TIME Research

A Rough Childhood Can Literally Age You Says a New Study

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Researchers say childhood adversity and psychiatric disorders may be linked to cellular changes that cause aging

Childhood trauma and psychiatric conditions may cause individuals to experience accelerated aging, according to research published last week.

In a study featured in Biological Psychiatry, scientists say they may have found evidence to suggest there is a link between aging at the cellular level and trauma or stress disorders.

To complete the study, researchers recruited 299 adults and separated them into different groups based on their experiences with childhood adversity, depression, anxiety or substance abuse.

The participants then had their DNA analyzed to study the lengths of their telomeres and any alterations to mitochondrial DNA (mtDNA). Telomere shortening and higher mtDNA content can serve as a yardstick to measure cellular aging.

“Results of the study show childhood adversity and lifetime psychopathology were each associated with shorter telomeres and higher mtDNA content,” read the report.

These effects were seen particularly in adults who had battled with major depression and anxiety disorders, along with parental loss or childhood maltreatment.

“Identifying the changes that occur at a cellular level due to these psychosocial factors allows us to understand the causes of these poor health conditions and possibly the overall aging process,” said Audrey Tyrka, associate professor of psychiatry and human behavior at Brown University.

[Science Daily]

TIME space

Cousins of Earth Found Deep in Space

Don't blink: This has been Kepler's field of vision for most of its time aloft as it has searched for tiny flickers around candidate stars
NASA Don't blink: This has been Kepler's field of vision for most of its time aloft as it has searched for tiny flickers around candidate stars

A flock of planets in their suns' habitable zones boost the odds for extraterrestrial life

When NASA scientists declared the planet-hunting Kepler telescope hopelessly crippled in the fall of 2013, the mission’s founding father and principal investigator Bill Borucki pointed out that its useful life wasn’t necessarily over. For one thing, there was reason to believe Kepler could use some clever engineering tricks to keep finding new worlds—which it has. For another, the probe had collected such mountains of data since its 2009 launch that it would take months or even years to plow through it all. There could well be major discoveries to emerge as the backlog was gradually processed.

Turns out he was right. Speaking at the American Astronomical Society’s winter meeting in Seattle today, astronomers announced the discovery of eight planets orbiting in their stars’ “Goldilocks Zone”—the region where temperatures are just right for water to exist in liquid form, a requirement for life as we know it.

“We’re not claiming they’re inhabited,” emphasizes Guillermo Torres, of the Harvard-Smithsonian Center for Astrophysics, lead author of a paper that describes the newly identified worlds. But astronomers do know that if a planet has significant amounts of water on its surface, and if it has a heat-trapping atmosphere like Earth’s, it’s ticked off two very important items on the biology checklist.

That’s the case, at least, if the planet has a surface—and unlike many of the exoplanets discovered so far, at least four of these worlds almost certainly do: they’re small enough to be rocky like Earth, not mammoth gas blobs like Jupiter or Neptune. One of the planets, known as Kepler 182f, was already described by another group last year, so this is more of a rediscovery. At the time, 182f was by far the Earthiest planet ever found, given its size and likely temperature. But two of the brand-new ones, says co-author David Kipping, also of Harvard, known as Kepler 438 and 442, respectively, are even more tantalizing. Kepler 182f is technically in its star’s habitable zone, but is thought to be quite cold nonetheless, at the outer edge of what is considered a good candidate for life.

Kepler 438, however, is just 10 percent larger than Earth and gets about 40 percent more energy from its star than Earth itself does, while 442, which is 20 percent larger than Earth, gets about 30 percent less. Neither is a perfect match, but both are better than 182f.

The bad news is that like the vast majority of Kepler planets, these new ones are too far away to be examined directly for signs of life, even with the next generation of giant Earth and space-based telescopes currently on the drawing boards. They’re also too distant for their existence even to be confirmed with 100 percent certainty. Kepler does its work by looking for a slight dimming of a parent star as a planet passes in front of it. But since other effects can produce a similar dimming (a background star passing in front of another one, for example), the gold standard for confirmation is to measure the gravitational tug a planet exerts on the star it orbits. If the wobble is there, and if its rhythm matches that of the dimming, it’s a slam dunk.

That can’t be done in this case since Kepler was not designed to analyze wobble, but the astronomers were able to accomplish the next best thing: they used software known as “Blender” to simulate all of the ways a planet candidate might be fooling observers and rule them in or out. In this case, says Kipping, the new finds have “been validated with 99.73 percent confidence as true planets.”

There’s one more thing, aside from their slightly larger size and the somewhat different levels of energy they absorb that keeps these planets from being true twins of Earth: they orbit “orange dwarf” stars that are smaller and dimmer than the Sun. But in some ways, that actually makes them more promising. Back in the days of the first exoplanet discoveries in the 1990’s, nobody was thinking much about anything but planets around Sun-like stars as possible places life might exist.

The discovery that a different species of star can be home to at least a distant cousin of Earth only widens the category of worlds on which biology might have taken hold. At the moment, we are still—as far as we know—alone in the universe. But that’s a moment that could be coming to an end soon.

TIME animals

Newly Discovered Fanged-Frog Gives Birth to Live Tadpoles

A newly discovered frog from the island of Sulawesi in Indonesia is the only known frog to give direct birth to tadpoles.
Jim McGuire—UC Berkeley A newly discovered frog from the island of Sulawesi in Indonesia is the only known frog to give direct birth to tadpoles.

As opposed to eggs, like most frogs

Scientists have discovered a rare frog in Indonesia that gives birth to live tadpoles, researchers report in a journal article published this week.

Herpatologist Jim McGuire found proof this summer that the frog, one of a group of roughly 25 species in Indonesia that have two fangs used for fighting, lays not eggs or even live froglets but live tadpoles. It’s the only frog species in the world to do so.

McGuire found the frogs on the Indonesian island of Sulawesi. He named to the species Limnonectes larvaepartus.

Jim McGuire—UC BerkeleyTwo tadpoles, each about 10 millimeters long, shortly after birth.

[Eureka]

TIME Biology

Smartphone Use Makes Your Brain More Sensitive to Touch

Apple Launches iPhone 5s And 5c In China
Lintao Zhang—Getty A customer inspects the new iPhone at the Wangfujing flagship store on September 20, 2013 in Beijing, China.

New study finds that brain activity is enhanced the more we thumb our devices

Swiping fingers across a smartphone screen can make the brain more sensitive to the touch of the finger tips, a new study suggests.

The study, published in Current Biology this week, shows that brain response to thumb stimulation is partly explained by how often people use their smartphones, reports the Washington Post.

“I was really surprised by the scale of the changes introduced by the use of smartphones,” said Arko Ghosh, one of the study’s authors from the Institute of Neuroinformatics at the University of Zurich.

Researchers recorded brain activity when people touched their thumbs, index and middle fingers to a mechanical object. Smartphone users broadcasted increased activity compared to non-smartphone users, and the activity was boosted the more people used their devices.

[Washington Post]

TIME space

Odds For Life on Mars Tick Up—a Little

High-tide: layering in a Mars rock photographed by Curiosity suggests the movement of long-ago water
NASA/JPL High-tide: layering in a Mars rock photographed by Curiosity suggests the movement of long-ago water

New findings about both methane and water boost the chances for biology

September of 2013 was a bad time for those who hope there’s life on Mars. We’ve had evidence for decades that water flowed freely across the surface of the Red Planet billions of years ago, and that evidence has only gotten stronger and stronger the closer we look. Not only was there potentially life-giving water back then: Mars also had the right kind of geology to support mineral-eating microbes. And while all of that was in the distant past, the detection of methane in the Martian atmosphere by Earth-based telescopes and Mars orbiters raised hopes that bacteria might still be thriving below the surface—not unreasonable, both because all manner of Earthly critters do perfectly well below-ground and because the vast majority of methane in our own atmosphere results from biological activity. Mars’s methane might come from a similar source.

But when the Curiosity rover sniffed the Martian air directly last year, it smelled…nothing. At most, there were just three parts per billion (ppb) of methane wafting around, and possibly much less than that. “We kind of thought we’d closed that chapter,” says Christopher Webster of the Jet Propulsion Laboratory, lead scientist for the instrument that did the sniffing. “A lot of people were very disappointed.”

Not any more, though. Just weeks after that dismal reading, Curiosity’s Tunable Laser Spectrometer (TLS) picked up a whiff of methane at a concentration of 5.5 parts per billion. “It took us by surprise,” says Webster, and over the next two months, he says, “every time we looked there was methane. Indeed, the concentrations even rose, to an average of 7.2 ppb over that period, he and his colleagues report in a new paper in Science.

And then, six weeks later, the methane was gone, and hasn’t been sniffed since. “It’s a fascinating episodic increase,” Webster says.

What he and his colleagues can’t say is where the methane is coming from. Because it’s transient, they think it’s probably from a fairly local source. But whether it’s biological or geological in origin, they don’t know. It’s wise to be cautious, however, says Christopher Chyba, a professor of astrophysics and international affairs at Princeton. “Hopes for biology on Mars have had a way of disappearing once Martian chemistry has been better understood. But figuring out what’s responsible for the methane is clearly a key astrobiological objective—whatever the answer turns out to be.”

That’s not the only important Mars-related paper in Science this week, either. Another, also based on Curiosity observations, concerns Mars’s long-lost surface water, and one of the most important points is that there’s a lot more of it left than most people realize—”enough,” says Jet Propulsion Laboratory scientist Paul Mahaffy, lead author of the paper, “to cover the surface to a depth of 50 meters [about 165 ft].” That doesn’t mean it’s accessible: it’s nearly all locked up in ice at the planet’s poles, but some is also entrained in the clay Curiosity dug into when it was prowling the Yellowknife Bay area of Gale Crater.

Some of that water, says Mahaffy, is tightly chemically bound to the clay and is not a big player in Mars’s modern environment. Some is not quite so locked down and has been interacting with the tenuous Martian atmosphere for the past three billion years. The hydrogen in Martian water, as in Earthly water, may contain both a single proton and a single electron, or a proton and electron plus a neutron—so-called heavy hydrogen, or deuterium. As the Martian atmosphere has thinned over the eons, the ratio of hydrogen to deuterium in the water has gradually been dropping, as the lighter version escapes more easily into space. Since the modern water is twice as rich in deuterium as the water from billions of years ago, that suggests that there was about twice as much surface water in total at the earlier time, but its hydrogen residue has vanished.

“That’s a fair bit of water,” says Mahaffy, “but it’s a lower limit. There could be much more beneath the surface today that we haven’t seen. It was a really interesting time. There were a lot of aqueous processes going on, and a lot of flowing water.”

Where there is (or was) water, there could be (or could have been) life. For Mars enthusiasts, that’s why December of 2014 is a lot better than September of 2013.

TIME animals

There Was a Big Bang for Birds

An ex-crocodile. Clearly a step up
Luis Costa—AFP/Getty Images An ex-crocodile. Clearly a step up

A sweeping new study tells a long genetic tale

If there’s a factory where birds are built, the workers were clearly smoking something the day they designed the hummingbird. And the ostrich. And the toucan. Imagine, too, the pitch meeting for the parrot, (“Let’s make this one talk!”), or the peacock (“So we got this crate of feathers…”).

Of course, that’s not how it really happened. Birds came along without our help, evolving from the Aves class into 23 orders, 142 families, 2,057 genera and finally 9,702 species—the most prolific speciation of all four-limbed vertebrates. The problem with such prodigious divergence is that it makes it hard to determine how the great bird explosion began in the first place. Now, however, in a pair of papers in Science, scientists report that they have an answer. Modern birds, they have learned, got their start like the universe itself—with something of a Big Bang, a burst of specialization that began 65 million years ago with the same asteroid hit that wiped out the dinosaurs and made room for mammals and other land animals.

This finding results from the work of hundreds of scientists at 80 labs and universities across 20 countries, done with the help of bird tissue collected from labs and museums around the world. Those specimens were sent to the Genome Tissue Institute in Beijing, where the basic sequencing was conducted. The first and most basic conclusion the investigators reached was a big one. “This confirms that there was a very rapid radiation and that major lineages of birds were in existence 5 to 6 million years after the extinction event,” says Joel Cracraft, an avian systemicist at the American Museum of Natural History in New York and a contributor to the papers. “They were very widely distributed as well.”

But there was much more to be learned, and that required the hundreds of others scientists to get busy parsing the genomes. A lot of their results live down in the technical weeds, where geneticists speak of such things as total evidence nucleotide trees and GTR+GAMMA models. Among the plain-English findings, however, there were some important top-line results. The investigators identified a sort of progenitor bird, for example, a so-called apex predator that came along shortly after the asteroid hit and was the great-great-great granddaddy of all extant land birds. The descendants that that founding father left can be connected in unexpected ways.

The gaudy flamingo and the proletariat pigeon turn out to belong to sister clades—or groups descending from one common ancestor. Similarly, there is a three-way kinship among the cuckoos; the bustards (medium-size game birds that include the paauw and its larger cousin, the straightforwardly named great paauw); and the turacos. The last group is a brilliantly colored and plumed family of birds that include the African banana eaters and the go-away birds, species that got their names because one of them, well, eats bananas and the other issues a warning call that sounds like it’s saying “go away,” which it sort of is.

Among the more granular discoveries, the investigators report that so-called vocal learners—birds with flexible repertoires of songs and mimicked speech—actually share some of their molecular brain structures with humans. And the very act of singing appears to change the birds’ epigenomes—the regulatory system that sits atop the genes and determines which ones are expressed—meaning that the more frequent the song the more specialized the bird’s genetic wiring will become.

But just in case the big, fun, colorful Aves class gets above itself, the papers do stress that every extant bird can trace its line back even further than the apex predator, all the way to a small and rather vulgar group of ancestors that are actually alive today; the saltwater crocodile, the American alligator and the Indian gharial—which is sort of an alligator with an absurdly skinny snout. For birds as much as for humans, it seems, no matter how high you climb, there are always a few embarrassing family members to keep you humble.

TIME animals

Watch a Slow-Motion Video of a Turkey on a Treadmill

No, it’s not running away from your fork

Animals on treadmills are having a moment today. But where “Munchkin the Teddy Bear” treads that moving belt in the name of cuteness, this turkey trots for science. Thomas Roberts, professor of Ecology and Evolutionary Biology at Brown University, spends his days watching turkeys run on treadmills, as Chris Duffy writes for Digg, to help “scientists understand how to build more efficient robots, to understand neuromuscular disorders, and to design better prosthetics for humans.”

Turkeys, which can reach speeds faster than six miles per hour, work well as research subjects due to their size and anatomy. And if you shoot in black and white and slow down the footage, as Duffy did here, they almost look like something out of an abstract art house film.

Dr. Roberts recently appeared on Duffy’s podcast, You’re the Expert, in which a team of comedians attempts to guess, à la 20 questions, what a professor studies. In addition to Roberts (who, yes, to answer one comedian’s question, studies something that rhymes with “smiology”), the show has featured academics who study sand, fish noises and canine cognition.

Now, for the million-dollar question: Does Roberts eat turkey on Thanksgiving? He does. “I just don’t think about it,” he admits.

Listen to the full episode below:

TIME Biology

See 40 Mind-Blowing Images Captured Through a Microscope

In stunning detail not visible to the human eye, the winning entrants in Nikon's Small World photography competition will give you a fresh view of the world

TIME animals

See the Most Amazing Biology Photos of the Year

The Society of Biology, a British group dedicated to the life sciences, holds an annual amateur photography competition. The theme this year was home, habitat and shelter

TIME animals

Meet the Lumbering, Quarter-Ton, Extinct Kangaroo

Don't call me Joey: Not a kangaroo—but not not one either.
Nobu Tamura—Wikimedia Commons Don't call me Joey: Not a kangaroo—but not not one either.

Sometimes the most fascinating animals are the ones that are no longer with us. The oddly named sthenurine is no exception.

Birds gotta fly, fish gotta swim, kangaroos gotta hop—unless you’re talking about the eight-foot-tall, quarter-ton, kangaroos known as sthenurines (and no, that is not a typo). These distant cousins of modern red and gray kangaroos went extinct about 30,000 years ago, and their fossils weren’t discovered until the 1800s. When the species at last came to light, it was not easy to take seriously, resembling nothing so much as cartoon versions of its modern cousins. “They were short faced,” says Brown University biologist Christine Janis, “not long-faced like modern kangaroos, and the smallest of them were as big as the largest modern kangaroos. It wasn’t clear,” she adds, “how they could hop at that size.”

And according to a new paper Janis just published in the journal PLoS ONE, they probably couldn’t. Instead, she and two co-authors conclude after several years of investigation involving more than 140 skeletons from kangaroos and related species such as wallabees, the sthenurines walked upright on two legs.

The evidence comes from virtually everywhere across the creatures’ anatomy. Their teeth, the scientists observe, look more suited to browsing on trees and bushes than nibbling on grass as modern ‘roos do. That implies the ability to stand upright on two legs to reach the branches.

“They also had flared hipbones,” says Janis, with ample room for large gluteal muscles that would have permitted them to put weight on one leg at a time, something today’s kangaroos never do. Modern kangaroos amble around on all fours—or fives, if you count the tail, which they use for balance—when they’re browsing. When they want to go fast, they hop.

That’s possible only because they have flexible backs and stiff, substantial tails, which sthenurines lacked. The sthenurine hands, moreover, were unsuitable for bearing their weight. “They would have had trouble walking on all fours,” says Janis. The animals’ very bulk would have put terrible strains on their tendons if they even tried to hop.

“Some have argued that the sthenurines might have had thicker tendons to compensate,” Janis says, “but that would have made the tendons less elastic. It just seems biomechanically unlikely.” Any arguments about tendons and other soft tissues are somewhat speculative in ancient specimens, of course. “Imagine that we only knew elephants as fossils,” says Janis. “How would we know for sure they had trunks?”

The other evidence all points in one direction, however. As Janis straightforwardly puts, “just about everything we looked at made us go, ‘oh, that fits in.'” In the often elegant study of anatomy, the answer that fits is usually the answer that’s right.

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