwhile, Grey Friars was destroyed in the 16th century during the Protestant Reformation, and its ruins became somewhat lost to history.

Setting out to find the lost king, archaeologists started digging beneath a parking lot in Leicester last summer where they believed they would find Grey Friars. They soon uncovered the remains of the monastery and a battle-ravaged skeleton that was later confirmed through a DNA analysis to be that of Richard III.

Read more at Discovery News

Mechanism Behind Squids' and Octopuses' Ability to Change Color Revealed

Color in living organisms can be formed two ways: pigmentation or anatomical structure. Structural colors arise from the physical interaction of light with biological nanostructures. A wide range of organisms possess this ability, but the biological mechanisms underlying the process have been poorly understood.

Two years ago, an interdisciplinary team from UC Santa Barbara discovered the mechanism by which a neurotransmitter dramatically changes color in the common market squid, Doryteuthis opalescens. That neurotransmitter, acetylcholine, sets in motion a cascade of events that culminate in the addition of phosphate groups to a family of unique proteins called reflectins. This process allows the proteins to condense, driving the animal's color-changing process.

Now the researchers have delved deeper to uncover the mechanism responsible for the dramatic changes in color used by such creatures as squids and octopuses. The findings -- published in the Proceedings of the National Academy of Science, in a paper by molecular biology graduate student and lead author Daniel DeMartini and co-authors Daniel V. Krogstad and Daniel E. Morse -- are featured in the current issue of The Scientist.

Structural colors rely exclusively on the density and shape of the material rather than its chemical properties. The latest research from the UCSB team shows that specialized cells in the squid skin called iridocytes contain deep pleats or invaginations of the cell membrane extending deep into the body of the cell. This creates layers or lamellae that operate as a tunable Bragg reflector. Bragg reflectors are named after the British father and son team who more than a century ago discovered how periodic structures reflect light in a very regular and predicable manner.

"We know cephalopods use their tunable iridescence for camouflage so that they can control their transparency or in some cases match the background," said co-author Daniel E. Morse, Wilcox Professor of Biotechnology in the Department of Molecular, Cellular and Developmental Biology and director of the Marine Biotechnology Center/Marine Science Institute at UCSB.

"They also use it to create confusing patterns that disrupt visual recognition by a predator and to coordinate interactions, especially mating, where they change from one appearance to another," he added. "Some of the cuttlefish, for example, can go from bright red, which means stay away, to zebra-striped, which is an invitation for mating."

The researchers created antibodies to bind specifically to the reflectin proteins, which revealed that the reflectins are located exclusively inside the lamellae formed by the folds in the cell membrane. They showed that the cascade of events culminating in the condensation of the reflectins causes the osmotic pressure inside the lamellae to change drastically due to the expulsion of water, which shrinks and dehydrates the lamellae and reduces their thickness and spacing. The movement of water was demonstrated directly using deuterium-labeled heavy water.

When the acetylcholine neurotransmitter is washed away and the cell can recover, the lamellae imbibe water, rehydrating and allowing them to swell to their original thickness. This reversible dehydration and rehydration, shrinking and swelling, changes the thickness and spacing, which, in turn, changes the wavelength of the light that's reflected, thus "tuning" the color change over the entire visible spectrum.

"This effect of the condensation on the reflectins simultaneously increases the refractive index inside the lamellae," explained Morse. "Initially, before the proteins are consolidated, the refractive index -- you can think of it as the density -- inside the lamellae and outside, which is really the outside water environment, is the same. There's no optical difference so there's no reflection. But when the proteins consolidate, this increases the refractive index so the contrast between the inside and outside suddenly increases, causing the stack of lamellae to become reflective, while at the same time they dehydrate and shrink, which causes color changes. The animal can control the extent to which this happens -- it can pick the color -- and it's also reversible. The precision of this tuning by regulating the nanoscale dimensions of the lamellae is amazing."

Another paper by the same team of researchers, published in Journal of the Royal Society Interface, with optical physicist Amitabh Ghoshal as the lead author, conducted a mathematical analysis of the color change and confirmed that the changes in refractive index perfectly correspond to the measurements made with live cells.

A third paper, in press at Journal of Experimental Biology, reports the team's discovery that female market squid show a set of stripes that can be brightly activated and may function during mating to allow the female to mimic the appearance of the male, thereby reducing the number of mating encounters and aggressive contacts from males. The most significant finding in this study is the discovery of a pair of stripes that switch from being completely transparent to bright white.

"This is the first time that switchable white cells based on the reflectin proteins have been discovered," Morse noted. "The facts that these cells are switchable by the neurotransmitter acetylcholine, that they contain some of the same reflectin proteins, and that the reflectins are induced to condense to increase the refractive index and trigger the change in reflectance all suggest that they operate by a molecular mechanism fundamentally related to that controlling the tunable color."

Could these findings one day have practical applications? "In telecommunications we're moving to more rapid communication carried by light," said Morse. "We already use optical cables and photonic switches in some of our telecommunications devices. The question is -- and it's a question at this point -- can we learn from these novel biophotonic mechanisms that have evolved over millions of years of natural selection new approaches to making tunable and switchable photonic materials to more efficiently encode, transmit, and decode information via light?"

Read more at Science Daily

Evolution On the Inside Track: How Viruses in Gut Bacteria Change Over Time

Humans are far more than merely the sum total of all the cells that form the organs and tissues. The digestive tract is also home to a vast colony of bacteria of all varieties, as well as the myriad viruses that prey upon them. Because the types of bacteria carried inside the body vary from person to person, so does this viral population, known as the virome.

By closely following and analyzing the virome of one individual over two-and-a-half years, researchers from the Perelman School of Medicine at the University of Pennsylvania, led by professor of Microbiology Frederic D. Bushman, Ph.D., have uncovered some important new insights on how a viral population can change and evolve -- and why the virome of one person can vary so greatly from that of another. The evolution and variety of the virome can affect susceptibility and resistance to disease among individuals, along with variable effectiveness of drugs.

Their work was published in the Proceedings of the National Academy of Sciences.

Most of the virome consists of bacteriophages, viruses that infect bacteria rather than directly attacking their human hosts. However, the changes that bacteriophages wreak upon bacteria can also ultimately affect humans.

"Bacterial viruses are predators on bacteria, so they mold their populations," says Bushman. "Bacterial viruses also transport genes for toxins, virulence factors that modify the phenotype of their bacterial host." In this way, an innocent, benign bacterium living inside the body can be transformed by an invading virus into a dangerous threat.

At 16 time points over 884 days, Bushman and his team collected stool samples from a healthy male subject and extracted viral particles using several methods. They then isolated and analyzed DNA contigs (contiguous sequences) using ultra-deep genome sequencing .

"We assembled raw sequence data to yield complete and partial genomes and analyzed how they changed over two and a half years," Bushman explains. The result was the longest, most extensive picture of the workings of the human virome yet obtained.

The researchers found that while approximately 80 percent of the viral types identified remained mostly unchanged over the course of the study, certain viral species changed so substantially over time that, as Bushman notes, "You could say we observed speciation events."

This was particularly true in the Microviridae group, which are bacteriophages with single-stranded circular DNA genomes. Several genetic mechanisms drove the changes, including substitution of base chemicals; diversity-generating retroelements, in which reverse transcriptase enzymes introduce mutations into the genome; and CRISPRs (Clustered Regularly Interspaced Short Palindromic Repeats), in which pieces of the DNA sequences of bacteriophages are incorporated as spacers in the genomes of bacteria.

Such rapid evolution of the virome was perhaps the most surprising finding for the research team. Bushman notes that "different people have quite different bacteria in their guts, so the viral predators on those bacteria are also different. However, another reason people are so different from each other in terms of their virome, emphasized in this paper, is that some of the viruses, once inside a person, are changing really fast. So some of the viral community diversifies and becomes unique within each individual."

Read more at Science Daily

Walrus Bones Found in Old London Burial Ground

During a recent excavation beneath the streets of London, archaeologists found a total of 1,500 human bodies, many buried hastily in a wave of epidemics that struck the quickly expanding city more than 150 years ago.

In one coffin, archaeologists came across a grisly mix of bones from at least eight human bodies, many of them cut up and showing evidence of autopsy. But nine of the bone fragments were decidedly not human. They were walrus.

"It came as something of a shock," said Phil Emery, an archaeologist with a company called Ramboll UK, who led the excavation. The nine bone fragments came from a Pacific walrus that was likely 13 feet long, Emery told LiveScience.

Behold the walrus

The bodies came from the old burial ground of St Pancras Church, and were interred there between 1822 and 1854, Emery said. During this time, London cemeteries were overwhelmed by the dead from a series of cholera, typhus and smallpox epidemics; the church and its burial ground, once outside greater London, have recently been engulfed by the burgeoning metropolis, he added.

Before 1822, the cemetery was characterized by small plots, as seen in most ordinary burial grounds, Emery said. But thereafter, ceremony fell to the wayside as the cemetery was overwhelmed — plots were replaced with mass graves, he said.

From 1822 to 1854, a total of 44,000 burials took place there, Emery said. "Under such conditions, one can understand that standards of decency and hygiene were difficult to maintain, to put it lightly," he explained.

Blame the med students

But how did a tusked beast the weight of a small car make its way from the North Pacific to a cemetery in foggy London? Emery and his team can only guess how the walrus was brought there from its native lands, but they suspect the animal was dissected by curious medical students.

That hunch comes from the fact that several of the bones within the coffin showed signs of dissection, such as skull fragments with holes drilled in them, he said. In 1832, within the range of dates when the bones would have been laid to rest there, a law was passed that allowed medical students to legally dissect cadavers, Emery said. Before that, cadavers were obtained from the gallows, or illegally snatched via grave robbery, he added.

The walrus limbs were likely dissected as a matter of curiosity, Emery said, perhaps as an exercise in comparative anatomy.

'Sea monster'

At the time, "very few Londoners would have seen one of these alive," Emery said. "It was the archetypal sea monster, often depicted on early sea maps as a sort of exotic beast. The animal would have captured peoples' imaginations."

Read more at Discovery News

Earth's Hellish Potential

It used to be that Venus was the only planet in the solar system thought capable of a runaway greenhouse effect — hence its furnace-like inhabitability. But new modeling suggests that Earth is perfectly capable of falling into a self-reinforcing heating cycle as well. Luckily, not even humanity’s greenhouse gas emissions are enough to trigger that planet-killing scenario on our home planet.

Just to review, a runaway greenhouse effect is where a planet gets stuck in a vicious cycle of heating and can’t stop. We’re not talking the anthropogenic kind of heating, of a few degrees Celsius. That kind of greenhouse heating is bad enough, but a runaway greenhouse effect would dry up the oceans and turn Earth into an autoclave: sterilized of life.

It’s long been thought that such a deadly cycle of heating was not possible on Earth because Earth is just far enough away from the Sun that our planet’s intake of solar energy is too low. But a paper in the July 28 issue of Nature Geoscience suggests Earth is close enough to the Sun after all.

Computer modelling by the University of Victoria’s Colin Goldblatt and colleagues shows that a planet that gets the same amount of solar irradiation as Earth could go either way: to a stable climate or a Venus-like disaster.

The numerical model calculated the balance between solar radiation taken in and thermal radiation released back into space by Earth’s surface and atmosphere. They found that with a lot more greenhouse gases and steamy air Earth could morph into another Venus.

“A runaway greenhouse could in theory be triggered by increased greenhouse forcing, but anthropogenic emissions are probably insufficient,” the researchers write.

On the other hand, they do hope that their work helps to identify exoplanets that are in habitable zones of their stars, and are likely to have avoided runaway greenhouses, since, those are the best places to expect life.

From Discovery News