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Today your dog makes use of his tail for wagging, pointing and chasing in a circle. But tails do far more than that: 360 million years ago, they helped the first land-walkers make the fateful evolutionary transition from water onto land. In a new study, researchers used stubby-tailed robots designed to move like amphibious “mudskipper” fish to show that the first land walkers may have used their tails to navigate treacherous shoreline conditions.
The findings, detailed in this week’s issue of the journal Science, could aid in the design of amphibious robots that can scamper efficiently across challenging surfaces such as sand that can flow around limbs and impede motion. (No telling what those nimble-footed robots might be used for, but it’s worth noting that the study was funded in part by the U.S. Army Research Office and the Army Research Laboratory.)
“Land is not just hard concrete or rocks. It can be composed of sandy and muddy loose terrain that flows upon contact, and moving across those kinds of materials is not trivial at all,” says study leader Daniel Goldman, a biophysicist at Georgia Tech who specializes in animal locomotion.
To gain more insights into the locomotion of early terrestrial vertebrates, or tetrapods, Goldman and his colleagues studied the movement of the African mudskipper, a small, amphibious fish that lives in tidal areas near shore and spends its time in both water and on sandy and muddy surfaces. Mudskippers use their nubby fins to stroll across land and are known to occasionally jump by thumping their tails.
The team’s observations revealed the mudskipper’s tail is only marginally useful for moving on flat surfaces—but becomes significantly more important when the creature has to propel itself up slippery inclines.
To better understand how the mudskipper was using its fins and tail in concert, the scientists used a 3D-printer to create a robot that mimics some of the creature’s key movements. Most importantly, the “MuddyBot” can do a push-up and thrust its front limbs backward—a movement called “crutching”—and it can place its powerful tail at different angles on the ground relative to its limbs.
“It’s not the most glamorous device,” Goldman says, “but it’s well-controlled. We’re using a robot to do science, and in this case, to talk about things that happened 360 million years ago.”The robot has two limbs and a powerful tail, with motion provided by electric motors. (Rob Felt, Georgia Tech)
Like the mudskipper, the MuddyBot needed a kick from its tail to ascend a 20-degree sandy incline. The tail was also useful for anchorage, so the robot didn’t slide backwards down the slope.
“By looking at robots, we were able to pick apart some of the benefits of using tails in concert with limbs,” Goldman says. “For steeply inclined materials in particular, if you don’t use your tail, you get stranded pretty quick.”
The findings are an important step—no pun intended—toward understanding the mechanical principles of early tetrapod locomotion and the importance of tails in particular, says John Nyakatura, an evolutionary biologist at the Humboldt University of Berlin who was not involved in the study.
“For a long time, salamander locomotion was regarded as the most adequate model [for early tetrapod movement],” says Nyakatura, who wrote a related news article about the findings for Science. “Since salamanders do not use the tail in this fashion on challenging supports like steep, sandy inclines, nobody thought of the tail.”
Nyakatura also praised the team’s innovative methods. “What I like about this paper is that it draws from different research approaches: robotics, simulations, biomechanics of living fishes,” he says. “The use of simulation and robots in particular offers great possibilities to functional inferences in paleontology. These approaches allow (you) to systematically vary individual parameters. The whole ‘parameter space’ can be explored, including parameter combinations that can’t be observed in living animals.”
John Hutchinson, a professor of evolutionary biomechanics at the University of London, agreed. Moving from water to land “was a major transition in vertebrate evolution, and it set the stage for everything that happened on land in the vertebrate group ever since,” says Hutchinson, who was not involved in the research. “Nobody’s ever used robots to shed light on this area, so it’ll be interesting to see where it goes.”
Dinosaurs tend to dominate our vision of the past. As large and imposing as they were in life, they loom even larger in our imaginations. But much more than just the "terrible lizards" lived and thrived during the Mesozoic era, and some of the creatures that lived alongside the dinosaurs actually bear a striking resemblance to the animals of today.
Sharks, for example, are some of the most successful creatures to ever live. Their fossil record stretches back about 400 million years and includes ancient species both strange and familiar. A new finding adds to the long-lived legacy of these marine predators. Fossil shark teeth were recently discovered alongside the bones of the most famous and complete T. rex skeleton ever found, helping to fill out a more detailed picture of life during the last days of the dinosaurian reign.
The tiny teeth, petrified tidbits about the size of a pinhead, look straight out of an 1980s videogame. They took a circuitous route to discovery, which started with the excavation of the nearly complete Tyrannosaurus known as “Sue” back in 1990. As the tyrannosaur’s bones were removed from the ground, the encasing rock, called matrix, was left around the bones to keep them safe until more detailed prep work could be carried out. Chicago’s Field Museum, where Sue resides today, saved the matrix for future sifting and study. Almost three decades later, those efforts yielded the tiny teeth of a shark that swam upstream in rivers to live in Sue’s neck of the woods.
"This shark lived at the same time as Sue the T. rex, it was part of the same world," said Pete Makovicky, the Field Museum's curator of dinosaurs and one of the authors of a study describing the new species, in a press release. "Most of its body wasn't preserved, because sharks' skeletons are made of cartilage, but we were able to find its tiny fossilized teeth."One of the tiny fossilized teeth recovered from Galagadon, so named for the shape of its teeth, which resemble the spaceships in the video game Galaga. (Terry Gates)
North Carolina University paleontologist Terry Gates led the work to characterize the new shark species in the Journal of Paleontology. An appropriate name for the ancient shark was immediately apparent to the researchers. Each of the small, triangular teeth look like the persistent space invaders in the 1981 arcade classic Galaga. Thus, Gates and colleagues named the shark Galagadon nordquistae, with the species name also honoring museum volunteer Karen Nordquist for finding the first fossilized tooth.
"It was so tiny, you could miss it if you weren't looking really carefully," Nordquist said in a press release. "To the naked eye, it just looks like a little bump, you have to have a microscope to get a good view of it."
Based on comparisons with other fossil shark teeth, the team proposes that Galagadon belonged to a major shark family called orectolobiformes, or carpet sharks. DePaul University paleobiologist Kenshu Shimada agrees with this identification. Galagadon, he says, “serves as another example of the diversification of this shark group not only in oceans worldwide, but also in the freshwater systems in the terrestrial environments near the end of the so-called ‘Age of Reptiles.’” While only the teeth of Galagadon are known so far, their shape suggests that the living animal would have looked something like today’s bamboo sharks, a subset of carpet sharks found in the warm waters of the Indo-Pacific.
What has intrigued paleontologists about Galagadon, though, is what the shark can reveal about the world that Sue stomped around in. “The new study, including the recognition of the new species, sheds light on the complex evolutionary history of the freshwater system that existed in North America when T. rex roamed the Earth,” Shimada says.
Even though dinosaurs often dominate the spotlight, it’s often the meeker species that help paleontologists reconstruct what ancient environments were really like. Smaller animals such as frogs, turtles and fish can help narrow down the details of ancient habitats like climate and systems of waterways.
Until now, it seemed that the body of Sue was deposited in a lake that had been created by a nearly-dried-up river. It was thought to be a relatively self-contained habitat. But the presence of a shark species only known in ocean environments indicates that the river was likely connected to the sea, allowing Galagadon and other species to swim inland. Without the shark teeth, paleontologists would have missed this watery connection. Whether Galagadon moved in formation like its video game namesakes, though, will have to wait for future finds.
There are two main theories about how humans populated the New World after crossing Beringia, the wide flat land-bridge that once connected Russia’s far east with Alaska. The first, the ice-free corridor route, theorizes that 13,500 years ago early humans followed a gap between the ice sheets covering the top of North America down the Canadian Rockies. The second, the coastal migration route, which has gained steam in recent years, is that they followed the Pacific coast down to areas below the ice, reaching the interior of the continent thousands of years earlier. Now, reports Lizzie Wade at Science, a new study of the coast along Alaska shows that 17,000 years ago it was ice-free and brimming with plants and wildlife, adding more weight to coastal route theory.
In the last couple decades, new discoveries have put the ice-free corridor theory under scrutiny. Researchers have found several sites of human habitation south of the ice sheets that date well before the gap in the ice opened, including Monte Verde in far southern Chile which has been dated to between 14,500 and 18,500 years ago, and possibly might even go back 19,000 years. That would mean humans made it south of the ice thousands of years before the crack in the ice along the Rockies ever opened. The most likely alternate is a boat trip along the Pacific coast.
Geology PhD candidate Alia J. Lesnek of the University of Buffalo wanted to see if such a coastal trip along Alaska’s Pacific boarder was even possible. So in the summer of 2015 she undertook a study of rocks on four islands in the Alexander Archipelago in southeastern Alaska.
She and her team calculated the exposure age of the samples, they looked at concentration of beryllium-10 atoms, which allowed them to calculate how long the rocks had been exposed to sunlight since the ice sheets melted off. They found the ice would have retreated around 17,000 years ago. Lesnek and her colleagues also used the latest carbon dating techniques to analyze the bones of ringed seals discovered in caves in the area. Seal bones that were marked by predators dated back around 17,000 years as well, the team writes, which “suggests that robust terrestrial and marine ecosystems were established soon after deglaciation.” Their research appears in the journal Science Advances.
“Our study provides some of the first geologic evidence that a coastal migration route was available for early humans as they colonized the New World," Lesnek says in a press release, “There was a coastal route available, and the appearance of this newly ice-free terrain may have spurred early humans to migrate southward.”
Lesnek and her team are careful not to characterize their study as evidence that people used the coastal route to enter the Americas. But it does show that is possible. “We now know that the glaciers may have blocked the coastal route for a few thousand years. However, these glaciers retreated around 17,000 years ago, which opened the door for human migration along the coast,” she tells George Dvorsky at Gizmodo. “The timing of glacier retreat lines up very well with the genetic and archaeological evidence for the peopling of the Americas.”
Nicholas St. Fleur at The New York Times reports that the research only represents about 10 percent of the coastline the early migrants would have followed, and more research needs to be done to see if the rest of the coastal highway to the America’s was open.
This research comes as the ice-free corridor hypothesis continues to bear scrutiny. One study looking at sediment cores in the gap show that the corridor was desolate and not habitable by humans for hundreds of years after the ice receded, meaning it would have been very difficult for humans to make the trip between the ice cliffs. A 2016 study of bison DNA from the time period also shows that the corridor opened from the south to the north, meaning any human artifacts in the gap likely came from people moving up into the corridor, not into the interior of the continent. Then again, Wade reports that another recent study indicates the ice corridor was open 15,000 years ago, putting the whole timeline in flux.
Ben Potter, an anthropologist at the University of Alaska Fairbanks not involved in the study, tells Dvorsky that he finds the new paper’s conclusions “plausible” but adds that the peopling of the Americas is likely very complex and may have involved both the coastal route and the ice-free corridor route. In either case, he says much more study is needed, though Lesnak and her team have produced a good start.
Sometime between 2013 and 2015, an underwater volcano located in the western Pacific’s Mariana Trench back-arc erupted, spewing forth a torrent of molten lava. As the sprawling tendrils hit the chilly seawater, they abruptly started cooling. The result: a nearly three-mile deep, labyrinthine network of glassy black lava that stretches roughly 4.5 miles across the ocean floor.
Researchers chanced upon this ethereal glass palace during a routine dive in December 2015, Robin George Andrews writes for The New York Times. The team had originally hoped to use robotic submersibles to uncover hidden hydrothermal vents, but the volcanic deposits proved to be a far more interesting find.
The lava labyrinth, which is newly documented in Frontiers in Earth Science, sits about 2.8 miles below the ocean’s surface. According to Eleanor Imster of EarthSky, this distance is greater than Mount Rainier’s height above sea level, officially making the eruption that produced the unusual phenomenon the world’s deepest.
Earther’s Maddie Stone reports that the scientists, led by Oregon State University marine geologist Bill Chadwick, initially noticed the surface of the structure was sediment-free and venting a milky hydrothermal fluid, suggesting the still-cooling lava was fresh. A second survey conducted in 2016 enabled the team to further pinpoint the timing of the eruption: As the study states, the lava flows exhibited a “rapidly declining hydrothermal system” that pointed toward the eruption occurring just months before the December 2015 expedition.It's likely the volcano that produced this formation erupted just months before the December 2015 expedition (Courtesy of Oregon State University/Bill Chadwick)
The new discovery is unique for several reasons: Rebecca Williams, a volcanologist at the University of Hull who wasn’t involved in the study, tells the Times’ Andrews that much of scientists’ current knowledge of underwater eruptions comes from studying old, perhaps even ancient, volcanoes.
Comparatively, the network found lurking in the little-explored depths of the Mariana is relatively youthful, enabling scientists to gain previously unprecedented insights on both the sea-based lava’s chemical alchemy and its burgeoning biological communities. As Brandon Specktor notes for Live Science, the team spotted mobile creatures including shrimp and lobsters colonizing the sprawling formation during return visits. Sessile species such as worms had yet to begin moving in.
Earther’s Stone further writes that researchers have only ever identified evidence of about 40 eruptions at depths below 1,640 feet. Prior to 1990, none had been found, likely due to a lack of sufficient technology.
“We know that most of the world’s volcanic activity actually takes place in the ocean, but most of it goes undetected and unseen,” Chadwick explained in a statement. “That is because undersea quakes associated with volcanism are usually small, and most of the instrumentation is far away on land.”
Still, increasingly advanced monitoring systems may soon point scientists toward similar gardens of glass. In fact, Chadwick says, the Axial Seamount, a volcano located off of the United States’ Pacific Northwest coast, has erupted three times in the last 20 years and is due for another eruption within the next several years.
He added, “Undersea volcanoes can help inform us about how terrestrial volcanoes work and how they impact ocean chemistry, which can significantly affect local ecosystems. It’s a special learning opportunity when we’re able to find them.”
The aftermath of the Big Bang—the moment our universe exploded into existence about 13.8 billion years ago—was a little anticlimactic.
After all the hullabaloo, the universe was cold and dark for quite some time, full of radiation and clouds of hydrogen gas. Stars didn't appear until millions of years later, a moment called the Cosmic Dawn. Now, reports Hannah Devlin at The Guardian, researchers detected signals from what they believe to be those very first stars. If the find is confirmed, it could give scientists a peek into the universe’s ancient origins.
As Sarah Kaplan at The Washington Post reports, the light from these stars is much too faint for telescopes to see. But scientists have proposed that when the first stars winked on, the twinkling balls of light would have interacted with remnant radiation from the Big Bang, leaving an indelible mark. And in 1999, astrophysicists suggested that this very faint signal might be detectable. By carefully scrutinizing this background radiation, known as the Cosmic Microwave Background (CMB), they believed they could find a dip in the spectrum from the early flickers of light.
Finding that signal, however, was no simple task. It was predicted to lie smack dab in the middle of the FM radio waves, which means terrestrial broadcasts and other natural signals could easily overwhelm the faint dip. According to a press release, in order to cut through the clutter, researchers used EDGES (Experiment to Detect Global EoR Signature), a small, very precise table-shaped antenna located in Western Australia.
In essence, the antenna gobbles up the radio data available, which researchers can then carefully sift through. As Kaplan reports, Peter Kurczynski, a program director for the National Science Foundation, likens the process to turning on all but one radio station, and then looking for the missing station. “The team have to pick up radio waves and then search for a signal that’s around 0.01% of the contaminating radio noise coming from our own galaxy,” Andrew Pontzen, a cosmologist at University College London tells Devlin. “It’s needle-in-a-haystack territory.”(NR Fuller/National Science Foundation)
After weeding out loud and close signals, the team did, in fact, find what they were looking for—a dip in the wavelength that suggested the Cosmic Dawn occurred about 180 million years after the Big Bang. For two years, they sought alternative explanations and repositioned the EDGES antenna to test the accuracy of their measurement. But they reached the same conclusion: They were seeing signals from the first twinkles in our universe. They published their find this week in the journal Nature.
Lead author Judd Bowman, astrophysicist at Arizona State University tells Kaplan that these early stars were quite a bit different from our sun and other modern stars. The stars were blue and burned fast, composed of the only elements in the early universe—helium and hydrogen. Eventually, the stars exploded and created heavier elements like oxygen and carbon, the ingredients necessary for life. “These stars made the seeds for everything that came out of them,” he says. “It's like the fertilizer on the field, in a way. You can’t grow the crops without putting the right ingredients in the mix. That's what these stars did.”
The signal dip was very different than the researchers anticipated. In fact, it was twice as large as models suggested. What that means, explains Devlin, is that the primordial hydrogen was absorbing twice as much radiation as predicted, and the early universe was likely even colder than believed, roughly -454 Fahrenheit.
For help interpreting the find, they consulted Tel Aviv University astrophysicist Rennan Barkana. In a companion study, he argues that the discrepancy can be explained by dark matter, a theoretical type of matter that helps explains our observations of the universe. Barkana argues that interactions between dark matter and normal matter can explain the radio signature.
Harvard astronomer Lincoln Greenhill, in an analysis for Nature, cautions that the find needs further confirmation. But it could have huge implications, allowing astronomers to map the 3D structure of the universe and giving new insights into these early dark ages. It might even help researchers finally crack the mystery of what dark matter really is.
Pitcher plants—carnivorous flora that can be found across the world—have long been known to dine on living things, usually small insects and spiders. These plants have occasionally been spotted preying on larger vertebrates, but scientists believed these were rare occurrences. Canadian researchers were therefore quite surprised when they repeatedly observed pitcher plants snacking on baby salamanders.
In August 2018, Alex Smith, a biologist at the University of Guelph, was conducting field work with a team of undergraduates in Ontario’s Algonquin Park, a vast stretch of hills, forests and lakes. Smith peered into a pitcher plant, expecting to find some small insects decaying in the liquid that pools inside the plant’s pitcher-shaped leaves. Instead, “I see a juvenile yellow spotted salamander,” Smith tells CBC Radio. “And I say, ‘WTF?’”
Smith consulted with Patrick Moldowan, an ecologist at the University of Toronto who studies the salamander biology. Moldowan recalled that a 2017 survey had observed eight salamanders—six still living and two dead—inside pitcher plants living in a naturally acidic, fishless bog in Algonquin. Pitcher plants have evolved to thrive in such hostile environments. Bog soils are poor in nutrients like nitrogen, so pitcher plants use nectar to entice prey, which get caught in the plant’s liquid pool and are eventually broken down by digestive enzymes.
In August and September of 2018, Moldowan conducted a more extensive survey of the site and found that around 20 percent of the pitcher plants he looked at contained captured salamanders. In total, 35 individuals were spotted. Some plants had more than one salamander inside.
In their latest study in the journal Ecology, the researchers write that the “high frequency of salamander captures in pitcher plants suggests that salamanders might be a substantial nutrient source for pitcher plants.” This reason the phenomenon may have gone unnoticed previously could just come down to a matter of timing. According to National Geographic’s Sandrine Ceurstemont, previous studies have typically looked at pitcher plants in the spring and summer. The scientists behind the new report, by contrast, timed their survey to coincide with the period of metamorphosis when young salamanders transition from aquatic to terrestrial environments, which happens in late summer and early fall.
The study authors speculate that as the salamanders are emerging onto land, they make the unfortunate decision to use pitcher plants for refuge. “When plants were approached or disturbed, most salamanders rapidly swam to the bottom of the pitcher and tightly wedged themselves out of sight in the narrow, tapered stem of the pitcher,” the researchers note. But it is also possible that the amphibians are drawn to the unassuming predators by insects that flock to the plants to feed on their nectar. And in some cases, the salamanders might accidentally be falling inside the plant.
Once trapped, it took between three and 19 days for the salamanders to die, according to the study. A variety of factors may have killed the animals, including drowning, starvation, infections and even heat. Temperatures inside the pitcher fluid might “exceed the tolerable thermal maximum of trapped salamanders,” the researchers write.
According to Smith, the new study offers a reminder of the many secrets that could be hiding in even well-trodden parts of the natural world. “This crazy discovery of previously unknown carnivory of a plant upon a vertebrate happened in a relatively well studied area on relatively well studied plants and animals,” he writes in an email.
The discovery also raises a number of intriguing questions that the research team hopes to investigate in the future, like whether pitcher plants are a significant form of mortality for young salamanders, and whether salamanders constitute a significant nutritional source for the plants. “This study and survey,” Smith writes, “are only the beginning.”
Astronauts have planted six U.S. flags on the Moon, but Earth is divided into nearly 200 individual countries. In the event that an extraterrestrial group stumbled upon the flags of Earth's resident countries out in the solar system, things could get confusing. One graphic designer has a solution: Why not devise a flag to represent planet Earth and all its residents.
Oskar Pernefeldt, a student at Beckman's College of Design in Stockholm, Sweden, came up with a international flag design for our humble galactic home, as Elizabeth Howell recently reported for Space.com. Pernefedt started the project as part of his degree, and chose to keep the aesthetic simple and clean. The flag features seven white, interconnected circles that form a flower-like emblem atop a blue background.
Though the layout might appear simple and straightforward, Pernefeldt actually took a strategic approach to creating the design, employing the scientific study of flags or vexillography. For dimensions, he went with the most common ratio for flags here on Earth, 2:3. The blue hue was selected to stand out against the darkness of space and the whiteness of a spacesuit, as he explains in his design proposal.
Initially, Pernefeldt thought the seven circles could represent the planet's seven continents, but later opted against that metaphor, he told Jay Cassano of Co.Exist. Earth's geology could change with climate or geoengineering, or a continent could get demoted (think Pluto's demotion from planet to dwarf planet). Either way, Pernefeldt wanted a timeless design and chose to evoke life's origins on Earth instead. While the "flower" serves as a symbol of the many organisms that inhabit Earth, the blue stands for Earth's water, the presence of which made life possible on our planet — and possibly others. The animated video below walks through the design logic:
While the idea might seem like its from outer space, the premise of intergalactic organizations uniting under one banner is quite common in science fiction, as Ishaan Tharoor points out for the Washington Post. Robert Heinlein's Starship Troopers book series has the Terran Federation. Star Wars has the Galactic Empire and the Rebel Alliance. As Jim Festante notes in a video for Slate, Pernefeldt's design bears a similar color scheme to the banner for the United Federation of Planets in Star Trek.
There's also a precedent here on Earth. Pernefeldt isn't the first to suggest a flag for planet Earth. In 1970, a farmer names James Cadle designed a flag that included graphic representations of the Sun and the Moon. Some research facilities focused on the search for extra terrestrial life added the banner to their flagpoles. There's also a flag designed for Earth Day and of course, the flag of the United Nations.
While pictures in Pernefeldt's proposal suggest that the flag could be used on future human colonies on Mars, it might be awhile before an international flag makes it to outer space. In the meantime, Pernefeldt hopes that his design serves as a reminder to Earth's residents that they all share the planet and thus are all tasked with taking care of it and its other residents.
Then again, aliens who reach the moon might not be all that confused by the American flags after all. After 46 years they have all either fallen apart or turned white.
The star GD61 is a white dwarf. As such, it’s insanely dense—similar in diameter to Earth, but with a mass roughly that of the Sun, so that a teaspoon of it is estimated to weigh about 5.5 tons. All things considered, it’s not a particularly promising stellar locale to find evidence of life.
But a new analysis of the debris surrounding the star suggests that, long ago, GD61 may have provided a much more hospitable environment. As part of a study published today in Science, scientists found that the crushed rock and dust near the star were once part of a small planet or asteroid made up of 26 precent water by volume. The discovery is the first time we’ve found water in a rocky, Earth-like planetary body (as opposed to a gas giant) in another star system.
“Those two ingredients—a rocky surface and water—are key in the hunt for habitable planets,” Boris Gänsicke of the University of Warwick in the UK, one of the study’s authors, said in a press statement. “So it’s very exciting to find them together for the first time outside our solar system.”
Why was water found in such a seemingly unhospitable place? Because once upon a time, GD61 wasn’t so different from our Sun, scientists speculate. But roughly 200 million years ago, when it exhausted its supply of fuel and could no longer sustain fusion reactions, its outer layers were blown out as part of a nebula, and its inner core collapsed inward, forming a white dwarf. (Incidentally, this fate will befall an estimated 97 percent of the stars in the Milky Way, including the Sun.)
When that happened, the tiny planet or asteroid in question—along with all the other bodies orbiting GD61—were violently knocked out of orbit, sucked inward, and ripped apart by the force of the star’s gravity. The clouds of dust, broken rock and water that the scientists recently discovered near the star are the remnants of these planets.
Even in its heyday, the watery body was probably still very small—perhaps comparable in size to our solar system’s dwarf planet Ceres, which orbits in the asteroid belt and is about .015 percent the mass of Earth. Additionally, like Ceres, the ancient planet or asteroid was extremely water-rich (26 percent water, far more than Earth’s .023 percent), and this water was similarly constituted as ice locked within a rocky crust.
To find all this out, the group of scientists (which also includes Jay Farihi of the University of Cambridge and Detlev Koester of the University of Kiel) used observations from two sources: a spectrograph on board the Hubble Space Telescope, through which they obtained data on ultraviolet light emitted by GD61, and a telescope at the W.M. Keck Observatory on Mauna Kea on Hawaii.
By looking at the light emitted from the star, which glows in certain patterns depending on the chemical signatures of gases present, they were able to determine the proportions of a number of elements (including oxygen, magnesium, aluminum, silicon, calcium and iron) contained within the cloud of dust that surrounds it. Using computer simulations of this stellar atmosphere, they were able to rule out a number of alternate possibilities that could have accounted for the abundance of oxygen, leaving only the explanation that it was brought there in water form.
Based on the amount of water and rocky minerals detected in the star’s atmosphere—and assuming it all came from one body—scientists speculate that the small planet or asteroid ripped up by the white dwarf was at least 56 miles in diameter, but perhaps much larger.
Although the star certainly isn’t home to any life at the moment due to its relatively cold temperature, the finding makes it seem more likely that other exoplanets contain water, which is necessary for life as we know it. Many scientists have speculated that small planets and asteroids like Ceres delivered water to Earth in the first place, so finding evidence of a watery body like this in another star system raises the possibility that the same process may have brought water to an Earth-sized planet elsewhere too.
“The finding of water in a large asteroid means the building blocks of habitable planets existed—and maybe still exist—in the GD 61 system, and likely also around a substantial number of similar parent stars,” Farihi said. “These water-rich building blocks, and the terrestrial planets they build, may in fact be common.”
Scientists are some of the biggest fans of science fiction. But making claims of intelligent life in other parts of the universe? That’s a pretty big step to take for many researchers. So it’s somewhat surprising that two theorists, Avi Loeb and Manasvi Lingam from Harvard and the Harvard-Smithsonian Center for Astrophysics, recently submitted a paper suggesting that one of the many possibilities behind the enigmatic fast radio bursts emanating from space could be gigantic alien spacecraft.
The suggestion is not just some academic daydream. Fast radio bursts were first discovered in 2007, when West Virginia University astrophysicist Duncan Lorimer analyzed data from Australia’s Parkes Observatory. He noticed a weird phenomenon—a high-energy burst lasting just a few milliseconds with no ready explanation. It was an unique anomaly until 2012, when Puerto Rico’s Arecibo radio telescope also recorded an FRB. Earlier this year, researchers revealed they recorded nine FRBs coming from a puny, faint galaxy 3 billion light years away in the Auriga constellation.
FRBs are strange. In total, researchers have only recorded 18 of the bursts. Few of them repeat, but not on a regular schedule. There’s no known astrophysical explanation for the bursts, and Cornell astronomer Shami Chatterjee, who pinpointed the FRBs in Auriga, joked with Dennis Overbye at The New York Times that there are more theories about what FRBs may be than actual recorded FRBs.
In other words, no one really knows what these things are. One reason Loeb and Lingam went out on a limb to suggest alien technology is that fact that bursts are so energetic. According to George Dvorsky at Gizmodo, the bursts have a brightness temperature, a measure of intensity of microwave radiation, of 1037 degrees. “This means that a hot surface would need to have that temperature in order to radiate at the observed level,” Loeb tells Dvorsky. “There is no known astronomical object that generates radio bursts at such a high brightness, which is tens of billions of times brighter than the known population of pulsars, for example.”
The researchers also argue in their paper, which is accepted for publication in The Astrophysical Journal Letters, that FRBs are suspect because they repeat, but not in any regular pattern, and because they cluster around a frequency that is not consistent with natural phenomena like pulsars. “These clues are consistent with an artificial origin,” Loeb tells Dvorsky. In other words, they might be produced by alien technology.
What would a technology that could produce that much energy look like? According to a press release, the researchers suggest that the technology could be a transmitter powering a light-sail-based spacecraft. That transmitter would need twice the surface area of Earth to receive enough solar power to operate. While that seems absurdly huge to us, they note that it is physically possible to build.
The transmitter would then focus a beam of radio waves on a light sail in space. In this scenario, FRBs detected on Earth are the beam of radio waves sweeping across the sky, passing over our telescopes for just a millisecond as it pushes the sail-powered craft through space.
A craft of that size, 20 times the largest current terrestrial cruise ship, could transport about a million tons of cargo, the researchers estimate. “That’s big enough to carry living passengers across interstellar or even intergalactic distances,” Lingam says in the press release.
Just because they thought it up, though, doesn't mean Loeb and Lingam necessarily believe that FRBs are the engines of intergalactic cruise ships. The researchers says the work is just speculative. “Science isn’t a matter of belief, it’s a matter of evidence,” Loeb says in the press release. “Deciding what’s likely ahead of time limits the possibilities. It’s worth putting ideas out there and letting the data be the judge.”
Berkeley SETI Research Director Andrew Siemion tells Dvorsky that FRBs are so unusual that it’s hard to rule anything out at the current moment. “We cannot...exclude the possibility that anomalous signals like fast radio bursts are produced by an advanced extraterrestrial technology, and even though it is undoubtedly an unlikely possibility, it must remain a possibility until we can rule it out,” he says.
Chatterjee told Overbye earlier this year that there are still many natural possibilities for FRBs, including strange interactions between a neutron star and debris swirling around it or some unknown aspect of a supermassive black holes.
Anders Sandberg of Oxford’s Future of Humanity Institute says the alien spacecraft explanation seems a bit far-fetched. "I like the out of the box thinking, but I would not bet any money on this explanation,” he tells Dvorsky. He points out that a spacecraft powered by radio waves is unnecessarily large and complicated, and any advanced civilization would likely use lasers or a more efficient technology. “By Occam’s razor, alien engineering needs to be a simpler explanation than a natural explanation before it starts to seem plausible.”
In March, a team of scientists embarked on a 10-week survey of reindeer populations on Svalbard, a Norwegian archipelago that sits between the mainland and the North Pole. Experts have been monitoring Svalbard reindeer since 1978, but this year, they made a grisly discovery: the remains of more than 200 reindeer, which appear to have starved to death.
Perhaps unsurprisingly, scientists believe that climate change is the culprit, according to Mindy Weisberger of Live Science. The Arctic has been particularly hard hit by climate change, warming at almost twice the rate of the global average. Svalbard offers a particularly alarming example of this phenomenon; it is warming faster than anywhere else on the planet, Jonathan Watts reported for the Guardian earlier this month.
Higher temperatures mean more rain has been falling on the archipelago. This past December, the region experienced a heavy bout of precipitation that froze when it hit the ground, forming thick layers of ice on the tundra. During the colder months, Svalbard reindeer typically use their hooves to dig through the snow to reach the vegetation below. But this year, they couldn’t break through the ice that covered their food source.
In the nearly 40 years that scientists have been monitoring the Svalbard reindeer, they have seen comparable death tolls only once before, after the 2007-2008 winter, according to the Agence France-Presse.
“It is scary to find so many dead animals,” Åshild Ønvik Pedersen, a terrestrial ecologist with the Norwegian Polar Institute (NPI), tells the Norwegian news outlet NRK, per a Google translation. “This is a terrifying example of how climate change affects nature. It's just sad.”
Scores of dead reindeer were not the only sign that this was a rough winter for the animals. The NPI revealed in a statement that both calves and adults on Svalbard displayed low body weights and an absence of fat on their backs—a clear indication that they hadn’t been getting enough to eat. There were also few pregnant females.
What’s more, researchers noticed that the reindeer seemed to be modifying their behavior in response to the rainy winters and a lack of fjord ice. For one, the animals were grazing on seaweed and kelp that remained accessible along the shoreline—though these food sources are not particularly nutritious and can cause digestive distress in reindeer. The animals were also climbing up steep mountains in search of food, which the researchers refer to as a “mountain goat strategy.” But reindeer are not as sure-footed as mountain goats, putting them at risk of falling. Finally, NPI researchers noted that the animals were migrating further to find food.
Svalbard’s reindeer are not the only ones suffering. Around the world, reindeer and caribou—which belong to the same species but differ in their behavior and geographic range—have plummeted by 56 percent, Jason Daley reported for Smithsonian last year. That decline is so dramatic that some researchers are concerned the animals cannot recover, which in turn could spell bad news for the Arctic ecosystem. As the National Oceanic and Atmospheric Administration explains, reindeer and caribou are the “region’s primary foragers, [helping] cycle nutrients from plants back into the soil, and their abundance is a primary control on predator and scavenger populations and behavior Arctic wide.”
NPI is now monitoring Svalbard reindeer through a tagging program called Climate Ecological Observation System for Arctic Tundra, or COAT. The goal is to get a better sense of how the reindeer’s health, habitat use and migration patterns are being affected by rapid and worrying changes to their ecosystem.
Around 252 million years ago, an event dubbed the Permo-Triassic extinction event or "The Great Dying" rewrote the story of life on Earth. Researchers aren’t sure exactly what led to this global catastrophe—there’s some evidence it was set off by an asteroid strike or huge volcanic eruptions—but what's clear is that up to 96 percent of marine species and 70 percent of terrestrial vertebrates said bye-bye.
Until recently, it was believed that the ancestors of modern day squamate reptiles—which include all lizards, snakes and legless lizards—appeared after this massive die-off, taking advantage of all the unfilled ecological niches. But, as Nicola Davis reports at The Guardian, a new study suggests that squamates actually evolved before The Great Dying and powered through this cataclysmic period. That finding would transform the lizard family tree—and make these scaly creatures the ultimate survivors.
Davis reports that the new research is based on a 240-million-year-old fossil collected from the Dolomites, part of the Italian Alps, by an amateur fossil hunter in the early 2000s. Researchers could never figure out where the small, lizard-like reptile fit in the evolutionary tree. According to a press release for the study in the journal Nature, paleontologists have now taken a fresh look at the three-inch creature using CT scans to create 3D images of rock-encased animal.
Sarah Kaplan at The Washington Post reports that those scans revealed details of the brain case, collar bone and wrists unique to squamate lizards, as well as bones that survive today in modern lizards as reduced vestigial structures.
The team also spent 400 days examining 150 specimens of other lizard-like creatures held in fossil collections around the world, and constructed the most detailed DNA family tree of living squamates (the word squamate, by the way comes from from Latin squama, or "scale"). They concluded the fossil is the oldest squamate ever discovered, and named it Megachirella wachtleri.
“The specimen is 75 million years older than what we thought were the oldest fossil lizards in the entire world and provides valuable information for understanding the evolution of both living and extinct squamates,” lead author of the study Tiago Simões of the University of Alberta says in the release.
That detailed DNA set and the Megachirella specimen are now allowing researchers to untangle the lizard family tree. “For the first time, having that information with this highly expanded data set, now it became possible to actually assess the relationship of not only this species but also of other species of reptiles,” Simões tells Kaplan.(MUSE - Science Museum, Trento, Italy)
Ruth Shuster at Haaretz reports that the data settles a long-simmering debate in reptile evolution, by showing that geckoes split from the common ancestor of all lizards before iguanas. Snakes split off from burrowing lizards likely sometime in the Jurassic period.
One of the most impressive aspects of Megachirella, or at least other similar proto-lizard species, is that it survived at all. The fact that early lizards made it through the Great Dying means they were made of tough stuff, or were small enough to avoid the fate of larger vertebrates. ““The Permo-Triassic extinction event was a dangerous time to be alive,” David Martill, a paleobiologist at the University of Portsmouth who wasn't involved in the study tells Davis. “Not much escaped its deathly touch.”
Evolution, however, is the flip side of extinction, co-author Massimo Bernardi of the University of Bristol tells Davis. After the extinction event, the lizards found a new world with less competition and fewer predators, which led to a burst of reptile diversification. Squamates "were actually there before the extinction, they went through [it] in some way, and they took the opportunities that opened up just after the extinction,” says Bernardi.
Kaplan reports that there are over 70 million years between Megachirella and the next known lizard fossil, which is more time than there is between humans and the dinosaurs. But there are clues to how this particular little Mega died. About 250 million years ago, the Dolomites were islands with sand beaches. It’s possible that the lizard was caught up by a thunderstorm, since it was found in a fossilized layer containing plant debris that was swept out to sea.
Which is probably a better way to go than getting fried by an asteroid, anyway.
Like any single male with a bachelor suite, the Bombay night frog knows that getting lucky is all about location. In India's Western Ghats mountain range, near the Koyna Lake south of Mumbai, this means a branch, leaf or rock overhanging a mountain stream. Once he sets up his seasonal abode, he’ll start calling a serenade to any nearby females moving around in the dark.
Little does he know that his overtures also attract a different species of admirer—one whose sole mission is to catch him in coitus.
“It’s a very unique experience,” says Bert Willaert, a biologist who has taken part in dozens of nightly expeditions—led by SD Biju, a frog expert at the University of Delhi—to capture the Bombay night frog’s mating habits on video. “During the monsoon it's constantly raining, so it’s very humid. These frogs are everywhere around the river,” Willaert says. But despite the volume of frogs and the sounds of the calls, actually getting footage of their escapades was a challenge.
"The difficult thing was to find a male being approached by a female,” Willaert says. But eventually the covert paparazzi tactics of Willaert and his colleagues paid off. Today, Willaert and his co-authors published a study in the open-access biomedical sciences journal PeerJ describing a hitherto unknown mating position in these frogs: the “new dorsal straddle.”
Once the female is smitten enough by a particular call, the footage revealed, she approaches the male then turns her back to him, resting her hind legs on his mouth. At this point the ball is in the male’s court. If he’s feeling the mood, he climbs on top of her. Here’s where it gets weird: Rather than getting frisky, he reaches around the female and grasps onto the stick or leaf that they are sitting on – the proverbial bed post of the Western Ghats.
This position is apparently highly unusual in the amphibian world. As far as researchers have observed — and besides Willaert there are plenty of biologists who spend a significant amount of time and resources watching amphibians mate — these are the only frog species into this kind of thing. All of the other 7,000-odd species in the world resort to only six other mating strategies. “This is quite unique from an evolutionary sense,” says Willaert, who was affiliated with the Amphibian Evolution Lab at the Free Brussels University while conducting the study.
What happens during this stage is a little unclear to Willaert and the other researchers, because their view was obscured by the wet and humid conditions of the monsoon season where they observed the mating process. But it’s likely that while the male hangs over the female, he deposits sperm on her. The female usually waits around five to 30 minutes before arching her back to send her mate off. After he leaves, she lays eggs and sits on them while the sperm trickles down and fertilizes the eggs.NSFW: Two Bombay night frogs enjoying the dorsal straddle position. (SD Biju)
The male remains nearby. Occasionally he’s so moved by the experience that he loses his balance and falls into the water, but otherwise he hangs out making territorial calls with puffed-out cheeks to ward off other males or potential predators. In fact, he will stay around well after the female leaves (the whole amorous sequence takes from half-an-hour to an hour), guarding the eggs until the tadpoles hatch and fall into the water below. While Willaert didn’t get near the frogs for fear of interrupting the process, he says that related species have even bitten other researchers in an effort to protect their eggs.
Inventive mating positions aren’t the only innovations that set this species apart. Bombay night frogs are among a small number of frog species in which the female also calls, although it’s a relatively rare occurrence. During the 40 nights that Willaert was in the field, he heard females calling only a handful of times, and managed to record the sound only once. It is difficult to tell why the females call, but Willaert thinks it might be a way to let males know they are ready to lay eggs. Or, it may simply be a way to inform males that they are nearby.
Females’ calls may have a higher frequency so they can be more easily detected over the sound of rushing water or other monsoon-season noise, says Sarah Conditt Humfeld, an associate professor of biology at the University of Missouri who has studied the ways that climate change affects the mating behavior of gray tree frogs and who was not involved in the study. The frequency characteristics of "the female call may have evolved to allow easy detection by males in this noisy environment,” she says.
Humfeld adds that the newly described mating position and female calling offer “a nice demonstration of the huge diversity of adaptations that have evolved in this ancient lineage of terrestrial vertebrates." Studies such as these point to the continuing importance of basic natural history research.
Knowing more about these frogs' mating habits could also help conservation biologists interested in breeding them for repopulation. Due to the Bombay night frog’s small and fragmented range of around 7,700 square miles, the International Union of Conservation of Nature and Natural Resources lists it as vulnerable, the category just below “endangered.” Deforestation is adding to the amphibians’ woes, says Willaert.
But while this mating strategy may be new to science, it certainly isn’t anything experimental for the animals. Indian night frogs diversified 70-80 million years ago—making the “new dorsal straddle" about as original as the missionary position.
Jack Ives has met His Holiness John Paul II and has been ambushed by bandits. He has dined with the king and queen of Thailand and been followed by the Chinese secret police—all in the name of mountain research.
Fueled by a boyhood love for mountains, Ives embarked on an academic career in geography beginning in the 1960s, which launched him onto the world stage in a political struggle over how these habitats and their inhabitants are perceived. In time, he became a pivotal force in bringing to the world's attention the importance of mountainous regions to an environmentally sustainable future.
Today, much of the conversation about climate change and sustainable development tends to focus on polar ice and the rainforests, and mountains still don't receive the full attention they deserve, Ives says. In his recent book, Sustainable Mountain Development: Getting the Facts Right, he details his efforts to include mountain regions in environmental legislation before and after the pivotal 1992 Rio Earth Summit. Here is why Ives thinks it is imperative that elevated regions remain in the picture for sustainability, and what he hopes for the future of mountain development:
Who or what inspired you to sit down and write this book?
It was really a conviction. I’m referring to colleagues of long standing … but also world leaders that I had the privilege of meeting. I felt that bringing that all together in the context of what was really a major political and research effort should be on the record.
Of the many anecdotes that you share in the book, which one best illuminates the joys or challenges of developing a mountain agenda?
I did my undergraduate work in England, and my dream was to organize expeditions to Arctic mountain areas. The place I chose was Iceland, and this led me to living on a rather poor sheep farm for quite long periods of time and getting to know the people and especially the farmer. I learned from him that my clever university learning could nowhere near match his understanding of the ecology of the surrounding environment on which he depended. Years later, ... [my colleagues and I] had a growing feeling that we have so much to learn from these wonderful mountain people who have been very much abused. They’re not ignorant. There is an enormous amount of ethological and environmental knowledge—and the experience of surviving in difficult environments—which is now coming into the main flow of knowledge.
In light of that, what is important for people to understand about the mountains and how they fit into the larger conversation about the environment?
We refer to the mountains as water towers of the world. Most of the major rivers of the world are supplied from heavy rainfall in the mountains and melting snow. If you mess up the mountain environment, you are going to impact the plains. Twenty percent of the Earth’s terrestrial surface is mountainous, and the mountains provide the living means for about 10 percent of the human population. If mountains are badly handled, as in many places they are, then the impact is far greater than just on that part of the world that is mountainous, because the downstream effects are properly going to be more serious than the effects in the mountains themselves.
You say that the students of this first group of mountain academics, and their students, are now “guardians of the mountains.” What is their task?
I would need to write a book on that question. Each country tends to have different problems, but creating awareness and giving credibility to the intelligence and determination of the mountain people themselves—I think this is the thing that we’ve helped lay the foundation for. There is an enormous increase in awareness, and the students that have worked with me are themselves teaching courses in mountain geography. When I was teaching in Boulder, Colorado, up until 1989, I don’t think there were more than three courses in mountain geography per se in the whole of North America. In my old-age wisdom, I have to realize that you don’t change the world in a few years. I just hope that we can change it sufficiently more before dreadful things like climate change and terrorism catch up with us.
What has been the most rewarding moment of your career?
This broad experience of finding a group of friends from all over the world. There’s been an international partnership of all shapes and colors, and we have developed this kind of community spirit, and I think this has been the great personal experience of my life.
I have to ask—what is the most beautiful place you have visited, with regard to the mountains?
Well, that is difficult to answer. We had our 60th wedding anniversary in Switzerland last year in the Emmental—that’s a farming community between the capital city of Bern and the Swiss Alps—where the buildings are 300-year-old farmhouses surrounded by flowers. That’s where I had my sabbatical year in 1976-77, and basically it was from that sabbatical year that what we’ve been talking about grew. I love mountain landscapes, but the real beauty is where you have this incredible mix of careful maintenance of landscape within a mountain setting. That to me is beauty—with the people included.
Around 70 percent of the world’s 1,240 known bat species feast on mosquitoes, roaches, flies and other insects, while much of the rest prefer nectar, fruit or blood. But there is also a fifth dietary option: In tropical regions around the world, around a dozen mysterious bat species subscribe to a carnivorous menu of lizards, frogs, birds, rodents, fish—or even other bats.
“When we think about carnivorous mammals, our minds tend to go to lions, wolves and things like that,” says Sharlene Santana, an integrative biologist at the University of Washington and curator of mammals at the Burke Museum of Natural History and Culture. “Very few people realize that there are bats with this specialized diet as well.”
The knowledge gap surrounding carnivorous bats also extends to science. Researchers know that meat-eating evolved in several separate events among formerly insectivorous bats, but past studies have failed to reach any consensus about the adaptations that made that dietary switch possible, leaving researchers in the (bat-filled) dark as to whether any commonalities exist between carnivorous bats that eat birds and reptiles in India, for example, and those that hunt amphibians and mammals in South America.
As it turns out, certain telltale physical characteristics are shared across carnivorous species. In the first analysis of its kind, published today in the Proceedings of the Royal Society B, Santana and her colleagues discovered commonalities in body size trends and skull anatomy, indicating that evolution arrived at similar solutions on multiple occasions to allow for bat species to break away from the bug-eating norm.
Santana and her colleagues turned to a method called geometric morphometrics—which uses spatial landmarks to analyze an object’s shape independently of its size—to examine 140 skulls from 35 species of insectivorous and carnivorous bats that were obtained through museum collections. They statistically compared the specimens for similarities and differences in skull size and shape and used data from the scientific literature to examine body sizes across species. The team also integrated information about the evolutionary relationships among species to account for the fact that closely related ones tend to be more similar than distantly related ones, which allowed them to pinpoint similarities in physical attributes that were due to diet rather than relation on the phylogenetic tree.
Carnivorous bats tend to be larger than insect-eaters, the researchers found. Their snouts are also elongated, which may help them take down relatively larger prey and to close their jaws faster, the researchers believe.
Among carnivorous species, however, those that prefer fish have become even more different: Their snouts are slightly shorter and broader than their land animal-eating relatives, and also project upward. Those adaptations, Santana says, would allow fish-eaters to increase their bite force and chew more thoroughly—all the better for dealing with the spiny bones of their prey, which they eat whole.
“The two fish-eating bat species in our study are separated by over 50 million years of evolution and come from completely different families, but their skulls share similar features,” Santana says. “They’re very different from bats that are eating terrestrial vertebrate prey.”
The bat skulls also shared features with other types of carnivores, especially dogs, bears and weasels. The latter are diminutive hunters that nevertheless are capable of taking down prey much larger than themselves. “Weasels are very small but highly predacious, so [the researchers’] results imply that the interaction of small size with predatory behavior selects for specific shapes, which is interesting and could be further explored using CT scans and biomechanical modeling” says Graham Slater, a paleobiologist at the University of Chicago, who was not involved in the research. “Ultimately, this study emphasizes the need to collect more basic data on carnivorous bats.”
Indeed, much remains to be discovered about these mysterious animals, including what their ancestors look like in the fossil record and how they behave in the field. “This novel approach to analyzing cranial shapes sets the table for now showing how these traits function in nature,” says Rodrigo Medellín, an ecologist at the National Autonomous University of Mexico, who was not involved in the work. “I can’t wait to run to the rainforest and play with the carnivores.”
A grisly scene unfolded off the coast of Vancouver Island, Canada when a male orca attacked and killed a newborn calf—with help from his mother. As Brandon Specktor reports for Live Science, this is the first recorded case of infanticide among orcas, and the only time that a non-human mother and son have been seen working together to kill an infant.
The incident took place in 2016 and was observed by marine biologists at the research station OrcaLab, who recently described the attack in the journal Scientific Reports. On that fateful day, scientists picked up strange calls on an underwater microphone and set out to investigate. They came across a 28-year-old mother traveling with several of her young, including an infant that was likely only a day old, judging by its visible fetal folds (only apparent a few days after birth) and a dorsal fin that was not yet erect. Lurking behind the family was a 32-year-old male and his 46-year-old mother.
Suddenly, the researchers write in the paper, they saw “erratic movements and splashing suggestive of a predation event.” They also noticed that the baby orca was not surfacing with its mother. When the adult male swam past the researchers’ boat, they could see that he had the calf’s fluke clamped in its mouth, the newborn’s body trailing beneath his jaw.
“We were a bit horrified, but more so I think we were fascinated,” Jared Towers, a cetacean researcher with Fisheries and Oceans Canada, tells Amy B. Wang of the Washington Post. “We knew that it was time to just collect as much data as we could to accurately record our observations.”
The researchers watched as the mother orca tried desperately to save her baby. At one point, she rammed the male so hard that his body undulated and a spray of blood and water flew into the air. But the mother of the male aggressor intervened in the fight, blocking the newborn’s mom from attacking her son. According to a video published on the Facebook page of the BC Killer Whale Research Report, the male and his mother spent the next four hours taking turns pushing and dragging the baby around. Unable to surface for air, the infant ultimately drowned.
Terrestrial species like primates and rodents have been known to commit infanticide, and the behavior has been infrequently observed among dolphins. Scientists have suggested a number of reasons why animals might kill infants of their own species—one of which is cannibalism. But the OrcaLab researchers did not see any signs of feeding, leading them to suspect that the infant was not killed as prey.
It is more likely, they suggest in the paper, that the male was trying to mate with the mother of the newborn calf. As Sarah Gibbens explains in National Geographic, female orcas are unable to breed while they are nursing their offspring. So once the mother stopped lactating, she would have been ready to mate once again.
But why did the male’s mother get involved in the killing? The researchers speculate that she may have been trying to ensure the success of her lineage by helping her son mate. Female orcas and their children can share strong bonds, and have been known to cooperate in predation. In this case, it is possible that mother and son were collaborating to remove an obstacle—the baby orca—that was preventing them from passing on their genes.
“I think we don’t give a lot of animals enough credit for their ability to plan and think ahead,” Towers said in an interview with Gibbens of National Geographic. “[B]ut I think that’s exactly what was happening here.”
1. “The U.S. space program enjoyed broad, enthusiastic support during the race to land a man on the Moon.”
Throughout the 1960s, public opinion polls indicated that 45 to 60 percent of Americans felt that the government was spending too much money on space exploration. Even after Neil Armstrong’s “giant leap for mankind,” only a lukewarm 53 percent of the public believed that the historic event had been worth the cost.
“The decision to proceed with Apollo was not made because it was enormously popular with the public, despite general acquiescence, but for hard-edged political reasons,” writes Roger D. Launius, the senior curator at Smithsonian’s divison of space history, in the journal Space Policy. “Most of these were related to the Cold War crises of the early 1960s, in which spaceﬂight served as a surrogate for face-to-face military confrontation.” However, that acute sense of crisis was fleeting—and with it, enthusiasm for the Apollo program.
2. “The Search for Extra-Terrestrial Intelligence (SETI) is part of NASA.”
The SETI Institute is a private, nonprofit organization consisting of three research centers. The program is not part of NASA; nor is there a government National SETI Agency.
NASA did participate in modest SETI efforts decades ago, and by 1977, the NASA Ames Research Center and the Jet Propulsion Laboratory (JPL) had created small programs to search for extraterrestrial signals. Ames promoted a “targeted search” of stars similar to our sun, while JPL—arguing that there was no way to accurately predict where extraterrestrial civilizations might exist—endorsed a “full sky survey.”
Those plans came to fruition on October 12, 1992—the 500-year anniversary of Columbus’ discovery of the New World. Less than a year later, however, Nevada Senator Richard Bryan, citing budget pressures, successfully introduced legislation that killed the project, declaring that “The Great Martian Chase may finally come to an end.”
While NASA no longer combs the skies for extraterrestrial signals, it continues to fund space missions and research projects devoted to finding evidence of life on other worlds. Edward Weiler, an astrophysicist and associate administrator of the Science Mission Directorate at NASA headquarters, told Smithsonian magazine: “As long as we have water, energy and organic material, the potential for life is everywhere.”
3. “The Moon landing was a hoax.”
According to a 1999 Gallup poll, 6 percent of Americans doubted that the Moon landing actually happened, while another 5 percent declared themselves “undecided.”
The Moon landing conspiracy theory has endured for more than 40 years, thanks in part to a thriving cottage industry of conspiracy entrepreneurs—beginning in 1974, when technical writer Bill Kaysing produced a self-published book, We Never Went to the Moon: America's Thirty Billion Dollar Swindle.
Arguing that 1960s technology was incapable of sending astronauts to the Moon and returning them safely, authors and documentary filmmakers have claimed, among other things, that the Apollo missions were faked to avoid embarrassment for the U.S. government, or were staged to divert public attention from the escalating war in Vietnam.
Perhaps one reason for the durability of the Moon hoax theory is that it is actually several conspiracy theories wrapped up in one. Each piece of “evidence” has taken on a life of its own, including such accusations as: the astronauts’ film footage would have melted due to the extreme heat of the lunar surface; you can only leave a footprint in moist soil; and the American flag appears to be fluttering in the non-existent lunar wind.
The scientific debunking of these and other pieces of evidence can be found at NASA’s website—or, at least, that’s what we’ve been led to believe.
Image by Associated Press. The Search for Extra-Terrestrial Intelligence Institute is a private, nonprofit organization and is not part of NASA. However, NASA did participate in modest SETI efforts decades ago but is no longer combing the skies for extraterrestrial signals. (original image)
Image by NASA. NASA lost three spacecrafts destined for Mars: the Mars Observer, the Mars Polar Lander, pictured, and the Mars Climate Orbiter. One myth about the U.S. space program is that during the 1990s, NASA deliberately destroyed its own Mars space probes. (original image)
Image by NASA. The expression "A-Okay" is attributed to astronaut Alan Shepard during the first U.S. suborbital spaceflight on May 5, 1961. Transcripts from that mission reveal that Shepard never said "A-Okay." It was NASA's public relations officer for Project Mercury, Col. John "Shorty" Powers, who coined the phrase. (original image)
Image by NASA. Proponents of unmanned space exploration make the case that the most essential element for sustaining public interest are missions that produce new images and data. Shown here is Mars rover Spirit in 2009. (original image)
Image by Bettmann / Corbis. Initially, John F. Kennedy saw winning the space race against the Soviet Union as a way to enhance America's prestige and, more broadly, to demonstrate to the world what democratic societies could accomplish. (original image)
Image by NASA. The Moon landing conspiracy theory has endured for more than 40 years, thanks in part to a thriving cottage industry of conspiracy entrepreneurs. (original image)
4. “During the 1990s, NASA deliberately destroyed its own Mars space probes.”
Mars is the planetary equivalent of Charlie Brown’s kite-eating tree. During the 1990s, NASA lost three spacecraft destined for the Red Planet: the Mars Observer (which, in 1993, terminated communication just three days before entering orbit); the Mars Polar Lander (which, in 1999, is believed to have crashed during its descent to the Martian surface); and the Mars Climate Orbiter (which, in 1999, burned up in Mars’ upper atmosphere).
Conspiracy theorists claimed that either aliens had destroyed the spacecraft or that NASA had destroyed its own probes to cover-up evidence of an extraterrestrial civilization.
The most detailed accusation of sabotage appeared in a controversial 2007 book, Dark Mission: The Secret History of NASA, which declared “no cause for the [Mars Observer’s] loss was ever satisfactorily determined.”
Dark Horizon “came within one tick mark of making it onto the New York Times bestsellers list for paperback non-fiction,” bemoaned veteran space author and tireless debunker James Oberg in the online journal The Space Review. In that same article, he points out the book’s numerous errors, including the idea that there was never a satisfactory explanation for the probe’s demise. An independent investigation conducted by the Naval Research Laboratory concluded that gases from a fuel rupture caused the Mars Observer to enter a high spin rate, “causing the spacecraft to enter into the ‘contingency mode,’ which interrupted the stored command sequence and thus, did not turn the transmitter on.”
NASA did have a noteworthy success in the 1990s, with the 1997 landing of the 23-pound Mars rover, the Pathfinder. That is, of course, if you believe it landed on Mars. Some say that the rover’s images were broadcast from Albuquerque.
5. “Alan Shepard is A-Okay.”
Several famous inventions have been mistakenly attributed to the space program—Tang, Velcro and Teflon, just to name a few.
Most of these claims have been widely debunked. However, one of the most enduring spinoffs attributed to NASA is the introduction of the expression “A-Okay” into everyday vernacular.
The quote is attributed to astronaut Alan Shepard, during the first U.S. suborbital spaceflight on May 5, 1961. The catchphrase caught on—not unlike the expression “five-by-five,” which began as a radio term describing a clear signal.
Transcripts from that space mission, however, reveal that Shepard never said “A-Okay.” It was NASA’s public relations officer for Project Mercury, Col. John “Shorty” Powers, who coined the phrase—attributing it to Shepard—during a post-mission press briefing.
Watch this video in the original article
6. “NASA's budget accounts for nearly one-fourth of government spending.”
A 2007 poll conducted by a Houston-based consulting company found that Americans believe that 24 percent of the federal budget is allocated to NASA. That figure is in keeping with earlier surveys, such as a 1997 poll that reported the average estimate was 20 percent.
In truth, NASA’s budget as a percentage of federal spending peaked at 4.4 percent in 1966, and hasn’t risen above 1 percent since 1993. Today, the U.S. space program accounts for less than one-half of 1 percent of all federal spending.
A 2009 Gallup poll found that most Americans—when told the actual amount spent by the space program—continue to express support for the current level of funding for NASA (46 percent) or an expansion of it (14 percent).
7. “The STS-48 UFO”
Photographs and videos taken by U.S. spacecraft have opened up a whole new vista for alleged UFO sightings. Among the most famous of these is a video sequence recorded by the space shuttle Discovery (Mission STS-48), while in orbit on September 15, 1991.
A description of the video appears on numerous websites and newsgroups:
“A glowing object suddenly appeared just below the horizon and ‘slowly’ moved from right to left and slightly upward in the picture. Several other glowing objects had been visible before this, and had been moving in various directions. Then a flash of light occurred at what seemed to be the lower left of the screen; and the main object, along with the others, changed direction and accelerated away sharply, as if in response to the flash.”
UFO enthusiasts claim the video shows that the space shuttle was being followed by extraterrestrial spacecraft, which then fled in response to a ground-based laser attack. The footage was aired by media outlets such as CNN’s “Larry King Live” (which challenged viewers to “Judge for yourself”).
The UFOs were, in fact, small fragments of orbital flotsam and jetsam. As space author James Oberg has explained, there are more than 50 sources of water, ice and debris on the shuttle—including an air dump line, a waste water dump line and 38 reaction control system (RCS) thrusters that are used for attitude control and steering.
So, his explanation for the events in the video?
“The RCS jets usually fire in 80-millisecond pulses to keep the shuttle pointed in a desired direction….These jets may flash when they ignite if the mixture ratio is not quite right…When small, drifting debris particles are hit by this RCS plume they are violently accelerated away from the jet. This is what is seen [in the video], where a flash (the jet firing) is immediately followed by all nearby particles being pushed away from the jet, followed shortly later by a fast, moving object (evidently RCS fuel ice) departing from the direction of the jet.”
Watch this video in the original article
8. “The Fisher Space Pen ‘brought the astronauts home.’”
In his book, Men from Earth, Buzz Aldrin describes a brief moment when it seemed that the Apollo 11 lander might be stranded on the lunar surface: "We discovered during a long checklist recitation that the ascent engine's arming circuit breaker was broken off on the panel. The little plastic pin (or knob) simply wasn't there. This circuit would send electrical power to the engine that would lift us off the Moon.”
What happened next is the stuff of legend. The astronauts reached for their Fisher Space Pen—fitted with a cartridge of pressurized nitrogen, allowing it to write without relying on gravity—and wedged it into the switch housing, completing the circuit and enabling a safe return.
True enough, except that the astronauts didn’t use the Fisher Space Pen. Aldrin relied on a felt-tip marker, since the non-conductive tip would close the contact without shorting it out, or causing a spark.
The myth endures, in part, because the Fisher Space Pen company knew an opportunity when it saw one. They began promoting their product as the writing instrument that had “brought the astronauts home.”
9. “President John F. Kennedy wanted America to beat the Soviet Union to the Moon.”
Had JFK not been assassinated in 1963, it is possible that the space race to the Moon would instead have been a joint venture with the Soviet Union.
Initially, the young president saw winning the space race as a way to enhance America’s prestige and, more broadly, to demonstrate to the world what democratic societies could accomplish.
However, JFK began to think differently as relations with the Soviet Union gradually thawed in the aftermath of the Cuban missile crisis and the costs of the Moon program became increasingly exorbitant. Nor was America confident at that time that it could beat the Soviet Union. And, in his recent book, John F. Kennedy and the Race to the Moon, space historian John Logsdon notes that the president also believed that the offer of a cooperative mission could be used as a bargaining chip in Washington’s diplomatic dealings with Moscow.
In a September 1963 speech before the United Nations, JFK publicly raised the possibility of a joint expedition: “Space offers no problems of sovereignty…why, therefore, should man’s first flight to the moon be a matter of national competition? Why should the United States and the Soviet Union, in preparing for such expeditions, become involved in immense duplications of research, construction and expenditure?”
But, the prospect of a U.S.-Soviet mission to the Moon died with Kennedy. Winning the space race continued to drive the Apollo program. Eventually, “the U.S. space program, and particularly the lunar landing effort,” Logsdon writes, became “a memorial” to JFK, who had pledged to send a man to the Moon and return him safely by the end of the decade.
10. “No Buck Rogers, No Bucks.”
For decades, scientists and policy-makers have debated whether space exploration is better suited to human beings or robots.
While there are many solid arguments in favor of manned exploration, the most frequently cited one is arguably the least convincing: without spacefaring heroes, the nation’s interest in space science and exploration will dwindle. Or, to paraphrase a line from The Right Stuff, “no Buck Rogers, no bucks.”
“Don’t believe for a minute that the American public is as excited about unmanned programs as they are about manned ones,” cautioned Franklin Martin, NASA’s former associate administrator for its office of exploration, in an interview with Popular Science. “You don’t give ticker tape parades to robots no matter how exciting they are.”
But the American public’s fascination with images taken by the Hubble Space Telescope and the sagas of the robotic Mars rovers Pathfinder (1997), Spirit (2004) and Opportunity (2004, and still operating) belies the assertion that human beings are vital participants. Proponents of unmanned space exploration make the case that the most essential element for sustaining public interest are missions that produce new images and data, and which challenge our notions of the universe. “There is an intrinsic excitement to astronomy in general and cosmology in particular, quite apart from the spectator sport of manned spaceflight,” writes the famed philosopher and physicist Freeman Dyson, who offers a verse from the ancient mathematician Ptolemy: “I know that I am mortal and a creature of one day; but when my mind follows the massed wheeling circles of the stars, my feet no longer touch the earth.”
When Darwin published Origin of Species, one thing was missing from his argument: a “missing link.”
Though the term never once appears in the book, Darwin knew that his claims could benefit greatly from paleontological evidence of a species transition—an intermediate species connecting, for instance, humans to apes and monkeys. Less than two years after the publication of Origins, he got his wish. On January 3rd, 1863, Charles Darwin received a letter from his paleontologist friend Hugh Falconer with news of a tantalizing find: Archaeopteryx.
This extraordinary fossil—bearing feathers as well as teeth, claws, a bony tail and other reptilian traits—was just the sort of creature that Darwin’s theory of evolution by natural selection predicted should exist. The feathers left no question that the Jurassic Archaeopteryx was a bird, but the creature also had a suite of saurian traits that pointed to a reptilian ancestry.
Falconer could hardly contain his glee. “Had the Solenhofen quarries been commissioned—by august command—to turn out a strange being ‘a la Darwin,'” he wrote his friend, “it could not have executed the behest more handsomely—than in the Archæopteryx.”
Today, some still refer to Archaeopteryx as that long-sought “missing link” between birds and dinosaurs. It certainly checks a lot of boxes for an animal that seems between what were thought to be two distinct categories of organism. But there’s good reason not to use the phrase—which Darwin himself knew. As Nicholas Pyenson, Smithsonian National Museum of Natural History curator of fossil marine mammals, puts it: “Life is really a tree, not a chain.”
“To me, the idea of a ‘missing link’ implies a linear chain of one species evolving into another, evolving into another, and so on,” says Smithsonian Human Origins Program anthropologist Briana Pobiner. That isn’t the pattern we see. Instead, evolution “produces a tree-like branching pattern with multiple descendants of an ancestor species existing at the same time, and sometimes even alongside that ancestor species.”
The chain metaphor that “missing link” implies would have us looking for straight lines, when the reality of evolution is much more discursive. Not every fossil creature can be slotted in as a direct ancestor to something alive today. That’s why paleontologists have come to abhor the term: it obscures the true pattern of evolutionary change.Archaeopteryx has long been considered a "missing link" between birds and dinos. But that term obscures the reality of how evolution works. (NMNH Paleobiology Dept / Smithsonian)
By Any Other Name
Paleontologists often prefer the term “transitional form” or “intermediate form,” because they imply that these species are parts of an ever-changing continuum. This isn’t just a matter of splitting hairs; erminology shapes our ideas and the way dramatic changes in the course of life are interpreted. Before (and even after) Darwin, naturalists sometimes saw species as part of a ranked hierarchy in which newer forms were somehow better than what came before. “Sloppy words lead to sloppy thinking,” as Pyenson says.
“In some sense, every species in a transitional form from its ancestor because it retains many ancestral traits but has enough unique traits to be a separate species,” Pobiner says. And given that every species alive today has fossils related to its ancestry, that’s a lot of transitional fossils. More often, Pobiner says, “paleontologists often use this term when talking about larger anatomical or ecological shifts that occurred during the history of life.”
Not that "transitional form" is without its own problems. The phrase can sometimes inadvertently cast an evolutionary cousin as an ancestor through popular translation. But it at least highlights that the organism in question helps inform what paleontologists have identified as a major shift in life’s history.
Evolution is constantly branching out, and drawing out lines of descent—from one ancestor species to its direct descendant—is almost always impossible due to the incomplete nature of the fossil record. “I look at the natural geological record,” Darwin wrote, “as a history of the world imperfectly kept.” Relating strata to pages of a book, he continued: “Of this volume only here and there a short chapter has been preserved; and of each page, only here and there a few lines.”
Paleontologists know these lines well, for of all the life that ever existed only a fraction was preserved and an even smaller portion as yet found. What's truly amazing, then, is that we are able to detect major changes at all!Darwin illustrated his tree of life in the 1859 version of Origin of Species. It was the only illustration that appeared in the book. (Wikimedia Commons)
How The Whale Got Its Handbones
We know much of the remarkable evolutionary story of whales thanks to transitional fossils. The very first whales, for instance, didn’t look anything like the minkes and orcas swimming around today’s oceans. About 55 million years ago, they were terrestrial animals with hooved feet that looked something like small deer with long tails. They were artiodactyls, members of the same group of mammals that includes hippos and cows today.
Over the course of about 10 million years, early whales at the water’s edge became increasingly amphibious until only the totally aquatic forms were left. This required major changes to how whales moved, what they ate and their senses. A growing accumulation of fossils since the 1970s inform how these changes unfolded; at the same time, you can see whales’ past forms in telltale signs like the handbones in a blue whale’s fin.
An entire flotilla of early whale fossils outlines these changes, such as feet that became paddle-like, spines adapted to up-and-down undulation to swim, and teeth suited to nabbing slippery fish. “Whales don’t look anything like their nearest relatives” alive today, says Pyenson, who is the author of the upcoming book Spying on Whales: The Past, Present, And Future of Earth's Most Awesome Creatures. "Fossils are what tells us about these connections.”
This is why the fossil record is so essential. “If we only had DNA to go on and no fossil record,” Pyenson says, “we’d still be scratching our head as to where whales came from.”
The Human Transition
Whales aren’t unique, of course. Transcendent evolutionary change applies to every organism, from redwoods to whales, from dinosaurs to sea slugs—to us. In fact, we are one of the core problems with the phrase “missing link.”
Many people associate the phrase distinctly with humans. For them, it conjures up the image of a beetle-browed, half-human, half-ape creature that would slot right in between us and chimpanzees. But, as we know, evolution doesn’t proceed along a linear path that would spit out such a being: we have a family tree, not a family ladder. Instead of a single fossil that answers all our questions, what we have is a varied group of fossil humans who help us understand that we are just part of a much larger tale.
There’s also a political reason experts have often avoided using the term. Anti-evolution organizations like Answers in Genesis and the Discovery Institute have often claimed that “missing links” are exactly that: missing. For every new facet of evolution a particular organism might show us, there is an evolution denier pointing to what has not yet been found as if it’s disproof. Relying on the term “missing link,” in other words, gives to much advantage to anti-science agitators, giving scientists all the more reason to abandon the term.
In reality, the human story stretches back millions of years, leaving us the last species standing—literally. We habitually walk in a way that no other animal does with our backs totally upright and our legs beneath us. How that happened has been a major research focus as paleontologists and anthropologists have looked to our past.
This change occurred relatively early on, between the time our ancestors split from chimpanzee ancestors over 6 million years ago and about 3.6 million years ago when prehistoric people walked through ash and gave us definitive proof that early humans were walking much like we do. But the story of humanity goes beyond the legs and spine. “The earliest hominins also had relatively smaller canines than other apes do,” Pobiner says, one of many changes related to alterations in diet, behavior, and more.
We've been able to piece together many of these changes thanks to transitional fossils. Without a modified DeLorean or TARDIS, though, we are left with the imperfect, incomplete, and nonetheless illuminating fossil record: an epic story of life in transition.
The movement of animals from the land into the sea has happened several times over the last 250 million years, and it has been documented in many different and singular ways. But now, for the first time, a team of researchers has created an overview that not only provides insight into evolution, but may also help more accurately assess humans’ impact on the planet.
The oceans are teeming with tetrapods—“four-legged” birds, reptiles, mammals and amphibians—that have repeatedly transitioned from the land to the sea, adapting their legs into fins. The transitions have often been correlated with mass extinctions, but the true reasons are only partly known based on fossils and through study of Earth's climate, for instance.
Those transitions are considered to be “canonical illustrations” of the evolutionary process and thus ideal for study; living marine tetrapods—such as whales, seals, otters and sea lions—also have a big ecological impact, according to Neil P. Kelley and Nicholas D. Pyenson, the two Smithsonian scientists who compiled the new look at these tetrapods, appearing this week in the journal Science.
Instead of gathering evidence from a single field, the pair pulled together research from many disciplines, including paleontology, molecular biology and conservation ecology, to give a far larger picture of what was happening when animals transitioned from the land to the sea across millennia.
Almost by necessity, scientists tend to work in narrow silos, so this research will help broaden their views and potentially make for quicker progress in understanding evolution. Knowing how these creatures adapted over the last few hundred million years, and especially how they've changed in the era since humans appeared, could help us become better stewards of the planet.
“It’s a one-of-a-kind summation of all that’s known about those different groups that evolved to go back to the sea,” says Louis L. Jacobs, a professor of earth sciences and president of the Institute for the Study of Earth and Man at Southern Methodist University. The paper lays it all out in a way that allows scientists to make comparisons across species, he adds.
“The review really gets at the heart of evolution and why the study of evolution is important,” says Sterling Nesbitt, an assistant professor of geosciences at Virginia Polytechnic Institute and State University. Nesbitt focuses on vertebrate evolution—not marine animals—but he says that the Smithsonian researchers’ work will help him and his students understand, for instance, how some land animals may have adapted to being able to live in trees.
The research also “provides the evolutionary context for understanding how living species of marine predators will evolve and adapt to life in the Anthropocene,” says Kelley, the paper’s lead author and a researcher in the National Museum of Natural History department of paleobiology. He adds that he purposely chose to use the term “Anthropocene” in the paper. Some scientists use it to describe the current geological era, but also to mean that it’s a time in which humans seem to be playing a dominant role in the direction of the planet.Over a period of 300 million years, many kind of species ranging from seals to mosasaurs independently developed similar streamlined forelimbs (for swimming) as they transitioned from living on land to the ocean. (Neil Kelley and Nick Pyenson, NMNH)
“It’s not just academic to imagine what the fate of these animals might be,” Kelley says, adding that marine predators in particular are ecologically important players. "It might have a big impact if we lose these predators,” he says.
The Kelley and Pyenson paper draws from 147 mostly peer-reviewed studies in a variety of fields, giving a rich overview of some of the parallel adaptations that occurred among a number of marine tetrapod species. That’s extremely tantalizing, says Jacobs.
Among its many threads, the work highlights a relatively new line of research called fossil pigment reconstruction, a technique that gives scientists the ability to determine, from a fossil, the color of an ancient bird’s feather or of a prehistoric reptile’s skin. Coloration can provide clues to the ways species adapt to their environment. One study, for instance, revealed that ancient marine reptiles had dark coloration, “possibly for temperature regulation or ultraviolent light protection,” the researchers write.
Genomic studies are also helping to piece together the reasons marine animals with different land ancestors appear to have developed similar adaptations when they went into the ocean, according to the authors. For instance, both beaked whales and seals have evolved to have the ability to store myoglobin—an oxygen-binding protein—in their muscles. This gives the deep divers the ability to survive underwater for long periods of time. Prior to genomics, scientists had not been able to trace that similar ability down to a molecular level, says Kelley.
But now, they can see that these different types of sea divers may have the same cellular mechanisms. “There’s a deep evolutionary connection there,” says Pyenson, curator of fossil marine mammals at the Natural History Museum. The question now is whether genetic sequences can be tied to specific behaviors or body type, or breathing ability, or fin development. “We don’t know yet, but we might in the next five years or so,” Kelley adds.Separated in time by more than 50 million years, modern dolphins and extinct ichthyosaurs descended from different terrestrial species but still developed a similar fish-like body. (Dolphin, NOAA. Ichthyosaur, courtesy of Lindgren et al, Nature Publishing Group)
The review also pulls together various studies that show humans’ impact on tetrapod evolution. Humans have hunted a variety of tetrapods almost to extinction, and human activity seems to be indirectly hastening the disappearance of others. Six of seven sea turtle species are threatened. And the Yangtze River dolphin, found only in that river in China, was declared extinct in 2006 as a result of shipping accidents and habitat degradation.
But some tetrapods have outwitted humans. Gray whales, which were thought to live only in the Pacific, have recently been found in the Atlantic. “The best guess for how they got there is they are moving through the Arctic,” says Kelley, noting that the ice has melted enough to allow a waterborne passage. The fossil record shows that gray whales once lived in the Atlantic some 100 million years ago, so their movement back may be a recolonization process, Kelley says.
Kelley and Pyenson hope that their paper motivates more collaborations, for instance, among paleontologists, biologists and conservationists, to bring the past and the present together—especially to take a closer look at marine animals. Humans “are having an outsize impact on the future,” says Pyenson. The review helps answer the question of “what is going to be the fate of these ecologically important species?”
“Understanding the ocean is vital for humans on this planet,” says Jacobs, noting that it plays an important role in the ecosystem. But he adds that humans are changing the ocean—leading to rising sea levels and rising temperatures, as well as changes in salinity and acidity, all of which are stressing animals. “We don’t know all the unforeseen consequences of what these physical changes will bring about.”An assortment of Cretaceous-era marine tetrapods from near the end of the "Age of Reptiles," including a sea turtle, an early flightless marine bird, a large mosasaur and a long-necked elasmosaur. (Artwork by Karen Carr/NMNH)
The golden morning light still casts long shadows on the badlands when we arrive at the drill site at 6:30 on July 14. The rig’s motor is burbling and rumbling in the quiet morning. The driller, Ben, and his assistant, Cody, are moving quickly and surely as they prepare to lower the drill bit onto the big blue X where I marked the spot for the first core. Since we first began planning to drill these cores, I have thought about this moment with a combination of dread and excitement. Dread because I have never been involved in coring before and am completely reliant on the expertise of the drilling team—a far cry from the low-tech activity of my yearly fossil collecting. Excitement because we are about to take samples of rocks from hundreds of feet underground, unweathered rocks that may preserve chemical and microscopic fossils we have never before detected.
Doug and Anders call out to me: “Do you want to come see the ground-breaking?” I’m over to the rig like a shot. Ben moves some controls on the drilling rig, the pipe starts to rotate, then advances, then begins to cut through the surface dirt and pebbles. Ben drills down about five feet in just a few moments, halts, then pulls the core catcher and liner back to the surface. He swings the section of pipe containing the core out onto a sawhorse-like contraption, where Cody extracts the clear Lexan liner. It contains our first section of core—mostly just near-surface dirt of no scientific interest—but this is just the start. Over the next hours Ben and Cody repeat the process over and over again: drilling down about five feet at a time, then halting, dropping the overshot down the inside of the drill pipe so that it latches onto the assembly that contains the liner and the core, then pulling this assembly to the surface and removing the cylinder of rock in its liner. At first it seems so slow, but then I remember that we on the science team have a lot to do!
With each core section we have to find out from Ben how far down he has drilled, which he reports to us in feet and tenths of feet. (American drillers work in American units!) Cody hands over the latest section of core in its liner, and one of us picks up the 25-pound tube of rock and takes it back to the worktable we have set up, where we label the liner with a Sharpie, mark the “up” direction, cut the liner to fit the core section precisely, cap the ends of the liner (red for bottom, blue for top), tape the caps on, measure the length of the core section (in centimeters since we are scientists), weigh it, record a brief description of the type of rock we see through the liner, then drill holes through the plastic liner to drain the water we have used to lubricate the drilling. Then we have to clean the sediment off of the core catcher and return it to Cody. I know we must look ridiculous as we rush around, getting in one another’s way, perhaps like inexperienced wait-staff in a very busy restaurant. Within 20 minutes the cores are coming out of the hole faster than we greenhorns can deal with them, and Anders and Doug have to provide reinforcements and steadying words. Fortunately it doesn’t go at this pace all day. The deeper the hole gets, the longer it takes to retrieve each segment, so we have slightly longer periods during which to process each core.
The day heats up in its customary way, breaking 100 by 2 p.m. But we are used to the heat. We do experience problems, though. Sometimes Ben will drill down five feet, but recover only three feet of core in the liner. His expression lets me know he doesn’t like this. Perhaps the last two feet of core he drilled are still at the bottom of the hole? He sends the drill back down and drills another two feet, but comes up with four feet of core—the bottom two feet from the previous run, plus two feet from this run. But it isn’t always this simple—sometimes even after several runs we still haven’t recovered quite as much core as the length we drilled down. And the situation is made more confusing because we are constantly converting back and forth between metric and American measuring units. And it is 100 degrees. And we have now been working as fast as we can for eight hours. And we still have four hours to go. Finally I realize that I need to pause long enough to get a good drink of water—I’m inured to the heat, but I’m not used to the frantic pace and I have forgotten the first rule of badlands work, which is to stay hydrated.
Image by Scott Wing. Ben Goody, left, and Cody Halliday coring. They used the poultry and livestock bedding to keep drilling water from escaping into the porous sand. (original image)
Image by Scott Wing. The products of our first day of coring. Drying in the hot Wyoming sun are segments of cores in their Lexan liners. (original image)
Image by Scott Wing. A detailed view of the bottom of a segment of core. (original image)
As the heat of the day passes and the light lengthens again, we realize that we have finally established a rhythm of work. Each of us has a “specialty,” we stay out of one another’s way, and we get the cores processed about as fast as Ben and Cody are producing them. The work may be repetitive, and there isn’t the possibility of the dramatic fossil find that I get with my normal collecting, but there is a huge satisfaction in seeing the growing pile of Lexan tubes, each containing a core section. By the end of our shift, at 7 in the evening, we are down well over 100 feet, more than a quarter of our target depth. Ben and Cody are replaced by A.J. and Brandon, the night-shift drillers. Elizabeth, Aaron and Brady arrive to take over for the evening science shift. Anders is pulling a superhuman double shift—he has been here all day and will continue until 7 a.m. tomorrow. Doug and Guy and Allie and Johan and I are almost reluctant to leave—we have this process down now, and feel pretty good about the system we have refined. But it doesn’t take long for us to convince ourselves it is time for dinner and bed.
We have had a long day, recovered a lot of core and are confident that every section is properly labeled, oriented, described and measured. Even more important, we have seen rocks that have a lovely dark brown color, indicating they preserve a lot of organic material, material that may include the chemical fossils we are looking for. But we will have to wait for the lab analyses later this year to know for sure.
Back in Greybull, we have a quick, late dinner at Lisa’s Restaurant, and then head to bed. We will be up at 6 in order to get breakfast and be ready to relieve the night shift at 6:45 tomorrow morning.
Over the next three days our crew drills two holes, each 450 feet deep, and recovers essentially 100 percent of the rocks that we have drilled through. These are the first cores ever obtained of a terrestrial environment during the PETM. We have cored the same time interval at two sites quite close together so that we can increase the amount of rock from each stratigraphic level. We want a large volume of samples because we don’t know what the concentration of molecular fossils will be, and because we want to be able to preserve part of the cores as an archive that future scientists can work on. Who knows if there will ever again be funding to undertake this sort of coring operation. It has taken a total of four days of 24-hour work, and we are proud of our efforts and a little giddy with exhaustion.
And what does one do with 900 feet of core, divided into about 200 segments and weighing thousands of pounds altogether? No problem, apparently, because Tom Churchill arrives shortly after we are done, having driven the two hours from Powell in his barley truck. We all load the cores in the back, and Tom heads back to Powell where the cores will be unloaded into his shed and stored on racks built for beehives. Once again, it’s the Churchills to the rescue of the paleontologists.
Scott Wing is a research scientist and curator in the Smithsonian Institution’s Department of Paleobiology.
Human beings have a long history of persecuting apex predators such as wolves, tigers and leopards. The loss of these predators—animals at the top of the food chain—has resulted in ecological, economic and social impacts around the globe. Rarely do the predators fully recover from human oppression, and when they do, we often lack data or tools to assess their recovery.
The sea otters in Glacier Bay, Alaska, are an exception. In a recent study, our team chronicled the incredible return of sea otters to an area where they’ve been absent for at least 250 years.
Our approach—which fuses mathematics, statistics and ecology—can help us better understand the role of sea otters in marine ecosystems and the ability of apex predators to return to an ecosystem after they’ve been absent. It may even help us learn what a changing climate means for many other species.
Although not typically viewed in the same vein as wolves, tigers and leopards, sea otters are an apex predator of the nearshore marine ecosystem—the narrow band between terrestrial and oceanic habitat.
During the commercial maritime fur trade in the 18th and 19th centuries, sea otters were nearly hunted to extinction across their range in the North Pacific Ocean. By 1911, only a handful of small isolated populations remained.Historic range (gray shading) and 1911 remnant populations (red icons) of sea otters. The populations at Queen Charlotte Islands and San Benito Islands went extinct by 1920. (CC BY)
But sea otter populations have recovered in many areas, thanks to a few changes. The International Fur Seal Treaty in 1911 protected sea otters from most human harvest. Wildlife agencies also made an effort to aid sea otter recolonization.
Eventually, sea otters began to increase in abundance and distribution, and they made their way to Glacier Bay, a tidewater glacier fjord and national park in southeastern Alaska. Glacier Bay is functionally one of the largest marine protected areas in the northern hemisphere.
Glacier Bay was completely covered by glacier ice until approximately 1750—about the same time sea otters vanished from the surrounding area due to over-harvest. It then endured the most rapid and extensive tidewater glacier retreat in recorded history. After glacier retreat, a rich environment emerged. This new environment supported high concentrations of wildlife, including sea otter prey species—such as crabs, mollusks and sea urchins—that were able to increase in size and abundance in the absence of sea otters.
Sea otters first reappeared at the mouth of Glacier Bay in 1988. Here they encountered vast habitat, abundant prey populations and protection from all human harvest.Glacier Bay National Park, southeastern Alaska. (Map used with permission from the National Park Service)
It’s challenging to estimate how populations grow and spread, due to their dynamic nature. Each year, animals move to new areas, increasing the amount of area and effort required to find them. Airplanes searching for sea otters have to cover more ground, usually with the same amount of time and money. Additionally, individuals may move from one area to the next during any time period for a number of reasons, including sea otter social behavior and their reaction to the environment. Because these challenges can interfere with accurate population estimates, it’s important to understand and address them.
Shortly after sea otters arrived in Glacier Bay, scientists from the U.S. Geological Survey began collecting data to document their return. Although the data clearly indicated that sea otters were increasing, we needed novel statistical methods to unveil the extent of this increase.
First, we developed a mathematical model using partial differential equations to describe the growth and spread of sea otters. Partial differential equations are commonly used to describe phenomena such as fluid dynamics and quantum mechanics. Therefore, they were a natural choice to describe how a mass – in our case, the sea otter population – spreads through space and time.
The new approach allowed us to incorporate our current understanding of sea otter ecology and behavior, including habitat preferences, maximum growth rates and where sea otters were first observed in Glacier Bay.
Second, we incorporated our equations within a hierarchical statistical model. Hierarchical models are used to draw conclusions from data that arise from complex processes. They provide flexibility to describe and distinguish among various sources of uncertainty, such as uncertainty in data collection and ecological processes.
Partial differential equations are not new to the field of ecology, dating back to at least 1951. However, by fusing these equations with formal statistical models, we can reliably infer dynamic ecological processes, while appropriately quantifying the uncertainty associated with our findings. It provides a data-driven way to analyze surveys of sea otter abundance for the past 25 years.
This gave us rigorous and honest estimates of colonization dynamics that incorporated our understanding of the ecological system.Group of sea otters in Glacier Bay National Park, 2016. (Photo by Jamie Womble)
Using our new approach, we discovered that the Glacier Bay sea otter population grew more than 21 percent per year between 1993 and 2012.
By comparison, the estimated growth rates of sea otters in other populations in Alaska, who were also recovering, have been limited to 17 to 20 percent. Furthermore, the maximum biological reproductive rate—the fastest rate sea otters can reproduce—is between 19 to 23 percent per year. That means that the Glacier Bay sea otter growth rate was near or at maximum, and greater than any recorded sea otter population in history.
In the wake of glacier retreat, sea otters went from nonexistent to colonizing nearly all of Glacier Bay in a span of 20 years. Today, they are one of the most abundant marine mammals in Glacier Bay. Recent observations have documented large groups of more than 500 sea otters in some parts of lower Glacier Bay, suggesting that prey resources are abundant.(via GIPHY)
The fusion of state-of-the-art statistical and mathematical methods depicted, for the first time, just how extraordinary the growth and spread of this population was.
Sea otters had great success in the wake of tidewater glacier retreat in Glacier Bay. While climate-induced loss of sea ice can negatively affect some wide-ranging apex predators—such as polar bears or walruses—other species may benefit from the emergence of newly available habitat and prey resources.
Humans have caused the global decline of apex predators, and these declines are often difficult to reverse. However, our results suggest that, when there is minimal human interference, apex predators can be widely successful at recolonizing suitable habitat.
They came for the vintage video game arcade, the sprawling art fair, and rare photo ops with their favorite celebrities. But they also came to learn.
Since its 2013 launch, the annual Washington, D.C. pop culture fest known as Awesome Con has blossomed into a national beacon of proud nerddom. Last weekend, some 60,000 enthusiasts from around the country descended on the Walter E. Washington Convention Center for a three-day celebration of all things nerd and culture. Brandishing homemade lightsabers and Tardises, and donning costumes inspired by franchises as diverse as Teen Titans, Spirited Away and The Last of Us, these dedicated fans had no trouble repping their sometimes-obscure passions.
But within Awesome Con is a series of lectures and panels that skew even more geeky than the rest of the conference: an educational series called Future Con that ties real-world concepts and cutting-edge scientific research in with the fiction. Run jointly by Awesome Con and Smithsonian Magazine, this series enlists NASA astrophysicists, university biologists and entertainment industry engineers to bring scientific expertise to bear on an assortment of intellectual properties ranging from Black Panther to Mass Effect.
Kicking off the lineup of Future Con presentations was a panel talk from NASA, held Friday afternoon, titled “NASA Science at Earth’s Extremes.” Experts delved into a selection of NASA’s current Earth science campaigns, showing the audience that NASA doesn’t just look outward to the stars—but also inward toward Earth.
Following presentations from glaciologist Kelly Brunt on Antarctic sledding expeditions and geologist Jacob Richardson on volcano recon in Hawaii and Iceland, environmental scientist Lola Fatoyinbo spoke on the carbon-rich equatorial mangrove ecosystems of Central Africa, and the importance of wedding on-the-ground fieldwork with observations from planes and orbiters. NASA is preparing to launch a pioneering mission called the Global Ecosystem Dynamics Investigation (GEDI—pronounced “Jedi,” of course) that will survey the verticality and dynamism of terrestrial forests with a LIDAR-equipped satellite. “May the forest be with you,” she concluded with a smile.
Soon after this panel came a live recording of Smithsonian’s AirSpace podcast, in which personnel from the Air and Space museum talked space stations with special guest René Auberjonois of Star Trek: Deep Space Nine, who felt the show accurately captured what living on a space station “would do to you at a psychological level.”
Air and Space Museum researcher Emily Martin posited that space stations are likely to play an increasingly large role as we push humanity beyond Earth. “We’re going to need to have these sorts of bus stops” for our astronauts, she said. Equipped with modern tech, she thinks modern spacefarers could make discoveries their forebears could only dream of. “Could you imagine an Apollo astronaut with a smartphone? Think of what they could do!”A Future Con panel discusses the science and social dynamics at play beneath the surface of Black Panther. (Lacey Gilleran)
Building on this theme of space exploration was a discussion on the mysteries of black holes, and one in particular located deep within our own galaxy. “There’s a four-million-solar-mass black hole sitting right in the middle of the Milky Way,” said NASA astronomer Jane Turner. She estimates that it sucks up the equivalent of an entire star each Earth year. A global alliance of scientists is on the verge of observing this black hole with an array of earthbound telescopes in an exciting an unprecedented project called the Event Horizon Telescope.
After this deep dive into the unknown, Future Con turned back toward the familiar and fun, putting on a widely attended panel talk on the science depicted in Marvel’s critically acclaimed blockbuster Black Panther. Panelists discussed the empowering message of Afrofuturism as well as particular real-life analogs to some of the wondrous “vibranium” technologies seen onscreen.
Lockheed Martin engineer Lynnette Drake argued that “graphene is very similar to vibranium in terms of what we use in the science world,” and her colleague Charles Johnson-Bey pointed out that absorptive nanofibers—like those in protagonist T’Challa’s panther suit—have a firm basis in reality. “We have nanomaterials we use to make materials lighter,” Johnson-Bey said. Some of them are even employed to diffuse lightning strikes on moving watercraft, in much the same way T’Challa’s armor absorbs and protects him from incoming energy.
Saturday’s lineup featured Future Con events on two more evergreen cultural phenomena: Harry Potter and Star Wars.
Duke biology professor Eric Spana walked a rapt crowd of Potterheads through the workings of heredity in Rowling’s books, concluding via a thorough analysis of salient—but fictional—case studies that sensitivity to magic must be an autosomal dominant trait. Where do Muggle-born witches and wizards come from, then? Spana had an answer for that too: thanks to spontaneously occurring germline mutations, he showed that it is perfectly reasonable to expect a teensy percentage of Muggle-born yet magic-sensitive kids to arise in any given population.
Spana puts the odds of being born magic-sensitive to Muggle parents at one in 740,000: “Powerball odds.” In other words, don’t hold your breath.The Awesome Con experience offered informative panels and personal engagement with artists, celebrities, and fellow nerds. (Lacey Gilleran)
Later in the afternoon, two of the designers who brought to life the widely adored Star Wars droid BB-8 talked about their prototyping process. Star Wars electronics engineer Matt Denton, who had started out in laboratory robotics but decided academia wasn’t for him, revealed that a host of BB-8 models were ultimately made for the screen, each with their own strengths and weaknesses. These included trike-mounted models, a lightweight model, a puppet model (for up-close emotional moments) and even a stunt model. The so-called “red carpet model,” a fully automotive droid that Denton’s coworker Josh Lee called “a whole new type of BB-8,” rolled out onstage to surprise and delight the fans.
Next were two thoughtful panels on increasing diversity in science and pop culture. In “Brave New Girls,” female scientists, science educators and science communicators discussed their experiences in the world of professional science, recounting stories of inspiration, hurdles overcome and successes achieved. Later, a second panel looked at trends in STEAM and diversity in comics and movies, stressing the importance of onscreen representation and the transformative effect of seeing someone who looks like you pursue dreams akin to yours.
Panelist Renetta Tull said that “Seeing Lieutenant Uhura in Star Trek was a big deal for me” as an African-American scientist and educator at UMBC. Some of her first major work in academia, on 3D imaging techniques, was inspired by the holodeck technology built into the Enterprise.
One of the most powerful sessions of the day was a screening of Stephen Hawking’s final film, Leaving Earth: Or How to Colonize a Planet. In the film, the legendary astrophysicist—who passed away this March—suggests that it’s time to start thinking seriously about a means of escaping Earth. “We can and must use our curiosity to look to the stars” for refuge, he says—Earth could be wiped out in any number of ways in the relatively near future.
The nearest potentially suitable destination for humankind is a planet slightly larger than ours orbiting the red dwarf Proxima Centauri. In order to reach this world, called Proxima B, we’d need to traverse an intimidating 4.2 light years of space. The solution, perhaps, will rely on the principle of solar sails. In time, a massive array of earthbound laser stations could fire simultaneously at a sail-equipped spacecraft, sending it hurtling into the black at a significant fraction of light speed. To protect voyagers from cosmic rays en route, biologists believe we might need to put them in a state of bear-like hibernation. Strangely enough, bears are effectively immune to radiation damage for the duration of their winter snooze.
The convention came to a close on Sunday, with a last smattering of Future Con topics addressing science in video games (Mass Effect got high marks for planetary dynamics, while Assassin’s Creed was chided for sketchy epigenetics), the many incarnations of the Batmobile (the panelists’ favorite was the 1989 model from Burton’s Batman, now on view at the National Museum of American History), and heady explorations of the deep universe and gravitational waves. Then, armed with heady visions of the future and a little more knowledge about the world around them, Awesome Con attendees compressed their lightsabers, bagged their d20s, and filed out into the cool March evening.
This event was made possible by Future Con sponsors Boeing, Netflix, and X, the moonshot company.
In 1942 Winston Churchill said: “The longer you can look back, the farther you can look forward.” And indeed, many cultures study history for political and military insight. I study fossils that are millions of years old because I am concerned about the future. As a paleontologist, I think it is time to establish a tradition that uses geological history to anticipate—and thus plan for—the future.
I didn’t always think this way. I became addicted to finding fossils because it was a kind of exploration, and because I loved the feeling of being transported through time simply by walking up and down the layered hillsides of Wyoming and Montana.
I continued in this happy phase of exploration through the first decade of my career. But things changed in 1990, when two climate scientists published a map—a computer simulation of global climate 50 million years ago. It showed a relatively cold world—winters that fell below freezing across northern Asia, Europe and North America.
I knew this map had to be wrong. For 100 years we paleontologists had been finding fossils that demonstrated winters were very mild in this time period, even in the Polar Regions and in the middles of continents at high latitudes.
We had found dawn redwood forests on the shores of the Arctic Ocean.
We had discovered fossil palm remains along the coast of Alaska.
In the middle of North America, where winters are bitter cold today, we had found fossils of alligators.
This is when it dawned on me that studying fossils was far more relevant than I had realized. Fossils test our understanding of how the planet works—they contain clues that improve our ability to predict climate, in both the past and in the future. I still loved finding fossils, but unlocking these clues became my new obsession.
For the last 25 years climate modelers and geologists have been working back and forth on this problem of how to explain the warm climates of the past. Today’s computer simulations agree better, though still not completely, with climate reconstructions from fossils and other evidence.
The result of this fertile argument between climate modelers and paleontologists is that the past has become a proving ground for hypotheses about how climate and other earth systems work. And the beauty of testing our understanding against what has already happened—the fossil record—is that we can find out if the models work, without waiting for decades or even centuries to pass. This is particularly important because the problems we face are urgent.Wing has spent much of his career studying fossil leaves. He’s trying to understand how a global warming event, that happened some 56 million years ago, altered terrestrial ecosystems in what is now Wyoming. (Amy Morey)
The geological record has proved to be a great place to test our ideas about Earth processes, but it also has produced surprises. Over the last few decades scientists have discovered a new kind of event in Earth’s climate history—planetary heat waves that lasted for thousands or hundreds of thousands of years.
The biggest of these occurred 56 million years ago, and it’s called the Paleocene-Eocene Thermal Maximum, or PETM.
The PETM was kicked off by a release—likely from methane stored in sea floor sediments—of 5,000 billion tons of carbon into the ocean and atmosphere—the amount we would generate if we were to burn the entire known modern-day fossil fuel reservoir. The release about doubled the amount of CO2 in the atmosphere.
This triggered a host of events: global temperature rose by 5 to 8 degrees C; the ocean became more acidic; warmer climate led to warmer soils, and warmer soils to faster decay of plant matter, which released even more CO2 to the atmosphere. With the slow rate at which CO2 is removed from the atmosphere by weathering and other processes, the PETM lasted 150,000 years.Many of Scott Wing’s explorations of climates past have unfolded here, in Wyoming. (Tom Nash)
During that time, many small deep-ocean species went extinct. The Arctic warmed so much that plants and animals moved across high-latitude land bridges between the northern continents. And there were massive die-offs of local populations of plants in mid-latitudes.
The parallels between the PETM and the present are strong. Though today’s world, with its vulnerable ice caps, is probably more sensitive to a carbon release than the world of 56 million years ago. But the biggest difference between the PETM and today is that we are adding CO2 in the atmosphere. We can change it.
CO2 levels are now 40 percent higher than they were before the industrial revolution. If we go for business as usual, the rest of this century will be like the start of the PETM on steroids—a similar or larger CO2 increase happening 10 times faster. What few realize is that this rise in CO2, and the heat wave it will cause, will persist for thousands or tens of thousands of years. As we have seen, that’s the way the planet works.
The long history of our planet makes you realize that change is inevitable, but it also shows you that the changes we are causing now are very large, exceptionally fast, and mind-bogglingly persistent. The consequences of what we do in the next decades will be felt for tens of thousands of years to come. That’s the most awesome responsibility imaginable, but it comes with our power to change the global environment.The warming period Wing studies, the PETM, is recognized by scientists as the best geological analogue for the human-induced global warming that is happening now. Wing’s plant fossils show that as the climate in Wyoming warmed 56 million years ago, it also became seasonally quite dry, resulting in extinction of some species, local extirpation of most, and the spread of dry-tolerant plants into this region (Scott Wing)
In one sense, I’m an optimist. We aren’t going to destroy the planet or drive ourselves extinct. With more than 7 billion people and 75 million more every year, human extinction is hardly our problem.
But examples of extreme environmental change from the past suggest that there is likely to be hardship and misery coming for billions of people. And we are already diminishing the diversity of life and compromising the ability of ecosystems to produce the resources we depend upon.
We are now as powerful as geological forces were in the past. So we have to learn to think on the planet’s timescale, not our own. We must turn from crisis management to planet management, but we will only do that when we realize our actions are not just for today, but for the ages. I hope people of the future will look back on us and see that we learned the lessons of deep time.
Editor’s Note: Adapted from a talk Scott Wing gave at the Annual Meeting of the New Champions 2016, the World Economic Forum’s Global Summit on Innovation, Science and Technology. The Smithsonian Institution partners with the World Economic Forum to broaden awareness of cultural heritage protection and preservation, science, health, technology, and other critical global issues. The World Economic Forum, committed to improving the state of the world, is the International Organization for Public-Private Cooperation. The Forum engages the foremost political, business and other leaders of society to shape global, regional and industry agendas. The Forum is headquartered in Geneva, Switzerland.
Sixty-six million years ago, nothing seemed more unlikely than the dominance of bipedal apes and flying dinosaurs. Yet here we are.
The Cretaceous was a world of enormous terrestrial dinosaurs, some small mammals, and what we now recognize as the predecessors to modern birds. Some, like Hesperornis, were flightless creatures with a beak full of teeth that lived in the ocean. Others, like Icthyornis, were flying fish-eaters. Most diverse of all were the group of birdlike animals called Enantiornithines, or “opposite birds” (named because some of their bones are organized in the opposite manner as modern birds). They lived all across the globe, in over 80 different taxa, many of them adapted for life in the trees.
Not a single one of those species made it past the Chicxulub asteroid that landed on the Yucatan Peninsula.
The asteroid’s impact created a blast one billion times stronger than the bomb at Hiroshima—but that was only the start of the devastation. What followed were global wildfires, years of nuclear winter and acid rain. Amazingly, around 30 percent of organisms did manage to survive, and those survivors included the ancestors to all modern life we see today.
A new study speculates that the trick might have required being able to live on the ground. The study, published today in Current Biology, looks at evidence for widespread forest disappearance and the emergence of what we know now as modern birds. The researchers postulate that because forests were wiped out globally, birdlike creatures that required those perches for survival were forced into extinction, while the ground-dwellers survived.
“What I like about this paper is that it puts down a chip, a marker,” says David Jablonski, a professor of evolution and paleontology at the University of Chicago who wasn’t involved in the study. “Here’s a hypothesis and now it can be more fully explored.”
For the authors of the new paper, coming up with the hypothesis in the first place involved assembling a team of specialists from across the world of paleontology, including those who study ancient pollen and birds. First, the paleobotanists, who studied rock samples from North Dakota. Nestled inside the dusty fragments are millions of microfossils—preserved remains of pollen spores, leaf litter, wood and other debris.
“Because of their very small size and extreme abundance in sediments (around 100,000 per gram of rock), it is possible to study the composition of the flora and its change through time with very high precision, as you can sample the rock record centimeter by centimeter,” said Antoine Bercovici, a paleobotanist at the Smithsonian Institution and an author on the new paper, by email.Ferns sprouting up in a fire-damaged forest. (Regan Dunn / The Field Museum)
Those microfossils from the boundary between the Cretaceous (the last geologic period of the dinosaurs) and the Paleogene (the period immediately following the asteroid) show a very particular pattern known as the “fern spike.” After millennia of spores from a wide variety of plants, suddenly 70 to 90 percent of the microfossil flora record comes from ferns. That’s because ferns reproduce with spores rather than seeds, which are much smaller and more easily spread through the wind, says Regan Dunn, another author on the paper and a paleobotanist at the Field Museum.
“When there’s a big forest fire or a volcanic eruption today, oftentimes the first things that come back are the ferns,” Dunn says. That spike in fern growth is apparent across the world, and it suggests that the ferns were monopolizing a landscape devoid of trees and other plant life. As far as the scientists can tell, it would’ve been a fairly gloomy world, between the ash-darkened skies and the unseasonal cold. But there was enough plant life left for vertebrates to eek out a living.
“When you destroy the environment, that affects every other living organism. You also see a decline in the insect faunas, and we know that because you can look at fossil leaves and see insect damage on them,” Dunn says. “The plants feed the bugs, and the bugs feed the birds, and the birds feed the mammals, so when you take the base out of that, you have massive repercussions.”
Daniel Field, a paleontologist at the UK’s University of Bath, has long been interested in the question of how a devastating mass extinction that occurred millions of years ago could ultimately produce the breathtaking diversity of bird species we see today. With this study, he and his team begin to piece together the answer. Using statistical analysis of the fossil record, combined with data on the forests, the researchers concluded that non-arboreal birds—those who didn’t live in trees—were much more likely to survive.
That’s not to say a ground-dwelling lifestyle was the only thing required for making it out of the mass extinction. Body size and diet likely had something to do with it, as well as other factors.
After all, there were dinosaurs the size of small birds who didn’t make it out—and researchers aren't yet sure why. “You’ve got to explain an extinction where the big dinosaurs went out, but the crocodiles didn’t. Where the mosasaurus went out, but sea turtles didn’t,” Jablonski says. “The fascinating thing to contemplate is, how do you have [a mass extinction] that removes 60 percent of organisms, but not 100 percent? It’s got to be really severe, but on the other hand, some of them are still standing.”
The next steps to filling in the picture will be figuring out what exactly happened to forests—the researchers currently think it took at least 1,000 years before they began to recover—and how everything else survived in the meantime. Birds diversified rapidly shortly after the extinction event, but scientists still aren’t sure exactly when it happened and how it varied among species.
The importance of piecing together this period of the past is also critical for predicting the future. The researchers say what happened to birds at the end of the Cretaceous could help us understand how human-made climate change might affect today’s birds. “What these kinds of studies show is that ecosystems, although remarkably resilient, really do have breaking points,” Jablonski says. “And that history should be considered extremely sobering.”
Astronomers hunting for planets outside our solar system just keep finding them in the darndest places. There are boiling hot Jupiters that hug their stars, rocky worlds like Earth that spin around multiple suns and even rogue planets that sail unbounded through the galaxy.
Now, astronomers using a gravitational magnifying glass have found a Venus-like planet orbiting a "failed star"—a massive but incredibly dim brown dwarf. This rarely seen pairing offers clues to the way planets and moons form, which may in turn help in the quest to find habitable worlds, whether they are Earth-like planets or life-friendly moons.
"I wouldn't say this proves anything, but it’s the first hint that there might be a universality in how companions form at all these different scales," says Ohio State University Andrew Gould, part of the team reported the find last month in the Astrophysical Journal.
Stars form when gravity pulls together cold clouds of gas and dust, and newborn stars then become surrounded by spinning disks of leftover material. Dense pockets within these disks coalesce to form planets. Similarly, Jupiter's largest moons are thought to have formed from a disk of so-called circumplanetary material around the infant gas giant.
But brown dwarfs occupy a niche in between stars and planets—they are just large enough to have begun the process of fusion, but too small to continue with it like larger stars. Intriguingly, the Venus-like world and its brown dwarf have a similar mass ratio to both Jupiter and its largest moons and to the sun and the outer icy planets. This hints that all these objects may have formed via a similar mechanism, just at different scales.
"If this object formed the same way Jupiter's moons formed, this means the process of forming moons from a circumplanetary disk like the Galilean satellites is universal," says David Kipping of Columbia University.
In this case, the newfound exo-Venus stands as a bridge between planets and moons. If its brown dwarf host was just a bit smaller, the star would really be considered a planet, and the new body would be described as an exomoon.
According to Kipping, the new system puts an upper limit on how large a moon can get compared to the object it orbits. While large bodies can be captured, a Jupiter-sized planet would not have enough gravitational clout to spawn an Earth-sized world in its circumplanetary disk. Building an Earth- or Venus-sized moon instead requires a host as massive as a brown dwarf, he says.
Figuring out such limits is important, because exomoons are of great interest to astronomers searching for habitable worlds. Although the large moons of our solar system lie too far from the sun to hold water on their surfaces, they are some of the most promising places to search for extraterrestrial life, as many boast subsurface oceans.
And astronomers think large exomoons orbiting distant gas giants could host surface water if they spin close enough to their stars. Although no exomoons have yet been discovered, instruments like NASA's Kepler telescope are eagerly searching for them.
So could this Venus-like planet host life? Probably not, says Gould. With no fusion-driven heat in their cores, brown dwarfs are incredibly dim, and this planet is likely too far from its star to be warm enough for habitability. Unfortunately, the method used to find the dark planet around a faint star presents challenges to further study.
To find the Venus-like planet, scientists used a planet-hunting technique known as microlensing, which relies on light from a star behind the brown dwarf. As the background star shines, the brown dwarf's gravity bends and magnifies its light in such a way that scientists can identify not only the extremely dim star but also its orbiting planet.Microlensing is a scaled-down version of the same effect, gravitational lensing, that bends and magnifies the light from far-off galaxies. Here, Hubble spies a red galaxy that is distorting the light from a background blue galaxy. (ESA/Hubble & NASA)
"It is extremely difficult—although probably not impossible—to see planets around brown dwarfs by any technique except microlensing," says Gould. "In the case of a brown dwarf, even though it's emitting little or no light, [microlensing] can still betray its presence."
But because microlensing relies on the precise lineup of the system with a background star, researchers can't easily study these worlds again, so they can't determine attributes such as the planet's atmosphere, which would help characterize its habitability.
The biggest challenge with microlensing, Gould says, is pulling out important details. The signal wraps up all the information about the mass, distance and velocity of the target star (and any orbiting worlds) compared to the background star. But astronomers often don't have enough data to tease them apart—much like if I gave you the square footage of my house and told you to determine its length, width and the number of floors.
Binary systems, where two stars are locked in a mutual orbit, almost always contain an extra piece of information that helps astronomers get the mass of any orbiting planets. On top of that, this newfound system lies about ten times closer to Earth than most previously known microlensed systems, making variations in its signal—and ultimately the planet's mass—easier to pull out.
Based on statistical evidence, Gould says that rocky planets around low-mass stellar pairs like this one are likely quite common, enough so that every star in a similar system may boast a terrestrial world. A small portion of those found in the future may well be warm enough to hold liquid water on their surface, and as microlensing surveys improve and space-based efforts continue, more of these worlds should be identified.
"We think that we're really just scratching the surface of what microlensing can tell us about systems people aren't even really thinking about right now," Gould says. "We're looking forward in the future to more microlensing detections."