Page 1

COLOPHON

EDITORIAL DESIGN DIRECTOR CARLOS MENDES GUERREIRO

SCIENTIFIC COUNCIL NADIA DRAKE

PAUL VOOSEN

DELANEY CHAMBERS

ELIZABETH PENNISI

ELAINA ZACHOS

MICHAEL ALLEN

JESSICA SCARFUTO

KATHERINE KORNEI

JASON BITTEL

MATT WILLIAMS

MITCH LESLIE

MARK GRIFFIRTHS

RONI DENGLER

LUCAS JOEL

ANDREA STONE

ANGUS CHEN

JASMIN FOX-SKELLY SARAH GIBBENS MINDY WEISBERGER DANIEL STONE DAVE MOSHER HIDEKI KATO MATT WARREN ROBERT F. SERVICE JOHN PICKRELL JOCELYN KAISER VIRGINIA MORELL SID PERKINS EMILY UNDERWOOD GRETCHEN VOGEL

PRINTING POKOPY LDA.


CONTENT

FLOATING MOUNTAINS ON PLUTO . 01

CAN IMMUNE CELLS OFFER NEW WAYS TO COMBAT HYPERTENSION . 11

SPINACH LEAF TRANSFORMED INTO HUMAN HEART TISSUE . 04

FLOODING HAS FLUSHED 43 BILLION PLASTIC PIECES TO SEA . 14

THE LEGACY THAT WILL LIVE ON FOR CENTURIES 15

THE ANIMALS THAT ARE ALMOST INVISIBLE 19

CHAMELEON BONES GLOW IN DARK, EVEN THROUGH SKIN . 05 THEY ACTUALLY SAY MARTIANS ARE WELCOME . 07

WHAT TO KNOW ABOUT THE GERMS IN YOUR HOME . 23 WHY YOUR BEST FRIENDS FEASTS ON SOME FECES . 25 FIVE THINGS TO RESTORE THE PLANET EARTH . 27 SLOTHS ARE SLOW, BUT THEY ARE NOT STUPID . 08

JUPITER’S GREAT RED SPOT MAY HAVE ONLY TEN TO TWENTY YEARS LEFT . 29


CONTENT

SCIENTISTS INVENT NEW FLOATING ‘FIREFLY’ LIGHT . 31

NEW ARTIFICIAL NERVES COULD TRANSFORM PROSTHETICS . 57

CAN THIS ROBOT BUILD AN IKEA CHAIR FASTER THAN YOU? . 32

COULD BRAIN STIMULATION HELP ZAP DIABETES . 60

LOW LIGHT SOLAR CELLS COULD CHARGE DEVICES INDOORS . 35

IT TURNS OUT ANDROMEDA IS YOUNGER THAN EARTH . 61 ICHTHYOSAUR MAY BE THE LARGEST THAT EVER LIVED . 38

THESE BATS USE STEALTH SONAR . 63

BLOOD TESTS SHOWS PROMISE FOR SPOTTING EARLY CANCERS . 39

THESE 59 GENES MAY MAKE YOUR DOG MORE ATHLETIC . 65 IS SWIMMING WITH DOLPHINS A GOOD IDEA? . 41

CANADIAN ICE CAP CONCEALS SUPERSALTY LAKES . 67

TOURISM IS WORSE FOR THE PLANET THAN WHAT WE THOUGHT . 44

SMILE! YOUR DOG’S BRAIN WILL LIGHT UP IN RESPONSE . 68

GETTING OLD GIVES YOU ITCHY SKIN . 45

PLAYING VIDEO GAMES IS GOOD FOR YOUR BRAIN . 69

FOSSILS REVEAL HOW ANCIENT BIRDS GOT THEIR BEAKS . 46

ANCIENT EARTH FROZE OVER IN A GEOLOGIC INSTANT . 71

WHO HAS THE CLEANER BED: CHIMPS OR US HUMANS? . 48

BEES ACTUALLY UNDERSTAND THE CONCEPT OF “ZERO” . 74 SEA MAMMALS ARE HUGE FOR A REASON . 75 CAN ADULTS REALLY MAKE NEW NEURONS . 77

EUROPA IS VENTING WATER INTO OUTER SPACE . 49 BIRD TREE OF LIFE WILL SOON FLY INTO VIEW . 50 SALTWATER TROUTS THAT EVOLVED TO LIVE IN FRESHWATER . 53 STICK INSECTS TRAVEL LONG DISTANCES . 54

JUPITER’S STORMS HAVE ROOTS BENEATH ITS SURFACE . 78

LIFE REBOUNDED JUST YEARS AFTER THE DINO-KILLING ASTEROID . 55

THE EARLIEST EVIDENCE OF BUTTERFLIES POSES A MYSTERY . 80


FLOATING MOUNTAINS ON PLUTO

FLOATING MOUNTAINS ON PLUTO

ICE VOLCANOES

FLOATING MOUNTAINS

Two pits near Pluto’s south pole could

Pluto’s mountains may be more like

be icy volcanic calderas. The pits are

icebergs in the ocean than mountains

located at the summits of two enor-

on Earth. Made of water ice, these big

mous mountains, Wright Mons and

blocks of material are probably floa-

Piccard Mons. Each mountain is a

ting on a “sea” of nitrogen ice, Mo-

couple of miles tall and at least 60 mi-

ore revealed. In some regions, these

les wide, similar in size and shape to

mountains are as large as the Rockies

or such a small world, Pluto has an in-

Hawaiian shield volcanoes. But instead

but are still buoyant enough to rise

credible diversity of features, including

of fiery lava, Pluto’s volcanoes would

high above denser nitrogen and car-

flowing glaciers, curiously pitted ter-

spew ices, perhaps nitrogen, carbon

bon monoxide ices. “Even the largest

rains, hazy skies, and multi-colored landsca-

monoxide, or a watery slurry dredged

mountains of Pluto could simply be

pes. Now scientists from the New Horizons

from a buried ocean. Jeff Moore of

floating,” Moore said during his pre-

mission have revealed that the distant dwa-

NASA’s Ames Research Center said du-

sentation. Near the western edge of

rf planet is even weirder than they thought,

ring a conference presentation that the

the ice field known as Sputnik Planum,

with potential ice volcanoes, floating mou-

team is not yet ready to conclude the-

giant sheets of water ice can be frac-

ntains, and misbehaving moons. Scientists

se features are indeed volcanoes, “but

tured and rearranged, producing what

presented this new set of observations from

they look very suspicious.” If they’re

Moore refers to as “anarchic terrain.”

the New Horizons spacecraft, which flew

real, they would be the first volcanoes

Jumbled chains of angular blocks,

past Pluto in July, on Monday at the Division

spotted in the outer solar system. And

some as much as 25 miles across and 3

for Planetary Sciences annual meeting, and

though the team plans to confirm the

miles high, form mountains that stretch

the data are showing that Pluto is not what

discoveries with additional data, some

chaotically near the otherwise smooth,

anyone expected.

members are already pretty convinced.

young plain. New analyses suggest

by NADIA DRAKE

F

that Sputnik Planum could be just 10

NEW DATA REVEAL FIVE SEEMINGLY IMPOSSIBLE THINGS ABOUT THE DWARF PLANET 01

“When you see a big mountain with a

million years old. It was basically “born

hole in the top, it generally points to

yesterday,” Stern said. “It’s a huge

one thing,” said Oliver White, also from

finding, that small planets can be

NASA Ames. “I’m having difficulty un-

active, on a massive scale, billions

seeing these volcanoes.”

of years after their formation.”


FLOATING MOUNTAINS ON PLUTO

Pluto’s four small moons have finally been revealed, and Nix, Styx, Kerberos, and Hydra are, like most things about this system, weirder than scientists had guessed. Kerberos and Hydra look as though they’re made of two smaller objects that slowly collided and stuck together, similar to the duck-shaped comet that the Rosetta spacecraft is now orbiting. “At some point in the past, there were more than just the four [small] moons of Pluto—there were at least six,” Mark Showalter of the SETI Institute, said at a press conference. Adding to the weirdness are the rapid rotation rates of the small moons. Hydra wins the race, spinning around itself once every 10 hours, but all the moons are pirouetting more quickly than expected. “We simply have not seen a satellite system that does this,” Showalter said. Plus, Nix has an odd, reddish crater on one face that scientists can’t fully explain yet. And Kerberos, which scientists guessed would be the dark sheep of the bunch, is actually just as bright as its three small siblings.


SPINACH LEAF TRANSFORMED INTO HUMAN HEART TISSUE

SPINACH LEAF TRANSFORMED INTO HUMAN HEART TISSUE by DELANEY CHAMBERS

S

cientists have found a way to use

“Without that vascular network, you

spinach to build working human

get a lot of tissue death.” One of the

heart muscle, potentially solving a

defining traits of a leaf is the branching

long-standing problem in efforts to repair

network of thin veins that delivers water

damaged organs. Their study, published

and nutrients to its cells. Now, scientists

this month by the journal Biomaterials, of-

have used plant veins to replicate the way

fers a new way to grow a vascular system,

blood moves through human tissue. The

which has been a roadblock for tissue en-

work involves modifying a spinach leaf in

gineering. Scientists have already created

the lab to remove its plant cells, which le-

large-scale human tissue in a lab using

aves behind a frame made of cellulose.

methods like 3D printing, but it’s been much harder to grow the small, delicate

“We have a lot more work to do, but

blood vessels that are vital to tissue heal-

so far this is very promising,” study co-

th. “The main limiting factor for tissue

-author Glenn Gaudette, also of WPI, says

engineering… is the lack of a vascular

in a press statement. “Adapting abun-

network,” says study co-author Joshua

dant plants that farmers have been

Gershlak, a graduate student at Worces-

cultivating for thousands of years for

ter Polytechnic Institute (WPI) in Massa-

use in tissue engineering could solve

chusetts, in a video describing the study.

a host of problems limiting the field.”

04


CHAMELEON BONES GLOW IN DARK, EVEN THROUGH SKIN

CHAMELEON BONES GLOW IN DARK, EVEN THROUGH SKIN by ELAINA ZACHOS

A

new study published this week

“We could hardly believe our eyes

in the journal Scientific Reports

when we illuminated the chame-

revealed just that. It’s the first

leons in our collection with a UV

time researchers have reported bone-

lamp,” lead author David Prötzel, a

-based fluorescence in vertebrates. The

doctoral student at the Bavarian State

proteins, pigments, and other materials

Collection of Zoology, says in a state-

that make up bones help them to glow

ment. “And almost all species showed

under ultraviolet light—just think of

blue, previously invisible patterns on

how your florescent smile lights up un-

the head, some even over the who-

der a black light. We’ve known that 75

le body.” The scientists said the gaps

percent of deep-sea creatures can glow

where the tubercles peaked through

in the dark, so this light-emitting cha-

the skin were “windows” that helped UV

racteristic is common in marine species.

rays reach the bone and get absorbed.

But biogenic fluorescence is rare in ter-

Blue is a rare color in the lizards’ fo-

restrial vertebrates. Only in March was

rested habitats, so glowing in the dark

the first fluorescent frog discovered in

would make them stand out from their

the Amazon. On January 15, a team of

green and brown backdrop.

German researchers published a paper showing that the bones of chameleons glow under UV light. They tested the light rays on 160 specimens that spanned 31 species of Calumma chameleons, which are endemic to Madagascar. Micro-CT scans revealed that a bright blue glow emanated from the lizards’ skele-

A NEW STUDY REVEALS THAT THE COLOR CHANGERS CAN ALSO GLOW UNDER ULTRAVIOLET LIGHT 05

tons and shined through their skin.


CHAMELEON BONES GLOW IN DARK, EVEN THROUGH SKIN

SHADE SHIFTERS Chameleons can change color depending on a lot of factors. A shift in mood, perhaps triggered by fear or anger, can cause them to shift shades, as well as varying

temperature,

humidity,

and

amounts of light. Males will sometimes make themselves brighter in order to attract females and establish dominance; more submissive shades are brown and gray. A change in color can also show if females are accepting or rejecting male partners, or it can indicate pregnancy. But chameleons can’t change to any color they want, and they can’t exactly mimic their environment. A lizard on a striped or polka dotted background won’t be able to adopt that funky pattern. Instead, species have a certain array of patterns and colors they can take on. Nerve impulses and hormone shifts can cause their skin to expand or shrink and blend different layers for different colors and patterns.


THEY ACTUALLY SAY MARTIANS ARE WELCOME

THEY ACTUALLY SAY MARTIANS ARE WELCOME by JESSICA SCARFUTO

D

T

espite the depiction of evil aliens

Using software that scanned the articles,

bent on world domination often

the team found that there were three

portrayed in movies, most peo-

times as many words indicating positive

ple don’t fear extraterrestrials—at least if

emotions (such as happy, excited, and

they’re microbes--according to three new

cool) than negative emotions. In the se-

studies presented here yesterday at the

cond study, the group asked more than

successfully created life in a lab. Partici-

annual meeting of American Association

500 participants write about their hypo-

pants used 10 times more positive words

of the Advancement of Science (AAAS),

thetical reactions, and the hypothetical

than negative words in response to the

which publishes Science. The study looked

reaction of humanity, to the announce-

news about alien life, and that the res-

at 15 articles from three news events across

ment that microbial extraterrestrial life

ponses were overall more enthusiastic

21 years: the 1996 discovery of possib-

had been discovered. Reactions were

than those given by the participants

le fossilized microbes on Mars, the 2015

overwhelmingly positive, with most par-

who read the article about human made

discovery of periodic dimming around Ta-

ticipants having 5 times as many positive

synthetic life. The study did not look at

bby’s Star (which was said to indicate the

words as negative in their prompts. In

whether people would feel differently

presence of an alien megastructure), and

the final study, Varnum’s group gathered

if actual beings were discovered rather

the 2017 discovery of Earth-like exoplanets

the reactions of over 500 different parti-

than microbes, so those reactions might

in the habitable zone of a star.

cipants to newspaper articles.

be quite different.

07

hey gave one group a New York Times article describing evidence of ancient microbial life on Mars,

and the other group read a New York Times article that claimed scientists had


SLOTHS ARE SLOW, BUT THEY ARE NOT STUPID

E

verybody knows that sloths are

cies of sloth have evolved long claws

slow. It’s true the tropical tree

that act like hooks and tendons that

dwellers possess the lowest me-

draw their digits closed when at rest.

tabolic rates of any non-hibernating

Sloths also have a network of blood

mammals. But when it comes to their

vessels running through their forearms

biology, the Central and South American

to keep their muscles cool and reduce

critters are anything but boring. For ins-

energy usage. Sloths are also shockin-

SLOTHS ARE SLOW, BUT THEY ARE NOT STUPID

tance, sloths are actually three times fas-

gly strong, even though their muscle

ter in water than they are on land, says

mass is 30 percent less than that of

by JASON BITTEL

Becky Cliffe, a zoologist and founder of

similarly sized animals. That’s because

the Costa Rica-based Sloth Conservation

their muscles are composed of slow-

Foundation. What’s more, they float.

-twitch fibers that provide loads of endurance while not using a lot of ener-

“Thirty percent of their body weight is

gy. One thing these muscles cannot do

just digesting, fermenting leaves,” says

is shiver, so sloths bask in sunlight to

Cliffe. “So they’ve quite a lot of gas in

raise their body temperatures—sort

there as well. They’re like big balls of

of like a reptile. Even their digestion is

air with arms and legs.” Sloth immobili-

sluggish—Cliffe says it can take up to

ty is just one of the many misconceptions

30 days to process a single leaf. Sadly,

Cliffe hopes to dispel with her new book,

their slowness has earned sloths a bum

Sloths: Life In The Slow Lane.

rap for being stupid. Some people say if “you fire a gun next to a sloth’s

“I really wanted to paint a picture of

head, it won’t even turn around,”

an animal that is actually perfectly

says Cliffe. In fact, sloths benefit by

adapted for survival,” she says. How

slowly reacting to danger. The tropical

long do you think you could hang upsi-

tree dweller evolved alongside the har-

de down in a tree? A minute? Ten? Slo-

py eagle, a bird of prey that can detect

ths do it all day, every day. The six spe-

even the tiniest of movements.

A NEW BOOK CHALLENGES MISCONCEPTIONS ABOUT THE CENTRAL AND SOUTH AMERICAN TREE DWELLERS 08


CAN IMMUNE CELLS OFFER NEW WAYS TO COMBAT HYPERTENSION?

SPHYGMOMANOMETER | AN INSTRUMENT FOR MEASURING BLOOD PRESSURE, TYPICALLY CONSISTING OF AN INFLATABLE RUBBER CUFF WHICH IS APPLIED TO THE ARM

CAN IMMUNE CELLS OFFER NEW WAYS TO COMBAT HYPERTENSION

“The immune system is an unexpected

These factors, which can include a high-

but important player in hypertension,”

-salt diet, stress, and a naturally overactive

says vascular biologist Tomasz Guzik of

sympathetic branch of the nervous system,

the University of Glasgow in the United

spur an initial increase in blood pressure

Kingdom. Scientists now suspect that

that damages blood vessels. Immune cells

immune cells collude with long-recogni-

detect that damage, and their response

zed culprits such as stress and dietary salt

sparks “a vicious circle that leads to

to drive up blood pressure. Safety tests of

the progressive elevation of blood

2-HOBA in people are already underway,

pressure,” Schiffrin says. Among other

and Harrison, who holds a patent on its

effects, immune cells disrupt the func-

t’s fairly easy to give mice hypertension.

use for hypertension, hopes to launch

tion of the endothelial layer, the lining of

Just regularly dose them with the hormo-

a full clinical trial, which might lead to a

the blood vessels, counteracting “all the

ne angiotensin II. But mixing a molecule

new class of treatments that work by res-

good things that the endothelial cells

called 2-HOBA into the animals’ drinking

training the immune system. More than 1

produce,” says physiologist Brett Mitchell

water returns their blood pressure almost to

billion people worldwide have high blood

of Texas A&M College of Medicine in

normal, vascular biologist David Harrison of

pressure, which promotes heart attacks,

College Station. For example, those cells

the Vanderbilt University School of Medici-

strokes, kidney damage, dementia, and

normally emit nitric oxide, which relaxes

ne in Nashville and colleagues have found.

other ailments. Current drugs include

blood vessels and reduces blood pressu-

Now, that observation could open an inno-

diuretics that reduce the amount of water

re—and immune cells inhibit nitric oxide

vative approach to treating hypertension in

in the body and blockers that decrease

production. The cells also wreak havoc in

people. Derived from buckwheat, 2-HOBA

how much blood the heart pumps. Yet

the kidneys, stimulating the organs to hold

stands out because of the way it seems to

about 15% to 20% of patients don’t im-

on to more sodium, which in turn spurs the

work—by influencing immune cells.

prove. “Clearly, we are not managing

body to retain more water. Scientists first

the condition appropriately at the

suggested that the immune system mo-

moment,” says vascular biologist Grant

difies blood pressure more than 50 years

Drummond of La Trobe University in Mel-

ago. But a 2007 study by Harrison, Guzik,

bourne, Australia.

and colleagues was a watershed.

I

by MITCH LESLIE

ACTIVATED IMMUNE CELLS MAY CONTRIBUTE TO HIGH BLOOD PRESSURE AND OFFER A TARGET FOR TREATMENT 11


CAN IMMUNE CELLS OFFER NEW WAYS TO COMBAT HYPERTENSION?

“The question of the decade,” Harrison says, has been what switches on the immune cells. His team thinks it has isolated one signal: oxidized lipids known as isoketals that form inside blood cells. In 2014, he and his colleagues discovered that these molecules are unusually abundant in certain immune cells of mice with high blood pressure—and that the same is true in patients with hypertension. Isoketals adhere to and damage proteins, and Harrison’s group found that the resulting injured proteins stimulate immune cells known as dendritic cells, which in turn activate T cells. It’s “a pretty good case,” says nephrologist Richard Johnson of the University of Colorado Anschutz Medical Campus in Aurora. Harrison’s potential blood pressure treatment, 2-HOBA, thwarts isoketals by muzzling their reactive ends. That probably won’t impair our defenses against pathogens. But researchers are divided over whether to test the more powerful immune-suppressing drugs that patients take for illnesses such as psoriasis, Crohn disease, and rheumatoid arthritis. Schiffrin argues that these drugs are too risky to use in hypertension, which people can live with for decades.


FLOODING HAS FLUSHED 43 BILLION PLASTIC PIECES TO SEA


FLOODING HAS FLUSHED 43 BILLION PLASTIC PIECES TO SEA

T

he Mersey River Basin near Man-

When researchers examined the den-

chester, U.K., is the most plastic

sity of plastic pieces in the riverbeds,

polluted watershed in the world,

they found more than a third of the

with more than half a million plastic par-

microplastics in the basins, or 17 billion

ticles per square meter of riverbed. That’s

particles, can float in seawater. The re-

one of the most dramatic findings of the

searchers estimate this single flooding

first global map of aquatic plastic pollu-

event contributes 0.5% to the total

FLOODING HAS FLUSHED 43 BILLION PLASTIC PIECES TO SEA

tion, published today in Nature Geoscien-

floating plastic in the world’s oceans.

ce. When large storms flood rivers, the

That means the amount of plastic in

by RONI DENGLER

plastic collected there washes out to sea.

the world’s oceans is greater than pre-

That means rivers are a significant source

viously imagined, the researchers say.

of plastic polluting the world’s oceans, the

But management strategies like those

study reveals. To find out how plastic goes

recently passed in the United States

from land to sea, researchers counted

and the United Kingdom that curb use

plastic particles known as microplastics—

of plastic microbeads—rounded plastic

tiny to microscopic bits of plastic made

particles found in exfoliating facial wa-

when sunlight breaks down large pieces

shes—could alleviate plastic pollution

of plastic—in the sediment of 10 rivers

in rivers, the team says.

across 40 sites in the Mersey and Irwell river basins in urban, suburban, and rural northwest England before and after the 2015 Boxing Day Flood—the largest flooding event on record in the region. The flood, which removed all traces of plastic debris at seven of the sites, washed 70% of the plastic—that’s 43 billion particles or about 0.85 metric tons—of plastic out to sea, the scientists found.

14


STEPHEN

HAWKING 1942 - 2018


THE LEGACY THAT WILL LIVE ON FOR CENTURIES

THE LEGACY THAT WILL LIVE ON FOR CENTURIES by ANDREA STONE

16


THE LEGACY THAT WILL LIVE ON FOR CENTURIES

EARLY YEARS Stephen Hawking, the British theoretical phy-

He became “arguably the most famous

Stephen William Hawking was born in Oxford,

sicist who found a link between gravity and

scientist in the world,” Rees said, “acclai-

England, on January 8, 1942, a date that he

quantum theory, and who declared that black

med for his brilliant research, for his best-

often noted was exactly 300 years after the

holes aren’t really black at all, has died, a spokes-

-selling books [about space, time, and the

death of Galileo. The first of four children of

person for the family told the Guardian and the

cosmos], and, above all, for his astonishing

Oxford University graduates Isobel and Frank

Associated Press. “He was a great scientist

triumph over adversity.” Hawking’s scientific

Hawking, he grew up in a prodigiously intel-

and an extraordinary man whose work

claim to fame was his revelation that the uni-

lectual family that read books at the dinner

and legacy will live on for many years,”

verse began in a singularity, an infinitely dense

table and that he later described as “slightly

Hawking’s children Lucy, Robert, and Tim said

point of space-time. Working with mathema-

eccentric.” His father, a noted researcher on

in a statement. “His courage and persisten-

tical physicist Roger Penrose, he would show

tropical diseases, wanted his son to go into

ce with his brilliance and humor inspired

that Einstein’s General Theory of Relativity “im-

medicine; young Hawking was drawn to the

people across the world. “He once said: ‘It

plied space and time would have a begin-

stars. Hawking attended St. Alban’s School

would not be much of a universe if it wasn’t

ning in the big bang and an end in black

and Oxford, where he studied cosmology

home to the people you love.’ We will miss

holes,” according to Hawking’s website, and

and fought off boredom before graduating

him for ever.” Hawking was 76 years old, more

that “the way the universe began was com-

with honors. He went on to Cambridge for his

than 50 years older than the age doctors told

pletely determined by the laws of science.”

doctorate, earning it in 1966, three years after

him he could expect to reach after being diag-

In the early 1970s, he was the first to show that

receiving the devastating diagnosis of ALS at

nosed in 1963 with amyotrophic lateral sclerosis

radiation escapes from black holes and that

age 21 and being given two and a half years

(ALS), also called Lou Gehrig’s disease. “Few, if

the holes aren’t completely black. His theory

to live.The scientist would credit his relationship

any, have done more to deepen our know-

explaining what came to be called Hawking

with Jane Wilde, whom he met shortly before

ledge of gravity, space, and time,” said British

radiation made him a scientific superstar. It

his diagnosis, with giving him a reason to live.

astrophysicist Martin Rees. In a reminiscence to

was, said Declan Fahy, an American University

The couple married in 1965 and had three chil-

mark the occasion of his Cambridge University

communications professor who studies scien-

dren, who survive him. But the strain of being

colleague’s improbable 70th birthday, he recal-

tists as celebrities and public intellectuals, “a

her husband’s caregiver even as he became a

led a young man who was unsteady on his feet

signature contribution to cosmology [just]

worldwide phenomenon took a toll, and they

and spoke with great difficulty. No one expec-

as the field became the most exciting pla-

divorced after 25 years of marriage. Hawking

ted him to live long enough to earn his Ph.D.

ce in physics.” Years later, Hawking would say

soon married one of his nurses, Elaine Mason.

Although his degenerative disease progressi-

that black holes do not have “event horizons,”

That marriage, tainted by allegations (later

vely crippled him and robbed him of speech,

or points of no return, and that one of space’s

dismissed by police) that his second wife was

Hawking did more than survive.

most mysterious objects may need rethinking.

abusive, also ended in divorce.


THE LEGACY THAT WILL LIVE ON FOR CENTURIES

LATER CELEBRITY Hawking became an international celebrity

“But I think the work would not have

in 1988 when his book, A Brief History of

raised him as high in the pantheon if

Time, was published. A layman’s guide to

he’d done it as someone who could

the universe that explains complex mathe-

go out skiing every weekend.” Hawking

matics and concepts in terms non-scien-

himself acknowledged that he “fit the ste-

tists can understand, it sold more than ten

reotype of a disabled genius,” though he

million copies and made him a household

never let his wheelchair slow him down. He

name. In the years that followed, Steven

traveled the world giving lectures, always

Spielberg produced the film version while its

accompanied by a retinue of caregivers. At

author appeared in a string of films and TV

Cambridge, he held the Lucasian Professor-

shows, including a six-part series, Stephen

ship of Mathematics, Isaac Newton’s former

Hawking’s Universe. He played a hologram

chair, and was director of research at the

of himself on Star Trek: The Next Generation

university’s Center for Theoretical Cosmo-

and an animated character in the Simpsons.

logy. In later years, Hawking completely lost

Hawking’s franchise wasn’t based solely on

his ability to speak after a bout of pneumo-

his work, though he’d already been elected

nia necessitated a tracheotomy. Commu-

at age 32 to Britain’s prestigious Royal Socie-

nicating took longer and longer. Toward

ty. “Because of his physical appearance,”

the end, he could form just one word per

Fahy said, “he became a symbol of pure

minute using a speech-generating device

intellect, an image journalists recycled

controlled by his right cheek muscle. Fears

over and over again. That image con-

that Hawking’s brilliance would soon be

nected with people around the world.” It

“locked in” his body prompted efforts to

also dismayed many of Hawking’s fellow

find ways to preserve his ability to express

physicists, who considered comparisons

himself. Before his final decline, Hawking

to Einstein to be “over the top.” He was

wrote on his website about the voice syn-

“a symbol of the overcoming of great

thesizer that kept him connected to the

difficulty, and that, obviously, you have

world. “It is the best I have heard,” he

to admire,” said Virginia Trimble, an astro-

wrote, “although it gives me an accent

nomer at the University of California, Irvine,

that has been described variously as

who was a fellow student at Cambridge.

Scandinavian, American or Scottish.”


THE ANIMALS THAT ARE ALMOST INVISIBLE by JASMIN FOX-SKELLY

W

e’ve all heard of squid and octopus

using

pigments

to blend in with their sur-

roundings, but what about becoming completely invisible? To become actually see through, and appear as if you aren’t there, you need to either allow light to travel through you unimpeded, or bend light around you - so that none reflects back at an observer. It’s a tricky task, but some animals are almost there.

I T’S A TRICKY TASK, BUT SOME ANIMALS ARE ALMOST THERE. 19


07


THE ANIMALS THAT ARE ALMOST INVISIBLE

GLASS OCTOPUS

CRANCHIIDAE OR GLASS SQUID

TOMOPTERIS DEEP SEA WORM

In the ocean animals have two choices if

The glass family of squid, of which there

This genus, or group of marine plank-

they want to hide. Creatures that live in the

are about 60 species, are almost entirely

tonic polychaete worms are almost

deep ocean close to the seafloor can blend

see through. They live, again in the pe-

completely transparent, making them

in with sand or rocks, or hide in coral. In the

lagic region of oceans around the world,

ver y difficult for predators to see. Pa-

deep ocean it is often pitch black anyway

between 200 and 1000m below sea level.

radoxically at least 11 species in the

and predators lack eyes, so being invisible is

Although their bodies are entirely trans-

group can also emit bright luminous

not necessary. Animals that live close to the

parent, their large eyes are opaque, whi-

colours. Most tomopteris worms glow

surface and want to hide can produce daz-

ch is a problem as predators swimming

blue, but one species, Tomopteris

zling displays of light in a process known as

below can easily see the shadow they

nisseni can produce yellow light and

bioluminescence, confusing predators be-

cast. However the glass squid (Cranchii-

is one of only few such creatures on

low who think they are looking at dappled

dae) uses a clever form of camouflage

the planet to do so. Some tomopteris

sunshine hitting the water’s surface. Animals

to hide them. It uses photophores - or-

worms can even distract predators by

that live in midwater though have neither

gans beneath its eyes - to produce light

releasing a glowing part of their body

of these options. This region is known as

in a trick called counter-illumination. This

called a parapodia, making the preda-

the pelagic zone, and it also happens to be

light looks very similar to the sunlight

tor chase after the dispelled body part

where most invisible animals live. Perhaps

filtering down from above, so it makes

rather than the worm itself.

the easiest way of becoming invisible is by

the squid completely invisible to preda-

being transparent and letting light travel

tors swimming below it. However the

completely through you. In open oceans,

light could make the squid very conspi-

which lack structures to hide behind, being

cuous to viewers looking at it from other

transparent is a great way of hiding from all

angles. Rather than an invisibility cloak,

viewpoints and angles. It’s so popular in fact

the glowing light could act like a beacon

that transparency has independently evol-

drawing predators to it. Researchers from

ved multiple times in completely unrelated

the University of Pennsylvania found that

animals. One such animal, the glass octopus

the squid’s photophores are amazingly

(Vitreledonella richardi) is so named becau-

able to match the amount of light they

se it is almost completely transparent. The

produce to that coming in from every di-

gelatinous creature can grow up to 45cm

rection, creating a sort of omnidirectional

(18in), if you include the tentacles.

invisibility cloak.


THE ANIMALS THAT ARE ALMOST INVISIBLE

SEA SALP

HYPERIIDS

SEA SAPPHIRES

A salp is a completely transparent barrel

Sometimes being transparent isn’t enough, and

Sea Sapphires (Sapphirina) are ant size

shaped creature which swims and feeds

organisms need other tricks up their sleeve to

creatures that live in warm tropical and

at the same time by pumping water

remain invisible. This is certainly the case for the

subtropical seas. They belong to a group

through its gelatinous body. They filter

Hyperiid, a little crustacean bearing a resem-

of crustaceans called copepods. Different

out the phytoplankton in the water to

blance to a shrimp. They are able to hide from

species emit a range of brilliant iridescent

feed on. Although they look a bit like

predators by being transparent. However that

colours, from vivid blues to reds and gol-

jellyfish they are actually more sophis-

only gets them so far. A plane of glass is also

ds. What is remarkable about them is that

ticated and are closely related to fish

transparent but you can still see it if you shine

one second they can shimmer brightly

and vertebrates - they have a heart and

a light on it, as the light is reflected back. This

and the next they appear almost to disa-

gills and can reproduce sexually. Salps

is a particular problem in the ocean because

ppear and the way they do this is fascina-

have a fascinating life cycle. For part

many predators use bioluminescence as a se-

ting. Their skin, or cuticle cells contain tiny

of it they live by themselves, but they

archlight when hunting for prey. A recent study

crystal plates arranged in a hexagonal

then clone themselves and form long

suggests there is more to the hyperiid’s ability to

honeycomb pattern. The crystals contain

strings and other shapes of connected

hide than simple transparency. It turns out they

guanine, one of the four bases that make

organisms. Individual salps synchroni-

are using a kind of nanotechnology to interfere

up DNA. The crystal layers are separated

se their swimming by communicating

with and bend light, cloaking themselves and

from each other by a soup-like fluid cal-

with one another via electrical signals.

almost rendering them invisible. The scientists

led a cytosol. A team of scientists found

found that the legs of one species were cove-

that the although the layers of guanine

red in tiny nano sized hair-like protuberances.

crystals are always exactly the same thi-

The body of this species, and six others were

ckness – 70 nanometers, the thickness

also covered in nano sized bumps or spheres

of the cytosol between the layers varies

ranging in size from under 100 nanometers to

from 50 to 200 nanometers. It is this va-

around 300 nanometers. The tiny size of the

riety which determines the colour of the

bumps could minimise light scattering and the

sea sapphire. Thicker layers of cytosol

scientists found that a combination of both na-

lead to longer wavelengths of light being

nostructures - the bumps and the hairs could

reflected, which make the copepod look

reduce reflectance by as much as 100 fold. The

red or magenta.

weird thing is that the researchers think these spheres could actually be bacteria.


WHAT TO KNOW ABOUT THE GERMS IN YOUR HOME

WHAT TO KNOW ABOUT THE GERMS IN YOUR HOME by SARAH GIBBENS

P

hilip Tierno is describing your

surface can create what’s called a biofilm,

to hundreds of different kinds of germs,

a slimy film of microorganisms. In a stu-

and everyday they slough off. The se-

dy published in the journal Biofilms and

cond source of germs comes from your

Microbiomes late last month, researchers

respiratory tree—your mouth and nose.

dissected rubber ducks—the plastic toys

Talking, coughing, and sneezing are com-

that linger in bathtubs. Inside, they found

mon ways to impart germs into the air.

pathogenic bacteria in 80 percent of the

The third way humans generate germs is

toys they tested. Surprising as it may be,

found at the opposite end of the body.

Tierno says if you’re swabbing for germs in the bathroom, you still haven’t found

“There are more germs in a single teas-

the germiest place in the home.

poon of feces than there were men who walked the face of the Earth,” says Tierno.

mattress. And your pillow. And other soft, squishy surfaces. The

“It is cleaner to eat from a toilet, com-

It’s the germs born here that make the kitchen

New York University pathologist and self-

pared to the drain,” he says, referring

one of the dirtiest rooms in any given house.

-described microbe hunter wrote a book

to the kitchen drain. “The sink drain is

Remnants from livestock enter the kitchen on

called the The Secret Life of Germs. He

the dirtiest area of the house.” It’s clo-

meat, or from the fertilizer used to grow vege-

knows where they are lurking. So what

sely followed by the kitchen sponge, he

tables. Germs may accumulate easy, he adds,

are germs, really? Tiny organisms are

adds. A 2011 study by NSF International,

but ridding them from a home simply requires

everywhere, but the ones considered

a consumer safety organization, catego-

some regular upkeep. Hand washing is also

“germs” includes a number of species of

rized the household objects with the hi-

an essential step to keep germs from entering

bacteria and viruses. You might also find

ghest germ count. Only differing slightly

your body. To really break up the biofilms in a

disease-causing fungi and protozoa in a

from Tierno, they found sponges and dish

home, Tierno recommends scrubbing surfaces

home, especially in areas that are exposed

rags were the dirtiest household items,

with a metal brush, soap, and water, and a 10

to humidity. In the bathroom, for instance,

followed by kitchen sinks, toothbrush

percent bleach solution when it’s really needed.

water that comes into contact with a hard

holders, pet bowls, coffee reservoirs, ba-

Most people, he adds, have strong enough

throom faucet handles, pet toys, coun-

immune systems to fend off household germs

tertops, stove knobs, and cutting boards.

on their own, but as modern medicine allows

There are three ways that human beings

people with suppressed immune systems to

generate germs, says Tierno. The first is

live longer, a greater number of people are

the skin. Your biggest organ is a home

more susceptible to the germs around us.

THE AVERAGE PERSON ENCOUNTERS THOUSANDS OF GERMS EVERY DAY MOST ARE HARMLESS 23


WHY YOUR BESTFRIEND FEASTS ON SOME FECES

WHY YOUR BESTFRIEND FEASTS ON SOME FECES

also be avid eaters of poop, have been

eaters only consumed poop that was no more

found to turn to poop eating due to nutri-

than 2 days old, the study authors reported. In

tional deficiencies in their diets caused by

the second survey — the poop eaters only —

starvation or disease, prior research has

38 percent of the dogs ate poop weekly, and

suggested. However, that doesn’t explain

62 percent sampled poop daily. And 85 per-

why otherwise healthy dogs would deve-

cent preferred their poop fresh, less than 2 days

lop a taste for waste. Puppies may learn

old. This preference emerged in both surveys,

this behavior from their mothers, who lick

linking it to an adaptive behavior practiced by

their babies when they are very young

the ancestors of domestic dogs — wolves, the

to encourage elimination and to clean

study authors reported. Wolves expel the eggs

fecal

them up afterward. But most dogs tend

of intestinal parasites such as tapeworms, rou-

freshness is a factor. And this predi-

to grow out of this youthful poop-eating

ndworms, pinworms and flukes in their feces,

lection for poop could be behavior

stage by the time they are 9 months old,

and these eggs typically don’t develop into an

according to the American Kennel Club.

infectious larval form for several days. By eating

by MINDY WEISBERGER

F

or

poop-seeking

pups,

that originated in dogs’ wolf ancestors,

fresh poop found in or near their den areas,

and is linked to parasite prevention, according to a new study. Also known as

FRESHER IS BETTER

wolves may perform a type of housekeeping

coprophagia, poop eating is widely dis-

To get to the bottom of why dogs eat feces, the

that reduces the risk of parasitic infection, the

tributed across the mammal family tree.

scientists conducted two online surveys, gathe-

researchers explained in the study. However,

The behavior — which is also found in

ring about 3,000 responses from dog owners

this hypothesis for the origins of poop eating in

rodents, rabbits, beavers, elephants and

in the U.S. and Canada. One survey investiga-

dogs doesn’t draw from observed behavior in

non-human primates, to name just a

ted the habits of dogs that ate poop and dogs

wolves, “and should be considered tentati-

few — is generally viewed as a second

that didn’t, while the other addressed only the

ve,” the study authors wrote. Another unsatis-

chance for an animal to extract nutrients

poo eaters, to gather data about frequency,

fying conclusion for disgruntled dog owners is

from its diet. Domestic dogs, which can

persistence of the behavior and the type of

that pooches’ poop-eating habits are hard to

poop that attracted them the most. About 16

change, the scientists found. They discovered

percent of responders to the first survey said

that dogs who fancied feces weren’t easily de-

that they had observed their dog eating poop,

terred, and regardless of the method owners

and feces feasting did not appear to be linked

tried — food additives, punishment for eating

to generally compulsive behavior or dietary

poo or rewards for leaving poop alone — their

deficiencies. Interestingly, 82 percent of the poo

reported success rate was 0 to 4 percent.

THE FRESHER THE POOP, THE MORE LIKELY A DOG WILL EAT IT — WHETHER YOU LIKE IT OR NOT 25


WHY YOUR BESTFRIEND FEASTS ON SOME FECES


FIVE THINGS TO RESTORE THE PLANET EARTH

FIVE THINGS TO RESTORE THE PLANET EARTH by DANIEL STONE

T

he Anthropocene. That’s the name that is starting to be used to describe the current epoch of Earth’s his-

tory. The “anthro,” of course, refers to how people have altered the planet. The dire effects of human activity—climate change and pollution, to name a couple—are well-known. But we are also learning how to make the planet a better place, as the examples here demonstrate. Advances in technology have enabled people to farm more efficiently, reclaim water more effectively, and replenish distressed land. In his “Anthropocene” series, photographer David Ellingsen combines relics of the human and natural worlds. The works reflect both hope and concern about how our species is remaking the planet.

27


FIVE THINGS TO RESTORE THE PLANET EARTH

1. Tree delivery

2. Plastic cleanup

3. Flying above ice

Can drones fight deforestation? Engineers

The Ocean Cleanup, a Dutch nonprofit, has an

San Diego Zoo Global, in partnership with Nor-

at U.K.-based BioCarbon Engineering have

idea to clear out the Great Pacific Garbage Pat-

throp Grumman, has outfitted an autonomous he-

developed seed-depositing drones desig-

ch, the sprawling expanse of floating plastic and

xacopter with high-resolution cameras and sensors

ned to plant a billion trees a year. More

trash in the North Pacific. Using floating screens

that can monitor sea ice and polar bear behavior.

nimble than current aerial methods, the

and anchors, the system will corral plastic on the

The project was devised to illustrate how the bears

drones can reach places humans can’t.

water and hold it until it can be collected.

are adapting to longer summers and melting ice.

4. City appetites

5. Crossing the road

Plenty, a Bay Area start-up, is using LED lights

Can the amount of roadkill be reduced? To

to boost growth in indoor hydroponic farms.

mitigate the danger to both animals and dri-

Designed for hyperefficiency, a Plenty farm

vers, Brazilian company ViaFauna is testing

can achieve yields up to 350 times as great

roadside sensors—similar to those used for

per square foot as conventional fields. The

speed traps—to identify disturbances on the

firm is exploring expanding to Chinese cities.

road and then illuminate signs to alert drivers.


JUPITER’S GREAT RED SPOT MAY HAVE ONLY TEN TO TWENTY YEARS LEFT

JUPITER’S GREAT RED SPOT MAY HAVE ONLY TEN TO TWENTY YEARS LEFT by DAVE MOSHER

lasted just 31 days. Business Insider asked

miles’ worth of atmosphere. Instead, our

Glenn Orton— a lead Juno mission team

planet’s dynamic atmosphere is in clo-

member and planetary scientist at NASA

se contact with features like oceans and

JPL — why Jupiter’s storms last so long.

land. Earth is also relatively small and

“They don’t, at least not all of them,”

rotates more slowly than Jupiter (which

Orton said in an email. “Think of the

spins once roughly every 10 hours). These

GRS [Great Red Spot] as a spinning

factors shape our world’s jet streams in a

wheel that keeps on spinning becau-

way that can disrupt weather systems and

se it’s caught between two conveyor

vortexes before things get too out of con-

belts that are moving in opposite di-

trol. But Orton said the Great Red Spot,

rections. The GRS is stable and long-

and other long-lived storms on Jupiter,

Get a good look at Jupiter’s Great Red

-lived, because it’s ‘wedged’ between

still won’t go on forever.

Spot while you can. The giant storm as

two jet streams that are moving in

we know it today is shrinking, and it mi-

opposite directions.” Jupiter’s jet stre-

“In truth, the GRS has been shrinking

ght fade into memory within your lifeti-

ams can move at speeds of more than

for a long time,” he said. In the late

me. NASA’s $1 billion Juno probe took

300 mph, so they impart great force onto

1800s, the storm was perhaps as wide as

stunning photos of the Great Red Spot

any storms that spin backward relative to

30 degrees longitude, Orton said. That

in July 2017 — the closest images we’ve

the planet’s rotation.

works out to more than 35,000 miles — four times the diameter of Earth. When

ever gotten of the giant tempest. Scientists were floored by the level of detail

“We’re not planning currently ever to

the nuclear-powered spacecraft Voyager

beamed back by the spacecraft. Jupiter’s

come as close without changing the

2 flew by Jupiter in 1979, however, the

super-storm is wider than Earth and has

orbit from its current configuration,”

storm had shrunk to a bit more twice the

been swirling around since perhaps the

Orton said. “This also assumes that the

width of our own planet.

1600s. By comparison, Earth’s longest

GRS maintains its current drift rate

recorded storm, Hurricane John in 1994,

in Jupiter’s atmosphere.” Earth do-

“Now it’s something like 13 degrees

esn’t permit storms to last for hundreds

wide in longitude and only 1.3 times

A SIGNATURE STORM ON

of years since, unlike Jupiter, its surface

the size of the Earth,” he said. “No-

PLANET NEPTUNE IS

is not shrouded in tens of thousands of

thing lasts forever.”

ALSO VANISHING 29


SCIENTISTS INVENT NEW FLOATING ‘FIREFLY’ LIGHT

SCIENTISTS INVENT NEW FLOATING ‘FIREFLY’ LIGHT by HIDEKI KATO

J

apanese engineering researchers say

“Ultimately, my hope is that such tiny

they have created a tiny electronic

objects will have smartphone capabili-

light the size of a firefly which rides

ties and be built to float about helping

waves of ultrasound, and could eventu-

us in our everyday lives in smarter

ally figure in applications ranging from

ways,” said the University of Tokyo pro-

moving displays to projection mapping.

fessor, who hopes it will be commercially

Named Luciola for its resemblance to the

viable in five to 10 years. The developers

firefly, the featherweight levitating parti-

expect Luciola to find applications in the

cle weighs 16.2 mg, has a diameter of 3.5

so-called Internet of Things, in which re-

mm (0.14 inch), and emits a red glimmer

gular objects, such as cars, or domestic

that can just about illuminate text. But its

appliances such as air-conditioners, are

minuscule size belies the power of the

connected to networks to send and re-

285 microspeakers emitting ultrasonic

ceive data. Equipped with movement or

waves that hold up the light, and have

temperature sensors, Luciola could fly

a frequency inaudible to the human ear,

to such objects to deliver a message or

allowing Luciola to operate in apparent

help to make moving displays with mul-

total silence. It took two years for Luciola

tiple lights that can detect the presence

to get this far, said circuit design specia-

of humans, or participate in futuristic pro-

list Makoto Takamiya, a member of the

jection mapping events. The Kawahara

Kawahara Universal Information Network

Universal Information Network Project

Project that developed the device.

is a government-funded program that is part of the Japan Science and Technology Agency and explores advances in information and communication technology.

31


CAN THIS ROBOT BUILD AN IKEA CHAIR FASTER THAN YOU ?

Although artificial intelligence systems may

those actions in concert. Feedback from force

be able to beat humans at board games, we

sensors also helped: When the robot nee-

still have the upper hand when it comes to

ded to insert a pin into a hole, for example,

complicated manual tasks. But now, scientists

it would slide the pin over the surface until it

have created robots that can do something

felt a change in force. Altogether, the robots

even most humans struggle with: Assemble

put together the chair in a little over 20 mi-

an IKEA chair. Putting together a chair requires

nutes, the researchers report today in Scien-

CAN THIS ROBOT BUILD AN IKEA CHAIR FASTER THAN YOU?

a combination of complex movements that,

ce Robotics. That included 11 minutes and 21

in turn, depends on such skills as vision, limb

seconds of planning time and 8 minutes and

by MATT WARREN

coordination, and the ability to control force.

55 seconds of actual assembly. How does that

Until now, that was too much to ask of even

compare with humans? We challenged seve-

a sophisticated robot. But researchers have

ral Science staffers to build the same chair, and

finally broken the dexterity barrier by combi-

they beat the robots’ time—but only by 50 se-

ning commercially available hardware, inclu-

conds. Unlike our humans, the chair-building

ding 3D cameras and force sensors, to build

bots were not fully autonomous, as scientists

two chair-building bots. To construct their IKEA

needed to program the sequence of steps

masterpiece, the robots first took pictures to

they took in advance. But the researchers say

identify each part of the chair. An algorithm

that with further advances in artificial intelli-

planned the motions the robots needed to

gence, robots could work this out themselves

manipulate the objects without causing any

by communicating with a supervisor—or

collisions; two robotic arms then performed

even by reading the manual.

32


LOW LIGHT SOLAR CELLS COULD CHARGE DEVICES INDOORS

LOW LIGHT SOLAR CELLS COULD CHARGE DEVICES INDOORS

I

by ROBERT F. SERVICE magine never having to charge your

Diffuse light solar cells aren’t new—but the

light kicks electrons on silicon atoms up

phone, e-reader, or tablet again. Rese-

best ones relied on expensive semicon-

to a higher energy level, allowing them

archers report that they have created

ductors. In 1991, chemist Michael Graetzel

to skip across neighboring atoms towards

solar cells that work at a record efficiency

of the Swiss Federal Institute of Technology

a positively charged electrode. There they

for making electricity from the low-intensity

in Lausanne invented so-called dye-sensi-

are collected and shunted into an electrical

diffuse light that is present inside buildings

tized solar cells (DSSCs) that work best in

circuit where they can do work. The depar-

and outside on cloudy days. The solar cells

dim light and are cheaper than the stan-

ted electrons leave behind vacancies in the

could one day lead to device covers that

dard semiconductors. Yet under full sun,

atoms called holes that, oddly enough, can

continually recharge gadgets without ever

the best DSSCs convert only 14% of the

also move around. Over time, the holes

having to plug them in.

energy in sunlight to electricity—versus

travel to the negatively charged electrode

about 24% for standard solar cells—es-

where they are filled with electrons from the

sentially because the energy comes too

external circuit. This rebalances the charges

fast for DSSCs to handle. When the ener-

in the solar cell’s silicon atoms, allowing it to

gy comes at a slower pace, as it does with

continue to generate electricity.

low-intensity indoor light, Graetzel’s DSSCs

DSSCs take things up a notch. They still

could convert up to 28% of the light ener-

have two electrodes that collect negative

gy they absorb into electricity. DSSCs also

and positive charges. But in the middle,

work a bit differently from standard silicon

instead of just silicon, they have a different

solar cells. In standard cells, absorbed sun-

electron conductor, typically a collection of

DYE-SENSITIZED SOLAR CELLS ALREADY HARVEST POWER IN BUILDINGS AROUND THE WORLD. 35


LOW LIGHT SOLAR CELLS COULD CHARGE DEVICES INDOORS

photon absorved in depletion zone electron-hole creation electron off

photon front electrial contact n-type depletion zone p-type back electrical contact

on

current hole

electron-hole recombination

titanium dioxide (TiO2) particles. TiO2 is a

of electricity. To get around this, researchers

sielewski, a chemist at Northwestern Uni-

poor light absorber, however. So, resear-

have tried to make their electrolyte layers

versity in Evanston, Illinois. The new devices

chers coat the particles with organic dye

thin, so that the holes don’t have to travel

still only convert 13.1% of direct sunlight to

molecules that are exceptional light ab-

very far to reach their goal. But any imper-

electricity. But he notes that because the di-

sorbers. Absorbed photons of light excite

fections in those thin layers can cause the

ffuse light efficiency is nearly 20% higher, it

electrons and holes on these dye molecu-

devices to short, a fatal blow that kills the

raises hopes that new ways might be found

les, just as in the silicon. The dyes immedia-

whole solar cell. Now, Graetzel and his col-

to boost the efficiency of the devices under

tely hand off excited electrons to the TiO2

leagues have now come up with a possible

full sunlight. And because DSSCs are far

particles, which zip them along to the po-

solution. They designed a combination of

cheaper to produce than silicon solar cells,

sitive electrode. The holes, meanwhile, are

dye and hole-conducting molecules that

if they can approach silicon’s efficiency at a

dumped into a charge-conducting liquid

wrap themselves tightly around TiO2 parti-

lower cost, that should be a winning formu-

called an electrolyte, where they percolate

cles, creating tight-fitting layers without any

la. Until then, diffuse light DSSCs can at le-

through to the negatively charged elec-

imperfections. That means slow-moving

ast help us power a host of devices without

trode. The problem with DSSCs is that the

holes have less distance to travel before

cords, plugs, or external power. Numerous

holes don’t move through the electrolyte

reaching the negative electrode. The tight

companies are already working to outfit

very quickly. As a result, holes tend to pile

layers, they report today in Joule, increase

building interiors with an earlier generation

up near the dye and TiO2 particles. If an

the diffuse light efficiency of their DSSCs to

of DSSCs. And Graetzel says he believes

excited electron ends up bumping into a

32%, near the theoretical maximum. “It’s

the new and improved cells will only speed

hole, they merge, generating heat instead

really a nice advance,” says Michael Wa-

up the adoption of the technology.


ICHTHYOSAUR MAY BE THE LARGEST THAT EVER LIVED

T

he ancient remains of a gigantic

13-foot-long Jurassic ichthyosaur found

marine reptile have been found

in Scotland.) Self-taught fossil hunter and

in southwestern England. Known

study coauthor Paul de la Salle was com-

as an ichthyosaur, the animal lived about

bing the beach at Lilstock, Somerset, in

205 million years ago and was up to 85

May 2016 when he found a large and pu-

feet long—almost as big as a blue wha-

zzling chunk of fossil bone. Suspecting it

le, say the authors of a study describing

might be an ichthyosaur, he sent images

ICHTHYOSAUR MAY BE THE LARGEST THAT EVER LIVED

the fossil published today in PLOS ONE.

to marine reptile experts Dean Lomax at

Biology textbook have long touted the

the University of Manchester in the U.K.

by JOHN PICKRELL

modern blue whale as the largest animal

and Judy Massare at SUNY Brockport in

that ever lived, but this and other fas-

New York. Further searching revealed

cinating fossil finds hint that there may

five fossil pieces that fitted together to

once have been even bigger creatures

form a 3.2-foot-long bone, which the

swimming Earth’s seas.

scientists identified as being from the lower jaw of an ichthyosaur. Based on

WHY IS THIS IMPORTANT?

the size of the bone, the scientists think

Ichthyosaurs were ocean-going con-

this ichthyosaur was bigger than any

temporaries of the dinosaurs, with body

previously known to science. Lomax and

shapes superficially similar to dolphins.

Massare travelled to Alberta, Canada, to

They reached their greatest diversity

examine the much more complete fossil

about 210 million years ago in the late

of Shonisaurus sikanniensis, a 69-foot-

Triassic, but some persisted into the late

-long ichthyosaur found in 2004. Com-

Cretaceous. They vanished from the fos-

paring the new fossil to the same bone in

sil record about 25 million years before

the jaw of Shonisaurus revealed that the

the mass extinction that wiped out the

new bone is 25 percent bigger. Scaling

non-avian dinosaurs. Most ichthyosaurs

up the animal’s full body gave the team

were much smaller than the newly dis-

their 85-foot size estimate. (Paleontolo-

covered creature—several species in the

gists also recently found a remarkably

genus Ichthyosaurus also found in the

complete 16-foot ichthyosaur in India.)

U.K. were just 5 to 11 feet long. (See a

Lomax says the discovery has led them

to reinterpret a whole series of isolated bones found near the village of Aust in Gloucestershire, England. Some collected as early as 1850, these fragments had long been interpreted to be the limb or other bones of terrestrial dinosaurs, but this never quite made sense. The scientists realized these pieces also belonged to giant ichthyosaurs—and possibly to ones even bigger than the newly identified animal. “We compared it with these Aust bones, and as soon as I saw it in person, my jaw just hit the floor,” Lomax says. “I realized this was a giant ichthyosaur and the biggest thing ever found in the U.K.” Darren Naish, a paleontologist at the University of Southampton in the U.K., agrees that the sizes of all these bones are astounding.

38


BLOOD TEST SHOWS PROMISE FOR SPOTTING EARLY CANCERS

BLOOD TESTS SHOWS PROMISE FOR SPOTTING EARLY CANCERS by JOCELYN KAISER

A BLOOD TEST COULD ONE DAY BE USED TO DETECT EARLY CANCERS. 39

T

he elusive dream is that a simple

people with 20 types of cancer and others

blood test could detect a small tu-

who are apparently cancer-free. The stu-

mor growing in your body, giving

dy has enrolled more than 10,000 people

doctors time to cure you before it’s too

so far. (The goal is 15,000 by the end of

late. Today, scientists at GRAIL, a biote-

this year.) The company reported today

chnology company based in Menlo Park,

on what Alex Aravanis, head of R&D, cal-

California, that has drawn more than a

led “early insights” from their Circulating

billion dollars in investment, announced

Cell-free Genome Atlas Study. With blood

progress toward that goal here at the an-

samples from 878 people with newly diag-

nual meeting of the American Association

nosed cancer and 580 people without the

for Cancer Research. Using full-genome

disease, GRAIL performed three different

sequencing to analyze DNA shed into the

kinds of assays that analyzed DNA across

blood by dying tumor cells, the widely wa-

the entire genome. One looked for muta-

tched company saw evidence of cancer in

tions in about 500 known cancer genes,

65% of a group of patients already known

a second detected abnormal numbers of

to have early disease. The results are simi-

copies of genes, and the third analyzed

lar to those published recently by other

patterns of methylation, which are chemi-

research teams. Although several com-

cal tags on DNA that turn genes off or on.

panies and academic labs are working on

The company also looked for mutations

this new form of cancer detection, GRAIL

that pop up in the white blood cells of

has drawn attention for the huge amount

healthy aging people and removed them

of money it has raised, the many scientific

from the analysis to leave only cancer-spe-

heavyweights who sit on its advisory bo-

cific patterns. GRAIL scientists then looked

ard, and its plan to use pricy whole-ge-

at how well each assay’s data would have

nome sequencing, which analyzes all 3

predicted cancer in the patients. For 196

billion base pairs in the human genome,

people with five highly lethal cancers that

to develop a cancer test. To build a refe-

are difficult to detect early—pancreatic,

rence set of what to look for in its blood

lung, ovarian, liver, and esophageal—the

test, GRAIL is cataloging cancer-related

methylation test did best, indicating can-

mutations in cell-free DNA in the blood of

cer in 65% of those whose cancer at the


BLOOD TEST SHOWS PROMISE FOR SPOTTING EARLY CANCERS

time of their blood sample had not spread detectably to other organs, besides lymph nodes. As expected, the detection rate was higher—95%—for metastatic cancers because these patients’ tumors are larger, can be in multiple organs, and release more DNA into the blood. Although the 65% sensitivity rate for nonmetastatic cancer needs to be confirmed in another set of people, it is on par with some other tests, such as one published recently from a group at Johns Hopkins University in Baltimore, Maryland, that sequenced a small set of genes and combined the results with measurements of several cancer-linked proteins in the blood.Medical oncologist Luis Diaz of Memorial Sloan Kettering Cancer Center in New York City, a co-author of the Hopkins study, says it may never be possible to detect more than about 65% to 70% of early cancers because many small tumors don’t shed enough DNA into the blood. The false positive rate for all three GRAIL tests was very low. Detecting a possible tumor from a blood test is only a first step; ideally, any liquid biopsy would also point to the organ that is the source of the cancer so that oncologists could use imaging to confirm any tumor and remove it before it has spread.


IS SWIMMING WITH DOLPHINS A GOOD IDEA?

IS SWIMMING WITH DOLPHINS A GOOD IDEA?

TELL US ABOUT DOLPHINS

WHAT SITES DID YOU STUDY?

It’s been difficult to say because you need

We made surveys of dolphins and tourists in

to have sites you can compare—such

the southern Egyptian Red Sea in the lagoons

as one with heavy tourism, one with an

of Samadai and Satayah. We also surveyed

intermediate amount, and one without

dolphins at Qubbat’Isa, which is a military

any. The tourists’ interactions always ha-

area, so there are no tourists. These are sandy,

ppen during a critical phase of spinner

shallow lagoons inside coral reefs; the water is

dolphins’ daily lives. These dolphins [slim

2 to 8 meters deep. Tourists from nearby ho-

ourist spots around the globe of-

animals with long beaks known for their

tels are taken on boats to places in the lagoons

fer people a chance to swim with

acrobatic, spinning leaps] spend the ni-

where the dolphins are resting. It’s impossible to

whales and dolphins. But what im-

ghts offshore, diving for fish, and they

say how many tourists swim with the dolphins.

pact do these activities have on the marine

come to lagoons at dawn to rest and

While there is a ticketing system at Samadai,

mammals, and should they be more stron-

sleep. So we’re interrupting their sleep.

the stats aren’t made public. And access to

gly regulated? Maddalena Fumagalli, a ce-

One long-term study in Hawaii showed

Satayah reef is totally uncontrolled; we don’t

tacean biologist at the University of Otago

that the spinner dolphins’ abundance has

know how many people are there on a given

in Dunedin, New Zealand, investigates

declined since the 1990s, and that may be

day. The local government at Samadai has im-

these issues in a study on spinner dolphins

linked to the increasing number of tourists

posed regulations and zoning: The main area

(Stenella longirostris) published today in

disturbing their sleep.

the dolphins use for resting is off-limits to swim-

by VIRGINIA MORELL

T

Royal Society Open Science. She spoke to

mers; boats with outboard motors are allowed

Science about her findings. This interview

only in one area, away from the dolphins’ pre-

has been edited for clarity and length.

ferred zone; and swimmers and divers are only allowed from 8 a.m. to 3 p.m. At Satayah there are no regulations, and the dolphins are repeatedly approached by swimmers and motorboats up to 9 hours each day. During our surveys, there were more swimmers (a median of 13 at midday) and fewer boats at Samadai. Because of the dolphins-only zone there, it’s up to the dolphins to initiate contact with people.

41


IS SWIMMING WITH DOLPHINS A GOOD IDEA?

WHAT WERE YOUR MAIN FINDINGS?

DID YOU SWIM WITH DOLPHINS?

WHAT DO YOU HOPE TO ACCOMPLISH?

The dolphins typically rest in tight schools;

Yes, but not as a tourist, as a researcher. For

We hope the Egyptian authorities and tour

they swim very slowly together and coor-

another study about the composition of the

operators come up with a management

dinate their breathing. They do very little

dolphin groups, we needed to build a photo

plan that includes a sense of stewardship.

acoustic communicating, and don’t make

ID catalog of the dolphins when they were

The spinner dolphins are wild animals, and

aerial displays. That changes when the

underwater. They tend to be very curious

we shouldn’t impose ourselves on them.

tourists arrive. Other studies have shown

about whatever is around them. Like peo-

The tour companies that take people to

that when disturbed from their sleep, the

ple, some are more curious or friendly than

swim with these dolphins need to acknow-

dolphins do more leaping. We saw this,

others. It depended, too, on if they’d had a

ledge the dolphins’ need to rest, and deve-

too. The Satayah dolphins made more

rough night feeding; then they really wan-

lop their tourism program around that need

aerial displays than those at Samadai. It’s

ted to rest and would avoid us. We never

by restricting the number of motorboats

actually a sign they are not happy. Some

forced any interactions; it was always up to

and using zones as they do at Samadai.

can be curious and a little friendly. They’ll

them. They could be playful at times, but

They should also educate the tourists about

approach people from the side, not the

intimidating, too. Sometimes, adult males

the dolphins’ ecology and explain why they

front, and swim in circles and maybe whist-

can be threatening. One made a very di-

are in the lagoons. The tourist program at

le. But if they don’t want people near them,

rect, frontal approach and then assumed an

Samadai is regulated, but the tourists were

they just swim away. The welfare of the Sa-

S-shaped posture, which is a threat. At the

still happy—and the dolphins were not so

tayah dolphins is clearly being adversely

same time, I could hear his train of echolo-

disturbed. That should be the goal of all ce-

affected by the unregulated tourism. And

cation clicks coming straight toward me. I

tacean tourism programs everywhere.

the dolphin protection measures at Sa-

immediately froze; I just stayed put, and he

madai reduce these negative effects. But

swam away. He made me realize that he—

whenever tourists arrived at both sites, the

and perhaps the whole group—didn’t want

dolphins consistently changed from resting

me there. The dolphins also swim away if

in small, tight groups to being active. The

they don’t want you near them; we saw this

time limits and zoning system at Samadai,

happen with the tourists.

though, helped by reducing the daily tourism interactions by about half.


CONTENT

06


TOURISM IS WORSE FOR THE PLANET THAN EDITOR’S WE THOUGHT LETTER

TOURISM IS WORSE FOR THE PLANET THAN WHAT WE THOUGHT

G

by SID PERKINS

oing on vacation may be fun

counted for only about 12% of that total,

for you, but it’s not great for

the team reports today in Nature Climate

Earth. Previous analyses typi-

Change. The United Nations World Tou-

cally tallied only carbon dioxide (CO2)

rism Organization has previously sugges-

emissions due to air travel. But the new

ted two ways to reduce the carbon foo-

study also includes emissions of CO2 and

tprint of global tourism: Travelers could

other planet-warming gases due to the

choose destinations closer to home and

construction and maintenance of such in-

use more public transportation, and go-

frastructure as hotels and airports, as well

vernments could offer tourism providers

as emissions associated with tourists’ pur-

incentives to boost their energy efficiency.

chases of food, beverages, and souvenirs.

To date, neither approach has been wildly

Using data collected by and within 160

successful, the researchers note. If recent

countries, the researchers estimate that

trends continue—and if the global eco-

global tourism in 2013 accounted for gre-

nomy grows as expected—the carbon

enhouse gas emissions equivalent to 4.5

footprint of global tourism will expand

billion metric tons of CO2, or about 8% of

more than 40% (to about 6.5 billion me-

global emissions that year. Air travel ac-

tric tons of CO2) by the year 2025.

44


GETTING OLD GIVES YOU ITCHY SKIN

GETTING OLD GIVES YOU ITCHY SKIN

Chronic itch is different from chemical itch,

cells would respond to the nylon fiber. They

which occurs when the immune system re-

scratched with fervor, confirming that the

acts to a foreign substance, such as oil from

Merkel cells were necessary to put a brake

a poison oak leaf or saliva in a mosquito

on the itchy sensations. They also boosted

bite. Instead, chronic—or mechanical—itch

the activity of Merkel cells that had been

is usually triggered by light pressure, such as

genetically engineered to fire when exposed

the brush of fibers from a sweater. The con-

to a chemical called clozapine N-oxide, and

dition is maddening, and when people re-

found that it reduced scratching in mice with

etting old can be a real itch. In

peatedly scratch their fragile, dry skin, it can

an itchy skin condition. The finding suggests

addition to having memory and

lead to major health problems, including in-

that increasing Merkel cell activity could help

muscle loss, many elderly people

fections, says study author Hongzhen Hu, an

treat alloknesis in people, the team writes.

develop supersensitive skin that gets itchy

anesthesiology researcher at the Washington

Past studies have shown that Merkel cells in

at the lightest touch. Scientists don’t know

University School of Medicine in St. Louis,

the skin are reduced in elderly people and

what causes this miserable condition, called

Missouri. Like people, mice visibly itch more

people with dry skin conditions. Hu and

alloknesis, or how to treat it. Now, however, a

with age. To find out why, Hu and colleagues

colleagues are now analyzing skin biopsies

study in mice has revealed a counterintuitive

used a hair-thin nylon filament to apply a pre-

from human patients with touch-related itch

mechanism for the disorder: a loss of pres-

cise amount of pressure to a patch of shaved

problems to determine whether their Merkel

sure-sensing cells in the skin. Although the

skin on young and old rodents’ necks. Young

cells are also depleted. The study “nicely

findings have yet to be replicated in humans,

mice didn’t respond much to the gentle tou-

explains why people with dry skin condi-

the study raises the possibility that boosting

ch, but the older mice scratched furiously at

tions or [the elderly] tend to have eleva-

the function of these cells could treat chronic

the spot. Analyzing skin samples from mice

ted itch sensitivity,” says Xinzhong Dong, a

itch in people, both young and old.

of both ages, the team found that older mice

neuroscientist at Johns Hopkins University in

had far fewer pressure-sensing Merkel cells

Baltimore, Maryland, who was not involved

than young mice did. The fewer Merkel cells

in the study. Still unresolved, however, is the

a mouse had, the more their touch-related

question of where the mechanical itch sig-

itch problems increased in response to the

nals come from in the first place, notes Mark

filament, the researchers report today in

Hoon, a neuroscientist at the National Insti-

Science. Next, the team tested how young

tute of Dental and Craniofacial Research in

mice genetically engineered to lack Merkel

Bethesda, Maryland.

by EMILY UNDERWOOD

G

45


FOSSIL REVEAL HOW ANCIENT BIRDS GOT THEIR BEAKS

FOSSILS REVEAL HOW ANCIENT BIRDS GOT THEIR BEAKS

As every schoolchild now knows, birds are

the pieces belonged to the same animal. In

dinosaurs, linked to their extinct relatives by

1880, Charles Darwin wrote that Ichthyornis

feathers and anatomy. But birds’ beaks—

was among “the best support for the the-

splendidly versatile adaptations that allow

ory of evolution” since On the Origin of

their owners to grasp, pry, preen, and tear—

Species was published 2 decades earlier. But

are nothing like stiff dinosaurian snouts, and

in the original Ichthyornis fossil, the upper

how they evolved has been a mystery. Now,

jaw is missing, and the toothed lower jaw re-

3D scans of new fossils of an iconic ancient

sembles that of other dinosaurs. So paleon-

bird capture the beak just as it took form.

tologists assumed that early birds made do

“This region of the [bird family] tree is

with a fixed upper jaw, like most other ver-

populated almost exclusively by flatte-

tebrates. In 2014, paleontologists in Kansas

The resulting 3D model captures Ichthyor-

ned specimens,” in which delicate features

found a new specimen of Ichthyornis. They

nis’s transitional position between modern

of the skull are lost, says Amy Balanoff, a

shared the fossil with Bhart-Anjan Bhullar at

birds and other dinosaurs, Bhullar and colle-

paleontologist at Johns Hopkins University

Yale University and his colleagues. Instead

agues report this week in Nature. Despite its

in Baltimore, Maryland, who was not in-

of extracting the fossil from the limestone

dinosaurlike teeth, Ichthyornis had a hooked

volved in the research. By bringing details

in which it is embedded, the researchers

beak, likely covered by a hard layer of kera-

from multiple specimens together, the new

used computerized tomography to scan

tin, on the tip of its snout. It also could move

scans offer an early glimpse of key features

the entire block of rock. Then they scanned

both top and bottom jaws independently

of bird skulls, including a big brain and the

three previously unrecognized specimens

like modern birds. That means beaks appe-

movable upper jaw that helps make beaks

that they found in museum collections, and

ared earlier than thought, perhaps around

so nimble. Ichthyornis, an ancient seabird

combined all the scans into a complete mo-

the same time as wings, Bhullar says. The

from about 90 million years ago, has long

del of Ichthyornis’s skull. They also re-exami-

agile jaw probably allowed the bird to preen

been famous for having a body like a mo-

ned the original fossil from the 1870s, hou-

its feathers and gave it a pincerlike grasp. At

dern bird, with a snout lined with teeth like

sed at Yale’s Peabody Museum of Natural

the same time, Ichthyornis retained powerful

a dinosaur. Paleontologists studying the first

History. Among unidentified pieces stored

jaw muscles. “more similar to what you’d see

Ichthyornis fossil, discovered in the 1870s in

with the fossil, they found a small fragment

in velociraptor than what you’d see in living

Kansas, initially thought the body came from

that, when scanned, turned out to contain

birds,” says Daniel Field, a paleontologist at

a small bird and the jaw from a marine rep-

two key bones from the upper snout—bo-

the University of Bath in the United Kingdom

tile. Further excavation convinced them that

nes that were missing in the new specimens.

who helped lead the work.

by GRETCHEN VOGEL

46


WHO HAS THE CLEANER BED: CHIMPS OR US HUMANS?

For the first time, scientists have compared

ves in. However, even the scientists were sur-

microbes in human and chimpanzee sle-

prised by the study’s findings. “We expec-

eping areas. The findings may surprise you.

ted to see a lot of ectoparasites and a lot

“Take your stinking paws off me, you

of fecal bacteria, because there’s been a

damn, dirty ape!” Charlton Heston’s line

lot of evidence showing that fecal bacte-

in the 1968 classic Planet of the Apes epi-

ria builds up in the fur of chimpanzees,”

tomizes the way most of us view our closest

says Thoemmes. It’s important to note that

mammalian relatives. Stinking. Dirty. But a

the study only looked at the kinds of bacte-

new study published today in the journal

ria present, not the overall quantity of mi-

Royal Society Open Science may lead us

crobes, says Jonathan Eisen, an evolutionary

to question that reputation. By swabbing

microbiologist at the University of California,

abandoned chimpanzee nests in Tanza-

Davis, who was not part of the research. “I

nia’s Issa Valley, scientists learned that just

guess it depends on how you define it,

3.5 percent of the bacteria species present

but to me, ‘dirtier’ means ‘more stuff,”

came from the chimps’ own skin, saliva, or

says Eisen. Furthermore, “it’s gross and

feces. In human beds sampled in a previous

everything, but sitting in your own mi-

study in North Carolina, the number was

crobes is not generally the problem for

a whopping 35 percent. “We need to re-

health,” says Eisen. For nearly a decade,

think what we think of as ‘clean’ within

Eisen has been working on a project cal-

our environment,” says study leader Me-

led microBEnet, or the Microbiology of the

gan Thoemmes, a Ph.D. student at North

Built Environment program, an attempt to

Carolina State University. Now, for starters,

better understand how the transition from

chimpanzees construct a new nest each ni-

living outside to inside has affected humans

ght, and they also take pains to lean over

and our interactions with the microbes

the side of their nests when defecating. So

around us. For instance, other studies have

it makes at least a little sense that their sle-

found links between the development of

eping spots would have lower concentra-

autoimmune disorders and allergies in hu-

tions of body-associated bacteria than the

mans with a decline in exposure to soil bac-

sheets we Americans spend a third of our li-

teria, says study leader Thoemmes.

WHO HAS THE CLEANER BED: CHIMPS OR US HUMANS? by JASON BITTEL

PARASITES WERE ALSO SCARCE IN CHIMP BEDS 48


EUROPA IS VENTING WATER INTO OUTER SPACE

EUROPA IS VENTING WATER INTO OUTER SPACE by PAUL VOOSEN

49

The Galileo spacecraft may be dead, but

plasma sensors reflected the alterations that

it still has stories to tell. Fifteen years after

a veil of ejected water, from one or many

the NASA probe burned up in Jupiter’s at-

vents, could cause in a region matching the

mosphere, newly analyzed magnetic and

telescope observations, they report today

plasma data from the mission have bols-

in Nature Astronomy. This indicates that a

tered evidence that Europa, the planet’s

region of the moon potentially 1000 kilome-

ice-bound moon, is likely venting water into

ters long could host such activity, though it

space. Researchers have long believed that

is impossible to say whether this is a single

Europa is home to a vast saltwater ocean,

plume or many, like the complex system of

trapped beneath a thick crust of ice, making

fractures and vents seen on Enceladus. NA-

the moon potentially habitable for life and

SA’s Europa Clipper spacecraft, set for laun-

a focus of upcoming robotic exploration.

ch as soon as 2022, will carry several instru-

Over the past decade, scientists using the

ments capable of capturing and analyzing

Hubble Space Telescope have made obser-

plume ingredients. If such an eruption does

vations that seemed to support the notion

exist, it will make exploration of the ocean

that Jupiter is venting some of this water to

dramatically easier. The mission’s primary

space, much like Saturn’s moon Enceladus.

sponsor in Congress, Representative John

But many other attempted observations

Culberson (R–TX), could not hold back his

have turned up dry. So scientists instead

glee last week in a hearing for a spending

returned to Galileo, which on 16 December

bill that supported the mission—breaking

1997 made its closest approach to Europa,

the journal’s embargo in the process: “The

flying only 400 kilometers above its surface.

science community has wanted to go

Over the course of 5 minutes, spikes the

there for years, Mr. Chairman,” Culberson

spacecraft recorded with its magnetic and

said, “and this bill makes that happen.”


BIRD TREE OF LIFE WILL SOON FLY INTO VIEW

BIRD TREE OF LIFE WILL SOON FLY INTO VIEW by JASON BITTEL

B

ird lovers—and evolutionary biolo-

sed on the sequences of whole genomes of

So even though some of the leaders of the

gists—can look forward to a new

about 40 species. Another team published

2014 avian tree effort launched the Bird

and improved avian family tree

a different tree in 2015 after comparing a

10,000 Genomes (B10K) Project, aiming to

being finished in 4 years, thanks to The

subset of the avian genome in hundreds

eventually sequence the whole genomes of

OpenWings Project officially launched this

of species. These phylogenies help resear-

all 10,560 bird species and from there build

last week at the American Ornithologi-

chers looking at the evolutionary histories

“the grand tree,” some bird researchers

cal Meeting in Tucson, Arizona. The $1.42

of specific avian traits or the story of birds

decided not to wait. Led by Brian Smith at

million effort will be the first to include DNA

overall. But some researchers who speciali-

the American Museum of Natural History in

data from the more than 10,500 known bird

ze in building trees were not satisfied. “The

New York City and Brant Faircloth at Loui-

species to establish how they are all related.

current need for large phylogenies and

siana State University in Baton Rouge, they

But it will not be the final word—another

the high priority placed on them by

are taking a cheaper, faster route with the

project seeking to sequence the full ge-

high impact journals can result in shor-

OpenWings Project. The U.S. National Scien-

nomes of every avian species will follow if

tcuts, wherein large-scale phylogenetic

ce Foundation–funded effort will tap extensi-

enough funding can be raised. OpenWings

trees are cobbled together from dispa-

ve museum collections as much as possible,

“will be a huge improvement over what

rate existing sources, even taxonomy,

instead of freshly caught bird samples, and

we have now,” says Harvard Universi-

but often without hard data behind

will sequence about 5000 short pieces of the

ty evolutionary biologist Scott Edwards.

the placement of many species,” Har-

DNA, focusing on regions that are very hi-

But, “Ultimately, OpenWings will be a

vard evolutionary biologist Gustavo Bravo

ghly conserved among all birds. The group

stepping stone to the grand tree that

and his colleagues wrote on 30 January in

plans to release data on an ongoing basis,

the whole genomes [will generate].” In

PeerJ. “The question is how far do you

rather than waiting for the project’s publica-

2014, biologists published an avian tree ba-

compromise?” Edwards adds.

tion, so other researchers can make use of it.

50


SALTWATER TROUTS THAT EVOLVED TO LIVE IN FRESHWATER

SALTWATER TROUTS THAT EVOLVED TO LIVE IN FRESHWATER by ELIZABETH PENNISI

Although we tend to think of evolution as happening over thousands, if not millions, of years, critical changes can take little more than a century. That’s what happened with a group of steelhead trout transplanted from the salty seas of California to the fresh waters of Lake Michigan for game fishermen in the 1890s. A new study shows that the fish, which typically live part of their lives in the ocean like salmon, developed key genetic differences that allowed it to live wholly in freshwater—in little more than 100 years. The discovery shows how quickly organisms can adapt to a new lifestyle—if they have some of the right

ALL IN JUST 100 YEARS! 53

genes to start with, says Michael Blouin,

population started to rebound and even

a geneticist at Oregon State University in

diversify, most likely because of interbre-

Corvallis. “The work is a nice example”

eding with newly introduced hatchery

of how evolution can happen “over very

fish, Willoughby and Christie report this

short time periods.” Steelhead already

week in Molecular Ecology. Three regions

had a taste for freshwater. They hatch

of DNA were quite different between the

in rivers hundreds of kilometers from

modern lake and saltwater steelhead.

the Pacific, spend long periods as adults

Two of those contain genes critical for

in the ocean, then return to their home

maintaining the fish’s internal salt ba-

rivers to spawn. And they even have a

lance: Freshwater fish must take in extra

form—the popular rainbow trout—that

salts, whereas saltwater fish must get rid

lives out its whole life in freshwater stre-

of them. Moving salt in opposite direc-

ams. But that saltwater steelhead so re-

tions requires different versions of the re-

adily made Lake Michigan their full-time

levant genes. Another DNA region seems

home was surprising. To find the genetic

to affect wound healing. This may help

basis of this quick adaptation, a team led

the lake steelheads recover from parasitic

by evolutionary biologist Mark Christie

lampreys, which are widespread in that

from Purdue University in West Lafayette,

freshwater. So how did the genes change

Indiana, and his postdoc Janna Willou-

so quickly from one version to another?

ghby sequenced the genomes of 264

Intriguingly, there was no sign that ste-

steelhead. Some came from the source

elhead had interbred with rainbow trout

waters in California that supplied the first

to get the genes they needed to thrive.

Lake Michigan fish, while others were col-

They also didn’t have to mutate, Christie

lected from the lake’s watershed in 1983

explains. Instead, there were likely a few

and 1998. By comparing those genomes,

steelhead among the first batch of trans-

they reconstructed the steelhead’s stru-

plants that already had the right versions

ggles to adapt. The first batch of trans-

of these genes—they simply survived

plants had a hard time, likely dying off by

and reproduced much more successfully

the hundreds. But the few that survived

than their peers. Eventually, the less well-

thrived, and between 1983 and 1998, their

-adapted steelhead disappeared.


STICK INSECTS TRAVEL LONG DISTANCES

STICK INSECTS TRAVEL LONG DISTANCES by MICHAEL ALLEN

S

tick insects can’t travel long distan-

tances. Stick insects make eggs that have

ces by themselves, but they’ve so-

a very hard shell, which can survive acidic

mehow managed to spread far and

environments, such as those in bird guts.

wide, even dispersing across unconnected

The team fed eggs from three species of

islands. Now, scientists have discovered

stick insect to brown-eared bulbuls (Hypsi-

one way they may have achieved this:

petes amaurotis, pictured), a medium-size

being eaten by birds. Many plants use birds

bird that is common in eastern Asia and

to disperse their seeds. Birds eat the fruits,

one of the main avian predators of stick

move away from the plant, and then poop,

insects in Japan. A few hours later the birds

depositing the plant’s seeds in a new loca-

passed the eggs, and the researchers fou-

tion. When insects are eaten it is assumed

nd that for each species, between 5% and

that they and their unborn young don’t

20% of the eggs had survived unharmed.

survive, but a team of researchers won-

A couple of eggs from one species, Ramu-

dered whether a similar mechanism helps

lus irregulariterdentatus, even hatched, the

insects transport their offspring long dis-

team reports today in Ecology.

BY BEING EATEN BY BIRDS 54


LIFE REBOUNDED JUST YEARS AFTER THE DINO-KILLING ASTEROID

LIFE REBOUNDED JUST YEARS AFTER THE DINO-KILLING ASTEROID

Some scientists hypothesize that life

Texas Institute for Geophysics in Austin,

might slowly creep back into impact

and his colleagues began to analyze

craters, perhaps because of toxic metals

the fine grains of sediment that made

such as mercury and lead scattered by

up the limestone. Relying on equations

the impact. Other impact craters tell a

that describe how long it takes tiny par-

tale similar to that idea: The 85-kilome-

ticles to settle through a liquid, they cal-

ter Chesapeake Bay crater, for instance,

culated that the grains were deposited

was devoid of life for thousands of years

on the sea floor rapidly after the impact,

after a comet or asteroid hit modern-

in just a few years. When Lowery and

-day Virginia some 35 million years

his colleagues peered into the layers of

ago. As part of an effort to understand

limestone, they found numerous fossils

hen a 10-kilometer-wide aste-

how planets respond to large impacts,

and burrows, evidence of small worms,

roid hit the Gulf of Mexico 66

a team of scientists in 2016 drilled into

shelled creatures known as foramini-

million years ago, it drove over

the 180-kilometer Chicxulub crater, the

fera, and plankton. Life was back. But

75% of Earth’s species to extinction, including

only impact structure linked to a global

how did life colonize Chicxulub’s grou-

the dinosaurs. But within just a few years, life

extinction event. The team brought up

nd zero so quickly? It had nothing to

returned to the submerged impact crater, ac-

hundreds of roughly arm-length sedi-

do with the magnitude of the impact or

cording to a new analysis of sediments in the

ment cores. Some bore the scars of the

the crater ’s size, Lowery says. Instead,

crater. Tiny marine creatures flourished thanks

extreme temperatures and pressures of

the deciding factor may have been the

to the circulation of nutrient-rich water. That

the event, which drove rocks to behave

crater ’s shape. Chicxulub’s northeastern

return of life could offer lessons in how marine

like a fluid: Mountains the height of the

flank was open to the Gulf of Mexico,

ecosystems might recover after the dramatic

Himalayas rose and fell within the span

which allowed deep, nutrient-carrying

shifts caused by climate change, the resear-

of minutes. One core, taken from rou-

water to circulate throughout the cra-

chers suggest. The new findings reveal “how

ghly 600 meters below the modern sea

ter, the team reports today in Nature. In

resilient life can be,” says Gareth Collins, a

floor, contained 76 centimeters of dull

contrast, the Chesapeake Bay crater was

planetary scientist at Imperial College London

brown limestone—not much to look at,

closed, which meant oxygen consumed

who was not involved in the research. “Such a

but perhaps the most treasured swath

by decomposing organic matter was

rapid recovery … is remarkable.”

of sediment from the entire drilling pro-

not replenished, and aerobic life would

ject, at least to Chris Lowery. Lowery, a

have quickly died. “You basically had a

paleoceanographer at the University of

dead zone,” Lowery says.

by KATHERINE KORNEI

W

ALL IN JUST 100 YEARS! 55


LIFE REBOUNDED JUST YEARS AFTER THE DINO-KILLING ASTEROID


NEW ARTIFICIAL NERVES COULD TRANSFORM PROSTHETICS

NEW ARTIFICIAL NERVES COULD TRANSFORM PROSTHETICS

already impressive: Some allow amputees

from other pressure sensor/ring oscillator

to control arm movement with just their

combos, are fed into a third device called a

thoughts; others have pressure sensors

synaptic transistor, which sends out a series

in the fingertips that help wearers control

of electrical pulses in patterns that match

their grip without the need to constantly

those produced by biological neurons. Bao

monitor progress with their eyes. But our

and her colleagues used their setup to de-

natural sense of touch is far more complex,

tect the motion of a small rod moving in di-

integrating thousands of sensors that tra-

fferent directions across their pressure sen-

ck different types of pressure, such as soft

sors, as well as identify Braille characters.

and forceful touch, along with the ability to

What’s more, they managed to connect

Prosthetics may soon take on a whole

sense heat and changes in position. This

their artificial neuron to a biological cou-

new feel. That’s because researchers have

vast amount of information is ferried by a

nterpart. The researchers detached a leg

created a new type of artificial nerve that

network that passes signals through local

from a cockroach and inserted an electrode

can sense touch, process information, and

clusters of nerves to the spinal cord and

from the artificial neuron to a neuron in the

communicate with other nerves much like

ultimately the brain. Only when the signals

roach leg; signals coming from the artificial

those in our own bodies do. Future ver-

combine to become strong enough do they

neuron caused muscles in the leg to con-

sions could add sensors to track changes

make it up the next link in the chain. Now,

tract, they report today in Science. Because

in texture, position, and different types of

researchers led by chemist Zhenan Bao at

organic electronics like this are inexpensive

pressure, leading to potentially dramatic

Stanford University in Palo Alto, California,

to make, the approach should allow scien-

improvements in how people with artifi-

have constructed an artificial sensory nerve

tists to integrate large numbers of artifi-

cial limbs—and someday robots—sen-

that works in much the same way. Made

cial nerves that could pick up on multiple

se and interact with their environments.

of flexible organic components, the nerve

types of sensory information, Shepherd

“It’s a pretty nice advance,” says Robert

consists of three parts. First, a series of do-

says. Such a system could provide far more

Shepherd, an organic electronics expert at

zens of sensors pick up on pressure cues.

sensory information to future prosthetics

Cornell University. Not only are the soft, fle-

Pressing on one of these sensors causes

wearers, helping them better control their

xible, organic materials used to make the

an increase in voltage between two elec-

new appendages. It could also give future

artificial nerve ideal for integrating with

trodes. This change is then picked up by a

robots a greater ability to interact with their

pliable human tissue, but they are also rela-

second device called a ring oscillator, which

ever-changing environments—something

tively cheap to manufacture in large arrays,

converts voltage changes into a string of

vital for performing complex tasks, such as

Shepherd says. Modern prosthetics are

electrical pulses. These pulses, and those

caring for the elderly.

by ROBERT F. SERVICE

57


EDITOR’S LETTER

46


CONTENT

45


COULD BRAIN STIMULATION HELP ZAP DIABETES

COULD BRAIN STIMULATION HELP ZAP DIABETES

When a 53-year-old man asked Dutch

when glucose, or sugar, in a person’s

doctors to treat his obsessive-compul-

bloodstream remains in chronically high

sive disorder (OCD) several years back,

concentrations. Type 1, which typically

they suggested a new but promising

begins in childhood, results when the

surgical treatment: implanted electrodes

immune system destroys the pancreatic

that would stimulate deep brain tissue

cells that make insulin, the hormone that

involved in decision-making, reward-

lets our cells use sugar as food. Type 2

-seeking, and motivation. The treatment

diabetes, typically triggered by a combi-

apparently helped him go off one of his

nation of bad genes, poor eating habits,

psychiatric medications, but it came with

and a lack of exercise, also damages the

a surprising side effect—it also seemed

body’s ability to produce its own insulin.

DBS significantly increased insulin sensi-

to improve his type 2 diabetes. Now,

As time goes on, cells are hard-pressed

tivity in all participants, the team reports

researchers think they know why. A new

to remove sugar from the blood, and

today in Science Translational Medicine.

study suggests that a boost in the activity

people require larger and larger amou-

Studies in mice have shown that dopa-

of dopamine, a neurotransmitter invol-

nts of insulin to keep their blood sugar

mine released by neurons in the same

ved in motivation and pleasure, impro-

stable. There is no cure for either dise-

general decision-making region they sti-

ves the body’s ability to process sugar.

ase. To test whether DBS was responsi-

mulated—called the ventral striatum—

ble for the man’s improvement (he went

plays a key role in regulating glucose

This is the first time such a pathway, pre-

from injecting 226 international units of

throughout the body. To see whether a

viously seen in mice, has been found in

insulin per day to just 180), Mireille Ser-

similar mechanism exists in humans, her

humans, says Mike Michaelides, a neu-

lie, an endocrinologist at the Academic

team gave 10 healthy men a drug that

roscientist at the National Institute on

Medical Center in Amsterdam, and col-

depletes dopamine levels. The men’s

Drug Abuse in Baltimore, Maryland, who

leagues recruited him for an experiment.

insulin sensitivity decreased in concert,

was not involved in the new research.

Fourteen other men and women with

bolstering the connection, they report.

That doesn’t make deep brain stimula-

DBS implants for OCD—but without dia-

tion (DBS) realistic for most people with

betes—joined him. Serlie and colleagues

diabetes, but other, less invasive brain

turned off the DBS devices for 17 hours

therapies that target dopamine might

and measured participants’ fasting blood

one day be feasible. Diabetes occurs

sugar levels and responses to insulin.

by EMILY UNDERWOOD

STIMULATING BRAIN CELLS WITH ELECTRICAL PULSES COULD HELP TREAT DIABETES 60


IT TURNS OUT ANDROMEDA IS YOUNGER THAN EARTH

IT TURNS OUT ANDROMEDA IS YOUNGER THAN EARTH by MATT WILLIAMS

S

ince ancient times, astronomers

Andromeda, as we know it today, is ef-

Andromeda has a wealth of young blue

have looked up at the night sky

fectively younger than our very own Solar

stars in its disk (less than 2 billion years

and seen the Andromeda galaxy.

System, which has it beat by about 1.5

old) that undergo random motions over

As the closest galaxy to our own, scien-

billion years! The study, titled “A 2-3 billion

large scales. This is contrast to the stars

tists have been able to observe and scru-

year old major merger paradigm for the

in the Milky Way’s disk, which are subject

tinize this giant spiral galaxy for millennia.

Andromeda galaxy and its outskirts“, re-

only to simple rotation.

By the 20th century, astronomers realized

cently appeared in the Monthly Notices

that Andromeda was the Milky Way’s sis-

of the Royal Astronomical Society. Led

In addition, deep observations conducted

ter galaxy and was moving towards us. In

by Francois Hammer, the Principle Inves-

between 2008 and 2014 with the Fren-

4.5 billion years, it will even merge with

tigator of the Galaxies, Etoiles, Physique

ch-Canadian telescope in the Hawaiian

our own to form a supergalaxy. However,

et Instrumentation (GEPI) department at

Islands (CFHT) indicated some interesting

it seems astronomers were wrong about

the Paris Observatory, the team included

things about Andromeda’s halo. This vast

the Andromeda galaxy in one major

members from the Chinese Academy of

region, which is 10 times the size of the

respect. According to recent study led

Sciences and the University of Strasbourg.

galaxy itself, is populated by gigantic cur-

by a team of French and Chinese astro-

For the sake of their study, the relied on

rents of stars. The most prominent of whi-

nomers, this giant spiral galaxy formed

data gathered by recent surveys that no-

ch is called the “Giant Stream”, a warped

from a major merger that occurred less

ted considerable differences between the

disk that has shells and clumps at its very

than 3 billion years ago. This means that

Andromeda and Milky Way galaxies. The

edges. Using this data, the French-Chine-

first of these studies, which took place be-

se collaboration then created a detailed

tween 2006 and 2014, demonstrated all

numerical model of Andromeda using the

WELL, SORT OFF YOUNGER 61


IT TURNS OUT ANDROMEDA IS YOUNGER THAN EARTH

two most powerful computers available in

mass distributions for both parent gala-

tures attributed to the smaller galaxy have

France – the Paris Observatory’s MesoP-

xies that merged to formed Andromeda,

an under-abundance in heavy elements

SL and the National Center for Scientific

which indicated that the larger galaxy

compared to the others – i.e. it was less

Research’s (CNRS) IDRIS-GENCI super-

was four times the size of the smaller. But

massive so it formed fewer heavy elements

computer. With the resulting numerical

most importantly, the team was able to

and stars. This study is immensely signifi-

model, the team was able to demonstrate

reproduce in detail all the structures that

cant when it comes to galactic formation

that these recent observations could be

compose Andromeda today – including

and evolution, mainly because it is the first

explained only by a recent collision. Basi-

the bulge, the bar, the huge disk, and the

numerical simulation that has succeeded

cally, they concluded that between 7 and

presence of young stars.

in reproducing a galaxy in such detail. It is

10 billion years ago, Andromeda consis-

also of significance given that such a re-

ted of two galaxies that had slowly achie-

The presence of young blue stars in its disk,

cent impact it could have left materials in

ved a encountering orbit. After optimi-

which has remained unexplained until now,

the Local Group. In other words, this stu-

zing the trajectories of both galaxies, they

is attributable to a period of intense star

dy could have implications that range far

determined that they would have collided

formation that took place after the colli-

beyond our galactic neighborhood. It is

1.8 to 3 billion years ago. This collision

sion. In addition, structures like the “Giant

also a good example of how increasingly

is what gave birth to Andromeda as we

Stream” and the shells of the halo belon-

sophisticated instruments are leading to

know it today, which effectively makes it

ged to the smaller parent galaxy, whereas

more detailed observations which, when

younger than our Solar System – whi-

the diffuse clumps and the warped nature

combined with increasingly sophisticated

ch formed almost 4.6 billion years ago.

of the halo were derived from the larger

computers and algorithms, are leading to

What’s more, they were able to calculate

one. Their study also explains why the fea-

more detailed models.


THESE BATS USE STEALTH SONAR

THESE BATS USE STEALTH SONAR

To find out how hoary bats navigate, resear-

-ins with wind turbines than other bat spe-

chers used infrared cameras and ultrasonic

cies in North America. The microcalls are so

microphones to record scores of them flying

quiet that they reduce the distance over whi-

through a riverside corridor in California

ch bats can detect large and small objects by

on five autumn nights. In about half of the

more than three times. That also cuts bats’

nearly 80 flights, scientists captured a novel

reaction time by two-thirds, making them

habitual

type of call. Shorter, faster, and quieter than

too slow to catch their insect prey. So why

squawkers. Sporting frosted

their usual calls, the new “micro” calls use

risk starvation and fatal crashes? Making

by RONI DENGLER

H

oary

bats

are

brown fur á la Guy Fieri, the

three orders of magnitude less sound ener-

normal-intensity calls might attract unwan-

water balloon–size bats bark high-pi-

gy than other bats’ yaps did, the researchers

ted aggression from potential rivals, say the

tched yips to navigate the dark night

report today in the Proceedings of the Royal

researchers, who conducted their study du-

sky by echolocation. But a new study

Society B. As bats approached objects, they

ring the bats’ mating season. Microcalls are

reveals that as they fly, those cries often

would often quickly increase the volume of

much more discreet, slashing the distance

drop to a whisper, or even silence, sug-

their calls. But in close to half the flights, re-

that other bats can “eavesdrop” from about

gesting the bats may steer themselves

searchers did not pick up any calls at all. This

92 meters to 12. So the stealth sonar might

through the darkness with some of the

stealth flying mode may explain one sad fact

simply be part of a larger tactic to keep rival

quietest sonar on record.

of hoary bat life: They suffer more fatal run-

males out of earshot.

LIKELY TO EVADE RIVALS 63


EDITOR’S LETTER

46


THESE 59 GENES MAY MAKE YOUR DOG MORE ATHLETIC

THESE 59 GENES MAY MAKE YOUR DOG MORE ATHLETIC by ELIZABETH PENNISI

Compare the sprinting Shetland sheep-

for studying how genotypes, or sets of

turn sport dogs such as pointers, setters,

dog with the sluggish St. Bernard, and

genes, result in phenotypes, or sets of

and retrievers into the Michael Jordans

it’s clear a dog’s genes play a large role

observable characteristics in all types of

of the canine world. He and colleagues

in how athletic it is. Now, at the Bio-

animals, he says. Past work on dogs has

compared the genomes of 21 individuals

logy of Genomes meeting here, scien-

yielded genes for friendliness, hair type,

from 10 sport hunting breeds with 27 in-

tists report identifying 59 genes linked

and other relatively simple traits. But

dividuals from nine terrier breeds.

to canine athletics, which apparently

this new study looked at more complex

affect everything from heart rate to

ones, thanks to a new resource: a soon-

Fifty-nine genes, or the regions that con-

muscle strength. Early results suggest

-to-be-released global database of the

trol them, stood out, with certain ver-

some may eventually help us unders-

whole-genome sequences of 722 dogs

sions of the DNA much more common in

tand human superstars.

across about 450 breeds, along with se-

the sport dogs, Kim reported at the me-

quences for canine relatives, including

eting. He and his colleagues could not

“Across dogs, all sorts of traits have

wolves, foxes, and jackals. Jaemin Kim, a

easily verify their effects on athletic per-

been selected for in an extreme way,”

postdoc working with canine genomicist

formance, but most are linked to traits

says Alexander Godfrey, a genomicist at

Elaine Ostrander at the National Human

including blood flow, heart rate, muscle

the Massachusetts Institute of Techno-

Genome Research Institute in Bethesda,

strength, and even pain perception. One

logy Whitehead Institute in Cambrid-

Maryland, focused on athleticism, in part

seems to help dogs remain calm after

ge, who was not involved in the work.

because he wondered why he wasn’t any

they hear a gunshot, he added, which

As such, dog genomics represents “a

better at his favorite sport: basketball.

may make them stable hunting compa-

pretty unique and powerful system”

He decided to start with the genes that

nions; a different version in terriers may

65


THESE 59 GENES MAY MAKE YOUR DOG MORE ATHLETIC

account for their well-known neuroti-

a mental attribute may matter more than

are great athletes that race around ke-

cism. To examine the role of these genes

physical ones do. “It looks like it’s more

eping livestock together and headed in

in other breeds, Kim needed a standard

of a training thing,” says Sarah Tishkoff,

the right direction, even though they are

way of assessing athleticism. He deci-

an evolutionary geneticist at the Univer-

not that muscular looking. Kim is starting

ded to use agility trials, competitions

sity of Pennsylvania who was not involved

to look at the genetic basis of that beha-

in which dogs, guided by their owners,

with the work. “It’s interesting to think

vior. Ostrander says the new results might

maneuver through an obstacle course

about what genes are associated with

one day help us better understand the

in the shortest time possible. Data from

what traits,” Godfrey says. “That it

genetic basis of athleticism in humans.

the United States Dog Agility Association

would be a gene that’s not involved

Already, other researchers have impli-

allowed him to calculate the best perfor-

with muscles is not obvious.” Even

cated one of the 59 genes in improving

ming breeds: border collies and Shetland

though agility trials are a good measure,

human performance by improving blood

sheepdogs. The worst were Newfoun-

Godfrey cautions that in general humans

flow, and it’s likely, she says, that others

dlands, bulldogs, and mastiffs.

are notoriously bad at objectively evalua-

will also prove important. Dogs suffer

ting their own and other people’s dogs.

many of the same health problems that

Then, he compared whole genomes from

And he wonders whether, even in agility,

people do, and canine versions of the re-

the best and the worst, looking for diffe-

judges wind up “scoring aspects of hu-

levant genes will be easier to track down.

rences in the 59 genes. Only one proved

man[like] behavior that they like” and

Because breeders work hard to bring out

to be significant, a gene called ROBO1

not agility per se, he points out. Ano-

specific traits in their dogs, “you get mu-

that affects learning ability. So when it

ther issue is that there are other types of

tations in pathways that have drama-

comes to agility, Kim said, it seems that

athleticism. Herding dogs, for example,

tic effects,” Tishkoff explains.


CANADIAN ICE CAP CONCEALS SUPERSALTY LAKES

CANADIAN ICE CAP CONCEALS SUPERSALTY LAKES by SID PERKINS

A

t least two large, supersalty

The radar was apparently bouncing off the

salt deposits laid down hundreds of millions

lakes lie deep beneath an

surfaces of subglacial lakes hundreds of

of years ago, which act like road salt to keep

ice cap in far northeastern

meters down, one covering about 5 square

the water liquid. The water must be at least

Canada, a new radar sur vey shows.

kilometers and the other a little more than

four or five times as salty as the ocean, the

The sur vey traced the mountainous

8 square kilometers, the researchers report

researchers estimate. That’s not too salty to

terrain underlying the Devon Ice Cap

today in Science Advances. How does the

host microbial life, as a similarly briny sub-

(pictured), a frozen mass almost the

water remain liquid at temperatures es-

glacial lake in Antarctica proves. But if these

size of Connecticut. But in a couple

timated at –14°C and –15°C, well below

Canadian lakes host an ecosystem, it has

of places, the researchers also saw

freezing? The researchers credit a fluke of

likely been isolated since the beginning of

strong, mirrorlike reflections.

geology: The lakes apparently sit atop thick

the last ice age about 120,000 years ago.

67


SMILE! YOUR DOG’S BRAIN WILL LIGHT UP IN RESPONSE

SMILE! YOUR DOG’S BRAIN WILL LIGHT UP IN RESPONSE by VIRGINIA MORELL

As every dog lover—and scientist—knows,

dogs process human faces? To find out,

a distinctive signature in a dog’s temporal

man’s best friend is good at reading faces.

scientists trained eight dogs—mostly border

lobe and other neural regions. In a follow-

Dogs can tell the difference between happy

collies—to lie still in a functional magnetic

-up experiment, the pooches’ brains were

and not-so-happy expressions, such as an-

resonance imaging scanner while viewing

scanned as they looked at faces expressing

ger and sadness. Like us, they watch the left

photos of strangers with either happy or

happiness, anger, fear, or sadness. The ha-

sides of peoples’ faces—where emotional

neutral expressions. The faces matched the

ppiness pattern was so distinctive that a

cues first appear. And they even seem to

gender of the dogs’ chief caretakers, becau-

machine learning program could pick it out

be able to interpret our emotions and mo-

se dogs have been shown to score lower

from brain activity linked to all the other

dulate their behavior accordingly. But what

on tasks involving faces of the opposite sex.

emotions—which suggests that our canine

are the neural mechanisms that control how

The results: A happy human face produces

pals really do know what we’re feeling.

68


PLAYING VIDEO GAMES IS GOOD FOR YOUR BRAIN

PLAYING VIDEO GAMES IS GOOD FOR YOUR BRAIN by MARK GRIFFIRTHS

Whether playing video games has ne-

reaction times and hand-eye co-ordina-

(10 to 14 people in each study), the resear-

gative effects is something that has been

tion. For example, research has shown that

chers reported that gamers with previous

debated for 30 years, in much the same

spatial visualisation ability, such as mentally

experience of playing such action video

way that rock and roll, television, and even

rotating and manipulating two- and three-

games were better at perceptual tasks such

the novel faced much the same criticisms

-dimensional objects, improves with video

as pattern discrimination than gamers with

in their time. Purported negative effects

game playing.

less experience. In another experiment,

such as addiction, increased aggression,

they trained gamers that had little previous

and various health consequences such as

To add to this long line of studies demons-

experience of playing action games, giving

obesity and repetitive strain injuries tend to

trating the more positive effects of video

them 50 hours practice. It was showed that

get far more media coverage than the po-

games is a study in the Proceedings of the

these gamers performed much better on

sitives. I know from my own research exa-

National Academy of Sciences by Vikran-

perceptual tasks than they had prior to

mining both sides that my papers on video

th Bejjanki and colleagues. Their newly

their training. In my own papers, I have

game addiction receive far more publicity

published paper demonstrates that the

pointed out many features and qualities

than my research into the social benefits

playing of action video games – the sort

that make video games potentially useful.

of, for example, playing online role-playing

of fast-paced, 3D shoot-em-up beloved of

For instance, in an educational context,

games. However there is now a wealth of

doomsayers in the media – confirms what

video games can be fun and stimulating,

research which shows that video games

other studies have revealed, that players

which means it’s easier to maintain a pupil’s

can be put to educational and therapeutic

show improved performance in percep-

undivided attention for longer. Because of

uses, as well as many studies which reve-

tion, attention, and cognition. In a series of

the excitement, video games may also be

al how playing video games can improve

experiments on small numbers of gamers

a more appealing way of learning than tra-

69


PLAYING VIDEO GAMES IS GOOD FOR YOUR BRAIN

ditional methods for some. Video games

innovative contexts. A number of studies

have an appeal that crosses many demo-

have shown that when children play video

graphic boundaries, such as age, gender,

games following chemotherapy they need

ethnicity, or educational attainment. They

fewer painkillers than others. Video games

can be used to help set goals and rehearse

have great educational potential in addi-

working towards them, provide feedback,

tion to their entertainment value. Games

reinforcement, self-esteem, and maintain a

specifically designed to address a specific

record of behavioural change.

problem or teach a specific skill have been very successful, precisely because they

Their interactivity can stimulate learning,

are motivating, engaging, interactive, and

allowing individuals to experience novel-

provide rewards and reinforcement to im-

ty, curiosity and challenge that stimulates

prove.

learning. There is the opportunity to develop transferable skills, or practice chal-

But the transferability of skills outside the game-

lenging or extraordinary activities, such as

-playing context is an important factor. What’s

flight simulators, or simulated operations.

also clear from the scientific literature is that the

Because video games can be so enga-

negative consequences of playing almost alwa-

ging, they can also be used therapeuti-

ys involve people that are excessive video game

cally. For instance, they can be used as a

players. There is little evidence of serious acute

form of physiotherapy as well as in more

adverse effects on health from moderate play.

70


ANCIENT EARTH FROZE OVER IN A GEOLOGIC INSTANT

ANCIENT EARTH FROZE OVER IN A GEOLOGIC INSTANT by LUCAS JOEL

tary freezes since at least the 1990s. But even

glacial rock layers in a smooth fashion—without

though computer models supported the idea,

any significant breaks—there was likely little to

there was little actual evidence from the planet’s

no missing time between the warm and frozen

rock record. That’s why Scott Maclennan, a Ph.D.

episodes, Maclennan says. But exactly how long

student studying geology at Princeton Universi-

it took for the freeze to finish is more difficult to

ty, and his advisers were excited when they got

discern. Maclennan explains that it could have

a tipoff from Robert Bussert, a geologist at the

been, from beginning to end, anywhere from

Technical University of Berlin, about rocks in nor-

1000 to 100,000 years. Many scientists think that

thern Ethiopia that supposedly formed around

such a rapid expansion of ice happened thanks

the same time as one of the suspected Snowball

to a so-called ice albedo feedback loop. Within

Earth episodes, known as the Sturtian glaciation.

such a loop, ice sheets reflect incoming sunlight

Earth’s ice is melting at a rapid clip today. But

Maclennan and colleagues ventured to the

back out into space, driving down atmosphe-

some scientists think that during several ancient

small town of Samre, Ethiopia, where they came

ric temperatures. These low temperatures, in

episodes, the planet plunged into a deep freeze

across a type of rock—which they later dated to

turn, drive even more ice growth, and as more

known as “Snowball Earth” when ice sheets

roughly 717 million years old—that could have

ice forms, more solar energy escapes out into

grew to cover almost the entire planet. However,

only formed through glacial activity. These rocks,

space. This process snowballed until, in this case,

the number of these episodes, their extent, and

called diamictites, are made of huge boulders

most of the planet froze. “Earth can do things

just how fast Earth turned into an ice cube have

transported great distances by glaciers. Buried

that you could never imagine” Dehler says.

long been a mystery. Now, analysis of a newly

just below those glacial rocks were older layers

The find supports theoretical models of snowball

discovered rock sequence in Ethiopia supports

of carbonate rocks. As the ancient superconti-

glaciation, which suggest that once ice extends

a Snowball Earth event some 717 million years

nent Rodinia was breaking apart, these rocks

down to 30 degrees of latitude, rapid planetwi-

ago and suggests it took place in mere thou-

formed in shallow waters with the aid of micro-

de glaciation follows. It also supports the only

sands of years—the geologic equivalent of a

bial marine organisms—a sign that the same

other find from the Sturtian glaciation that has

cold snap. The new work, grounded in Earth’s

location was warm just a bit earlier in time, Ma-

been dated with high precision—rocks from

rock record, means the Snowball Earth hypo-

clennan explains. Together, these layers suggest

northwest Canada that put the onset at about

thesis is “hanging in there, big time” says

the ancient climate quickly shifted from tropical

717 million years ago. “Given how crazy the

Carol Dehler, a geologist at Utah State University

paradise to frozen wasteland, Maclennan and

planet’s climate must have been to bring

in Logan, who was not involved in the research.

colleagues report this month in Geology. Becau-

about a snowball Earth, this positive test for

Geologists have suspected these rapid plane-

se the carbonate rock layers transition into the

the hypothesis is surprising,” Maclennan says.

71


BEES ACTUALLY UNDERSTAND THE CONCEPT OF “ZERO”

H

umans’ invention of zero was

64% of the time they chose this option

crucial for modern mathema-

rather than a picture containing two or

tics and science, but we’re not

three shapes, the authors report today

the only species to consider “nothing” a

in Science. This suggests that the insects

number. Parrots and monkeys understand

understood that “zero” is less than two

the concept of zero, and now bees have

or three. And they weren’t just going for

joined the club, too.

the empty picture because it was new and interesting: Another group of bees trai-

Honey bees are known to have some

ned to always choose the larger number

numerical skills such as the capacity to

tended to pick the nonzero image in this

count to four, which may come in han-

test. I n further experiments, the resear-

dy when keeping track of landmarks in

chers showed that bees’ understanding

their environment. To see whether these

of zero was even more sophisticated: For

abilities extended to understanding zero,

example, they were able to distinguish

researchers trained 10 bees to identify the

between one and zero—a challenge

smaller of two numbers. Across a series of

even for some other members of the zero

trials, they showed the insects two diffe-

club. Advanced numerical abilities like this

rent pictures displaying a few black sha-

could give animals an evolutionary ad-

pes on a white background. If the bees

vantage, helping them keep track of pre-

flew to the picture with the smaller num-

dators and food sources. And if an insect

ber of shapes, they were given delicious

can display such as thorough grasp of the

sugar water, but if they flew toward the

number zero, write the researchers, then

larger number, they were punished with

this ability may be more common in the

bitter-tasting quinine. Once the bees had

animal kingdom than we think.

BEES ACTUALLY UNDERSTAND THE CONCEPT OF “ZERO” by MATT WARREN

learned to consistently make the correct choice, the researchers gave them a new option: a white background containing no shapes at all. Even though the bees had never seen an empty picture before,

WE’RE NOT THE ONLY SPECIES TO CONSIDER “NOTHING” A NUMBER 74


SEA MAMMALS ARE HUGE FOR A REASON

SEA MAMMALS ARE HUGE FOR A REASON by ANGUS CHEN

In general, aquatic mammals tend to be

The scientists think this is because it’s too

larger than their closest land-bound relati-

chilly to survive in the ocean as a warm-

ves. The largest sea lions are twice as big as

-blooded animal without sufficient size.

the largest bears, for example, and mana-

The amount of heat your body can ge-

tees outweigh their cat-size hyrax cousins

nerate depends on how many cells you

by nearly 500 kilograms.

have, and small animals simply don’t have enough to replace the heat they lose to

To find out why, researchers looked at the

the water. On top of that, a small body

sizes of four different evolutionary groups

means a lot of surface area where heat

of sea mammals—roughly 4000 living and

can be lost relative to their overall body

3000 fossil species—beginning with the

mass. That means in the frigid sea, it’s

time they diverged from their terrestrial

better to be bigger. There’s a limit on how

relatives. Once they began an aquatic life,

massive any creature can get, of course.

these mammals all evolved toward larger

Your maximum size generally depends on

sizes over the past 60 million years or so.

how you eat. Smashing shellfish as a lifes-

Their land relatives, on the other hand,

tyle, as sea otters do, might not be enou-

didn’t trend toward any particular size, the

gh to sustain 100 metric tons, but baleen

team reports today in the Proceedings of

whales like the blue whale can take ad-

the National Academy of Sciences.

vantage of krill, a rich food source.

75


SEA MAMMALS ARE HUGE FOR A REASON


CAN ADULTS REALLY MAKE NEW NEURONS

CAN ADULTS REALLY MAKE NEW NEURONS by EMILY UNDERWOOD

O

Hen, a neuroscientist at Columbia Univer-

niches of neural stem cells constantly re-

sity. But he and others suggest that the stu-

generate parts of the rodent brain. But the

dy left much room for error. The way the

carbon-dating evidence did not persuade

tissue was handled, the deceased patients’

him that people maintain similar stem cell

psychiatric history, or whether they had

reserves: The method involves “a lot of

brain inflammation could all explain why

assumptions and steps in which there

the researchers failed to confirm earlier,

can be contamination or false posi-

encouraging studies, Hen says. The first

tives,” he says. For the new analysis, his

ver the past 20 years, evidence

evidence of neurogenesis in adult humans

team spent 5 years collecting brain tissue

that adult humans can produce

came in 1998 from the brains of deceased

from 59 people who had died or had such

hundreds of new neurons per

cancer patients who had received injec-

tissue removed during surgery for epilepsy

day has fueled hope that ramping up cell

tions of a chemical called bromodeoxyuri-

at different ages, ranging from before bir-

birth could be therapeutic. Boosting neu-

dine while they were still alive. The chemi-

th to 77 years of age. They used fluores-

rogenesis, researchers speculate, might

cal labels newly divided cells, and in their

cent antibodies to label proteins specific

prevent or treat depression, Alzheimer’s

brain tissue, it showed up in a sprinkling of

to cells at different states of maturity. With

disease, and other brain disorders. But a

neurons in the hippocampus—a seahorse-

an electron microscope, they also looked

controversial study in Nature this week

-shaped structure involved in memory and

for the characteristic long, slender, simple

threatens to dash such hopes by sugges-

learning. In 2013, Jonas Frisén’s lab at the

shapes of young neurons. The team found

ting that the production of neurons de-

Karolinska Institute in Stockholm buttres-

that people have large numbers of neural

clines sharply after early development and

sed the case by carbon dating individual

stem cells and progenitors early in life—an

grinds to a halt by adulthood.

neurons in brain tissue from 55 deceased

average of 1618 young neurons per square

people. From the cells’ ages, the group

millimeter of brain tissue at birth. But these

The results of the “exhaustive search” for

calculated that every day, humans replace

cells did not go on to form a proliferating

new neurons in adult human and monkey

700 of their neurons in the dentate gyrus,

layer of neural stem cells, and production

brains “will disappoint many,” says neu-

a sliver of hippocampus thought to enco-

of new neurons dropped 23-fold between

roscientist Paul Frankland of the Hospital for

de memories. Arturo Alvarez-Buylla of the

1 and 7 years of age, the team reports. By

Sick Children in Toronto, Canada. “It raises

University of California, San Francisco, who

adulthood the supply of young neurons

concern that levels of neurogenesis are

has been studying the brain’s capacity to

had petered out entirely. “We just don’t

too low to be functionally important”

produce new cells since the 1980s, was

see what other people are claiming” in

in humans, adds another observer, René

skeptical. He is known for showing how

adults, Alvarez-Buylla says.

77


JUPITER’S STORMS HAVE ROOTS BENEATH ITS SURFACE

JUPITER’S STORMS HAVE ROOTS BENEATH ITS SURFACE by PAUL VOOSEN

The gaseous veil of Jupiter’s surface has long

ppler shifts in Juno’s radio signal collected on

cast a pall over scientists’ quest to unders-

Earth. In these data, Juno’s scientists discove-

tand the giant planet’s depths. In particu-

red an asymmetry in Jupiter’s north-south

lar, researchers have debated whether the

gravitational field that reflected shifting mas-

bands of east-west winds that sculpt Jupiter’s

ses driven by rising winds from 3000 kilome-

distinctive surface, complete with the curli-

ters deep within the planet. These flows of

cues of stormy cyclones, extend deeper into

hydrogen and helium, the team shows, are

the planet, or are merely superficial. Now, a

driven up by energy lost from the planet’s

series of papers from NASA’s Juno spacecraft,

deeper interior, which rotates like a solid

published today in Nature, has revealed that

because of crushing high pressures. When

the roots of Jupiter’s winds indeed run deep.

compared with similar observations taken by

Since arriving at the gas giant in 2016, Juno

Cassini before its dive into Saturn last year,

has swung around the planet in an elliptical

the NASA missions could soon clarify the

53-day orbit; with each pass, Jupiter’s gravity

internal dynamics of gas giants, helping un-

has tugged the spacecraft back and forth,

derstand their origins—and the composition

revealing glimpses of its interior through Do-

of worlds beyond our solar system.

78


THE EARLIEST EVIDENCE OF BUTTERFLIES POSES A MYSTERY

P

icture a butterfly. Is it on a flower sucking up sweet nectar with its tonguelike proboscis? Well, hold

that thought. Thanks to the earliest butterfly fossils yet discovered, researchers now estimate proboscis-sporting butterflies were around well before flowering plants. After digging the delicate relics out of rocks in northern Germany, resear-

THE EARLIEST EVIDENCE OF BUTTERFLIES POSES A MYSTERY

chers examined the scales that cover but-

by RONI DENGLER

terfly and moth wings, bodies, and legs

archers suggest the appendage likely hel-

(pictured) under a powerful microscope. Some scales were solid and decorated with a herringbone pattern. That indicated its owner had jaws to chew food because most butterfly families with solid scales have mandibles. But other scales researchers inspected were hollow with

ped the winged insects avoid becoming dehydrated in the hot and arid climate of the time by getting sustenance from another source: sweet secretions beaded up into droplets on seed-bearing—as opposed to flowering—plants.

markings that distinctly resemble those of a living class of the insects that uses its proboscis to eat. Ancient phytoplankton and pollen grains nestled in the sediment date the early butterfly fossils to roughly 200 million years ago, researchers report today in Science Advances, whereas flowering plants began growing across the landscape only about 140 million to 160 million years ago. So, what good was

INSECTS HAD EVOLVED A

a proboscis if not for slurping up flowers’

WAY TO EAT FOOD THAT

sugary goodness? Instead of nectar, rese-

WASN’T AVAILABLE YET 80


NEXT ISSUE . JUNE 2018

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Based on typing style, models can pr edict gender with up to 95% accuracy

But it might be a while befor e they’re ready for diabetics

A large vestibular system helps the animal maintain posture while chasing its prey

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