Glowing Millipede: Surprise Find in Calif. Foothills

The faint blue-green glow of this millipede redefines how we look at the evolution of bioluminescence across the tree of life.

Not seen for nearly 50 years, the small, blind millipede Xystocheir bistipita, was recently rediscovered in the foothills of San Luis Obispo, Calif. by entomologist Paul Merek of the Virginia Polytechnic Institute.

During the day, it’s a light tan color with salmon pink spots. But at night, this millipede has a very faint blue-green glow, which was only noticed on its rediscovery.

Analysis of Xystocheir bistipita‘s DNA revealed that the millipede actually belonged to a different genus, Motyxia — the only genus of bioluminescent millipede in the western hemisphere. The identity-challenged millipede was then renamed Motyxia bistipita.

The researchers ranked the light intensity and toxicity of all the millipedes in its newly acquired family and found that M. bistipita is pretty dull and less toxic compared to its mountain-dwelling cousins, which are larger and much more luminous.

The brighter the millipedes were, the more cyanide they contained, which suggests the millipedes at higher elevations use bioluminescence as a forewarning to predators.

But M. bistipita has very few predators — so why does it still glow in the dark?

Unlike fireflies that glow because of an enzymatic reaction that converts a pigment called luciferin into a new compound that emits light, bioluminescence in millipedes is caused by the reaction of a photoprotein that uses magnesium and molecules that contain oxygen.

This reaction may have initially evolved to help the millipede survive the oxidative stress of living in a hot, dry environment, reports Wendy Moore from the University of Arizona in the Proceedings of the National Academy of Sciences. The millipede’s glow may then be a by-product of this process.

Read more at Discovery News

Dragons of Xanadu: Sculptures Discovered in Legendary City

The remains of three colorful dragon heads made of clay have been discovered in a huge palace in Xanadu, a city constructed by the grandsons of Genghis Khan.

The palace sprawls over 9,000 square meters (about 100,000 square feet), or nearly twice the floor space of the modern-day White House.Archaeologists have been excavating the palace, learning how it was designed and decorated.

Made of fine, red, baked clay the dragon heads would have been attached to the ends of beams and used asdecoration. They “are lifelike and dynamic” and “have yellow, blue, white and black coloring” glazed on them, researchers wrote in a report published recently in the journal Chinese Cultural Relics.

The construction of Xanadu, known in China as Shangdu, started in 1256 at a time when the Mongol Empire, led by Möngke Khan (grandson of Genghis Khan), was in the process of taking over China. After Möngke Khan’s death in 1259, his successor, Kublai Khan (also a grandson of Genghis), finished the conquest of China.Kublai had helped design Xanadu and when he became ruler he used the city as China’s capital during the summer months.

“The site is composed of a palatial district, an imperial city and an outer city, containing remains of three layers of city walls, and occupies an area of 484,000 square meters [about 120 acres],” the archaeologists wrote in their report.

While Xanadu was occupied only briefly, being destroyed in 1368, it became a place of legend, its name romanticized in popular culture as awondrous exotic place where one of the most powerful rulers in the world held court. The discovery of the dragon heads, and other remains from Xanadu, paints a picture of what the site looked like.

While the dragon heads are some of the most eye-catching finds at the palace, archaeologists also discovered a type of ramp called “mandao,” meaning “path for the horses” inChinesewhich allowed horses and vehicles access to the palace.

These ramps “would have been strongly connected to the pastoral way of life of the Mongols,” the archaeologists wrote.

The ramps were important because horses and pastoral animals were an essential part of Mongolian life. Recent research suggeststhat an unusually wet climate in Mongolia helped these animals flourish in Genghis Khan’s time, helping him and his successors conquer a vast amount of territory.

Archaeologists also found artifacts showing more of the rich colors that would have been seen by those who set foot in Xanadu at the time. These artifacts include the remains of aclayfish head whose body “is glazed yellow and green” with “bright and lifelike” scales, the archaeologists wrote.

Read more at Discovery News

Cassini to Get Final View of Saturn's Weird 'Spongy' Moon

As NASA’s Cassini spacecraft enters the final phase of its epic mission around Saturn, mission scientists are planning the probe’s final flyby of one of the strangest moons in the solar system.

So far, images of the irregularly-shaped 168 mile (270 kilometers) wide Hyperion have only been captured of the approximate same side, showing the moon’s signature “spongy” appearance. During the final flyby, expected on Sunday (May 31) at 6:36 a.m. PDT (9:36 a.m. EDT), mission scientists hope that Cassini will have the opportunity to photograph the other side of the moon so we can gain a better picture of its composition.

But predicting which side of Hyperion will be facing Cassini at flyby is a nigh-on impossible task; the moon is tumbling chaotically as it orbits Saturn, denying orbital dynamics experts the chance to accurately calculate the object’s spin.

Hyperion has an unusually low density (and therefore gravity) for an object of its size, a factor that scientists believe can be to blame for the moon’s porous appearance. Through Hyperion’s evolution, rocky impactors have struck the satellite, compressing the surface rather than excavating it, so any material blown off the surface is lost to space, leaving this weird pock-marked surface.

Unfortunately, Sunday’s flyby won’t be as close as the closest Cassini has come to Hyperion. In 2005, Cassini cruised past Hyperion at a distance of 314 miles (505 km) — the final flyby will be 21,000 miles (34,000 kilometers) from the moon.

Read more at Discovery News

Shark Files: Shark Skeletons Had Boney Start

The discovery of bone in the jaw of an ancient shark indicates modern sharks are far more advanced than previously thought, say researchers.

The finding, reported in the journal PLOS one , challenges evolutionary models suggesting animals with skeletons built of cartilage evolved into those with more advanced bony skeletons.

“Fish-like sharks were thought to be primitive because they only had cartilage, and never evolved to develop the bones,” says the study’s lead author, palaeontologist John Long of Flinders University.

“So now we’re turning that idea on its head by saying that early fossil sharks actually had bone in their skeleton and now they’ve lost it.”

The 380-million-year old fossil was unearthed in the Western Australian Kimberley region’s Gogo formation in 2005 by Long and colleagues.

The fossil, named Gogoselachus Lynnbeazleyae, is the first shark to be found in this area.

It remains include both sides of the lower jaw, parts of the shoulder girdle that supported the pectoral fins, several gill arch bones, about 80 teeth, and several hundred scales.

Evolution of Tissue

While modern sharks have a miniscule amount of bone in the roots of their teeth, they do not have any bone in their main skeleton.

Instead, their skeletons are built out of cartilage comprising tiny structures called tesserae, a soft rubbery tissue that is the precursor to bones in other animals.

However, when the authors recently examined the microstructure of the cartilage of Gogoselachus using micro CT scanning, they discovered the matrix holding the cartilage together in the jaw contained bone cells.

“Our fossil shark is the first to show a true cellular matrix made of bone binding the tiny cartilage units together,” says Long.

“We’re looking at a shark which has actually evolved from something that previously had a lot more bone in the skeleton, and eventually modern sharks would lose that bone and just become entirely cartilaginous.”

“So our fossil has given us a window into the evolution of tissues, and the reason sharks are so successful today is because they’ve reduced the bone in their skeleton and become more lightweight with an entirely cartilaginous skeleton,” he says.

Unique in the World

Long says the revolutionary new insights into the early evolution of shark cartilage was only possible because of the degree of preservation achieved by the Gogo formation.

Most fossil fishes from the Devonian period between 360 to 400 million years ago, are squashed flat in rock.

However, fossils in the Gogo formation occur in limestone nodules that preserve them in three dimensional form.

“Gogo is an ancient tropical reef, not a coral reef because they’re relatively recent, but a reef made of algae and sponge-like creatures,” says Long.

“It had a great abundance of life, many kinds of fishes, armoured placoderms which are an extinct group, but also early bony fishes like lung fishes and ray fin fishes, which are the dominate fishes today.

“We expect there should be more sharks there, except for some reason they’re not common on this particular reef where other kinds of fishes dominate.”

Read more at Discovery News

Colliding Galaxies May Erupt With Mega Jets

Powerful jets of material spewing from the edge of monster black holes may be more likely to arise where two galaxies have merged together, a new study suggests.

Like a cosmic version of Old Faithful (the famous Yellowstone geyser), some black holes at the center of galaxies will spew jets of material into space that stretch for thousands of light-years. You can see an illustration of what these gushing pillars look like in a video of the galaxy crash discovery.

Using data from the Hubble Space Telescope, new research suggests these jets are more likely to be found in galaxies that are the product of galaxy mergers. However, the authors of the  research say merging two galaxies isn't always a recipe for creating galactic jets.

In the study, scientists used the Hubble Space Telescope to look for the radio waves emitted by the massive jets that spew particles into space at nearly the speed of light. These jets are thought to be created by activity taking place near the edge of a supermassive black hole (and astronomers think most, if not all, galaxies in the universe have a supermassive black hole at their center).

When a black hole is gobbling up material, the friction and movement of the particles may generate light. If the black hole is particularly gluttonous, surrounded by a buffet of matter, it may create enough light to outshine all the stars in the galaxy. These bright regions around a galactic center are called active galactic nuclei, or AGNs.

The researchers compared AGNs that produce jets and those that don't, as well as non-AGN galaxies with no jets. From there, they looked into the history of these galaxies, looking for evidence that the current galaxy was the product of a merger.

What they found was that more than 90 percent of the surveyed AGNs with jets were also the product of galaxy mergers. But, not all galaxy mergers necessarily created jets.

"We found that most merger events in themselves do not actually result in the creation of AGNs with powerful radio emission," said Roberto Gilli, of the Osservatorio Astronomico di Bologna, Italy, and an author on the paper. "About 40 percent of the other galaxies we looked at had also experienced a merger and yet had failed to produce the spectacular radio emissions and jets of their counterparts."

In a statement, the European Space Agency said: "Although it is now clear that a galactic merger is almost certainly necessary for a galaxy to host a supermassive black hole with relativistic jets, the team deduced that there must be additional conditions which need to be met."

It's possible that the merger of two galaxies shovels more gas toward the black hole at the new galaxy's center, which could increase the amount of food for the black hole to feast on, thus increasing the likelihood of jets forming.

Read more at Discovery News

What Is 'Manhattanhenge?'

Today through Saturday marks a biannual solar event called Manhattanhenge, where the rising or setting sun aligns with the east-west grid of Manhattan streets.

Astrophysicist Neil deGrasse Tyson coined the term back in 2002, inspired by the famous Stonehenge site in the United Kingdom, where the sun sets in alignment with the stones every summer solstice.

Technically, "Manhattanhenge" occurs around the summer solstice, not on the solstice itself. That's because of the orientation of Manhattan's famous grid pattern — established by the the Commissioners’ Plan of 1811 — is not perfectly aligned with the geographic north-south line; it's rotated 29 degrees east, shifting the dates of alignment.

If that alignment had been perfect, Manhattanhenge would have occurred on the equinoxes every year: the first day of spring and autumn, respectively.

(Historical side note: The goal of the 1811 plan was "a free and abundant circulation of air" to stave off disease. The right angles were also favored because "straight-sided and right-angled houses are the most cheap to build." The rigid Manhattan grid has been much-maligned over the last 200 years, but recently has come back into favor with city planners.)

This kind of alignment is not unique to Manhattan; any city with a uniform street grid will have dates where the sun aligns with those streets, including Chicago, Toronto and Montreal.

But Manhattan also boasts a clear view of the horizon, looking across the Hudson River toward New Jersey. Plus you've got all those tall buildings lining the streets, creating the perfect vertical frame to show the setting sun to best advantage.

Tyson has been outspoken in the past about astronomical inaccuracies in film and television. For instance, you can always spot a fake sunrise onscreen, because the sun will move up and to the left as it rises. In reality, the sun always rises up and to the right. Directors tend to film a sunset for such scenes and then just run it backwards to portray a sunrise, thinking nobody will notice. (And they'd probably get away with it, too, if it weren't for those meddling astrophysicists!)

The term Manhattanhenge technically applies to the setting sun phenomenon that flanks the summer solstice, usually around May 28 and July 12, although the precise dates vary slightly year to year. A similar alignment occurs with the rising sun around the winter solstice, usually Dec. 5 and Jan. 8.

From Discovery News

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

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

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

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

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

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

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

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

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

Leg Genitals and Other Adventures in Sea Spider Sex

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

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

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

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

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

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

File Sea Spiders Under: It’s Complicated

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

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

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

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

Read more at Wired Science

Dinosaurs May Have Been Warm-Blooded

Dinosaurs were warm-blooded animals that had many traits in common with mammals, finds controversial new research.

The study, published in the journal Science, counters other popular theories, which say that dinosaurs were either cold-blooded and reptile-like, or occupied a unique intermediate category of animals that were neither fully cold nor warm-blooded.

“Upon re-analysis, it was apparent that dinosaurs weren’t just somewhat like living mammals in their physiology — they fit right within our understanding of what it means to be a ‘warm-blooded’ mammal,” author Michael D’Emic, a Stony Brook University paleontologist, said in a press release.

The “re-analysis” refers to D’Emic’s work revisiting yet another Science paper, published last year, which compiled a huge dataset on growth and metabolism of hundreds of living animals. D’Emic admits that this dataset was “remarkable” and “unprecedented.”

Yet, that earlier study found that dinosaurs would have fit into the intermediate category between ectothermic (cold-blooded, with body temperature controlled largely by the surrounding environment) and endothermic (warm-blooded, like us).

D'Emic looked at that study again, focusing on two primary aspects.

First, the original study had scaled yearly growth rates to daily ones in order to standardize comparisons.

"This is problematic," D'Emic said, "because many animals do not grow continuously throughout the year, generally slowing or pausing growth during colder, drier, or otherwise more stressful seasons. Therefore, the previous study underestimated dinosaur growth rates by failing to account for their uneven growth. Like most animals, dinosaurs slowed or paused their growth annually, as shown by rings in their bones analogous to tree rings."

He added that very stressful or seasonal environments can also impact growth, and would have really affected dinosaurs. He believes that these factors were underestimated in the earlier study.

The second aspect of his re-analysis took into account the widely held view that all dinosaurs did not become extinct: some evolved to become birds. Today’s birds are warm-blooded, so he argues that dinosaurs must have been this way too.

"Separating what we commonly think of as 'dinosaurs' from birds in a statistical analysis is generally inappropriate, because birds are dinosaurs–they’re just the dinosaurs that haven't gone extinct," he explained.

If D'Emic's theory about warm-blooded dinosaurs holds, then this would lead to still more re-evaluation of other data on things like the big sails and head ornaments on some dinosaurs. Certain past studies have linked these to body temperature regulation. If they didn’t serve that function, then perhaps they were used more for flashy mating displays or other types of visual communication.

Holly Woodward, an assistant professor in the Center for Health Sciences at Oklahoma State University, supports re-examining prior studies, even those that appear seamless.

As she said, "D'Emic's study reveals how important access to the data behind published results is for hypothesis testing and advancing our understanding of dinosaur growth dynamics."

Read more at Discovery News

Mystery Deepens Over Rare Roman Tombstone

Mystery has deepened over a Roman tombstone unearthed earlier this year in western England, as new research revealed it had no link with the skeleton laying beneath it.

The inscribed stone was discovered during the construction work of a parking lot in Cirencester.

Made from Cotswold limestone, it was found laying on its front in a grave — directly above an adult skeleton.

When it was turned over, the honey colored stone revealed fine decorations and five lines of Latin inscription which read: “D.M. BODICACIA CONIUNX VIXIT ANNO S XXVII,” possibly meaning: “To the shades of the underworld, Bodicacia, spouse, lived 27 years.”

The discovery was hailed as unique since the stone was believed to be the only tombstone from Roman Britain to record the person found beneath.

In fact, while the dedication on the tombstone is to a woman, the skeleton beneath it was that of a male.

It turns out the gravestone and skeleton were also laid at different times — the inscribed stone was early Roman, dating to the 2nd century A.D., while the burial was most certainly late Roman, from the 4th century A.D..

“We believe the tombstone to have been re-used as a grave cover perhaps as long as two centuries after it was first erected,” Ed McSloy, Cotswold Archaeology’s finds expert, told Discovery News.

Martin Henig and Roger Tomlin, leading experts in Roman sculpture and inscriptions at the University of Oxford, noted that the back of the stone is very roughly worked, almost unfinished, in strong contrast to the finely sculpted front.

Unlikely to have been a free-standing tombstone, the five-foot-long inscribed stone may have rather been set into walls, possibly those of a mausoleum.

Who the grave belonged to remains a mystery.

“Reading the letters, the most plausible interpretation of the name is Bodicacia, a previously unknown Celtic name,” McSloy said.

Indeed the name appears to be a variant of a Celtic name with same root as Boudicca. This was the rebel queen of the Iceni, a British tribe, who unsuccessfully attempted to defeat the Romans.

Bodicacia’s tombstone was also unique. The pediment, which is the decorated, triangular portion at top of the stone, shows the Roman god Oceanus.

A divine personification of the sea in the classical world, the god was portrayed with a long mustache, stylized long hair, and crab-like pincers above the head.

Read more at Discovery News

Sacrificed Humans Discovered Among Prehistoric Tombs

A prehistoric cemetery containing hundreds of tombs, some of which held sacrificed humans, has been discovered near Mogou village in northwestern China.

The burials date back around 4,000 years, before writing was developed in the area. In just one archaeological field season — between August and November 2009 — almost 300 tombs were excavated, and hundreds more were found in other seasons conducted between 2008 and 2011.

The tombs were dug beneath the surface of the ground and were oriented toward the Northwest. Some of the tombs had small chambers where finely crafted pottery was placed near the deceased. Archaeologists also found that mounds of sediment covered some of the tombs, which could have marked the location of these tombs.

Within the tombs, archaeologists found entire families buried together, their heads also facing the Northwest. They were buried with a variety of goods, including, necklaces, weapons and decorated pottery.

Human sacrifices were also evident in the burials. In one tomb, “the human sacrifice was placed on its side with limbs bent and its face toward the tomb chamber. The bones are relatively well preserved, and the individual’s age at death is estimated at around 13 years,” archaeologists wrote in a paper published recently in the journal Chinese Cultural Relics.

Predicting the future

The goods found in the tombs included pottery decorated with incised designs. In some cases, the potter made numerous incisions shaped like the letter “O,” with the O’s forming patterns on the vessel. Sometimes, instead of making O’s, the potter would incise wavy lines near the top of the pot.

The researchers also discovered artifacts that could have been used as weapons. Bronze sabers were found that researchers say could have been used for cutting. They also found stone mace heads. (A mace is a blunt weapon that can smash a person’s skull in.) Axes, daggers and knives were also found in the tombs.

Archaeologists also found what they call “bone divination lots,” or artifacts that could have been used in rituals aimed at predicting the future. Bone divination was practiced widely throughout the ancient world. In fact, when writing was developed in China centuries later, some of the earliest texts were written on bones used for divination.

Qijia culture

Most of the tombs belong to the Qijia culture, whose people used artifacts with similar designs and lived in the upper Yellow River valley.

“Qijia culture sites are found in a broad area along all of the upper Yellow River as well as its tributaries, the Huangshui, Daxia, Wei, Tao and western Hanshui rivers,” Chen Honghai, a professor at Northwestern University in China, wrote in a chapter of the book “A Companion to Chinese Archaeology” (Wiley, 2013).

Honghai wrote that people from the Qijia culture lived in a somewhat arid area. To adjust to these conditions, the Qijia people grew millet, a cereal suited to a dry environment; and raised a variety of animals, including pigs, sheep and goats.

People from the Qijia culture lived in modest settlements (smaller than 20 acres), in houses that were often partially buried beneath the ground. “Remains of buildings are mainly square or rectangular, and they are usually semi-subterranean. The doors usually point south, identical to the current local custom of building houses, as rooms on the sunny side receive more light and warmth,” Honghai wrote.

Read more at Discovery News