Speaker 1: Welcome. This is Rebecca Shore for Radio Eye, and today
Speaker 1: I will be reading the Smithsonian Magazine dated April May
Speaker 1: twenty twenty six. As a reminder, Radio Eye is a
Speaker 1: reading service intended for people who are blind or have
Speaker 1: other disabilities that make it difficult to read printed material.
Speaker 1: Please join me now for the first article, which is
Speaker 1: part two of an article from the March edition. One
Speaker 1: of the Ally's secret weapons against the Nazis was a
Speaker 1: twenty one year old woman armed with the microphone and
Speaker 1: a script of lies by April White. In the first part,
Speaker 1: we learned the story of Agnes Bernauer, a twenty one
Speaker 1: year old German Jewish refugee who became an unexpected Allied
Speaker 1: weapon during World War II by broadcasting propaganda under the
Speaker 1: persona Vicky with three Kisses. Using a seductive, affectionate radio
Speaker 1: voice and popular big band music translated into German, Bernauer
Speaker 1: helped draw in German soldiers listening to clandestine Allied stations
Speaker 1: that were designed to sound like official Nazi broadcasts. Her
Speaker 1: on air character evoked romance, nostalgia, and longing, subtly encouraging
Speaker 1: listeners to question the sacrifices demanded by the Nazi cause
Speaker 1: while disguising subversive messages beneath entertainment. Our story's first part
Speaker 1: places Bernauer's work within the Rise of Black Propaganda, a
Speaker 1: secret Allied strategy that mixed truthful details with deliberate deception
Speaker 1: to confuse, demoralize, and emotionally manipulate enemy audiences. Operating from
Speaker 1: a hidden English estate, the Political Warfare Executive and OSS
Speaker 1: assembled refugees, defectors, and artists to weaponize radio and disinformation.
Speaker 1: Though many listeners suspected the broadcast's true origins, their popularity
Speaker 1: unsettled Nazi leadership and demonstrated how modern media, emotion and
Speaker 1: repetition could blur truth and fiction, foreshaft gioing the power
Speaker 1: of disinformation in the modern world. Here now is Part two. Meanwhile,
Speaker 1: inside Buchenwald, the concentration camp, prisoner Ougen Kogan tuned in
Speaker 1: on a Pilford radio. He transcribed the questionable reports of
Speaker 1: approaching Allied troops on scraps of paper to be passed
Speaker 1: among his fellow prisoners. It was all important for us
Speaker 1: to remain well informed about the situation at the fighting
Speaker 1: fronts so that we could take appropriate measures in time,
Speaker 1: Cogan wrote after being liberated as the fighting dragged into
Speaker 1: the spring of nineteen forty five. Each night brought stories
Speaker 1: crafted to exploit cracks and German morale and complicate the
Speaker 1: logistics of the war machine in the Allies, telling Nazi
Speaker 1: officials were abandoning the cause in droves, and those who
Speaker 1: remained lived extravagantly. Some were said to have fled via
Speaker 1: submarine to Argentina, a fiction that caused an international man hunt.
Speaker 1: Another reports sugested that Nazi leader Hermann Geering had moved
Speaker 1: his family in a trove of stolen art to a
Speaker 1: castle in the Alps, while civilians in Berlin died from
Speaker 1: lack of shelter. For Bernauer, the best lies were the silliest,
Speaker 1: like the time she told listeners that the government requested
Speaker 1: they each send a urine sample to the Ministry of
Speaker 1: Health in Berlin. She liked to think she clogged up
Speaker 1: the German postal service for days. By March nineteen forty five,
Speaker 1: the Allied broadcasts had a grateful audience and were beginning
Speaker 1: to have a noticeable effect on the German people. Giebels
Speaker 1: reported in his diary the Nazi propagandists worried that the
Speaker 1: enemy now proposes to bring into action his big psychological
Speaker 1: warfare guns. He was right. As Allied troops prepared to
Speaker 1: enter Germany, the broadcasters at Milton Bryan prepare to unveil
Speaker 1: their biggest lie, Operation Intruder. The Allies had long known
Speaker 1: that German radio stations signed off as air force approached
Speaker 1: to prevent being used as beacons. With the power of
Speaker 1: the medium wave transmitter that aired soldatanzen Deer West, broadcasters
Speaker 1: could hijack the Nazi frequencies and segue seamlessly from authentic
Speaker 1: content into fraudulent news. The capability had been held in reserve.
Speaker 1: Now it would be unleashed to cause a stampede of
Speaker 1: the population by suggesting to them that the Party has
Speaker 1: given an evacuation order for a chosen few and is
Speaker 1: leaving the rest to be destroyed where they are according
Speaker 1: to a top secret memo. Bernauer balked at the idea,
Speaker 1: she would later tell her family. Everyone at m B
Speaker 1: knew that their broadcasts targeted not only German soldiers but
Speaker 1: also unsuspecting civilians. Only now the propagandists would be putting
Speaker 1: them in harm's way. Despite her hesitations, Bernauer participated in
Speaker 1: this unprecedented effort to tangle supply lines and stymy the
Speaker 1: movement of German troops. On March twenty fourth, nineteen forty five,
Speaker 1: the fraudulent German evacuation orders for those on whose preservation
Speaker 1: the continued life of the nation depends were given. As
Speaker 1: for everyone else, the evacuation of a great number of
Speaker 1: our compatriots will for the time being be impossible. Their
Speaker 1: duty therefore is to stick it out, and, if need be,
Speaker 1: faced death bravely. According to a memo written in late
Speaker 1: March by a Nazi officer in Westphalia, Germany, considerable misunderstandings
Speaker 1: and great unrest were caused among the population by the
Speaker 1: intrusion of enemy wireless announcements on the German wireless Bernauer
Speaker 1: would always regret her part in that. After the war,
Speaker 1: even Britain's top propagandist Sefton Delmer, seemed abashed. On a
Speaker 1: visit to Germany just months before the war ended, he
Speaker 1: saw the roads crowded with refugees. I did not stop
Speaker 1: to ask any of them whether it was a message
Speaker 1: on Radio Cologne or Radio Frankfurt. German's days targeted an
Speaker 1: operation Intruder that had first started them on their trek.
Speaker 1: He wrote, I did not want to know, but the
Speaker 1: confusion caused one delay for which Bernauer would later be
Speaker 1: very grateful. As Operation Intruder continued into April, a train
Speaker 1: left the bergen Belsen concentration camp in northern Germany. It
Speaker 1: was loaded with twenty five hundred prisoners bound for Teratzine,
Speaker 1: a camp in German occupied Czechoslovakia, about seventy five miles
Speaker 1: west of Berlin. The train stopped abruptly, its progress halted
Speaker 1: by reports of approaching forces and nearby Allied bombings. No
Speaker 1: one knew what was true or false, the ultimate goal
Speaker 1: of black propaganda. What is clear is that the German
Speaker 1: troops believed what they heard, abandoning the train and those
Speaker 1: crammed on it, who were later discovered by American soldiers.
Speaker 1: Ilma Bernauer's dear cousin, was among those liberated that afternoon.
Speaker 1: Ilma's mother, Gazella, did not survive. She died in Auschwitz
Speaker 1: in nineteen forty two. The fight was finally over. According
Speaker 1: to the propagandists. It is expected that the end of
Speaker 1: the war will be announced in the very near future,
Speaker 1: simultaneously with the death of the Furer. The stations reported
Speaker 1: on April twenty ninth, nineteen forty five. The assumption that
Speaker 1: the Furor has already been quietly liquidated in the last
Speaker 1: days by Heinrich Himmler is now confirmed. As usual, the
Speaker 1: news was almost accurate. Hitler died by suicide the following day,
Speaker 1: and Germany surrendered a week later. The voices of Atlantic,
Speaker 1: Zender and zoldatn Sender West fell silent at dawn on
Speaker 1: May first. There was no more reason to lie. There
Speaker 1: was no grand on air send off, just a note
Speaker 1: at the end of that night's script zogbeim abshid Liza
Speaker 1: servus say good bye silently. But where is the most
Speaker 1: listened to station in Europe since May first? Wondered a
Speaker 1: Swiss newspaper. As the war in Europe drew to a
Speaker 1: close less than a week after the German surrender, the
Speaker 1: answers started to emerge. Radio Atlantic disclosed as Allied propaganda
Speaker 1: roofs and associated press headline blared. Some of Germany's best
Speaker 1: pre war actors entertained the enemy and shipped at his morale.
Speaker 1: Allied officials did not confirm the scoop because one said,
Speaker 1: there's a war on the other side of the world.
Speaker 1: Even then, it was clear that the disinformation model built
Speaker 1: at Milton Bryan would be expanded upon and used again next.
Speaker 1: The Librea tar Pits have been sucking in visitors for millennia.
Speaker 1: Paleontologists are still finding out what lies within the ouze
Speaker 1: by Richard Conneff. Unusually for a major tourist attraction, the
Speaker 1: phrase death trap features prominently in the signage and the
Speaker 1: lore at the Librea tar Pits, the celebrated fossil site
Speaker 1: in the heart of Los Angeles. Death trap for meat eaters,
Speaker 1: says the sign at one site, though in truth it's
Speaker 1: a death trap for plant eaters too. Over the past
Speaker 1: sixty thousand years or so, animals by the millions, including
Speaker 1: giant ground sloths, saber toothed cats, dire wolves, and ten
Speaker 1: ton Columbian mammoths, were stuck in the goo and died here,
Speaker 1: and were quickly preserved in exquisite detail by the same
Speaker 1: stuff that killed them. For scientists, the Librea death trap
Speaker 1: matters because the animals entombed here, now mostly extinct, are
Speaker 1: remnants of a lost North America. Not so long ago,
Speaker 1: big scary animals, both predator and prey dominated the landscape,
Speaker 1: much as they still do. In parts of Africa to day.
Speaker 1: Their abrupt disappearance roughly thirteen thousand years ago makes Librea
Speaker 1: a tantalizing window into the American past what the International
Speaker 1: Union of Geological Sciences calls one of the most important
Speaker 1: fossil localities in the world. Emily Lindsay, a Librea paleoecologist
Speaker 1: with a passion for the strangeness of giant ground slots,
Speaker 1: goes further, there is almost nothing on Earth of any
Speaker 1: time period that can match the number of fossils and
Speaker 1: the diversity of fossils. This range includes megafauna and microfossils, plants, insects, snails,
Speaker 1: even fungi, all preserved together. Lindsay and Reagan Dunn, a
Speaker 1: former river guide and ski instructor turned paleobotanist, are the
Speaker 1: scientific leads at Librea. The big question researchers hope these
Speaker 1: fossils can answer is why such a world suddenly disappeared
Speaker 1: when it did, and what, if anything, those findings can
Speaker 1: tell us about our own world. For non scientists, though,
Speaker 1: Librea's death trap image has a different appeal. Lots of
Speaker 1: screenwriters live in the area, says Done. Her eyes widen
Speaker 1: but do not quite roll. You sometimes see them around
Speaker 1: with their laptops. Act one. Seen one often takes place
Speaker 1: at the sizeable lake pit by Librea's front gate, just
Speaker 1: off Wiltshire Boulevard. The location is production friendly, just fifteen
Speaker 1: minutes from major Hollywood studios, and suitably apocalyptic, with methane
Speaker 1: bubbling ominously from the surface and a statue of a
Speaker 1: desperate mammoth mired hip deep in tari liquid. In the
Speaker 1: recent Nimbi ce television series Librea, a sinkhole opens here
Speaker 1: and drops attractive people into a primeval underworld. And in
Speaker 1: the nineteen eighty eight movie Miracle Mile a boy meets Girl,
Speaker 1: Boy loses girl, boy finds Girl's story. The happy couple
Speaker 1: are racing away from a nuclear apocalypse when their helicopter
Speaker 1: suddenly spins down into the tar. As the goo rises
Speaker 1: around them, they console themselves with the thought that their
Speaker 1: fossilized remains might some day be displayed in a museum.
Speaker 1: Such depictions may be Hollywood kitsch, but they live in
Speaker 1: the hearts of fans. This is right where the movie
Speaker 1: Volcano Happened. Right, exclaims a middle aged man and a
Speaker 1: cowboy hat to two pals one morning as they stride
Speaker 1: past the tar pit bound for the George See Page
Speaker 1: museum on the Librea grounds. In that nineteen ninety seven movie,
Speaker 1: Librea gives rise to a volcano which flings flaming lava
Speaker 1: bombs and sends a river of molten rock flowing through
Speaker 1: the city. Perhaps as a nod to the site's morbid reputation,
Speaker 1: the man in the cowboy hat has dressed for his
Speaker 1: Librea visit and a black T shirt printed with lyrics
Speaker 1: from the heavy metal group Venom. We suck the blood
Speaker 1: of the Beast and hold the key to Death's door
Speaker 1: for visitors. The first clue that there is something different
Speaker 1: about the land around the museum is the bare patches
Speaker 1: among the trees, where the exposed earth is a little
Speaker 1: too dark and dead leaves are stuck in place. On
Speaker 1: one such patch, a stray soccer ball waits like an
Speaker 1: invitation to come closer. Don't. In fact, there are fences
Speaker 1: to keep you away. These dark patches have always been
Speaker 1: the real hazard, not the lake out front. Lindsay, who
Speaker 1: is the excavation site director, dismisses the lake as a
Speaker 1: giant hole in the ground left behind by commercial mining
Speaker 1: in the late nineteenth century. The almost ordinary patches of
Speaker 1: ground are more deadly for being less obvious. What they
Speaker 1: hide beneath the leaves is not a lake or even
Speaker 1: a pit, but a shallow seep. The dirt is saturated
Speaker 1: with asphalt, the lowest grade of crude oil. Long before
Speaker 1: commercial mining, Native Americans harvested the asphalt here to waterproof
Speaker 1: baskets and boats. Early Spanish colonists likewise used the asphalt
Speaker 1: to seal their roofs. They were the ones who named
Speaker 1: the place librea, which means the tar. The oil pushes
Speaker 1: up through narrow cracks in the rock from oil deposits
Speaker 1: between what five hundred and one thousand feet underground. The
Speaker 1: asphalt didn't pull its victims down into the earth, as
Speaker 1: Hollywood likes to suggest. Even a shallow puddle was enough
Speaker 1: to lock creatures in its adhesive grip, where they died
Speaker 1: of exposure or starvation, or were finished off by predators
Speaker 1: that often then got trapped themselves, as did many scavengers
Speaker 1: following behind. Inside the museum, school children and parents flock
Speaker 1: to an exhibit that invites them to pull up on
Speaker 1: the handle of a shaft stuck in tar and see
Speaker 1: what being trapped might have been like. These encounters suggest
Speaker 1: that most of these people would have gone the way
Speaker 1: of the parished mammoths. There are, however, other quieter ways
Speaker 1: to approach Librea. The museum as part of Hancock Park,
Speaker 1: a twenty three acre refuge from the traffic and chaos
Speaker 1: of central Los Angeles. Parents wander with the child or
Speaker 1: two down winding paths shaded by live oak trees. School
Speaker 1: groups picnic under the date palms. An exercise class works
Speaker 1: through its routine at the foot of a slope. Visitors
Speaker 1: can amble in through the museum's back gates and visit
Speaker 1: Project twenty three, a fenced in area where a palaeontological
Speaker 1: excavation is in progress. Now a wooden crate stands open,
Speaker 1: revealing what looks like a crude sculpture roughly five feet tall.
Speaker 1: It's a tableau of death, a cataclysmic mix of blackened ankles, teeth, femurs,
Speaker 1: and skulls jammed together. This mass grave was carefully excavated
Speaker 1: and set aside during construction at the site. The bones
Speaker 1: in the crates are still embedded in asphalt, just as
Speaker 1: they were underground before removing them from the crates. Sean
Speaker 1: campbell a palaeontological preparator at the museum uses a laser
Speaker 1: to measure each one and carefully documents its position relative
Speaker 1: to the others. Next, Campbell goes to work excavating a
Speaker 1: large rib, spraying on solvent to soften the asphalt that
Speaker 1: holds it in place. The asphalt yields to gentle scraping
Speaker 1: with dental tools and accumulates in glistening little heaps, like
Speaker 1: couscous cooked in motor oil. So far, Campbell says as
Speaker 1: he works, I have a baby ground sloth, a baby bison,
Speaker 1: a baby horse. Visitors often pay special attention to the
Speaker 1: babies in the collection. People are just like, oh God,
Speaker 1: that's so terrible, And I'm like, yes, but they would
Speaker 1: have died forty thousand years ago by now anyway. But
Speaker 1: at least they're now present for the scientific record for
Speaker 1: us to study and analyze them and learn more about
Speaker 1: their lives. He continues with his roster of the dead
Speaker 1: in the crate. One deer, a few dwarf prong horns,
Speaker 1: tons of coyotes, at least three adult dire wolves, and
Speaker 1: at least one sub adult sabertoothed cat, a partially articulated
Speaker 1: rodent time and geological upheaval below ground have left many
Speaker 1: of the bones battered, including the rib. Campbell wraps it
Speaker 1: in aluminum foil to keep it intact as he gently
Speaker 1: rocks it back and forth out of the dirt. Then
Speaker 1: he brings it to a bench and wraps it again,
Speaker 1: this time an orthopedic casting tape. A half hour in
Speaker 1: the sun will harden it, leaving it ready to be
Speaker 1: cleaned up and repaired more durably at a lab inside
Speaker 1: the museum. What comes out of the ground here is
Speaker 1: true buried treasure. A nearly intact sabertoothed cats skull unearthed
Speaker 1: near by in the nineteen sixties sold at auction in
Speaker 1: two thousand nine for three hundred thirty four thousand, six
Speaker 1: hundred dollars, but the museum doesn't sell its discoveries. A
Speaker 1: volunteer named Lynne Schneider, retired from a career as a
Speaker 1: government contractor, has been working for months on a dire
Speaker 1: wolf skull that's very broken up. Now. She says she's
Speaker 1: almost getting to the point where I can start consolidating
Speaker 1: a bone and gluing it together. Barbara Hill, another volunteer
Speaker 1: and a former aerospace worker, stands on the opposite side
Speaker 1: of the same blackened mass of bones. Both women volunteer
Speaker 1: two days a week. Hill divides her time between Project
Speaker 1: twenty three and the prep lab inside the museum, though
Speaker 1: that schedule can change depending on where she is needed most.
Speaker 1: It feels like a custody battle. Hill jokes of her
Speaker 1: split schedule. At the lab, preparators stand at a long
Speaker 1: horseshoe shaped bench facing out into the public visitors watched
Speaker 1: through plate glass windows. Jars of Q tips, toothpicks, and
Speaker 1: foam tip make up applicators stand at the ready for
Speaker 1: the cleaning and sorting process. Manicure sticks the kind peutitions
Speaker 1: used for pushing back cuticles, are very nice for removing
Speaker 1: stubborn matrix, says Connie Clark, a staff preparator, referring to
Speaker 1: the sediment that hardens around fossils. An electric toothbrush is
Speaker 1: good for removing a clay layer alongside the bone. Consolidates
Speaker 1: and glues are degreasers for cleaning the bones. In the
Speaker 1: old days, they used boiling kerosene, Clark says, but boiling
Speaker 1: of flammable liquid, she says, is not ideal. Like Schneider
Speaker 1: and Hill, the other preparators are mostly long time volunteers,
Speaker 1: an anthropologist, a veterinarian, a software developer, a fun mix.
Speaker 1: Clark says, today they're working from a gallon paint can.
Speaker 1: It's the oily couscous that originally surround the bones out
Speaker 1: at Project twenty three, now dried and thoroughly cleaned. When
Speaker 1: the preparators view them through a microscope, items in the
Speaker 1: mix sharpened in to bits of sticks, shells, bones, plants,
Speaker 1: and insects. They use the bristles of a fine artist's
Speaker 1: paintbrush to nudge pieces to one side or another, sorting
Speaker 1: them by type. Next the gallon can, the results of
Speaker 1: recent sortings occupy clear plastic boxes. Clark carefully opens a
Speaker 1: box full of the glossy, blackened heads of insects, some smooth,
Speaker 1: some pitted, Their rounded skull like shapes resembling the singed
Speaker 1: aftermath of a mass catastrophe. Sometimes a sneeze or a
Speaker 1: deep sigh will send things rocketing away, she warns. Dung
Speaker 1: beetle fossils have lately become Hill's specialty. A palaeontologist helpfully
Speaker 1: told the volunteers that the underside of a dung beetle's
Speaker 1: head looks like a toilet seat, and so far, in
Speaker 1: a few days of microfossil sorting, Hill has found two
Speaker 1: dung beetle heads that may represent previously unknown species. She
Speaker 1: hopes to find another today. It's a treasure, Hill says, playfully,
Speaker 1: giving herself a pep talk. You're going to find it.
Speaker 1: Open a whole new page of history. The big animals
Speaker 1: that thrill the popular imagination may have died at Librea
Speaker 1: only once or twice in a decade, but across millennia
Speaker 1: those numbers added up. In the museum's collection rooms, sabertoothed
Speaker 1: cat skulls fill a line of cabinets eight and a
Speaker 1: half feet high and fifty feet long, while drawers full
Speaker 1: of sabertoothed cat astragali or ankle parts and other bones
Speaker 1: are lined up like spoons. A public display Wow's museum
Speaker 1: goers with four hundred dire wolf skulls in almost military formation.
Speaker 1: Another four hundred thirty are stored in back for scientific research.
Speaker 1: Is it real? A visitor demands, in front of a
Speaker 1: massive skeleton of a Harlan's ground sloth. It's a standard
Speaker 1: questionablebrea and becka Prater, an educator on staff confirms that, yes,
Speaker 1: it's real. We have found over nine thousand of their fossils,
Speaker 1: so we do have a fully articulated skeleton of a
Speaker 1: Harlan's ground sloth here. Then scrupulously she adds those nine
Speaker 1: thousand bones probably came from about sixty individuals. Like nearly
Speaker 1: all skeletons at natural history museums, this one is a composite.
Speaker 1: The bones of individual animals rarely turn up intact or
Speaker 1: even in the same place. So whoever had that skull
Speaker 1: never knew the guy with those ribs, and probably never
Speaker 1: was friends with the sloth that now holds his legs up.
Speaker 1: So we frankenstein them altogether and build these big composite
Speaker 1: skeletons with the pieces we find. The viewer goes away satisfied,
Speaker 1: but the is it real question will inevitably recur. The
Speaker 1: challenge for Librea, says Lindsay, is that it's a spectacle,
Speaker 1: and it's also in the middle of the worst city
Speaker 1: to be a spectacle. People come to el expecting to
Speaker 1: see made up experiences like Universal Studios or Disney's Hollywood Land,
Speaker 1: which builds itself as a place where moving moments come
Speaker 1: to life. When they come to Librea, Lindsay says, they're like, oh,
Speaker 1: it's the Librea tar pit's experience. It doesn't always fully
Speaker 1: register that these fossils are real and they're still coming
Speaker 1: out of the ground. In the third largest city in
Speaker 1: North America, several seeps on the property are active enough
Speaker 1: to require fencing. Other smaller seeps turn up from time
Speaker 1: to time, and green traffic cones labeled sticky and gooey
Speaker 1: worn pedestrians away. Workers scoop asphalt out of inconvenient areas
Speaker 1: and empty it into the lake pit, which is periodically
Speaker 1: pumped out by a hasmat service. There are seeps outside
Speaker 1: the museum grounds too, Nearby homeowners who do not realize
Speaker 1: they live above an oil field sometimes called to complain,
Speaker 1: your tar is coming up in my garage. Old seeps,
Speaker 1: now cut off from their source, also libraried and pockets
Speaker 1: around the neighborhood As preparatoris continue to sort through the
Speaker 1: original batch of twenty three crates. Construction for a new
Speaker 1: wing of the Los Angeles County Art Museum recently brought
Speaker 1: thirty seven more crates to the museum. Faced with so
Speaker 1: many specimens, some seemingly insignificant. When does a palaeontologist decide
Speaker 1: to stop excavating. Librea is planning a major redesign with
Speaker 1: a new center for ice age research that will emphasize
Speaker 1: lessons from microfossil research. The aim is to get it
Speaker 1: done in time for the twenty twenty eight Olympics in
Speaker 1: Los Angeles. Microfossils are really cool, really important done, the
Speaker 1: botanist tells an evening audience of museum donors. They're superabundant
Speaker 1: if you look hard enough, and if you know how
Speaker 1: to look for them. And these small critters are really
Speaker 1: important for ecosystem function. While the monsters for which Librea
Speaker 1: is now celebrated roamed widely across the region, size kept
Speaker 1: their smaller counterparts mostly local. We study them to interpret
Speaker 1: what the environment was like right here at the tar
Speaker 1: pits and the surrounding area. And these small fossils tell
Speaker 1: really big stories. A twenty twenty three paper published in
Speaker 1: the leading journal Science shed new light on the abrupt
Speaker 1: disappearance of species including the western horse, the American lion,
Speaker 1: a bison species, saber toothed cats, and dire wolves. Lindsay
Speaker 1: and Dunn's collaborators at Marshall University and the University of California,
Speaker 1: Irvine used updated techniques to remove all traces of asphalt
Speaker 1: from the fossils, which is crucial for accurate carbon dating,
Speaker 1: and then says done. They said, oh my god, we
Speaker 1: know the timing of the extinction event, but what was
Speaker 1: the extinction event? Botanists like Dunn thought that phytoliths might
Speaker 1: hold the answer. These infinitesimal stones form when plant species
Speaker 1: take up silica from groundwater and channel it into shapes
Speaker 1: that are visible only under a high powered microscope, and
Speaker 1: then only after grinding up stony matrix and running it
Speaker 1: through a series of acid baths and heavy liquid flotation treatments.
Speaker 1: Different types of plants left behind differently shaped phytoliths. On
Speaker 1: her computer screen, Done points out examples. You see kind
Speaker 1: of like a spiky golf ball at the top center.
Speaker 1: Those are palms. The one on the left with these
Speaker 1: parallel lines. That's a fern. The one that's like a
Speaker 1: worm with spirals on it. It comes from the veins
Speaker 1: and leaves. Phytoliths are everywhere in the plant world. When
Speaker 1: you run your hand up a blade of grass and
Speaker 1: feel a spiky edge, she says, you're touching phytoliths, and
Speaker 1: they provide clues about the habitat. Certain phytoliths from the
Speaker 1: upper surface of a leaf can reveal, for instance, whether
Speaker 1: the plant lived under forest cover or in open grassland.
Speaker 1: By studying fossil phytoliths, seeds, pollen, and other plant remains
Speaker 1: from Librea, the botanists constructed a time line of what
Speaker 1: the habitat there was like in different time periods. The
Speaker 1: post glacial pine forests of fifty four thousand years ago
Speaker 1: gave way to juniper and oak woodlands thirty thousand years ago,
Speaker 1: and then about thirteen thousand, two hundred years ago to
Speaker 1: open habitat populated by drought and fire adapted plants. But again,
Speaker 1: the question is why the megafauna extinction event didn't happen
Speaker 1: only at Librea. Ice age fossils found scattered across the
Speaker 1: continents suggest that it was a global event. Librea is different,
Speaker 1: mainly because of the abundance and the extraordinary preservation of
Speaker 1: the evidence there. Scientists worldwide have debated possible explanations for
Speaker 1: the sudden extinction. One is that at the end of
Speaker 1: the glacial period, the climate rapidly became warmer and drier,
Speaker 1: changing habitats in ways that put pressure on cold adapted
Speaker 1: plants and wildlife. Another commonly sighted explanation, the overkill theory,
Speaker 1: is based on the fact that human populations expanded around
Speaker 1: this time, including in southern California, where evidence suggests that
Speaker 1: people were present in the Channel Islands by about thirteen thousand,
Speaker 1: two hundred years ago. These growing human populations led to
Speaker 1: heavier hunting, which intensified the pressure on large animals. A
Speaker 1: third model, put forward by Lindsay Dunn and their colleagues
Speaker 1: in the twenty twenty three paper emphasizes fire. As humans
Speaker 1: traveled through this already drying landscape, they made fires wherever
Speaker 1: they went, causing conflagrations and adding to the stresses on
Speaker 1: vulnerable species. The same asphalt that preserved bones and insect
Speaker 1: parts so well was terrible at preserving ash and charred materials.
Speaker 1: And we'll have to leave it there for now. We'll
Speaker 1: have part two next week. This concludes readings from the
Speaker 1: Smithsonian Magazine for today. Your reader has been Rebecca Shore.
Speaker 1: Thank you for listening, and have a great day.