Staghorn coral is listed as threatened under the U.S. Endangered Species Act. NOAA Fisheries has proposed it be reclassified as endangered. Photo by Albert Kok

Our oceans are taking a beating from overfishing, pollution, acidification and warming, putting at risk the many creatures who make their home in seawater. But when most people think of struggling ocean species, the first animals that come to mind are probably whales, seals or sea turtles.

Sure, many of these large (and adorable) animals play an important part in the marine ecosystem and are threatened with extinction due to human activities, but in fact, of the 94 marine species listed under the Endangered Species Act (ESA), only 45 are marine mammals and sea turtles. As such, these don’t paint the whole picture of what happens under the sea. What about the remaining 49 that form a myriad of other important parts of the underwater web?

These less charismatic members of the list include corals, sea birds, mollusks and, of course, fish. They fall under two categories: endangered or threatened. According to NOAA’s National Marine Fisheries Service (pdf), one of the groups responsible for implementing the ESA, a species is considered endangered if it faces imminent extinction, and and a species is considered threatened if it is likely to become endangered in the future. A cross section of these less-known members of the ESA’s list are described in detail below.

1. Staghorn coral (Acropora cervicornis), pictured above, is one of two species of coral listed as threatened under the ESA, although both are under review for reclassification to endangered. A very important reef-building coral in the Caribbean and the Gulf of Mexico, it primarily reproduces through asexual fragmentation. This means that its branches break off and reattach to a substrate on the ocean bottom where they grow into new colonies.

While this is a great recovery method when only part of a colony is damaged, it doesn’t work so well when most or all of the colony is killed—which often is the result from disturbances afflicting these corals. Since the 1980s, staghorn coral populations have steeply declined due to outbreaks of coral disease, increased sedimentation, bleaching and damage from hurricanes. Although only two coral species are currently on the ESA list, 66 additional coral species have been proposed for listing and are currently under review.

The white abalone population off the coast of California continued to decline even after the closure of its short-lived fishery in the 1970s. Photo by John Butler, NOAA

2. The white abalone (Haliotis sorenseni), a large sea snail that can grow to ten inches long, was the first marine invertebrate to be listed under the ESA but its population hasn’t recovered. The commercial fishery for white abalone collapsed three decades ago because, being spawners that jet their eggs and sperm into the water for fertilization with the hope that the two will collide, the animals depend on a large enough population of males and females being in close proximity to one another to reproduce successfully.

Less than 0.1% of its pre-fished population survives today, and research published in 2012 showed that it has continued to decline since its ESA listing more than a decade ago. The researchers recommended human intervention, and aquaculture efforts have begun in an effort to save the species.

Johnson’s seagrass is the first, and only, marine plant listed under the Endangered Species Act. Photo by Lori Morris, St. Johns River Water Management District

3. Johnson’s seagrass (Halophila johnsonii), the lone marine plant species listed, is classified as threatened and makes coastal habitats and nurseries for fish and provides a food source for the also-endangered West Indian manatees and green sea turtles. However, its most important role may be long-term ocean carbon storage, known as blue carbon: seagrass beds can store more carbon than the world’s forests per hectare.

The main threats to Johnson’s seagrass are nutrient and sediment pollution, and damage from boating, dredging and storms. Its plight is aggravated by its tiny geographic range–it is only found on the southeast coast of Florida. The species may have more trouble recovering than other seagrass species because it seems to only reproduce asexually–while other seagrasses can reproduce like land plants, by producing a flower that is then fertilized by clumps of pollen released underwater, the Johnson’s seagrass relies on the sometimes slow process of new stems sprouting from the buried root systems of individual plants.

Short-tailed albatrosses have made a remarkable recovery since they were believed to be extinct in the 1940s. They still face threats today though, from habitat loss to being caught unintentionally by fishing gear. Photo by U.S. Fish and Wildlife Service

4. The short-tailed albatross (Phoebastria albatrus) differs from some of its neighbors on the ESA list in that an extra layer of uncertainty is added to the mix: During breeding season, they nest on islands near Japan, but after breeding season ends, they spread their wings and fly to the U.S. In the late 19th century, the beautiful birds are thought to have been fairly common from coastal California up through Alaska. But in the 1940s, their population dropped from the tens of millions to such a small number that they were thought to be extinct. Their incredible decline was due to hunters collecting their feathers, compounded by volcanic damage to their breeding islands in the 1930s.

Today they are doing better, with over 2,000 birds counted in 2008, but only a few islands remain as nesting sites and they continue to be caught as bycatch, meaning that they are often mistakenly hooked by longline fishing gear.

Atlantic salmon used to be found in most major rivers in New England, now they are only found in a small section of Maine. Photo by E. Peter Steenstra/USFWS

5. Salmon are a familiar fish frequently seen on the menu. But not all species are doing well enough to be served on our plates. Salmon split their time between freshwater (where they are born and later spawn) and the ocean (where they spend their time in between). Historically, Atlantic salmon in the U.S. were found in most major rivers on the Atlantic coast north of the Hudson, which flows through New York State. But damming, pollution and overfishing have pushed the species to a point where they are now only found along a small section of the Maine coast. Twenty-eight populations of Pacific salmon are also listed as threatened or endangered. Efforts on both coasts are underway to rebuild populations through habitat restoration, pollution reduction and aquaculture.

The five organisms listed here are just a few of the marine species on the ESA’s list. In fact, scientists expect that as they learn more about the oceans, they will reveal threats to more critters and plants.

“The charismatic marine species, like large whales [and] sea turtles…were the first to captivate us and pique our curiosity to look under the waves,” says Jonathan Shannon, from the NOAA Fisheries Office of Protected Species Resources. “While we are learning more about the ocean and how it works every day, we still have much to learn about the different species in the ocean and the health of their populations.”

 Learn more about the ocean from the Smithsonian’s Ocean Portal. 

The invasive Spanish slug, one of the worst alien pests in Europe, is naturally repelled by ecosystems if soils house a healthy population of earthworms, new research suggests. Photo by Xauxa Håkan Svensson

They creep through a garden, lubricated by their own secretions, leaving a trail of mucus behind. In their wake is destruction–their rapacious appetites can require them to consume several times their own body weight each day, chomping roots and leaves with guillotine-like jaws and thousands of backward-pointing teeth. Hermaphroditic as adults, they lay tiny pearls of eggs easily mistaken for fertilizer beads in potting soil, allowing them to rampantly proliferate in gardens and nurseries.

They’re slugs, and their fleshy, squishy bodies are basically one huge stomach on a foot, driven by one overarching goal: to consume. Although some native slugs help decompose dead organic matter, returning nitrogen and other nutrients to the soil, the voracious hunger of several invasive species can destroy gardens and farms in the damp regions of the globe that slugs prefer to roam. Slugs are known to devour ornamentals, leafy shrubs and–because they enjoy slithering underground–bulbs, tubers and plant roots. If you see large, irregular holes in your hostas, you know who to thank.

New research, however, suggests that there might be simple ways to ward off slug damage. A study published this week in the journal BMC Ecology by scientists at the University of Natural Resources and Life Sciences Vienna shows that earthworms burrowing in the soil can protect plants overhead from being a slug’s next meal. Further, higher plant diversity also decreases the destruction slugs can wreak on individual plants.

To come to these findings, the researchers used large incubators to create mini grassland ecosystems in a laboratory setting. Different incubators contained different levels of plant diversity–between three to 12 species of either grasses, forbs, or legumes. After four weeks of plant growth, researchers introduced to the soil of some of the incubators a healthy amount earthworms (about 333 per square meter) who were free to burrow, convert organic matter into richer and more fertile soil, aerate soil, excrete nutrients in a more accessible form for plants and do the myriad of other things that earthworms do.

Five weeks later, two Spanish slugs (Arion vulgaris)–a critter in the top 100 worst alien species of Europe according to projects funded by the European Commission–were added to select micro-ecosystems and left there for one week. Throughout this week, plants were monitored periodically for slug damage.

If you’re hoping for an epic battle between slugs and earthworms, think again. Instead, the mere presence of earthworms reduced the number of leaves damaged due to slugs by 60 percent. Additionally, the researchers found that slugs ate 40 percent less in bins with high plant diversity than in those with low.

“Our results suggest that two processes might be going on,” explained lead author Johann Zaller in a statement. “Firstly, earthworms improved the plant’s ability to protect itself against slugs perhaps through the build-up of nitrogen-containing toxic compounds. Secondly, even though these slugs are generalists, they prefer widely available food.” As a result, in highly diverse ecosystems “slugs eat less in total because they have to switch their diets more often since plants of the same species are less available,” he added.

Earthworms may play a crucial role in helping plants defend themselves from being devoured by slugs. Photo by Flickr user goosmurf

Gardeners are familiar with the idea that varying up their plant beds helps preserve the plants most tasty to invasive slugs. But the tenacity of these slugs and their insatiable appetites cause many horticulturalists hover over their plants like helicopter parents, employing all sorts of methods to curb slug infestation.

Approaches vary in their effectiveness and efficiency. For example, those with the time and inclination to coddle their plants can tent cardboard overnight on the ground around prize plants to create a moist shelter for the nocturnal gastropods. Removing the newspaper in the morning often yields a writhing clutch of slugs, which can then be removed and killed. Quicker methods can be found with slug bait, but many can increase the toxicity of surrounding soil and can be harmful to wildlife and pets if ingested. Salting slugs–death by dessication–also can be harmful to nearby plants, as salt can interfere with the plant’s ability to uptake water.

Some gardeners place copper strips around the perimeter of flower beds–the copper supposedly reacts with slug slime to produce a kind of electric shock, repelling the creatures. Others use cans of stale beer, buried around a garden, as traps–the slugs, lured by beer’s fermented smell, get caught in the can, can’t escape and then drown. But the new results suggest that earthworms–already the gardener’s best friend because of their ability to improve soil fertility–may be even more effective than all these methods, highlighting the idea that organisms in soil can affect the health of organisms above ground.

Such interactions are largely ignored in ecological research, according to Zaller. “What we know from other studies is that earthworms change the nutrition of plants, thus enabling them to better respond to herbivores,” he told Surprising Science in an email. “As a response against herbivores, plants usually change their chemistry and they build up (costly) secondary chemicals in their leaves. If the nutrition of the plant is improved by the activity of earthworms, more of these defense compounds can be build up and the plant is better protected against herbivores.”

Of course, “one has always be very cautious in translating results from a specific experiment into the natural world,” Zaller continued. “In ecology many results are context specific, species-specific etc. Whether our results can be applied to other invasive slug species (or herbivores in general) would of course demand specific experiments. However, I would guess the mechanisms we suggest happening in our setting should be similar in settings involving different species.”

Could this gator’s teeth hold clues for regenerating humans’ pearly whites? Photo by Flickr user montuschi

Humans drew the short end of the toothbrush when it comes to our pearly whites’ longevity. Other animals such as reptiles and fish frequently lose and replace their teeth by growing new ones, but people are stuck with the same set of mature adult teeth their entire lives. If they lose a tooth–or all 32–dentures are usually the only option.

Oddly enough, alligators’ deadly chomps may hold a clue for how scientists could coax humans into regrowing teeth. These reptiles belong to the order Crocodilia, who, with their famous cheerful grins, caused songwriters to warn that you should never smile at a crocodile. To the bane of Captain Hook and other victims of gator and croc attacks, the large reptiles often regrow their razor teeth multiple times. Researchers think that, given time, technology may advance so that we can borrow these reptilian smiles. But first, scientists need to understand just how these animals keep their smiles toothy.

In a paper published this week in the Proceedings of the National Academy of Sciences, an international team of researchers attempted to get at the mechanisms behind the superior tooth regenerating abilities of one species of Crocodilia–the American alligator–in the hopes of applying the results to humans.

In humans, organs such as hair, scales, nails and teeth “are at the interface between an organism and its external environment and therefore, face constant wear and tear,” the researchers write. But alligators have evolved ways to deal with these challenges. The carnivores can replace any of their 80 teeth up to 50 times throughout their 35 to 75-year lives. Small replacement teeth grow under each mature alligator tooth, ready to spring into action the moment a gator loses a tooth.

To figure out the molecules and cells responsible for replacement, the researchers used X-rays and small tissue samples from alligator embryos, hatchlings and 3-year old juveniles’ developing teeth. They also grew tooth cells in the laboratory and created computer models of the process. Alligator teeth appear to cycle continuously, they write, but in fact the animals’ teeth seem to go through three distinct phases: pre-initiation, initiation and growth.

Once an alligator loses a tooth, these three phases kick off. The dental lamina, or a band of tissue associated with the initial stages of tooth formation in many animals, begins to bulge. This triggers stem cells and an array of signaling molecules that direct the process of forming a new tooth.

These results may be applicable to humans’ pearly whites. Alligators’ flesh-chomping incisors are surprisingly similar to well-organized, complex vertebrate teeth such as ours. In humans, a remnant of the dental lamina–the structure crucial to tooth formation–still exists and sometimes wrongly activates and begins forming toothy tumors. If the researchers could better tease out the molecular signaling pathways behind alligator tooth replacement, they reason, they they may be able to induce those same chemical instructions in humans to coax the body into forming a new tooth after one gets kicked out in a soccer game or has to be removed after becoming infected.

Alternatively, doctors may be able to shut off the molecules responsible for conditions that cause uncontrolled tooth formation. Individuals suffering from cleidocranial dysplasia syndrome grow many unusually shaped, peg-like teeth, for example, and people with Gardner syndrome also grow supernumerary, or extra, teeth.

While the researchers still need to clarify more molecular details behind alligator tooth growth, this initial study does hint that doctors and dentists may someday be able to selectively bestow patients with the reptiles’ tooth-regenerating abilities.

“Based on our study, it may be possible to identify the regulatory network for tooth cycling,” the researchers conclude. “This knowledge will enable us to either arouse latent stem cells in the human dental lamina remnant to restart a normal renewal process in adults who have lost teeth or stop uncontrolled tooth generation in patients with supernumerary teeth.”

Either way, they note that “Nature is a rich resource from which to learn how to engineer stem cells for application to regenerative medicine.”

Periodical cicadas, like the one pictured above, have missed a lot of news about insects since they last appeared. Photo via Wikimedia Commons

After 17 years underground, billions of cicadas are ready to emerge and see sunlight for the first time. They will blanket the East Coast until around mid-June, buzzing like jackhammers in harmony as they search for a mate. Since 1996, the periodical insects, which belong to a group called Brood II, have lived as nymphs two feet deep in the soil, feeding on nothing but the liquid they suck out of tree roots. Once they crawl up to the surface, they molt, mate, lay eggs and die within a month.

Scientists are still trying to determine how periodical cicadas know when to emerge. But in the last 17 years, researchers have made some other important discoveries about other insects, some of whom also enjoy swarming the United States. Here are 17 news items about the bugs’ brethren since 1996.

1. British researchers figured out how insects fly. In 1996, scientists at the University of Cambridge solved the mystery of how many winged insects can produce more lift than can be explained by aerodynamic properties. The team unleashed hawkmoths into a wind tunnel with smoke and then took high-speed photos of the insects in flight. By studying how the smoke moved around the moths’ wings, researchers were able to determine that flying insects create whirling spirals of air above the front edges of their wings, providing more lift.

2. Cuba claimed that the United States brought an insect infestation to the island. In 1997, Cuban authorities accused the U.S. of staging a biological attack the previous year by using a crop-duster to spread insects over the island. But what really happened? An American commercial airliner had flown over the country and released smoke to signal its location, an event that coincided with bug infestations on Cuba’s potato plantations.

3. A plague of crickets ravaged the Midwest. In 2001, hordes of crickets descended upon Utah, infesting more than 1.5 million acres in 18 of the state’s 29 counties. The damaged wreaked on the ironically named Beehive State’s crops totaled nearly $25 million. Michael O. Leavitt, Utah’s governor at the time, declared the infestation an emergency and sought help from the U.S. Department of Agriculture in combating the little critters.

4. Scientists uncovered an entire new order of insects. In 2002, entomologists discovered a group of inch-long wingless creatures that comprised a new order, a taxonomic rank used in the classification of organisms. The first to be identified in 88 years at that time, the order, dubbed Mantophasmatodea, consists of insects with features similar to praying mantises. The finding became the 31st known insect order.

5. A swarm of butterflies, thought to be one single species, turned out to be 10 of them. In 2004, researchers used DNA barcoding technology to study the Astraptes fulgerator butterfly, whose habitat ranges from Texas to northern Argentina. What they found was remarkable: an insect that was thought to be one species was actually 10 different species. The species’ habitats overlapped, but the butterflies never bred with its doppelganger neighbors.

6. Researchers pinpointed the world’s oldest known insect fossil. Until 2004, a 400 million-year-old set of tiny insect jaws—originally found in a block of chert along with a well-preserved and well-studied fossil springtail—lay untouched for almost a century in a drawer at the Natural History Museum in London. The rediscovery and subsequent study of the specimen meant that true insects appeared 10 million to 20 million years earlier than once thought. The researchers believe these ancient insects were capable of flight, which would mean the tiny creatures took to the skies 170 millions years ago, before flying dinosaurs.

7. Brood X invaded the East Coast. In 2004, another group of cicadas known as Brood X emerged after 17 years underground. The bugs’ motto? Strength in numbers. This class is the largest of the periodical insects, including three different species of cicada.

8. America’s bee population started to plummet. By spring of 2007, more than a quarter of the country’s 2.4 million honeybee colonies had mysteriously vanished. Something prevented the bees from returning to their hives, and scientists weren’t sure why, but they gave it a name: colony-collapse disorder. According to a recent report by the U.S. Department of Agriculture, the phenomenon continues to plague apiaries across the country, and no cause has been determined.

9. Gypsy moths destroyed thousands of trees in New Jersey. In 2007, gypsy moths ravaged more than 320,000 acres of forest in the Garden State. One of North America’s most devastating forest pests, the insect feeds on the leaves of trees, stripping branches bare. Agricultural officials said the infestation was the worst of its kind since 1990.

10. Scientists figured out how to extract DNA from preserved insect specimens. In 2009, researchers removed a barrier from the study of early insects, a practice that often left ancient specimens destroyed. In the past, too much tinkering around with tiny specimens meant that the samples often became contaminated or eventually deteriorated. The scientists soaked nearly 200-year-old preserved beetles in a special solution for 16 hours, a process that allowed them to then carefully extract DNA from the bugs without damaging them.

11. Hundreds of ancient insect species were found lodged in one chunk of amber. In 2010, a team of international researchers discovered 700 new species of prehistoric insects inside a block of 50-million-year-old amber in India. The finding signaled to scientists that the area was much more biologically diverse than previously thought.

12. The first truly amphibious insects were discovered. In 2011, a study reported that 11 species of caterpillar with the ability to live underwater indefinitely were found in freshwater streams in Hawaii. The twist? The same insects studied were land-dwellers too.

13. Scientists discovered a cockroach with more than just a spring in its step. In 2011, a new species of cockroach, for whom jumping and hopping accounts for 71 percent of movement, was found in South Africa. Saltoblattella montistabularis can cover a distance 50 times its body length with each hop. Dubbed the leaproach, the insect relies on its powerful hind legs, which are twice the length of its other limbs and make up 10 percent of its body weight, to propel it forward in high-speed bursts.

14. Japanese scientists documented radiation-induced mutations in butterflies. When a massive earthquake and tsunami severely damaged the Fukushima nuclear power plant in 2011, dangerous radioactive materials were spewed into the air and waterways. The following year, Japanese researchers said they observed dented eyes and stunted wings in local butterflies, mutations they believe were a result of radiation exposure.

15. The East Coast suffered a stink bug epidemic. In the summer of 2011, growing numbers of stink bugs prompted the Environmental Protection Agency to issue an emergency ruling that would allow farmers to use lethal insecticides. The insects had invaded crops of apples, cherries, pears and peaches from Virginia to New Jersey.

16. The world’s largest insect was discovered in New Zealand. Scientist Mark Moffett, known as Doctor Bugs, discovered the world’s largest insect, a surprisingly friendly female Weta bug, while traveling in New Zealand in 2011. The massive creature has a wingspan of seven inches and weighs three times as much as a mouse. Here’s a video of the bug eating a carrot out of Moffett’s hand.

17. A fly found in Thailand was determined to be the smallest in the world. Discovered in 2012, the fly, named Euryplatea nanaknihali, is 15 times smaller than a house fly and tinier than a grain of salt. But don’t let the miniature bugs fool you: they feed on tiny ants by burrowing into the larger insects’ head casings, eventually decapitating them.

Tweets from around the world, plotted by location as part of a new study. Click to enlarge. Image via First Monday/Leetaru et. al.

It’s hard to appreciate just how quickly and thoroughly Twitter has taken over the world. Just seven years ago, in 2006, it was an idea sketched out on a pad of paper. Now, the service is used by an estimated 554 million users—a number that amounts to nearly 8 percent of the all humans on the planet—and an estimated 170 billion tweets have been sent, with that number climbing by roughly 58 million every single day.

All these tweets provide an invaluable source of news, entertainment, conversation and connection between people. But for scientists, they’re also valuable as something rather different: raw data.

Because Twitter features an open API (which allows for tweets to be downloaded as raw, analyzable data) and many tweets are geotagged, researchers can use billions of these tweets and analyze them by location to learn more about the geography of humans across the planet. Last fall, as part of the Global Twitter Heartbeat, a University of Illinois team analyzed the language and location of over a billion tweets from across the U.S. to create sophisticated maps of things like positive and negative emotions expressed during Hurricane Sandy, or support for Barack Obama or Mitt Romney during the Presidential election.

As Joshua Keating noted on Foreign Policy‘s War of Ideas blog, members of the same group, led by Kalev Leetaru, have recently gone one step further. As published in a new study earlier this week in the online journal First Monday, they analyzed the locations and languages of 46,672,798 tweets posted between October 23 and November 30 of last year to create a stunning portrait of human activity around the planet, shown at the top of the post. They made use of the Twitter decahose, a data stream that  captures a random 10 percent of all tweets worldwide at any given time (which totaled 1,535,929,521 for the time period), and simply focused on the tweets with associated geographic data.

As the researchers note, the geographic density of tweets in many regions—especially in the Western world, where computers, mobile devices, and Twitter are all used at peak levels—closely matches rates of electrification and lighting use. As a result, the maps of tweets (such as the detail view of the continental U.S., below) end up looking a lot like satellite images of artificial light at night.

Click to enlarge. Image via First Monday/Leetaru et. al.

As a test to see how well tweets matched artificial light use, they created the composite map below, in which tweets are shown as red dots and nighttime lighting is shown as blue. Areas where they correspond in frequency (and effectively cancel each other out) are shown as white, and areas where one outweighs the other remain red or blue. Many areas end up looking pretty white, with some key exceptions: Iran and China, where Twitter is banned, are noticeably blue, while many countries with relatively low electrification rates (but where Twitter is still popular) appear as red.

Click to enlarge. Image via First Monday/Leetaru et. al.

The project got even more interesting when the researchers used an automated system to break down tweets by language. The most common language in Twitter is English, which is represented in 38.25 percent of all Tweets. After that came Japanese (11.84 percent), Spanish (11.37 percent), Indonesian (8.84 percent), Norwegian (7.74 percent) and Portugese (5.58 percent).

The team constructed a map of all tweets written in the 26 most popular languages, with each represented by a different color, below:

Click to enlarge. Image via First Monday/Leetaru et. al.

While most countries’ tweets are dominated by their official languages, many are revealed to include tweets in a variety of other languages. Look closely enough, and you’ll see a rainbow of colors subtly popping out from the grey dots (English tweets) that blanket the U.S.:

Click to enlarge. Image via First Monday/Leetaru et. al.

Among other analyses, the research team even looked at the geography of retweeting and referencing—the average distance between a user and someone he or she retweets, as well as the average distance between that user and someone he or she simply references in a tweet. On average, the distance for a retweet was 1,115 miles and 1,118 for a reference. But, counterintuitively, there was a positive relationship between the number of times a given user retweeted or referenced another user and their distance: Pairs of users with just a handful of interactions, on the whole, were more likely to be closer together (500-600 miles apart) than those with dozens of retweets and references between them.

This indicates that users who live far apart are more likely to use Twitter to interact on a regular basis. One explanation might be that the entities with the most followers—and thus the most references and retweets—are often celebrities, organizations or corporations, users that people are familiar with but don’t actually have a personal relationship with. A global map of retweets between users is below:

Click to enlarge. Image via First Monday/Leetaru et. al.

The paper went into even more detail on other data associated with tweets: the ratio between mainstream news coverage and number of tweets in a country (Europe and the U.S. get disproportionate media coverage, while Latin America and Indonesia are overlooked), the places Twitter has added the most users recently (the Middle East and Spain) and the places where users have, on average, the most followers (South America and the West Coast).

There are a few caveats to all this data. For one, though the tweets analyzed number in the tens of millions, they are still just 0.3 percent of all tweets sent, so they might not adequately represent all Twitter patterns, especially if users who enable geotagging behave differently than others. Additionally, in the fast-changing world of Twitter, some trends might have already changed significantly since last fall. But as Twitter continues to grow and as more data become available, it stands to reason that this sort of analysis will only become more popular for demographers, computer scientists and other researchers.

New isotopic analysis of Apollo-era Moon rocks shows that the water locked inside them likely came from our planet . Image via Wikimedia Commons/Gregory H. Revera

In September 2009, after decades of speculation, evidence of water on the surface of the Moon was discovered for the first time. Chandrayaan-1, a lunar probe launched by India’s space agency, had created a detailed map of the minerals that make up the Moon’s surface and analysts determined that, in several places, the characteristics of lunar rocks indicated that they bore as much 600 million metric tonnes of water.

In the years since, we’ve seen further evidence of water both on the surface and within the interior of the Moon, locked within the pore space of rocks and perhaps even frozen in ice sheets. All this has gotten space exploration enthusiasts pretty excited, as the presence of frozen water could someday make permanent human habitation of the Moon much more feasible.

For planetary scientists, though, it’s raised a knotty question: How did water arrive on the Moon in the first place?

A new paper published today in Science suggests that, unlikely as it may seem, the Moon’s water originated from the same source as the water that comes out of the faucet when you open a tap. Just as many scientists believe the Earth’s entire supply of water was initially delivered via water-bearing meteorites that traveled from the asteroid belt billions of years ago, a new analysis of lunar volcanic rocks brought back during the Apollo missions indicates the Moon’s water has its roots in these same meteorites. But there’s a twist: Before reaching the Moon, this lunar water was first on Earth.

A closeup of a melt inclusion inside lunar rocks. These inclusions reveal clues about the water content trapped within the Moon. Image via John Armstrong, Geophysical Laboratory, Carnegie Institution of Washington

The research team, led by Alberto Saal of Brown University, analyzed the isotopic composition of hydrogen found in water within tiny bubbles of volcanic glass (supercooled lava) as well as melt inclusions (blobs of melted material trapped in slowly cooling magma that later solidified) in the Apollo-era rocks, as shown in the image above. Specifically, they looked at the ratio of deuterium isotopes (“heavy” hydrogen atoms that contain an added neutron) to normal hydrogen atoms.

Previously, scientists have found that in water, this ratio changes depending on where in the solar system the water molecules initially formed, as water that originated closer to the Sun has less deuterium than water formed further away. The water locked in the lunar glass and melt inclusions was found to have deuterium levels similar to that found in a class of meteorites called carbonaceous chondrites, which scientists believe to be the most unaltered remnants of the nebula from which the solar system formed. Carbonaceous chondrites that fall to Earth originate in the asteroid belt between Mars and Jupiter.

Higher deuterium levels would have suggested that water was first brought on to the Moon by comets—as many scientists have hypothesized—because comets largely come from the Kuiper belt and Oort Cloud, remote regions far beyond Neptune where deuterium is more plentiful. But if the water in these samples represents lunar water as a whole, the findings indicate that the water came from a much closer source—in fact, the same source as the water on Earth.

The simplest explanation for this similarity would be a scenario in which, when a massive collision between a young Earth and a Mars-sized proto-planet formed the Moon some 4.5 billion years ago, some of the liquid water on our planet was somehow preserved from vaporization and transferred along with the solid material that would become the Moon.

Our current understanding of massive impacts, though, doesn’t allow for this possibility: The heat we believe would be generated by such an enormous collision would theoretically vaporize all lunar water and send it off into space in a gaseous form. But there are a few other scenarios that might explain how water was transferred from our proto-Earth to the Moon in other forms.

One possibility, the researchers speculate, is that the early Moon borrowed a bit of Earth’s high-temperature atmosphere the instant it formed, so any water that had been locked in the chemical composition of Earth rocks pre-impact would have vaporized along with the rock into this shared atmosphere after impact; this vapor would have then coalesced into a solid lunar blob, binding the water into the chemical composition of lunar material. Another possibility is that the rocky chunk of Earth was kicked off to form the Moon retained the water molecules locked inside its chemical composition, and later on, these were released as a result of radioactive heating inside the Moon’s interior.

Evidence from recent lunar missions suggests that lunar rocks—not just craters at the poles—indeed contain substantial amounts of water, and this new analysis suggests that water originally came from Earth. So the findings will force scientists to rethink models of how the Moon could have formed, given that it clearly didn’t dry out completely.

Helpless babe or capable professional navigator? Photo by Samuel Blanc

With their big, glossy black eyes and downy fluff, baby Weddell seal pups are some of the most adorable newborns in the animal kingdom. But these cute infants are far from helpless bundles of joy. New research published in the journal Marine Mammal Science reveals that Weddell seal pups likely possess the most adult-like brain of any mammal at birth.

The seal pups’ brains, compared to adult seals’ brain proportions, are the largest known for any mammal to date. The researchers write that this is “remarkable” considering that the pups are quite small at birth compared to many other newborn mammals.

To arrive at these findings, a team of researchers from the Smithsonian Environmental Research Center and the National Museum of Natural History traveled to Antarctica to collect fresh pups specimens. They took advantage of the fact that many pups never make it to adulthood due to stillbirths, abandonment and accidental death, such as being crushed by an adult. The researchers collected 10 dead seal pups (which quickly freeze in the Antarctic temperatures), conducted a few measurements and then decapitated and shipped the frozen heads back to the Smithsonian. They also tossed in a couple adult Weddell seal heads into the mix, one of which had died from acute toxemia–possibly from its gut being punctured by a fish spine–and the other whose cause of death could not be determined.

Back in the U.S., the researchers partially thawed the skulls in a lab and–like a well picked-over Thanksgiving turkey–manually peeled the tissue off of the baby seal faces. Then, they drilled into the skulls to extract the intact brains. Finally, they put the bones into a tank full of flesh-eating beetles to remove any remaining scraps of meat. Clean skulls and brains in hand, they went about taking measurements, and they also drew upon measurements of some older Weddell Seal skull specimens from the museum’s collection.

Remarkably, baby Weddell seal brains are already 70 percent developed at birth, the team found. Compare this to human infants, whose brains are a mere 25 percent of their eventual adult mass. As a Smithsonian statement explains, baby animals born with proportionally larger brains usually live in challenging environments in which they need to act quickly in order to survive. Other animals that share this trait include most marine mammals, zebras and wildebeest.

For Weddell seal pups, large brains likely help with diving under ice sheets and orienting themselves under water at less than three weeks old–an extremely dangerous task for any mammal, newborn or not. The pups must acclimate quickly since Weddell seal mothers abandon their young at about 6 weeks old, meaning they need to be able to completely fend for themselves when that day arrives.

In nature, however, everything comes with a price. The Weddell seal pups may have the biggest, best developed brains on the block when compared to what they will be as adults, but this metabolically taxing organ requires excessive energy to maintain. A pup weighing just 65 pounds needs between 30 to 50 grams of glucose per day in order to survive, and the team estimates that the energetically hungry brain may account for a full 28 grams of that demand. 

Luckily for the seal pups, their mothers’ milk is almost exactly matched to the babies’ caloric needs. Weddell seal milk supplies about 39 grams of sugar per day. Females seals, however, lose significant weight while tending to their young, which jeopardizes their own survival. At their mother’s cost, the babies’ brains are allowed to thrive. That is, until their mother decides she’s had enough with the nurturing and leaves her pups to survive on their own.   

New research shows our brains have a specialized system to anticipate the location of moving objects, located in V5 region of the visual cortex. Image via Wikimedia Commons/Calebrw

Throwing a baseball is hard. As xkcd pointed out just yesterday, accurately throwing a strike requires that a pitcher release the ball at an extremely precise moment—doing so more than half a millisecond too early or too late causes it to miss the strike zone entirely. Because it takes far longer (a full five milliseconds) just for our nerve impulses to cover the distance of our arm, this feat requires the brain to send a signal to to the hand to release the ball well before the arm has reached its proper throwing position.

The one feat even more difficult than throwing a fastball, though, might be hitting one. There’s a 100 millisecond delay between the moment your eyes see an object and the moment your brain registers it. As a result, when a batter sees a fastball flying by at 100 mph, it’s already moved an additional 12.5 feet by the time his or her brain has actually registered its location.

How, then, do batters ever manage to make contact with 100 mph fastballs—or, for that matter, 75 mph change-ups?

In a study published today in the journal Neuron, UC Berkeley researchers used fMRI (functional magnetic resonance imaging) to pinpoint the prediction mechanisms in the brain that enable hitters to track pitches (and enable all sorts of people to envision the paths of moving objects in general). They found that the brain is capable of effectively “pushing” forward objects along in their trajectory from the moment it first sees them, simulating their path based on their direction and speed and allowing us to unconsciously project where they’ll be a moment later.

The research team put participants in an fMRI machine (which measures blood flow to various parts of the brain in real time) and had them watch a screen showing the “flash-drag effect” (below), a visual illusion in which a moving background causes the brain to mistakenly interpret briefly flashed stationary objects as moving. “The brain interprets the flashes as part of the moving background, and therefore engages its prediction mechanism to compensate for processing delays,” said Gerrit Maus, the paper’s lead author, in a press statement.

Because the participants’ brains thought these briefly flashing boxes were moving, the researchers hypothesized, the area of their brain responsible for predicting the motion of objects would show increased activity. Similarly, when shown a video where the background didn’t move but the flashing objects actually did, the same motion-prediction mechanism would cause similar neuron activity to occur. In both cases, the V5 region of their visual cortex showed distinctive activity, suggesting this area is home to the motion-prediction capabilities that allow us to track fast-moving objects.

Previously, in another study, the same team had zeroed in on the V5 region by using transcranial magnetic stimulation (which interferes with brain activity) to disrupt the area and found that participants were less effective at predicting the movement of objects. “Now not only can we see the outcome of prediction in area V5, but we can also show that it is causally involved in enabling us to see objects accurately in predicted positions,” Maus said.

It’s not much of a leap to suppose that this prediction mechanism is more sophisticated in some people than others—which is why most of us would whiff when trying to hit the fastball of a major league pitcher.

A failure in this mechanism might be at work, the researchers say, in people who have motion perception disorders such as akinetopsia, which leaves the ability to see stationary objects completely intact but renders a person essentially blind to anything in motion. Better understanding how neurological activity in the V5 region—along with other areas of the brain—allows us to track and predict movement could, in the long-term, help us develop treatments for these sorts of disorders.

Thousands of Dutch fans celebrate a soccer match between Netherlands and Germany in the Ukranian city of Kharkiv in 2012. The fans and their German counterparts likely share hundreds of genetic ancestors from the past thousand years. Photo courtesy of Flickr user Aleksandr Osipov

Last month, a trio of engineers debuted an app that allows Icelanders to determine if they’re actually related to a potential date. Why, you ask? Because the entire population of Iceland, roughly 320,000 people, derives from a single family tree, and it’s very possible to bump into a former flame at a family gathering.

The case of Iceland is an extreme one, but the idea that we are all distant cousins, in the scope of human history, is well accepted. A new study, published today in the journal PLOS Biology, explains this degree of relatedness in modern-day Europeans.

The study reveals that just about any two random people from anywhere in Europe, even those living on opposite sides of the continent, share hundreds of genetic ancestors from only 1,000 years ago. In fact, a person living in the United Kingdom shares a chunk of genomic material with someone living in Turkey 20 percent of the time.

Researchers from the University of California, Davis and the University of Southern California studied genomic data for 2,257 Europeans from a massive database of genome-mapped individuals known as the Population Reference Sample. They measured ancestral ties going back 3,000 years by analyzing long segments of genome, passed down from generation to generation, shared by individuals.

Distant relatives share these long blocks of genome because they have both inherited them from common ancestors. First cousins share about one-fourth of their genome, inherited from a shared set of grandparents. Second cousins share just one-sixteenth of their genome, thanks to the same pair of great-grandparents. The researchers detected 1.9 million of these shared DNA sequences within the data pool, and then used their varying lengths to infer how long ago the shared ancestors lived.

These shared chunks of genome become shorter and shorter between more distant relatives because DNA strands undergo recombination, shuffling our genetic makeup around, with each successive generation. For example, a shared block of genome is shorter between second cousins than it is between first cousins. The longer a shared segment, the more recent the common ancestor.

As we might expect, the numbers of shared genetic ancestors dramatically decrease as geographic distance (in this case, across Europe) increases. This means that people who live near each other are more likely to be related to each other than those who don’t. For example, someone living in England will have a higher degree of relatedness to a fellow Briton than he would with someone from Germany. Researchers found that two modern Europeans living in neighboring populations, for example two adjacent countries, share between two and 12 genetic ancestors from the last 1,500 years.

This pattern can be seen in historically small or more isolated populations too, where fewer possible ancestors exist. Such is the case on the Italian and Iberian peninsulas—areas least affected by Slavic and Hunnic migrations between the fourth and eighth centuries—where people share more ancestors with each other than people in most other regions of Europe. Additionally, those living in Western Europe are also somewhat less related to each other than people living in Eastern Europe, a historically tight-knit region in terms of population.

However, some findings deviate from this genealogical norm. The researchers found that people from the United Kingdom shared more recent ancestors with people living in Ireland than with other UK residents. Recent ancestry also tied Germans more closely with Polish people than with other Germans. These instances likely reflect human migration in recent centuries, as smaller populations moved into larger ones.

Although this study looked only at European lineage, the researchers suggest that such patterns probably exist in the rest of the world. In any case, such research in human history brings us closer to learning more about the most recent common ancestor of all modern humans, which scientists believe who, according to mathematical models, might have walked the Earth roughly as early as 3,500 years ago (PDF). This common ancestor, a product of the intermixing of once-isolated population groups, could have lived much earlier than this if remote populations managed to prevent its members from mating with far-flung explorers, but the recent paper’s finding seems to support the idea that distant populations converged relatively recently when compared to the long history of ancient humans.

Recent testing shows that, contrary to prior findings, new plastic helmets reduce the risk of concussions by 45 to 96 percent. Image via Journal of Neurosurgery, Rowson et. al.

In the past century or so, football helmets have come a long way, evolving from crude “leatherheads” crafted by shoemakers to plastic-and-rubber hybrids that can be customized to fit a player’s head and have radios built in.

Nevertheless, the sport currently faces a serious and growing problem: brain injuries. Studies have shown that former NFL players are about three times more likely to die from Alzheimer’s, Parkinson’s and Lou Gehrig’s diseases as the general population, a result of the alarming number of concussions they experience over the course of their careers. The NFL has responded by changing its rules to minimize head impacts, instituting stricter guidelines for concussed players returning to games and pouring money into attempts to develop safer helmets.

But some critics argue that, no matter how much research we undertake, there’s simply no way to create a concussion-proof helmet—no technology can stop a fundamentally violent game from inflicting harm. A 2011 study, in fact, found that with many types of impacts, modern helmets were no better than vintage leather ones at protecting players’ heads.

But now, fans who find their desire for a safe game at odds with their love of it can take comfort in a new study, published today in the Journal of Neurosurgery, that determines otherwise: Compared to “leatherheads,” new helmets are indeed much more effective at protecting the human head. Researchers from Virginia Tech came to the finding by using an automated head impact simulation system to test the effectiveness of a pair of vintage Hutch H-18 leather helmets from the 1930s against 10 plastic helmets currently in use, and found that, depending on the force of impact, modern helmets reduced the concussion risk by anywhere from 45 to 96 percent.

The impact system used in the study, simulating a frontal impact (A) and a side impact (B). Image via Journal of Neurosurgery, Rowson et. al.

The team used the system to measure four different types of head impacts (on the front, side, rear and top of the head), and dropped the head from a range of heights (12, 24, 36, 48 and 60 inches) with each helmet on to simulate in-game impacts of a variety of intensities. Sensors inside the head were used to measure the force of each type of impact. This same type of testing, developed by the Virginia Tech team, has been used extensively to classify the safety of modern helmets on a 1 through 5-star scale.

The researchers found that there was some difference in the performance of the modern helmets—but, as you’d probably expect just from looking at them, the vintage leather helmets performed significantly more poorly than any of the plastic ones. At the lowest intensity impacts (from a 12 inch drop height), the modern helmets reduced the impact on the head by by 59 to 63 percent, and at the medium-intensity impacts (from 36 inches), they provided a 67 to 73 percent reduction. The researchers didn’t even try dropping the head with the leather helmets on from 48 or 60 inches for fear of damaging them.

At the same time, it’s worth noting that the vintage helmets tested were each about 80 years old, so their age might have meant weaker leather fibers than if pristine leatherheads had been tested. Additionally, the leather helmets had presumably taken some beating during their years of use, while the plastic ones were unused before being subjected to the drops, which might have further skewed the results.

Still, both these factors were also included in the previous 2011 finding that leather helmets were just as effective as modern ones—so what accounts for the fact that this experiment so thoroughly contradicted it? The authors of this study say that the experimental setup used in the previous one—in which two helmeted heads were smashed together, one with a modern helmet and the other with either a modern or leather one—distorted the findings and masked the differences between helmet types. Some of the impact, they say, was actually absorbed by the padding in the modern plastic helmet even when the leather one was being tested.

Of course, given the distressing numbers on the concussions suffered by football players even with the latest helmets, this sort of testing shouldn’t suggest that the goal of designing safer head gear has been achieved. But it should give us a bit of hope in showing that 100 years of helmet design has provided some benefits—and future efforts to create and rigorously test new helmet technologies might be able to cut down on concussions long-term.

The creamy sticks of color seen here are just the latest in a long history of lipsticks—historical records suggest that humans have been artificially coloring their lips since 4,000 B.C. Photo by Flickr user ookikioo

Lipstick has seen a fair share of funky ingredients in its long history of more than 6,000 years, from seaweed and beetles to modern synthetic chemicals and deer fat. In recent years, traces of lead have been found in numerous brands of the popular handbag staple, prompting some manufacturers to go the organic route. This week, more dangerous substances joined the roster.

Researchers at Berkeley’s School of Public Health at the University of California tested 32 different types of lipstick and lip gloss commonly found in the brightly lit aisles of grocery and convenience stores. They detected traces of cadmium, chromium, aluminum, manganese and other metals, which are usually found in industrial workplaces, including make-up factories. The report, published in the journal Environmental Health Perspectives, indicated that some of these metals reached potentially health-hazardous levels.

Lipstick is usually ingested little by little as wearers lick or bite their lips throughout the day. On average, the study found, lipstick-clad women consume 24 milligrams of the stuff a day. Those who reapply several times a day take in 87 milligrams.

The researchers estimated risk by comparing consumers’ daily intake of these metals through lip makeup with health guidelines. They report that an average use of some lipsticks and lip glosses results in “excessive exposure” to chromium, and frequent use can lead to overexposure to aluminum, cadmium and manganese.

Minor exposure to cadmium, which is used in batteries, can result in flu-like symptoms such as fever, chills and achy muscles. In the worst cases, the metal is linked to cancer, attacking the cardiovascular, respiratory and other systems in the body. Chromium is a carcinogen linked to stomach ulcers and lung cancer, and aluminum can be toxic to the lungs. Long-term exposure to manganese in high doses is associated with problems in the nervous system. There are no safe levels of chromium, and federal labor regulations require industrial workers to limit exposure to the metal in the workplace. We naturally inhale tiny levels of aluminum present in the air, and many FDA-approved antacids contain the metal in safe levels.

Despite the presence of these metals in lipstick, there’s no need to start abandoning lipstick altogether—rather, the authors call for more oversight when it comes to cosmetics, for which there are no industry standards regulating their metal content if produced in the United States. 

After all, cadmium and other metals aren’t an intended ingredient in lipstick—they’re considered a contaminant. They seep into lipstick when the machinery or dyes used to create the product contain the metals themselves. This means trace amounts are not listed on the tiny stickers on lipstick tubes, so there’s no way to know which brands might be contaminated.

Concern about metals in cosmetics came to the forefront of American media in 2007, when an analysis of 33 popular brands of lipstick by the Campaign for Safe Cosmetics showed that 61 percent of them contained lead. The report eventually led the Food and Drug Administration (FDA), which doesn’t regulate cosmetics, to look into the issue, and what it found wasn’t any better: it found lead in all of the samples tested, with levels four times higher than the earlier study, ranging from 0.09 parts per million to 3.06 parts per million. According to the Centers for Disease Control and Prevention, there is no safe level of lead for humans.

So we’ve got cadmium, chromium, aluminum, manganese and lead in our lipstick. What else? Today, most lipstick is made with beeswax, which creates a base for pigments, and castor oil, which gives it a shiny, waxy quality. Beeswax has been the base for lipstick for at least 400 years–England’s Queen Elizabeth I popularized a deep lip rouge derived from beeswax and plants.

Lipstick as we know it appeared in 1884 in Paris, wrapped in silk paper and made from beeswax, castor oil and deer tallow, the solid rendered fat of the animal. At the time, lipstick was often colored using carmine dye. The dye combined aluminum and carminic acid, a chemical produced by cochineals–tiny cacti-dwelling insects–to ward off other insect predators.

That early lipstick wasn’t the first attempt at using insects or to stain women’s mouths. Cleopatra’s recipe for homemade lipstick called for red pigments drawn out from mashed-up beetles and ants.

But really, any natural substance with color was fair game for cosmetics, regardless of its health effects: Historians believe women first starting coloring their lips in ancient Mesopotamia, dotting them with dust from crushed semi-precious jewels—these lovely ancients were eating tiny bits of rocks whenever they licked their lips. Ancient Egyptians used lip color too, mixing seaweed, iodine and bromine mannite, a highly toxic plant-derived chemical that sickened its users.

From mannite to heavy metals, humanity’s quest for painted beauty doesn’t seem to have progressed far from toxic roots. The sacrifices we make for fashion!

Our bodies convert asparagusic acid into sulfur-containing chemicals that stink—but some of us are spared from the pungent aroma. Photo by Gunnar Magnusson

If you’ve ever noticed a strange, not-entirely-pleasant scent coming from your urine after you eat asparagus, you’re definitely not alone.

Distinguished thinkers as varied as Scottish mathematician and physician John Arbuthnot (who wrote in a 1731 book that “asparagus…affects the urine with a foetid smell”) and Marcel Proust (who wrote how the vegetable “transforms my chamber-pot into a flask of perfume”) have commented on the phenomenon.

Even Benjamin Franklin took note, stating in a 1781 letter to the Royal Academy of Brussels that “A few Stems of Asparagus eaten, shall give our Urine a disagreable Odour” (he was trying to convince the academy to “To discover some Drug…that shall render the natural Discharges of Wind from our Bodies, not only inoffensive, but agreable as Perfumes”—a goal that, alas, modern science has still not achieved).

But modern science has, at least, shed some light on why this one particular vegetable has such an unusual and potent impact on the scent of urine. Scientists tell us that the asparagus-urine link all comes down to one chemical: asparagusic acid.

Asparagusic acid, as the name implies, is (to our knowledge) only found in asparagus. When our bodies digest the vegetable, they break down this chemical into a group of related sulfur-containing compounds with long, complicated names (including dimethyl sulfide, dimethyl disulfide, dimethyl sulfoxide and dimethyl sulfone). As with many other substances that include sulfur—such as garlic, skunk spray and odorized natural gas—these sulfur-containing molecules convey a powerful, typically unpleasant scent.

All of these molecules also share another key characteristic: They’re volatile, meaning that have a low enough boiling point that they can vaporize and enter a gaseous state at room temperature, which allows them to travel from urine into the air and up your nose. Asparagusic acid, on the other hand, isn’t volatile, so asparagus itself doesn’t convey the same rotten smell. But once your body converts asparagusic acid into these volatile, sulfur-bearing compounds, the distinctive aroma can be generated quite quickly—in some cases, it’s been detected in the urine of people who ate asparagus just 15-30 minutes earlier.

Of course, the whole asparagus-urine scent issue is complicated by an entire separate issue: Some people simply don’t smell anything different when urinate after they eat asparagus. Scientists have long been divided into two camps in explaining this issue. Some believe that, for physiological reasons, these people (which constitute anywhere from 20 to 40 percent of the population) don’t produce the aroma in their urine when they digest asparagus, while others think that they produce the exact same scent, but somehow lack the ability to smell it.

On the whole, the evidence is mixed. Initially, a pair of studies conducted in the 1980s with participants from France and Israel found that everyone produced the characteristic scent, and that a minority of people were simply unable to smell it. People with the ability to detect the scent, though, were able to smell it even in the urine of those who couldn’t smell it, indicating that the differences were rooted in perception, not production.

More recent studies, though, suggest the issue is a bit more complicated. The most recent study, from 2010, found that differences existed between individuals in both the production and detection of the scent.

Overall, scientists now conclude that most of the difference is in perception—that is, if your urine doesn’t seem to smell any differently after you eat asparagus, it’s likely that you simply can’t perceive the sulfurous compounds’ foul odor, but there’s a small chance it’s because your body digests asparagus in a way that reduces the concentration of these chemicals in your urine.

It’s still unclear why some people don’t produce the smell, but we do seem to have a clear explanation of why some people don’t perceive it. In 2010, the genetic sequencing company 23andMe conducted a study in which they asked nearly 10,000 customers if they noticed any scent in their urine after eating asparagus, and looked for genetic similarities among those who couldn’t. This peculiarity—which you might consider useful if you eat asparagus frequently—appears to stem from a single genetic mutation, a switched base-pair among a cluster of 50 different genes that code for olfactory receptors.

We’re still waiting for some enterprising team of scientists to attempt gene therapy to convert smellers into non-smellers—but given other priorities to use genetic modification to cure blindness and breast cancer, it seems likely that those suffering from asparagus-scented urine might have to wait a while.

VOTO, a new device that converts the heat from a fire into readily usable electricity. Photo via Point Source Power

In the wealthy world, improving the energy system generally means increasing the central supply of reliable, inexpensive and environmentally-friendly power and distributing it through the power grid. Across most of the planet, though, simply providing new energy sources to the millions who are without electricity and depend on burning wood or kerosene for heat and light would open up new opportunities.

With that in mind, engineers and designers have recently created a range of innovative devices that can increase the supply of safe, cheap energy on a user-by-user basis, bypassing the years it takes to extend the power grid to remote places and the resources needed to increase a country’s energy production capacity. Here are a few of the most promising technologies.

1. VOTO: Millions of people around the world use charcoal and wood-fueled stoves on a daily basis. VOTO (above), developed by the company Point Source Power, converts the energy these fires release as heat into electricity, which can power a handheld light, charge a phone or even charge a spare battery. The company initially designed VOTO for backpackers and campers in wealthy countries so they can charge their devices during trips, but is also trying to find a way to make it accessible to residents of the developing world for daily use.

The Window Socket. Photo by Kyuho Song & Boa Oh

2.Window Socket: This is perhaps the simplest solar charger in existence: Just stick it on a sunny window for 5 to 8 hours with the built-in suction cup, and the solar panels on the back will store about 10 hours worth of electricity that can be used with any device. If there’s no window available, a user can just leave it on any sunny surface, including the ground. Once it’s fully charged, it can be removed and taken anywhere—inside a building, stored around in a bag or carried around in a vehicle. The designers, Kyuho Song and Boa Oh of Yanko Design, created it to resemble a normal wall outlet as closely as possible, so it can be used intuitively without any special instructions.

The Berkeley-Darfur Stove. Photo via Berkeley Lab Cookstove Projects

3. The Berkeley-Darfur Stove: In the past few years, a number of health researchers have come to the same conclusion: that providing a safe, energy-efficient wood-burning cookstove to millions of people in the developing world can directly improve health (by reducing smoke inhalation), aid the environment (by reducing the amount of wood needed for fuel) and alleviate poverty (by reducing the amount of time needed to devote to gather wood every day).

Many projects have pursued this goal, but Potential Energy, a nonprofit dedicated to adapting and scaling technologies to help improve lives in the developing world, is the furthest along, having distributed more than 25,000 of their Berkeley-Darfur Stoves in Darfur and Ethiopia. Their stove’s design achieves these aims with features such as a tapered wind collar, a small fire box opening, nonaligned air vents that reduce the amount of wind allowed to stoke or snuff the fire (which wastes fuel) and ridges that ensure the optimal distance between the fire and pot in terms of fuel efficiency.

Photo via deciwatt.org

4. GravityLight: Along with wood-burning stoves, the kerosene-burning lamps that provide light throughout the developing world have recently become a target for replacement for one of the same reasons: The fumes generated by burning kerosene in closed corners are a major health problem. A seemingly simple solution is GravityLight, developed by the research initiative deciwatt.org.

To power the device, a user fills an included bag with about 20 pounds of rock or dirt, attaches it to the cord hanging down from the device and lifts it upward. The potential energy stored in that lifting motion is then gradually converted to electricity by the GravityLight, which slowly lets the bag downward over the course of about 30 minutes and powers a light or other electrical device during that time. It’s currently priced at about $10, and because it requires no running costs, the development team estimates that the investment will be paid back in about 3 months, as compared to the cost of kerosene.

Image via Uncharted Play

5. SOCCKET: Soccer—known simply as football in nearly every English-speaking country besides the U.S.—is easily the most popular sport in the world. The newest product of Uncharted Play, a for-profit social enterprise, seeks to take advantage of the millions of people already playing the sport to replace kerosene lamps with electric light generated in a much different manner. Their ball uses an internal kinetically-powered pendulum to generate and store electricity. After about 30 minutes of play, the ball stores enough energy to power an attachable LED lamp for 3 hours. Development of the product was funded via Kickstarter, and the first ones will ship in the next few weeks. A percentage of all retail sales will go to providing SOCCKETs to schools in the developing world.

How many unborn brothers and sisters did this sand tiger shark devour to be here today? Photo by Amada44

Baby animals may seem irresistibly adorable, but in reality many of them are calculating killers. Hyena, wolf or even dog litter runts are pushed aside by their larger siblings and left to go hungry; fuzzy white egret chicks will kick their weaker clutch mates out of the nest to certain doom; and  baby golden eagles sometimes go so far as to snack on their smaller brothers and sisters while their mother looks on.

Perhaps most disturbing of all, however, is the case of the baby sand tiger shark. While sharks may not be the most snuggly animals to begin with, the sand tiger shark sets a new precedent for fratricide. This species practices a form of sibling-killing called intrauterine cannibalization. Yes, “intrauterine” refers to embryos in the uterus. Sand tiger sharks eat their brothers and sisters while still in the womb.

Even by nature’s cruel standards, scientists admit that this is an unusual mode of survival. When sand tiger sharks develop in their mother’s uteri (females have both a left and right uterus), some–usually the embryo that hatched first from its encapsulated, fertilized egg–inevitably grow faster and larger than others. Once the largest embryos cross a certain size threshold, the hungry babies turn to their smaller siblings as convenient meals. “The approximately 100 mm hatchling proceeds to attack, kill and eventually consume all of its younger siblings, achieving exponential growth over this period,” a team of researchers who investigated the phenomenon wrote this week in Biology Letters.  

Size differential between a recent hatchling (H) and an older embryo (E) from the same uterus in a typical litter the researchers samples. Photo by Chapman et al., Biology Letters

From what began as two uteri full of a dozen embryos results in just two dominating baby sand tiger sharks coming full term. What’s more, once the unborn babies consume all of the living embryos, they turn to their mother’s unfertilized eggs next, in a phenomenon called oophagy, or egg-eating. By the time those two surviving babies are finally ready to be introduced into the big, bright world, all of the pre-birth inner feasting has paid off. They emerge from their mother measuring in at about 95 to 125 centimeters long, or a bit longer than a baseball bat, meaning fewer predators can pick them off than if they had shared food with siblings and were smaller.   

This peculiar situation has implications for the genetic makeup of the species. Female sand tiger sharks, like many animals, mate with multiple males. Oftentimes in nature, females determine which males will sire the next generation by selectively choosing to mate with the most impressive bachelor (or bachelors) around. If mating with multiple males at any given time–as sharks, insects, dogs, cats and many other animals sometimes do–the babies that the female eventually produces share the same womb with siblings that may have different fathers. 

In this case, however, there are two modes of selection at work. Females may choose mates, but that does not guarantee those males’ genes will make the cut. The embryos the males sire will also have to survive the subsequent frenzy of cannibalism going on inside the female’s body. 

To find out whether some males are mating but missing out on actually producing offspring, the authors of this new study undertook microsatellite DNA profiling of 15 sand tiger shark mothers and their offspring. The researchers collected the sharks from accidental mortality events near protected beaches in South Africa between 2007 to 2012. By comparing the embryo genetics, the researchers could determine how many fathers were involved in fertilizing the eggs.

Nine of the females, or 60 percent, had mated with more than one male, the researchers found. When it came to which embryos hatched and grew large first (and thus would have survived if their mothers hadn’t have been killed), 60 percent shared the same father. This means that even if a female mates with more than one male, there is no guarantee that the male has been successful in passing on his genes. Rather, he could have just provided a convenient entree for another male’s offspring.

This also explains some male sand tiger shark behavior and physiology. Male sand tiger sharks often guard their mates against other males just after copulation. Males of this species also produce a conspicuously large amount of sperm compared to other sharks. Both of these characteristics increase the likelihood that the embryo fertilized by that male will successfully implant in the female’s uterus earlier, giving it a significant head start for developing more quickly than its siblings, which makes it more likely that the recent mate’s offspring will eat the others that may come along.

As for the females sand tiger sharks, some researchers think they actually may not have much of a choice when it comes to mating with multiple males.  It could be that females just give in to some amorous partners because the energetic cost of resisting those advances outweighs the cost of just conceding to the act–a behavior biologists call the convenience polyandry hypothesis. In this case, however, females may still get the final laugh since the males they first mated with and most likely preferred will have the greater chance of actually triumphing as the father of their children. “[Embryonic cannibalism] may allow female sand tigers to engage in convenience polyandry after mating with preferred males without actually investing in embryos from these superfluous copulations,” the researchers speculate.

While the females did invest in initially developing those doomed embryos, those investments are much smaller than what would be required to bring multiple embryos to full term. Those smaller embryos also represent resources allocated to the stronger, dominate embryonic winners, which thus have a better chance of surviving and passing on their mother’s genes than if she had spent the energy to instead birth multiple, weakling babies. In a way, the mother shark is providing nourishment for her strongest babies by producing multiple embryos that the most robust can eat. 

“This system highlights that competition and sexual selection can still occur after fertilization,” the authors write. For example, the first embryo to implant may not end up being the the one that survives the gladiator arena of the sharks uterus. While this new research still needs to delve into the details of the competition that takes place within the uterus, a picture is emerging based upon these initial findings: Females may chose which males to mate with or may be coerced into reluctantly mating, but male sperm fitness and the quality of the embryos they produce could also carry significant weight in which animals ultimately wind up as winners in this system. 

“This competition can play an important and probably under-appreciated role in determining male fitness,” the authors conclude. 

A baby cao vit gibbon learns to search for food. Photo: Zhao Chao 赵超, Fauna and Flora International

You probably haven’t heard of the world’s second rarest ape, the cao vit gibbon. Scientists know of only one place the species still lives in the wild. In the 1960s, things got so bad for the cao vit gibbon that the species was declared extinct. But in 2002, to the surprise and elation of conservationists, the animals—whose shaggy coats can be a fiery orange or jet black—turned up along Vietnam’s remote northern border. Several years later, a few gibbons were found in China, too.

Also known as the eastern black-crested gibbon, the cao vit gibbons once covered an expanse of forest spanning from southern China and northern Vietnam just east of the Red River, but today only about 110 individuals survive. This gibbon is highly inclined to stick to the trees—in a previous study, during more than 2,000 hours spent observing gibbons in the field, researchers saw only once and very briefly one young male cao vit gibbon come down from the canopy and walk on a rock for a few seconds. Population surveys based on watching the animals in the branches reveal that the gibbons live in 18 groups scattered throughout the area. That makes it the second least populous species of ape, just after the Hainan gibbon, another type of extremely rare gibbon living in the same area of Asia.

In 2007 and 2009, Vietnam and then China hustled to establish special protected areas dedicated to preventing the cao vit gibbon’s extinction. Much of the area surrounding the remaining populations of gibbons is quickly being converted to agricultural fields and pasturesor cut down to make charcoal to sell and use at home, a common practice in the area. Hunting—though illegal—is also an issue, as exotic wild meat dinners are popular with locals in the region.

For an endangered species to recover rather than just survive, it needs to grow in numbers. But any given patch of land can only support so many animals given the amount of food and space that’s available. If populations exceed this threshold—called a carrying capacity—then animals will either starve, get picked off by predators or have to move somewhere else. 

Researchers from Dali University in Yunnan, the Chinese Academy of Sciences in Kunming and the Chinese Research Academy of Environmental Sciences in Beijing wanted to find out how much of the protected forest the cao vit gibbons had expanded into, and also how many animals that pocket of land could eventually support. To answer this question, they turned to high-resolution satellite images, describing their results in the journal Biological Conservation.

Once they acquired aerial images of the gibbons’ habitat, they classified it into forest, scrub, shrub land and developed areas. This was important because gibbons can only live high in forest canopies, meaning the latter three categories were out of bounds for potentially supporting the animals. Overall, the area could be divided into five different zones that were split apart by either roads or rivers. From there, the researchers plugged the data into computer models that ranked possible gibbon habitat from high to low quality.

Habitat quality over the five zones the researchers identified. Stars mark sites where gibbons currently live. Image from Fan et al., Biological Conservation

Their results revealed several bits of news, some good and some bad. First, from the models it seems that 20 groups of gibbons could eventually live in the protected forest areas before the population reaches its carrying capacity threshold. However, as human development creeps closer and closer, that disturbance could lower that figure. As things stand, the gibbons will likely reach their carrying capacity in the current habitat in 15 years, which doesn’t bode well for building up the species’ numbers.

There are a couple options. The protected area isn’t all great habitat, it turns out. Some of it is just mediocre for gibbons. If that span of forest could be improved, it could eventually support up to 26 groups of animals. The researchers also identified two other potential areas where gibbons could live if they could somehow manage to travel there (no gibbon has ever been known to cross a river or a road). But these patches of welcoming forest, located in Vietnam, are not protected, so they likely will not remain forests for long. If the government decided to protect those areas, the researchers write, they could serve as places for cao vit gibbons to live in the future, especially if narrow corridors of trees connecting the two areas were protected and restored as well.

If these patches of forest were protected, gibbons would not be the only species to benefit. Numerous other species of primates and monkeys, civets, pangolins, porcupines, birds, bats and many more depend upon those last remaining jungle habitats for survival. “In summary, the last remaining population of cao vit gibbon is nearing its carrying capacity in the current remaining forest patch,” the authors write. “Forest protection and active forest restoration using important food tree plantings to increase habitat quality and connectivity should be the most critical part of the ongoing conservation management strategy.”