The Washington Post - USA (2022-05-24)

E2 EZ EE THE WASHINGTON POST.TUESDAY, MAY 24 , 2022

SCIENCE NEWS

BY WILL DUNHAM

A young girl’s tooth excavated from a cave wall in northeastern Laos is providing new insight into the mysterious extinct human species called Denisovans and revealing their resourcefulness in adapting to both tropical and chilly climes. The tooth is one of the few physical remains known of Denis- ovans, a sister lineage to Nean- derthals who until now had been known only from scrappy dental and bone fossils from a single site in Siberia and one in the Himala- yas. The molar, between 164,000 and 131,000 years old, belonged to a girl about 4 to 6 years old and had not yet erupted. The humid Laotian conditions meant ancient DNA was not preserved in the molar, unlike other Denisovan remains. The researchers determined it was Den- isovan based on its shape — short and heavily wrinkled — and enamel characteristics. Ancient proteins indicated the molar came from a girl. It was unearthed in a lime- stone cave called Ta m Ngu Hao 2, known to locals as Cobra Cave, in the Annamite Mountains. “This is the first time that a Denisovan has been found in a warm region,” said paleoanthropologist Fabrice Demeter of the University of Copenhagen’s Lun- dbeck Foundation GeoGenetics Centre, lead author of the study published last week in the journal Nature Communications. “It means that they were adapt- ed to opposite environments, from cold and high altitude to warm and low altitude regions. In this regard, they were like us, modern humans,” Demeter said. The existence of Denisovans was unknown until the tip of a finger bone about 40,000 years old was found in 2010 in a cave in the Altai Mountains of Siberia. Three molars also were found at that site. A partial Denisovan jawbone from about 160,000 years ago subsequently was discovered in a Tibetan cave. “We would like to know a great deal more about Denisovans. But I think it’s i mportant to know that just like the Neanderthals were

known from Western Europe and the Near East, the Denisovans were a similar and closely related species that was found across a huge part of Asia,” University of Illinois paleoanthropologist and study co-author Laura Shackel- ford said. The Laotian cave is about 2,400 miles from the Siberian cave. “Unfortunately, we know very little about what they looked like since there are so few fossils available,” Shackelford said. Neanderthals possessed a strong double-arched brow ridge, relatively large noses and relatively large front teeth. Genome studies have shown that our species, Homo sapiens, interbred with Denisovans as re- cently as 30,000 years ago. As a result, some modern people share about 5 percent of their DNA with Denisovans including Indigenous populations in Papua New Guin- ea, Australia and the Philippines, with smaller DNA percentages among the broader Southeast Asian populations. “This discovery [of the molar] is particularly important as it is the first direct evidence of the presence of Denisovans in South- east Asia,” said Eske Willerslev, director of the Lundbeck Founda- tion GeoGenetics Centre and a study co-author. A common ancestor to Deniso- vans, Neanderthals, and Homo sapiens is thought to have lived in Africa 700,000 to 500,000 years ago, with a branch that led to Denisovans and Neanderthals splitting off 470,000 to 380,000 years ago. Homo sapiens first emerged in Africa roughly 300,000 years ago, then spread worldwide. By 200,000 years ago, four different archaic human species inhabited Asia including the Den- isovans, Homo erectus, and di- minutive island-dwelling peoples called Homo floresiensis and Homo luzonensis. Our species then joined the fray. Scientists have been searching in northeastern Laos for decades for prehistoric human remains. The cave bearing the tooth was situated near another where 70,000-year-old Homo sapiens remains were found. — Reuters

A girl’s tooth found in Laos sheds more light on Denisovans, enigmatic group of extinct humans

SCIENCE SCAN

BY ERIN BLAKEMORE

The Amazon is teeming with life. And many of the animals there get caught on camera when they encounter camera traps set up by wildlife researchers eager for a look at their lives. But until now, there hasn't been a central set of information about those images. A massive archive — with rec- ords for over 150,000 snapshots taken between 200 1 and 2020 — has now been collected in one place. An international team of 120 institutions describes the new data set in an article in the journal Ecology. Camera trap data has been “de- ficient and scattered,” the researchers write — a missed op- portunity to study and inventory wildlife in the Amazon in a nonin- vasive way. N ow, they’re making it freely available (but asking schol- ars to let them know how they use it). It’s an attempt not just to get the information in one place but to enable researchers to study some of the biggest challenges that face the region. Many — such as climate change, deforestation and fire — are human-caused. The area is the world’s most biodiverse, and many of its thousands upon thousands of species have not been documented or studied. The camera traps in the data set have snapped photos of 317 animal species in Brazil, Bolivia, Colombia, Ecuador, French Gui-

ana, Peru, Suriname and Ven- ezuela. More than 50,000 photos — nearly half of the data set — were provided by Wildlife Con- servation Society scientists. The data includes information on things such as which species was captured, what bait was used, where an image was taken and what the landscape is like there. Among the most photographed were lowland pacas, rodents with lines of deer-like spots; black ra- zor-billed curassow birds; and gold tegus, a kind of lizard that can grow up to 3 feet long and weigh up to nine pounds. Camera traps are growing in popularity as a way to get information about animals without disturbing or killing them. Trig- gered by infrared sensors, the static cameras are used to check up on animal populations long term and take censuses of their numbers. They also provide insight into how animals prey and mate — activities that human presence could interrupt. The project has been a “massive effort,” the researchers write. And it’s just the beginning: By releasing the data, the researchers say they hope they can create more connections between camera trap researchers and increase coordination for future surveys.

BIODIVERSITY

Massive archive of Amazon ‘camera traps’ seeks to provide a better study of life in the rainforest

AMAZONIA CAMTRAP : A dataset of mammal, bird, and reptile species recorded with camera traps in the Amazon forest Ecology

BY JACOB FEUERSTEIN

As Hurricane Ida’s remnants
spread over the Mid-Atlantic on
Sept. 1, 2021, thousands of people
in Bucks County, Pa., faced a
seemingly impossible choice:
take cover from a potential torna-
do or move higher to avoid flood-
ing.
The situation was unusual but
not unheard of. Ida’s powerful
thunderstorms were loaded with
both spin and moisture. Soon
after a particularly intense thun-
derstorm began to rotate, the
National Weather Service de-
clared a rare tornado emergency
for a swath of Pennsylvania and
New Jersey.
The warning came with an
urgent action item: “To protect
your life, TAKE COVER NOW!
Move to an interior room on the
lowest floor of a sturdy building.”
Almost simultaneously, the
moisture-laden storm began to
unload exceptionally heavy rain.
Then, the Weather Service de-
clared a dire flash flood emergen-
cy. At the bottom of this warning,
an equally firm call to action was
posted: “Move to higher ground
now!”
Thunderstorms that produce
simultaneous tornadoes and
flash flooding, known as “dual
hazard” or “TORFF” events
(TORFF is short for tornado and
flash flooding) to meteorologists,
have long posed a dilemma:
When flash flooding threatens,
the worst place to be is below
ground; when tornadoes strike,
high ground is incredibly danger-
ous.
In the past two decades, thou-
sands of such concurrent events
have taken place across the Unit-
ed States, leaving many that are
in the path of destruction uncer-
tain on what they should do.
While the Weather Service is im-
proving their communication
about compound hazards, re-
searchers say individuals should
respond to the hazard most press-
ing at t he time and be prepared to
quickly move locations if neces-
sary.

How and where they happen

In 2013, a tragedy underscored
the dangers of these double-im-
pact events. As the El Reno torna-
do threatened populous suburbs
of Oklahoma City on May 31, the
local Weather Service office de-
clared a strongly-worded tornado

emergency: “THIS IS AN EXTREMELY DANGEROUS AND LIFE THREATENING SITUATION. IF YOU CANNOT GET UNDER- GROUND GO TO A STORM SHELTER OR AN INTERIOR ROOM O F A STURDY BUILDING NOW.” A family of seven heeded this advice to hurry underground, sheltering in a storm drain. But the tornado was followed by exceptionally heavy rain, which led to a round of flash flooding. All seven were killed as swiftly mov- ing water filled the drain. Flash floods resulted in more fatalities than tornadoes that evening. Like both tornadoes and heavy rain, TORFF events generally occur in environments with abun- dant moisture and powerful winds. But forecasting TORFF events can be difficult because wet, windy environments are as- sociated with many potential weather hazards. Erik Nielsen, an assistant professor at Texas A&M University who has been studying these events for nearly a decade, and Russ Schumacher, an associate professor at Colorado State Uni- versity, conducted the first scientific study on TORFF events. Be- tween 2008 and 2020, the pair documented locations that saw both a tornado warning and a flash flood warning within a half- hour. They found thousands of examples, spread from Hawaii to Florida and from California to Maine. TORFF events are most common, according to Nielsen, when individual thunderstorm cells co- alesce into larger storm complex- es. They also occur frequently amid landfalling tropical storms and hurricanes. Occasionally, even individual supercells or single rotating thunderstorms are known to produce both tornadoes and flash flooding. Forecasting TORFF events brings together numerous forecasting challenges at once, Niel- sen said. Forecasters must predict the potential for a tornado, which is tricky by itself. At the same time, they must forecast the amount of precipitation and its potential to trigger flooding. Then they must predict the evolu- tion of the storms themselves. “This is even before you get to the communication challenges of concurrent, collocated hazards

with contradicting lifesaving calls to action,” Nielsen said.

Warnings for such events Even after the 2013 tragedy, it took several years for TORFF events to gain significant atten- tion. In fact, it wasn’t until 2017, when Hurricane Harvey hit, that TORFF events gained national awareness. Katy C hristian, a research associate with the University of Okla- homa’s Cooperative Institute for Severe and High-Impact Weather Research and Operations, wrote in an email that Harvey was the event that “catapulted TORFF events into the national spot- light.” “During Harvey, you had embedded tornadoes within heavy tropical rainbands that were also producing widespread cata- strophic flash flooding,” Chris- tian wrote. “The conflicting response actions from these overlapping hazards ended up creat- ing a new separate hazard of the public being unsure of what actions to take to protect themselves.” Jen Henderson, who researchers TORFF events at the Te xas Te ch University Risk and Equity in Disasters Lab, said that the Weather Service’s warning process wasn’t set up to deal with concurrent hazards with conflicting action items. “Our weather warning systems were designed to detect and warn for singular threats — they’re biased toward a more siloed and scientific classification of threats,” Henderson wrote in an email. A tornado expert may be issu- ing a tornado warning, while someone else with heavy precipitation expertise may be manag- ing the flood alerts. As a result, Henderson explained, the warnings for different types of hazards are sent by different people “who may not be aware of the other threats in the heat of the moment.” But as the visibility of TORFF events continues to increase, the Weather Service is providing training to their forecasters on how to address the overlapping hazards. Barb Boustead, a meteorologi- cal instructor with the Weather Service’s Warning Decision Train- ing Division, wrote in an email that the Weather Service “is rais-

ing awareness about TORFF hazards among its forecasters and staff by providing training about these overlapping hazards.” Boustead said the training includes tips to better communicate between different depart- ments, such as “being in adjoin- ing workstations and communi- cating directly with each other.” “The training also encourages offices to use social media to communicate both hazards with equivalent weight, to make it clear that both threats are possible during an event,” Boustead said. As a TORFF event is occurring, Weather Service forecasters have also learned a variety of ways to help the public decide what actions to take. According to Chris- tian, these strategies can include strategically triggering wireless emergency alerts for whichever hazard appears more imminently pressing, trimming tornado warnings as soon as the twister has passed and editing warning action items during events so that overlapping headlines do not contradict one another.

Tips on surviving When the forecast calls for the potential for both tornadoes and flooding, there are several things people can do to be prepared. Well before a TORFF scenario develops, Christian advises that, “If you live in a flood-prone area, you should have a designated place where you can safely shelter from both the tornado and flash flood threat and arrive there before the storms even start.” Should both flash flooding and tornadoes prove imminent, she continues that you should “take whatever safety measure corre- sponds to the most pressing hazard at that location and time. If you have to shelter from a tornado during an ongoing flash flood threat, if possible, you should shelter in a safe building or home that does not require driving af- terward. Nearly half of flash flood fatalities are vehicle-related, so you want to avoid driving in flooded roadways if at all possible.” “Further,” she adds, “because the flash flood threat often comes directly after the tornado threat, you should be prepared to quickly emerge from your tornado shelter and get in a position to protect yourself from flooding impacts.”

CAPITAL WEATHER GANG

Facing the dual hazards of tornadoes and floods

BY DAVE KINDY

The Thescelosaurus moved
stealthily along the seashore.
Stretching about 12 feet long and
weighing about 500 pounds, the
thickly muscled dinosaur was
probably looking for food — or
trying to avoid becoming a meal.
Featuring prominent bony
eyebrows and a pointy beak,
Thescelosaurus plodded along
on two feet with the bulk of its
body leaning forward while a
long tail stretched backward for
balance. Suddenly, the dinosaur
lifted its head and looked
around, alarmed as the calm was
broken by unnerving natural
forces.
The ground started shaking
with intense vibrations while
water in the nearby sea sloshed
about in response. The sky filled
with burning embers, which
drifted down and set fire to the
lush primordial forest.
Thescelosaurus panicked and
looked to flee — but it was too
late. Everything changed in a
heartbeat as a 30-foot-high wave
of mud and debris came racing
up the seaway from the south,
sweeping away life and limb in
the process. The dinosaur was
caught in the destructive deluge,
its leg ripped off at the hip by the
devastating surge.
That moment — 66 million
years ago at the end of the
Cretaceous period, when an
earth-shattering asteroid ended
the reign of the dinosaurs — is
frozen in time today through a
stunning fossil found last year at
the Tanis dig site in North Dako-
ta. This perfectly preserved leg
clearly shows the skin, muscle
and bones of the three-toed
Thescelosaurus.
While the details of the death
scenario described above are em-
bellished, they’re based on re-
markable new findings and ac-
counts by Robert DePalma, lead
paleontologist at Ta nis.
“We’re never going to say with
100 percent certainty that this
leg came from an animal that
died on that day,” the scientist
said. “The thing we can do is
determine the likelihood that it
died the day the meteor struck.
When we look at the preserva-
tion of the leg and the skin

around the articulated bones, we’re talking on the day of impact or right before. There was no advanced decay.” DePalma and the dinosaur leg were featured this month in two episodes of “Nova” on PBS: “Di- nosaur Apocalypse: The New Evidence” and “Dinosaur Apoca- lypse: The Last Day.” Biologist and natural historian David At- tenborough was host of the pro- grams, which were produced in conjunction with the BBC. The leg and several other rel- ics discovered at the North Dako- ta site are the first actual fossils found showing the death and destruction that took place when a 10-mile-long space rock struck the Yucatán Peninsula in the G ulf of Mexico. This impact event 66 million years ago doomed the dinosaurs and led to the mass extinction of 75 percent of animal and plant life on Earth. At the time, the world was a much warmer place. There were no icecaps, and water levels were higher. The North American con- tinent was split in two by the Western Interior Seaway. Tanis is on what was the edge of that massive river, which became a conduit of carnage after the asteroid struck. The shock waves from nearly 3,000 miles away caused the seaway to erupt with a tsunami of epic proportions. As D ePalma p ointed out, T hes- celosaurus never stood a chance.

“You would not want to be there on that day,” he said. “There was a turbulent wall of death heading up the river. In addition, all these glowing spherules are falling out of the sky. They’re like beads of super- heated glass reentering the Earth’s atmosphere after being ejected from the crater site at the Yucatán. Then there was all this seismic shaking. It was really hell on earth.” A dinosaur’s loss, though, is a paleontologist’s gain. After Ta nis was discovered in 2008, scientists began to realize the fossils there were probably created during that big-impact moment. A series of key discoveries were made, including the dinosaur leg, the embryo of a pterosaur still in its shell, a turtle pierced by a chunk of wood and the well-preserved skin of a tricer- atops. Many of these fossils were being presented to the public for the first time in the PBS docu- mentaries. Perhaps most telling were the fossilized fish unearthed at the site in 2019, which caught many scientists by surprise. In those petrified remains, researchers found the embedded evidence they needed to substantiate the claim t hat the animals died when the asteroid struck: the glass spheres, known as ejecta, that came raining down from the sky that fateful day.

“Those were fish that died on that day,” DePalma said. “We know that because they had ejecta from the impact in their gills.” Researchers have unearthed countless samples of these glass spheres, all containing the signa- ture chemical components typi- cal of a major impact event. Made up of sand and other earthly materials, the molten glass was ejected into the atmosphere by the explosion caused by the asteroid striking the planet — estimated to be the equivalent of 10 billion atomic bombs. In- side one of those circular fossils is a tiny speck of rock that may be from the killer asteroid itself. DePalma, a postgraduate re- searcher at the University of Manchester in England and ad- junct professor of geosciences at Florida Atlantic University, has headed efforts at Tanis since

He and other scientists on
the team have published several
major papers describing the dis-
coveries and outlining the scien-
tific methodology used to date
the fossils and other evidence.
DePalma asserts that what
happened then is directly rel-
evant to the world today.
“I’ve been asked, ‘Why should
we care about this? Dinosaurs
have been dead for so long,’ ” he
said. “ It’s n ot j ust for p aleo nerds.
This directly applies to today.
We’re seeing mass die-offs of
animals and biomes that are
being put through very stressful
situations worldwide. By looking
through this window into the
past, we can apply these lessons
to today.”
To produce the “Nova” epi-
sodes, DePalma worked directly
with one of his heroes — the
96-year-old Attenborough — in
reviewing the discoveries and
discussing their importance.
“Sir David and I interacted
and consulted on everything,”
DePalma said. “It was a tremen-
dous experience. He cannot sti-
fle his enthusiasm. When we
were looking at the fossils and
talking about what they meant,
you couldn’t separate the two of
us. We kept going on and on
about them. We w ould have been
there all day if no one had
stopped us.”

RETROPOLIS

Stunning fossil reveals the day dinosaurs died

BBC STUDIOS An imagined dinosaur scene just after the asteroid strike that caused a mass extinction, from the “Nova” documentary on PBS.

WCS ECUADOR An image of a puma from a camera trap in Ecuador.

The Washington Post - USA (2022-05-24)

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