Skip to Content

Found 330,060 Resources

Scientists Think Comb Jellies May Have Come Before All Other Animals

Smithsonian Magazine

Researchers have long debated which branch of the animal family tree is the oldest—and as technology has advanced, some surprising contenders have emerged. At first, scientists thought that sponges came first, but about a decade ago, comb jellies became a possibility, too. Now, reports Laura Geggel for LiveScience, a new study makes the case that comb jellies actually came first.

The study, published in the journal Nature Ecology & Evolutioncomes on the heels of another paper in the journal Current Biology that claims sponges were the first instead.

It all comes down to a difference in approach. Researchers who were part of the study in Current Biology analyzed a huge genetic dataset and found that sponges were at the base of the evolutionary tree. But the researchers that were part of the Nature Ecology & Evolution study used a different method. Instead of looking at a gigantic quantity of data, they focused in on a smaller number of what they call “contentious relationships”—branches of the tree on which different types of data analysis produce contradictory results.

When they focused in on the individual genes of animals in contentious categories and compared them to those of their closest relatives, the researchers discovered that often, a difference of just one gene out of hundreds of thousands can deliver a completely different result. They then looked at each gene to determine the creatures' closest relatives, using that information to place them on the tree of life. This analysis consistently put comb jellies, not sponges, at the bottom of the tree.

That might come as a surprise to sponge-first supporters. Those who think that sponges came first often use the sponge’s much simpler genetic structure as support for the idea that it predates other, more complicated lifeforms. But this latest study suggests that comb jellies have specific genes that suggest they came first.

The comb jelly controversy has been alive and well since scientists first started to use genetic analyses to link species together. As Geggel reports, a 2008 study that supported comb jellies as the oldest animals threatened to topple the simple sponge from its place—and opinion has vacillated back and forth ever since.

“We believe that our approach can help resolve many of these long-standing controversies and raise the game of phylogenetic reconstruction to a new level,” says Antonis Rokas, who co-authored the paper, in a press release. It’s proof that scientists are constantly devising better—and different—ways to go in-depth with genetic data. Rokas tells George Dvorsky at Gizmodo: “Some of the controversies that we’ve examined, including the jellies/sponges one are devilishly difficult to decipher.” So don’t expect the debate to end anytime soon.

Scientists Think These Creepy Wasps Are Going to Save Oranges

Smithsonian Magazine

Citrus greening is threatening to collapse the American citrus industry: a cold glass of orange juice or a refreshing mojito could become a luxury commodity. The citrus industry is pouring millions of dollars each year into trying to find a cure for the disease, which causes citrus trees to produce small, bitter fruits with damaged seeds.

Since 2005, citrus greening has laid siege to citrus is Florda. A little bug just a tenth of an inch long—the Asian citrus psyllid—carries the disease, and these critters have been spreading across the country, most recently popping up in California. Now, on the West coast, as Hillary Rosner reports for National Geographic, researchers are hoping to turn one invasive species against another to help stem the spread of citrus greening.

The psyllids in California don't seem to be carrying the disease-causing bacterium, yet. The federal government has a strict quarantine in place on the movement of citrus crops from infected areas to help keep California disease-free. But the psyllids are in California, and the worry is that the disease bacterium could arrive at any time. To help prevent California from sharing Florida's fate, parasitic wasps from Pakistan are being bred in the state, Rosner says.

As part of their life cycle, the wasps, which are even smaller than the psyllids, lay their eggs on the psyllids' bellies. Parasites are, in general, highly specific, and the wasp in question—Tamarixia radiata—only goes after Asian citrus psyllids, not other native psyllids, so far as we know. The researchers were careful to look out for possible ecological side effects before they started releasing the wasps a few years ago. These sorts of safeguards are incredibly important. After all, there are a number of prominent examples of this sort of project gone wrong.

Likely the most well-known example of a biocontrol disaster took place in Australia in the 1930s. In the days before agricultural pesticides, Australia's sugar cane industry was being battered by beetles. To stop the bugs from killing their crops, the Australians brought a hardy predator in from South and Central America, the cane toad. The large, poisonous cane toad has no specialized predators in the land down under, and no diseases to keep it in check. The toads eat all sorts of insects and snails, and their spread over subsequent decades wrecked havoc on Australia's ecosystem. Other examples abound of humans deliberately tweaking the balance of the ecosystem to deleterious effect.

The field of biological control—using one species to keep another in check—is a growing one. Cornell University's Anthony Shelton's biocontrol website lists dozens of wasps, flies, bacteria, fungi, beetles, and other bugs that have been approved for use to control the populations of other species.

Assuming an imported predator or pathogen takes and there's no negative consequences on the rest of the ecosystem, biological control is extremely efficient—far cheaper than constantly relying on pesticides. When it works, biocontrol is great, say Russel Messing and Mark Wright in a review article on the issue in the journal Frontiers in Ecology in 2006:

In successful biological control, the results can be dramatic. Invasives that threaten entire regional economies or vast areas of natural land can be reduced to a fraction of their previous abundance and sustained at low levels indefinitely, without additional cost of management inputs.

The problem is that most introduced predators aren't so picky with their diets, they write.

A substantial number of introduced biocontrol agents do indeed feed on non-target species. In Hawaii, 22% of 243 agents were documented to attack organisms other than their intended targets, while across North America, 16% of 313 parasitoid species introduced against holometabolous pests (insects that undergo complete metamorphosis) also attacked native species.

We don't have a particularly strong track record when it comes to biocontrol, but scientists have been getting much, much more careful in recent decades.

In an ideal world, we wouldn't be trying to tamper with the balance of the ecosystem by bringing in predators from elsewhere. But we don't live in an ideal world—we brought the citrus greening psyllids to America, and now we have to deal with them.

Scientists Think These Skulls May Be New Human Ancestor

Smithsonian Magazine

Since the first Neanderthal fossil was discovered in the 1850s, scientists have debated the difference between humans and their relatives. The two species definitely mated, but there are some big differences between them, from Neanderthals’ big brows and squat figures to their distinctive DNA. Now, reports Ben Guarino for The Washington Post, skulls that seem to be both human and Neanderthal just added an intriguing twist to that debate.

The skulls, which are described in a new paper in the journal Science, were discovered in Lingjing, China in 2007 and 2014 and are between 100,000 and 130,000 years old. Researchers are calling them “a morphological mosaic” because of a collage of characteristics.

They’ve got Neanderthals’ ear canals, eastern Eurasian humans’ low and flat brainpans, and similarities to early modern Old World humans, too.

The skulls are distinctive enough that they seem to belong to an entirely different species—one that’s neither human nor Neanderthal, but that shares characteristics of both. One explanation is that they’re Denisovans, a recently discovered ancient human cousin thought to have interbred with both humans and Neanderthals. As SmartNews reported in 2015, only two teeth and a finger bone have given scientists clues about Denisovans so far. But Science Magazine’s Ann Gibbons spoke with experts who say the skulls fit what science knows about Denisovans thus far—even though the research team itself carefully avoids saying the word in its paper or press materials.

Okay, so the team won’t take a stand on whether the skulls are Denisovan. But they tell Gibbons that they do think they’re “a kind of unknown or new archaic human.” The skulls seem to point to region-specific evolution in eastern Asia at a time when multiple hominid species existed.

For Erik Trinkaus, one of the paper’s authors, the skulls are an important glimpse back in time, filling in a gap in the human fossil record. In a release, he says that the skulls point to “the unity and dynamic nature of human evolution.”

As Guarino points out, the team wasn’t able to get genetic material from the skulls, so it will be impossible to figure out which species they’re part of until they’re analyzed and compared to what we know about other hominids. For now, the skulls have raised questions they can’t answer—but they’ve also just made the question of which hominids coexisted and when even more intriguing.

Scientists Think They Could Have Found Earth’s Oldest Fossil

Smithsonian Magazine

Around 3.7 billion years ago, Earth as we know it was still in progress. Asteroids bombarded its surface. On land, mountains rose and small areas of shallow water formed. But was that long-gone water a proving ground for the first remnants of life on Earth? As The New York Times’ Nicholas Wade reports, a newly-discovered fossil that could be Earth’s oldest is shedding new light—and plenty of controversy—on the ancient origins of our planet.

Australian and British scientists have discovered fossils in the Isua Greenstone Belt of Greenland that they claim to be the oldest ever found on Earth—a find so significant, they sat on the discovery for four years to allow enough time for verification. Now, they've finally published their research in the journal Nature.

The fossils are called stromatolites, which are layers of ancient microorganisms that grew in shallow water. The surface of the colony traps sand, which is eventually incorporated into their mat-like layers—the ancient remnants of which are recorded in the geologic record. Oddly enough, stromatolites are older than the world’s oldest rocks, since scientists think that the rocks they co-existed with (Earth’s oldest) have been crushed and destroyed by plate tectonic and erosion. The stromatolites in question were discovered in southwest Greenland, which is already home to some of Earth’s oldest rocks.

As Wade reports, it’s likely that scientists will debate many aspects of the find. Since the fossils are 220 million years older than any others yet found, they challenge scientific assumptions about how life formed on Earth.

The fossils' current estimated age means they formed toward the end of a period called the Late Heavy Bombardment, when the just-formed planet was continually pelted with asteroids and comets. But scientists are still debating how intense this bombardment was and whether it would even be possible for life to form, writes Wade. The other option is that the microbes crept in just after the bombardment ended. If that’s true, it means that life must have evolved much faster than previously thought—in just 100 million years.

If life sprung up on Earth this quickly, then perhaps another planetary neighbor could also have supported life at some point. Mars is thought to have been strikingly similar to Earth during the Late Heavy Bombardment, so it’s possible that the red planet generated life of its own during this time.

Since the discovery is so explosive, it will doubtless generate plenty of controversy. For one, natural abiotic processes could produce structures that appear to be stromatolites, reports Ed Yong at the Atlantic. Additionally, the rocks in the Isua Greenstone Belt are highly deformed and most have been twisted and smashed under high temperatures and heat. 

To support their assertion that these wavy layers were once creatures, the researchers studied the chemistry of the rocks to tease out the signatures of life. “The chemical evidence could be interpreted as signs of life, but there’s always been some element of doubt,” lead author of the study Allen Nutman tells Yong. “But what we have now is something very different—something tangible and visible you can see, rather than a reading that’s come out of an instrument.”

Another concern is the difficulty in dating the most ancient objects on Earth. The scientists used radiometric dating to determine the stromatolites' age, Joel Achenbach reports for The Washington Posta method that relies on measuring the proportion of radioactive elements in the rocks.

In an article on the find in Nature, University of Washington geobiologist Roger Buick tells Alexandra Witze that he has “about 14 queries and problems that need addressing before I believe it.” But if it is true, it might be time to update our vision of that roiling, immature Earth.

Scientists Think They’ve Found the Oldest Fossil Ever

Smithsonian Magazine

How old is life on Earth? It’s a question that intrigues and infuriates scientists—and geologists think the answer lies inside Earth’s oldest rocks. There, ancient microbes left behind clues to their long-ago existence. And now, reports The Washington Post’s Sarah Kaplan, scientists peering into some of those ancient stones think they’ve found the earliest-ever evidence of life on Earth.

A new study, published in the journal Nature, describes fossilized microorganisms thought to be between 3.77 and 4.28 billion years old. They were found in Quebec, Canada’s Nuvvuagittuq greenstone belt, which is home to some of Earth’s most ancient rocks. Inside, researchers found the fossils of what they say are long-gone bacteria left behind during Earth’s tumultuous early days.

The jasper belt in which the fossils were found is thought to have once been an undersea vent. There, researchers say, the vents played hosts to prehistoric microbes—much like modern vents, where heat-loving bacteria loves to gather. The team thinks that the remnants of some filament-like microbes absorbed iron deposits from the water after they died and slowly turned into stone. Over time, the rocks became part of the bigger belt and the rock emerged from the sea. Now, researchers think they see the remnants of those tiny fossilized structures. They look like tiny tubes.

But the tubes’ size has some scientists skeptical. As geobiologist Frances Westall tells The New York Times’ Carl Zimmer, the filaments are too big to be that old, both compared to other finds in the same rock belt and because bacteria at the time would have had to be super small to sustain low-oxygen conditions on early Earth. Another geobiologist tells Kaplan that the dating process used by the research team is controversial and that the rock could be much younger than the paper contends. Other experts aren’t sure the tubes are the remnants of life at all.

The team begs to differ. The tubes look remarkably similar to remnants left by organisms in much younger rocks. The reserachers say that the existence of carbon-12 isotopes inside graphite also found in the rocks—tell-tale signs of carbon and, hence, life—makes their case even stronger. And if they’re right, the find is staggering indeed.

If life did exist on Earth 4.28 billion years ago, that would be half a billion years earlier than scientists previously thought. Even the youngest estimate for the new microbes' age, 3.77 billion years, is still 70 million years older than the next oldest microbes. The microbes described in the new study are pretty different from the ones now thought to be the world’s oldest. And that, in turn, would mean that Earth was able to sustain relatively diverse kinds of bacteria early on. At the time, Earth was in the midst of a scourge of meteorites as extraterrestrial rocks pounded the new plant's surface. That barrage wasn't exactly hospitable to any would-be Earth inhabitants—so if microbes managed to set up camp there anyway, the discovery could change the way scientists see the period now called the Late Heavy Bombardment.

It’s an intriguing possibility, but one that will be subject to intense scrutiny. And that’s okay—if the fossils have really been around since a few million years after Earth came into being, they can surely withstand a few years of scientific argument and validation.

Scientists Thought All Galaxies Had Dark Matter, but They Just Found One Without It

Smithsonian Magazine

Dark matter is just that—it’s dark.

Spread across the universe, this mysterious matter doesn't interact with light, which makes it extremely difficult to detect. Scientists have yet to directly measure dark matter, but it's thought to make up around 27 percent of the universe (compared to just 5 percent made up of known matter like stars and galaxies). Without dark matter, theoretical models of our universe simply wouldn't add up.

But the idea that dark matter is a necessary ingredient for galaxies to form is being put to the test, reports Will Dunham at Reuters. Astronomers have found a distant galaxy that seems to contain no—or almost no—dark matter.

Researchers detected the sparse, see-thru galaxy called NGC1052-DF2 using the Dragonfly Telephoto Array, a New Mexico-based telescope built of camera parts that is designed to detect very faint galactic structures. They then followed up the analysis, collecting more data using the Hubble Space Telescope as well as the Gemini North and Keck Observatories in Hawaii.

Analysis shows the ultra-diffuse DF2 lies about 6.5 million light years away and is roughly the same size as our own Milky Way galaxy, but contains 200 times fewer stars. The scopes detected 10 compact groups of these stars, also known as globular clusters, within the galaxy, according to a press release from Gemini. But those clusters were moving much slower than the scientists' models predicted, suggesting that there was less mass in the system than would be expected if dark matter was present. The researchers detail their results in a study published in the journal Nature.

“If there is any dark matter at all, it's very little,” says Pieter van Dokkum of Yale, leader of the research team.“The stars in the galaxy can account for all of the mass, and there doesn't seem to be any room for dark matter.”

DF2 upends current theories about how galaxies form, which predict that the gravity of dark matter is necessary for early galaxies to hang together. “It’s like you take a galaxy and you only have the stellar halo and globular clusters, and it somehow forgot to make everything else,” van Dokkum says of DF2 in the press release. “There is no theory that predicted these types of galaxies. The galaxy is a complete mystery, as everything about it is strange. How you actually go about forming one of these things is completely unknown.”

While the find may seem to refute the existence of Dark Matter—or suggest that it's unnecessary for galaxy formation—it actually may do just the opposite. The discovery of DF2 marks an important step in confirming the dark matter's existence.

As Nola Taylor Redd at Space.com reports, theories that dispute the existence of dark matter argue that the gravitational effects scientists attribute to the substance could be explained by tweaks to what we know about gravity and astrophysics. “In those theories, dark matter is not real but an illusion, caused by our lack of knowledge of gravity on large scales,” van Dokkum says. “If that's the case, every galaxy should show a dark matter signature — it’s not something you can turn on or off in those models.” But DF2 does not appear to have dark matter, which suggests that the matter not just an "illusion" or a glitch in the equation.

As Ryan F. Mandelbaum at Gizmodo reports, in 2016 the same team of astronomers found another ultra-diffuse galaxy called Dragonfly 44 that appears to be made of 99.99 percent dark matter, showing just how weird and variable these diffuse galaxies can be.

So if dark matter wasn’t present to help DF2 form, how did it come to be? As Redd reports, the researchers think it could have formed when two other galaxies merged. The diffuse DF2 could be made of gas and debris cast off during that merger. Another possibility is that interstellar winds collected enough material to help the low-mass galaxy to coalesce.

According to the press release, the team has identified 23 other diffuse galaxies, including three with properties similar to DF2, and hope to begin examining them in detail soon to tease out their secrets.

Editor's note April 2, 2018: This article has been corrected to state that DF2 is 6.5 million light years away, not 6.5 billion light years. We apologize for the error.

Scientists Track, For the First Time, One of the Rarest Songbirds on Its Yearlong Migration

Smithsonian Magazine

At .48 ounces, your average Kirtland’s warbler weighs about as much as a handful of tortilla chips (seven, stacked), or about the same as one baby carrot. And every year, this rare North American songbird travels nearly 4,000 miles round trip, across mountain ranges, the body of a continent, the Gulf Stream and open ocean. Most of this journey has been a mystery, until now.

Using light-level geolocators, Smithsonian scientists have for the first time tracked and mapped the migratory paths of Kirtland’s warblers for an entire year, following them from their breeding grounds in Michigan to their winter homes in the central Bahamas and back. The scientists hope the data will enable conservation managers to better understand how to manage habitat for the warblers, which were close to extinction in the 1970s and have made a significant comeback as an endangered species.

The research, published in the Journal of Avian Biology, also represents a breakthrough for studying other small species’ migrations, which are an elusive but pivotal element of their lives.

“However difficult it may be, it is critical that we understand the full annual cycle of birds, not just what is happening during breeding,” says Nathan Cooper, lead author of the study and postdoctoral fellow at the Smithsonian’s Migratory Bird Center, part of the Smithsonian Conservation Biology Institute. “There is a significant amount of mortality for songbirds that happens during migration, indicating that the conditions birds encounter while migrating might be major factors in a species’ overall success or failure.”

“We know so little about migration for so many species,” says Pete Marra, head of the Migratory Bird Center and co-author on the paper. “This is the rarest songbird in North America, one of the most endangered. The goal is to move toward tracking the same individuals throughout the year to understand where and why birds are dying, and we’re getting closer with this species.”

Kirtland’s warblers are easy to study in one respect; they only nest in dense, young jack pine forests predominately in specific regions in Michigan. But those forests depend upon frequent fires to propagate the jack pines’ seeds, and fire suppression in the mid-century, coupled with nest predation by the brown-headed cowbird, devastated the species. In 1966 the U.S. Fish and Wildlife Service declared the birds endangered; in 1974, researchers identified only 167 singing males.

By planting new young jack pine forest and implementing a cowbird removal program, conservation managers helped the warblers begin to recover their numbers. Today, their population is estimated at about 2,300 males. It’s a success story, but continued management is crucial.

“As the songbirds migrate, they pass through a gate of automated telemetry towers already up in Florida,” says Pete Marra. “They will be auto-detected and the data saved and downloaded.” More towers are already up along the north shore of Lake Erie in Ontario and will be going up as well in the Michigan breeding grounds. (Nathan Cooper)

Although scientists know a great deal about the birds on their breeding grounds in Michigan, they know less about their distribution in the Bahamas during the winter, and migration—which kills an estimated 44 percent of Kirtland’s populations—has remained an unknown.

“Given that they’re flying 2,000 miles in two weeks, it makes a lot of sense that there could be a lot of mortality during that period,” Cooper says. “But we don’t know if it’s driven by things that happen during migration, or if it is set up by events that happen during the wintering period.” For instance, a drought in the Bahamas can mean less food, so the birds might be malnourished before they even begin the strenuous, stressful flight of migration. “That’s why things like climate change [contributing to drought in the Bahamas] can affect migration and, in turn, the breeding period.”

The more widely used satellite and GPS tracking devices that work well on larger animals are too bulky and heavy for most birds, but in the 1990s, British researchers developed light-level indicating devices that were small enough to attach to wandering albatrosses. The concept of using light levels to determine location has been used by mariners for centuries. By determining precise sunrise, midday and sunset times, one can calculate a rough position, because the length of a day varies predictably depending upon one’s latitude and longitude.

New light-level geolocators are finally small enough for even diminutive songbirds to carry them, Cooper says.

“They measure the intensity of sunlight every two minutes and save it to the device. It gathers that data over the whole year. We can estimate sunrise and sunset time every day of the year, and from that you can get day length and solar noon,” Cooper says. That data enables researchers to roughly estimate and map the birds’ location.

The silver antenna of a miniature archival geolocator peeks out from between the bird’s wings. These .5 gram tracking devices record several types of data, including the duration of each migration―on average, the birds travelled 1,700 miles in only 16 days. (Nathan Cooper)

In 2014, Cooper and his team attached 60 geolocators, each weighing .5 grams, to male warblers at least two years old that they captured at breeding sites throughout Michigan’s Lower Peninsula. A year later, they returned to the same sites and recaptured nearly half of the same birds, retrieving 27 of the geolocators, now loaded with data.

“We were very happy with that,” Cooper says. “That’s a high rate for a geolocator study. It’s not uncommon to only get a third back, or less. But Kirtlands’ breeding range is limited, and we can look for them effectively. They’re site faithful, and they’re really easy to catch.” Scientists will set up a mist net near a known nesting site, then play the song of a male warbler. “Birds are in the net often before the first song is over. These guys are really aggressive.”

The data confirmed some of what researchers already believed, particularly that the vast majority of the birds winter in the central Bahamas. The biggest surprise, Cooper says, is that one bird spent the whole winter in Cuba.

“That finding is important because it gives us some hope for the future in terms of wintering grounds” if the Bahamas become untenable due to sea level rise or drought conditions killing off the birds’ winter food supply, he says. “This species could possibly evolve a new wintering location relatively rapidly as long as that baseline variation is there in the first place, and now we have evidence that it is.”

Watch this video in the original article

Using prevailing winds and weather patterns in spring and fall to follow what’s called a “loop route,” the birds averaged 1,700 miles in just 16 days. Another critical new piece of information was locating the stopover areas where they rested and refueled during migration. On the southbound flight, most birds stopped in southern Ontario or the upper mid-Atlantic states for their first rest.

They also stopped along the coastline in North or South Carolina to fuel up before making the jump across the open ocean to the Bahamas. For the return trip on a more westerly route, the birds crossed the Gulf Stream from the Bahamas and stopped along the Florida coast to recuperate. Further along, they stopped in southeastern Georgia, northern Florida, or southwestern South Carolina before making the jump over the Appalachians.

“Stopover has been a pretty big unknown for this species, but it’s potentially very important,” Cooper says. Conservation managers will have a better sense now of where the birds need habitat with sufficient shelter and food to rest and recover. Citizen scientists and birders can target these areas to help identify and monitor the birds as they travel. In April, Cooper and Marra will team up with the Cornell Lab of Ornithology to organize a “Kirtland’s Warbler Migration Blitz” specific to the Kirtland’s warbler as they return from their winter sojourn, and birders can focus on these stopover areas to try to identify the birds as they pass through.

Knowing stopover locations and travel routes will help Cooper and other scientists with the next innovative step in better understanding these birds, using a collaborative tracking system called Motus (Latin for movement) operated by Bird Studies Canada. On Cat Island in the Bahamas, Cooper and his team in March will be fitting 100 Kirtland’s with digitally encoded radio transmitters, a.k.a., nano-tags, enabling scientists to track the birds as they move past strategically located receivers.

“As the songbirds migrate, they pass through a gate of automated telemetry towers already up in Florida,” he says. “They will be auto-detected and the data saved and downloaded.” More towers are already up along the north shore of Lake Erie in Ontario and will be going up as well in the Michigan breeding grounds.

Marra says the integration of smaller technologies with citizen science programs applied to study these birds helps researchers get ever closer to the goal of understanding how they survive over the course of a full year.

“If we can track them throughout the year, we can ask much more sophisticated questions about their fundamental biology. Things that happen to individuals throughout the year drive their biology,” he says. “For example, climate change studies have been geared mostly toward the breeding period, but that’s only three months of the year. These birds are exposed to sea-level rise, changing weather patterns, the entire year, and we have to protect these populations throughout the year.” 

Scientists Trained Monitor Lizards Not to Chow Down on Poisonous Toads

Smithsonian Magazine

Cane toads spell big trouble in Australia—not just for humans, who consider them an invasive species, but for greedy, omnivorous monitor lizards, who die when they eat the poisonous toads. Now, reports Rebecca Morelle for the BBC, scientists have come up with an ingenious, if simple, solution for the mass poisonings of one of Australia’s most beloved reptiles: Train them not to eat poisonous toads by feeding them small, less-poisonous cane toads.

Monitor lizards, which the locals call goanna, have special significance in Australia, where they are a sacred symbol in aboriginal art and culture. Though Australia has a high diversity of goanna, Morelle reports that up to 90 percent of one species, yellow-spotted monitors, have died from eating the toads.

"A goanna only has to mouth a toad for less than 30 seconds and it can kill them," Lead researcher Georgia Ward-Fear tells Morelle. The potent amphibians number in the hundreds of millions, spread in various habitats across northern Australia. And that’s a real problem for monitor lizards, which feed on pretty much everything.

Cane toads were imported to Australia in the 1930s as a means of pest control for sugar cane farmers, but with few predators, they quickly began to multiply and spread. These days, they’re considered an invasive species, and Australian officials say their biological effects are a “key threatening process” for the continent’s environment.

To help monitors fight back against the toads, a team of conservation scientists decided to train the lizards not to eat them. By feeding wild, yellow-spotted monitor lizards smaller, less-potent cane toads, they were able to convince them not to eat toads at all. The small toads were potent enough to make the lizards slightly sick without doing permanent damage, Morelle reports.

“Just one or two toad meals were enough to convince a goanna not to eat another toad,” the team notes in a release. The team suggests that conservationists release the small, less-toxic toads into the wild to help lizards gain “an opportunity to learn rather than to die.” They recently published their results in the journal Biological Letters.

Perhaps Australia’s monitor lizards will be inspired to eat fewer toads in 2016—or at least fewer deadly ones.

Scientists Transformed Men's Skin Cells Into Immature Sperm Cells

Smithsonian Magazine

Around 7.5 percent of men in the U.S. visit a fertility doctor at some point in their life, according to the CDC. Around 18 percent of those men go on to be diagnosed with infertility. As the Guardian reports, across the world, around one percent of men cannot produce any sperm at all. Researchers are hoping to give those men a chance at fathering their own children, however, with a new method that manufactures sperm cells from skin cells.

Although scientists haven’t proved the method is totally viable, the results of a recent study look promising. As the Guardian describes, researchers recruited three infertile men and collected skin cell samples from them. They manipulated those skin cells to become stem cells—generic cells that can grow into any other type of specialized cell in the body. Then, they inserted those human stem cells into the testes of live mice. There, the stem cells formed into immature sperm cells.

The researchers told the Guardian that they think the cells, if inserted into the men’s testes, would have formed into mature, healthy sperm, although further testing is the only way to find out for sure.

As NPR points out, if viable, the method could lead to some potentially tricky situations. For example, a person’s sperm could be manufactured without his permission or knowledge, and then sold on the blackmarket. It could also mean that, so long as some living cellular material is preserved, someone who has died can still father a child. As one bioethicist told NPR, “I think we’re going to have to craft a new human right: the right to consent to being a parent."

Scientists Try Out 2,300-Year-Old Brain Surgery Techniques

Smithsonian Magazine

Between 2,300 and 2,500 years ago, up in the Altai Mountains of Siberia, a man sustained a serious head injury. It's believed that head injury left him with a blood clot between his brain and his skull. Afterwards, likely, he would have had intense headaches and movement problems. He would have vomited, more than a person should. And so, perhaps in an effort to cure him, without any of the knowledge or tools available to modern neurosurgeons, a large hole was chiseled into his skull.

Despite that, with a lasting hole in his head, the man survived. 

We know this because his skull, discovered in Siberia last year, shows signs of healing over the broken bones. It was found and analyzed along with two other skulls from the same era that also show signs of trepanation, the oldest known form of neurosurgery. Now, as reported by the Siberian Times, a team of neurosurgeons, anthropologists and archeologists say that—thanks to a series of hands-on experiments—they have a clearer image of just how such early medical feats were accomplished.

The team from the Russian Academy of Science' s Institute of Archaeology and Ethnography first studied each skull under a microscope to deduce the instrument likely used to detach pieces of bone. They ultimately concluded that a single kind of tool—a bronze knife—was employed to make the holes in two stages, explains the Siberian Times, quoting neurosurgeon Aleksei Krivoshapkin:

First, a sharp cutting tool removed the surface layer of bone carefully without perforating the skull itself. Then, with short and frequent movements a hole was cut into the skull.

Professor Krivoshapkin said: 'All three trepanations were performed by scraping. From the traces on the surface of the studied skulls, you can see the sequence of actions of the surgeons during the operations.

'It is clearly seen that the ancient surgeons were very exact and confident in their moves, with no traces of unintentionally chips, which are quite natural when cutting bone.'

An archeologist made a replica of the kind of knife likely used. Next, Krivoshapkin attempted to replicate the 2,300-year-old surgery using a modern-day skull (no longer attached to a person, of course). According to The Siberian Times, it took him 28 minutes and some considerable elbow grease to accomplish the task, but the results “were found to mirror those found in the ancient patients.”

The team notes that the people of the Pazyryk tribe, to which the Altai Mountain skulls belonged, were skilled in working with animal bones to make different tools and objects. That knowledge likely aided them in their surgical attempts on humans, though archeologists involved think the culture may have also been aided by some of the medical teachings coming from ancient Greece.

While scientists now better understand the techniques of early trepanation in Siberia, there’s one question left unanswered: did the ancient patients have any kind of anesthesia to help them through the no doubt agonizing experience of having their heads cut open? We can hope they did, but bone samples don’t offer conclusive insight into such mysteries.

Scientists Turn Algae Into Crude Oil In Less Than An Hour

Smithsonian Magazine
Researchers believe they have figured out a way to make a promising biofuel that is cheap enough to compete with gasoline

Scientists Turn Algae Into Crude Oil In Less Than An Hour

Smithsonian Magazine

Out of all the clean energy options in development, it is algae-based biofuel that most closely resembles the composition of the crude oil that gets pumped out from beneath the sea bed. Much of what we know as petroleum was, after all, formed from these very microorganisms, through a natural heat-facilitated conversion that played out over the course of millions of years.

Now, researchers at the U.S. Department of Energy's Pacific Northwest National Laboratory in Richland, Washington, have discovered a way to not only replicate, but speed up this "cooking" process to the point where a small mixture of algae and water can be turned into a kind of crude oil in less than an hour. Besides being readily able to be refined into burnable gases like jet fuel, gasoline or diesel, the proprietary technology also generates, as a byproduct, chemical elements and minerals that can be used to produce electricity, natural gas and even fertilizer to, perhaps, grow even more algae. It could also help usher in algae as a viable alternative; an analysis has shown that implementing this technique on a wider scale may allow companies to sell biofuel commercially for as low as two dollars a gallon.

"When it comes down to it, Americans aren't like Europeans who tend to care more about reducing their carbon footprint," says lead investigator Douglas C. Elliott, who's researched alternative fuels for 40 years. "The driving force for adopting any kind of fuel is ultimately whether it's as cheap as the gasoline we're using now."

Scientists have long been intrigued by the laundry list of inherent advantages algae boasts over other energy sources. The U.S. Department of Energy, for instance, estimates that scaling up algae fuel production to meet the country's day-to-day oil consumption would take up about 15,000 square miles of land, roughly the size of a small state like Maryland. In comparison, replacing just the supply of diesel produced with bio-diesel from soybeans would require setting aside half of the nation's land mass.

Besides the potential for much higher yields, algae fuel is still cleaner than petroleum, as the marine plants devour carbon dioxide from the atmosphere.  Agriculturally, algae flourishes in a a wide range of habitats, from ocean territories to wastewater environment. It isn't hazardous like nuclear fuel, and it is biodegradable, unlike solar panels and other mechanical interventions. It also doesn't compete with food supplies and, again, is similar enough to petrol that it can be refined just the same using existing facilities.

“Ethanol from corn needs to be blended with gas and modified vegetable oil for use with diesel," says Elliott. "But what we're making here in converting algae is more of a direct route that doesn't need special handling or blending."

Or, as algae researcher Juergen Polle of Brooklyn College puts it: "We cannot fly planes with ethanol. We need oil," he tells CBS News.

But while the infrastructure for corn-based ethanol production has expanded to the extent that most cars on the road run on gasoline blends comprised of 10 percent biofuel, the ongoing development of algae fuel has progressed ever-so glacially since the initial spark of interest in the 1980s. Industry experts attribute this languishing to the lack of a feasible method for producing algae fuel running as high as 10 dollars a gallon, according to a report in the New York Times. However, the promise of oil from algae was tantalizing enough that ExxonMobil, in 2009, enlisted the expertise of world renowned bioengineer Craig Venter's Synthetic Genomics lab to fabricate a genetic strain of lipid-rich algae, as a means to offset the expense of cultivating and processing the substance into a commercially attractive resource. Yet, despite investing $600 million into a considerably ambitious endeavor, the project was beset with "technical limitations," forcing the company to concede earlier this year that algae fuel is “probably further” than 25 years away from becoming mainstream.

The hydrothermal liquefaction system that Elliott's team developed isn't anything new. In fact, scientists tinkered with the technology amid an energy crisis during the 1970s as a way to gasify various forms of biomass like wood, eventually abandoning it a decade later as the price of gasoline returned to more reasonable levels. PNNL's lab-built version is, however, "relatively newer," and designed simply to demonstrate how replacing cost-intensive practices like drying the algae before mixing in chemicals with a streamlined approach makes the entire process much more cost-effective across all phases. Elliott explains, for example, that the bulk of the expenditures are spent on raising algae, which is either grown in what’s called an open-pond system, similar to natural environments, or in well-controlled conditions found in closed-loop systems. The open-pond system isn't too expensive to run, but it tends to yield more contaminated and unusable crops while artificial settings, where algae is farmed inside clear closed containers and fed sugar, are pricey to maintain.

"People have this slightly inaccurate idea that you can grow algae anywhere just because they'll find it growing in places like their swimming pool, but harvesting fuel-grade algae on a massive scale is actually very challenging," Elliott says. “The beauty of our system is you can put in just about any kind of  algae into it, even mixed strains. You can grow as much as you can, any strain, even lower lipid types and we can turn it into crude."

Forbes energy reporter Christopher Helman has a good description of how this particular hydrothermal liquefaction technique works:

"You start with a source of algae mixed up with water. The ideal solution is 20% algae by weight. Then you send it, continuously, down a long tube that holds the algae at 660 degrees Fahrenheit and 3,000 psi for 30 minutes while stirring it. The time in this pressure cooker breaks down the algae (or other feedstock) and reforms it into oil.

Given 100 pounds of algae feedstock, the system will yield 53 pounds of 'bio-oil' according to the PNNL studies. The oil is chemically very similar to light, sweet crude, with a complex mixture of light and heavy compounds, aromatics, phenolics, heterocyclics and alkanes in the C15 to C22 range."

Operating what's essentially an extreme pressure cooker at such a constant high temperature and stress does require a fair amount of power, though Elliott points out that they've built their system with heat recovery features to maximize the heat by cycling it back into the process, which should result in a significant net energy gain overall. As a bonus, the ensuing chemical reaction leaves behind a litany of compounds, such as hydrogen, oxygen and carbon dioxide, which can be used to form natural gas, while leftover minerals like nitrogen, phosphorus and potassium work well as fertilizer.

"It's a way of mimicking what happens naturally over an unfathomable length of time," he adds. "We're just doing it much, much faster."

Elliott's team has licensed the technology to the Utah-based startup Genifuel Corporation, which hopes to build upon the research and eventually implement it in a larger commercialized framework. He suggests that the technology would need to be scaled to convert roughly 608 metric tons of dry algae to crude per day to be financially sustainable.

"It's a formidable challenge, to make a biofuel that is cost-competitive with established petroleum-based fuels," Genifuel president James Oyler said in a statement. "This is a huge step in the right direction."

Scientists Turn Packing Peanuts Into Battery Components

Smithsonian Magazine

In a scientific breakthrough that would be the envy of George Washington Carver himself, scientists may have come up with the most ingenious use of the peanut yet. But these are not the popular legume that Carver fashioned into foods, dyes and cosmetics—they are packing peanuts. A team of chemical engineers at Purdue University has now developed a fascinating way of reusing packing peanuts for the manufacture of carbon anodes, a component of rechargeable batteries that outperform competitive batteries in the market.

Packing peanuts have proven to be incredibly helpful in ensuring the safe arrival of bulky parcels with negligible added weight. However, they are a devil to dispose of. Because they take up so much space and are expensive to transport, many curbside recycling services no longer accept peanuts. As a result, only a fraction of packing peanuts are properly recycled.

The remaining majority gets dumped in landfills where they can pose a significant environmental threat. In addition to taking multiple generations to decompose, polystyrene (Styrofoam being the common brand) based peanuts contain chemicals that are believed to be carcinogenic. In response to criticism of these harmful environmental effects, manufacturers introduced non-toxic starch based, biodegradable peanuts. Yet, the researchers at Purdue claim that this “green” alternative may also contain potentially hazardous chemicals that are used to “puff up” these peanuts.

Vilas Pol, an associate professor at Purdue’s School of Chemical Engineering and lead author of the study, says his inspiration for the project came while ordering materials for his new experimental battery research lab. “We were getting a lot of equipment and chemicals contained in many boxes all full of packing peanuts, and at some point I realized that all these peanuts were going to waste,” says Pol. “We wanted to do something that was good for society and the environment.”

Lithium-ion batteries primarily consist of a positive electrode (cathode) made of a lithium-based substance, a negative electrode (anode) made of carbon, a polymeric membrane separating them and an electrolyte fluid substance that can carry charge through the membrane. When the battery charges, positive lithium ions move from the positive cathode to the negative anode and are stored on the carbon. Conversely, when the battery is in use, the lithium ions flow in the opposite direction, generating electricity.

After an initial analysis revealed that the primary components of packing peanuts are carbon, hydrogen and oxygen, the team sought to develop a process that could utilize the carbon to create an anode for a lithium ion battery. By heating the peanuts under specific conditions, the team was able to isolate the carbon, taking special care to dispose of the oxygen and hydrogen through the formation of water vapor, so as not to create a by-product that was hazardous to the environment. The team then applied additional heat to the remaining carbon, molding it into very thin sheets capable of serving as an anode for their battery.

Surprisingly, the new “upcycled” battery vastly exceeded the scientists’ expectations—storing more overall charge, by about 15 percent, and charging faster than other comparable lithium-ion batteries. It turns out that the team’s unique manufacturing process inadvertently altered the structure of the carbon to their advantage. Further investigation revealed that when water was released from the starch, it produced small pores and cavities—increasing the overall surface area capable of holding the lithium charge. Pol and his colleagues also discovered that their process increased the spacing between the carbon atoms—facilitating a faster charge by allowing the lithium ions more efficient access to each carbon atom. “It’s like you have a bigger door for lithium to travel through,” says Pol. “And this bigger space motivates lithium to move faster.”

In addition to the inherent positive environmental impact of reusing peanuts that would otherwise crowd landfills, the isolation of pure carbon from the peanuts requires minimal energy (only 1,100 degrees Fahrenheit). By contrast, the temperature required to produce conventional carbon used for battery anodes is between 3,600 degrees and 4,500 degrees Fahrenheit and takes several days, states Pol.

The researchers have applied for a patent for their new technology, in hopes of bringing it to market in the next two years, and plan to investigate other uses for the carbon, as well. “This is a very scalable process,” says Pol. And “these batteries are only one of the applications. Carbon is everywhere.

Scientists Turn Up the Heat on Herbivores and Their Food

Smithsonian Environmental Research Center
By Joe Dawson Plants can seem pretty boring. They just sit there, after all. Sure, they can be pretty; they can make us sneeze. But what else do they do? A lot, it turns out. They are able to shift their own water and energy resources from leaves to stems to roots and back, grow […]

Scientists Uncover a “Hidden” Portrait by Edgar Degas

Smithsonian Magazine

For decades, art conservationists have relied on methods like the chemical analysis of miniscule flecks of paint and detailed knowledge of the exact pigments used to restore paintings faded by the years. Now, using a powerful X-ray scanner called a synchrotron, a group of researchers have uncovered an early draft of a portrait by Edgar Degas.

Since 1922, art historians have known that Degas’ Portrait of a Woman was painted on top of an earlier image. The painting was completed in the 1870s, but just a few decades later parts began to fade, revealing a ghostly image lurking underneath. Experts long believed that it was caused by an earlier draft that Degas had made on the same canvas, but traditional restoration methods made it impossible to find out more without destroying the painting. In a new study published in the journal Scientific Reports, however, a team of conservators and scientists were able to peer beneath the paint using the high-powered scanner.

“The X-ray fluorescence technique used at the Australian Synchrotron has the potential to reveal metal distributions in the pigments of underlying brushstrokes, providing critical information about the painting,” study co-author Daryl Howard writes in an email to Smithsonian.com. “This detector allows us to scan large areas of an object such as a painting in a short amount of time in a non-invasive manner.”

The synchrotron can determine the distribution of pigments down to a fraction of a millimeter. Once the scan is finished, the data can be reconstructed by a computer to make full-color digital recreations of the artwork, paint layer by paint layer. Similar to a hospital X-ray machine, the synchrotron uses high-intensity light to take a look beneath the surface of a subject. When scanning the portrait, Howard and conservator David Thurrowgood not only got a look at the long-lost image: they could even see what color it once was.

An image of the underpainting taken using a conventional x-ray. (Daryl Howard/David Thurrowgood)

“The big advantage of a data set like this is that it becomes possible to virtually (digitally) dismantle a painting before a conservation treatment starts,” Thurrowgood writes. “We can immediately see where changes and additions have been made, if there are any unexpected pigments, if there are pigments which are known to degrade in response to particular environments.”

The reconstruction of the underpainting bears a striking resemblance to Emma Dobigny, a woman who posed for several of Degas’ other paintings. But while Thurrowgood and Howard believe the synchrotron can be powerful tools for conservators, it hasn’t been easy to get the art world on board.

“The technique is well outside of the experience level many conventionally trained conservators, and there have been well meaning questions like ‘will it burn a hole in it?’” Thurrowgood writes. “Educating people about the techniques and understanding their fears has been an important issue as these paintings are very valuable, culturally and financially.”

That meant years of testing many kinds of paints before they could turn the machine on a priceless piece by Degas. However, the researchers were able to demonstrate that the technique is even less destructive and provides much better detail than a standard X-ray.

In the past, conservators have had to physically scrape off tiny flecks of the original paint to analyze its chemistry, and even X-rays can produce damaging radiation. A synchrotron scan, on the other hand, allows researchers to figure out a pigment's chemistry without touching the painting, and it uses purer, more powerful light than an X-ray that leaves behind much less radiation.

“Care of art over hundreds of years is a complicated problem, and this is a tool which gives a completely new set of information to use for approaching that problem,” Thurrowgood writes. “The needs of individual artworks can be understood in a way that was not previously possible, and the future survival of the painting can be approached very differently.”

Scientists Unlock Magic Mushrooms' Mysterious Chemical Compound

Smithsonian Magazine

Magic mushrooms make us feel real groovy thanks to a chemical compound called psilocybin, which, once it is converted by the body into the molecule psilocin, has a hallucinogenic effect. Scientists have known the chemical structure of psilocybin since the late 1950s, but the biochemcial pathways that allow ‘shrooms to make the compound have remained obscure—until now.

As Stephen K. Ritter reports for Chemical & Engineering News, researchers at Friedrich Schiller University in Jena, Germany have isolated four enzymes that magic mushrooms use to make psilocybin. The team was also able to create the first enzymatic synthesis of psilocybin—a potentially ground-breaking step towards commercializing the compound, which in recent years has been shown to be helpful in treating anxiety, depression and other psychological disorders.

For the study, which was published in the German journal Angewandte Chemie, researchers sequenced the genomes of two different mushrooms species: Psilocybe cubensis and Psilocybe cyanescens. As Mike McRae points out for Science Alert, a 1968 paper investigating psilocybin’s biosynthesis theorized that the process began with a molecule of tryptophan, an essential amino acid. The new study found that tryptophan was indeed the initial building block, but that the order of events proposed by the earlier paper was otherwise incorrect. Gizmodo’s George Dvorksy explains how the process works:

"It starts with a special kind of tryptophan molecule, with an extra oxygen and hydrogen stuck on, like an anglerfish with a big head and a tail and an extra piece hanging off like the headlight. An enzyme the researchers named PsiD first strips a carbon dioxide molecule off of the tail. Then, an enzyme they called PsiK phosphorylates it, meaning it replaces the headlight’s oxygen with a special setup of phosphorus with some oxygen attached. A final enzyme, called PsiM, works to replace two hydrogen atoms on the tail with methyl groups, or carbon atoms with three hydrogens attached."

Once they figured out how mushrooms make psilocybin, researchers genetically modified E. coli bacteria to synthetically produce the enzymes involved in the compound’s production, Sam Lemonick of Forbes reports. 

“The new work lays the foundation for developing a fermentation process for production of this powerful psychedelic fungal drug, which has a fascinating history and pharmacology," Courtney Aldrich, a medicinal chemist at the University of Minnesota who was not involved in the research, tells Ritter of Chemical & Engineering News.

Although psilocybin was long disregarded by the scientific community—it is, after all, an illicit drug—recent studies have suggested that the compound can be helpful in treating a host of psychological conditions. Psilocybin has been shown to reduce anxiety in patients with life-threatening cancers, alleviate symptoms of depression, and even help people kick nicotine habits.

Psilocybin is still a controlled substance in many places, so it will likely be a long time before it is accepted by the community as a medical treatment. But the new study is a promising first step in unlocking the healing powers of funky fungi.

Scientists Use "The Moth Radio Hour" to Create Brain Atlas

Smithsonian Magazine

The most popular model of how the brain works says that speech and language are processed in specialized sections of the left hemisphere, like Broca’s Area, Wernicke’s Area and the Angular Gyrus. And while those spots are critical to producing speech, new research shows that understanding speech takes place all over the brain, and single words are often processed in multiple parts of the brain, writes Benedict Carey for The New York Times.

Using a functional MRI scanner, researchers Jack Gallant and Alexander Huth of the University of California, Berkeley, recorded blood flow in the brains of seven test subjects as they listened to two hours of "The Moth Radio Hour," a podcast of sometimes funny and sometimes emotional autobiographical stories told by regular people.

The study, published this week in Nature, describes changes in bloodflow as the subjects processed the podcast. Researchers then compared that data to a transcription of the radio show. This allowed them to understand exactly where in the cerebral coretx the meanings of each word are encoded. Combining this information, the team created a “brain dictionary” showing where each word and the concept behind the word is processed.

It turns out that words aren’t just processed in the language centers—they light up areas all over the cortex.

A word like “love” can stimulate an area of the brain associated with strong emotion. It can also activate networks all over the cortex at once associated with sexuality, parents, or pets. “Murder” it turns out, sparks lots of areas.

“Consider the case of just the word ‘dog,’” Gallant tells Carey. “Hearing that is going to make you think about how a dog looks, how it smells, how the fur feels, the dog you had as a kid, a dog that bit you on your paper route. It’s going to activate the entire network for ‘dog.’”

The researcher's "semantic atlas" of the brain shows where exactly each word activates, and is available online through a 3-D brain viewer. "To be able to map out semantic representations at this level of detail is a stunning accomplishment," Kenneth Whang, a program director in the National Science Foundation's Information and Intelligent Systems division, says in a press release.

It turns out that among the seven individuals studied, the brain processes specific words and emotions in similar areas. This has implications for “mind reading” applications, like developing ways that people with motor neuron diseases who are otherwise unable to communicate could be understood. “It is possible that this approach could be used to decode information about what words a person is hearing, reading, or possibly even thinking,” Huth tells Ian Sample at The Guardian.

But we’re not there just yet. Though the map was pretty consistent from person to person, there were still discrepancies. And overall the number of people studied was small. Gallant notes in the press release: “We will need to conduct further studies across a larger, more diverse sample of people before we will be able to map these individual differences in detail.”

Scientists Used Human Tissue to 3-D Print a Tiny Heart

Smithsonian Magazine

Researchers have successfully 3-D printed a miniature heart complete with cells, blood vessels, ventricles and chambers. The engineered organ—crafted using “ink” made from the patient’s cells and biological materials, according to Bloomberg’s Michael Arnold—marks the first time scientists have moved beyond printing simple tissues lacking blood vessels.

The impressive prototype, newly described in Advanced Science, is roughly the size of a rabbit’s heart. Still, lead author Tal Dvir of Tel Aviv University explains in a statement, “larger human hearts require the same technology,” raising hopes that the technique can eventually be adapted to create functional heart patches or even power full organ transplants.

As Live Science’s Yasemin Saplakoglu reports, Israeli researchers built the grape-sized heart by extracting a fatty tissue sample from a patient and then separating this tissue into its component cells. After tweaking the cells’ function using genetic engineering and turning the non-cellular materials into a bio-ink gel, the team transferred them to a 3-D printer programmed to print a heart modeled on CT scans and an artist’s rendering. Three to four hours later, the tiny heart was ready—albeit still not functional.

Before coaxing the organ to “life,” or some semblance of it, Arnold notes that the scientists will need to wait about a month for the cells to mature. Currently, Delphine Matthieussent reports for Agence France-Presse, the cells can contract, but they lack the ability to pump. According to Saplakoglu, the heart’s cells must “beat in unison” in order to pump blood efficiently throughout the body. Once this feat is accomplished, Dvir tells AFP, the team hopes to transplant 3-D printed hearts into animal subjects.

The technology is still far from ready for testing in humans, but as study co-author Assaf Shapira, also of Tel Aviv University, tells Live Science, 3-D printed hearts could one day help supplement the low number of donor organs available for transplant. Given the fact that such manufactured organs would be personalized to each patient, the process would avoid risks associated with the immune system’s rejection of transplanted foreign tissue.

Heart disease is the leading cause of death in the United States, claiming the lives of more than 600,000 men and women every year. Oftentimes, Aristos Georgiou reports for Newsweek, the only treatment for advanced cardiac failure is a heart transplant. Unfortunately, heart donors—and organ donors in general—are in short supply.

This is where regenerative medicine comes into play: As the statement outlines, “Patients will no longer have to wait for transplants or take medications to prevent their rejection. Instead, the needed organs will be printed, fully personalized for every patient.”

Before this vision can become reality, however, scientists will need to figure out how to print a full-size, functioning heart—a daunting question considering the fact that such an operation would require “billions of cells,” according to Bloomberg’s Arnold, as opposed to the mini-heart’s comparatively paltry millions. Additionally, Camila Hochman Mendez, a researcher at Texas Heart Institute who was not involved in the study, tells Live Science’s Saplakoglu, printing a higher-resolution organ capable of carrying enough oxygen and nutrients to support a human body would take months, spanning a lengthy period of time the cells would likely not be able to survive.

The University of Sheffield’s Sam Pashneh-Tala, an expert who was also not involved in the new research, characterizes the heart as a “showpiece” in an interview with Newsweek’s Georgiou.

“This construct did not demonstrate any function as a heart,” Pashneh-Tala says. “... The approaches outlined are certainly exciting, but the study itself highlights that several challenges remain before a 3-D printed heart could be a viable clinical option for the treatment of organ failure.”

Dvir is more optimistic about the team’s findings. Although he acknowledges the need to “develop the printed heart further,” he concludes, “Maybe, in ten years, there will be organ printers in the finest hospitals around the world, and these procedures will be conducted routinely.”

77545-77568 of 330,060 Resources