Transcripts
Hi, I know you just pressed play on this episode,
Amy Martin:but I'm about to ask you to stop listening to me. Yes, this is a
Amy Martin:strange way to start a new season of our show, I know, but
Amy Martin:this is my request or my invitation. If you're so
Amy Martin:inclined, in just a moment, please press pause and spend 10
Amy Martin:or 15 seconds listening to whatever you can hear around
Amy Martin:you. All the voices, anything making any sort of noise at all,
Amy Martin:and then press play again. That part's crucial. Please do come
Amy Martin:back. Okay. Are you ready? Three, two, one.
Amy Martin:What did you hear? Could you hear any sounds that weren't
Amy Martin:made by people? If so, consider yourself lucky, because human
Amy Martin:beings have become very, very loud.
Flight Attendant:In preparation for takeoff, may we now remind
Flight Attendant:you to fasten your seatbelts.
Amy Martin:This relentless noise we make. It's not normal.
Amy Martin:For most of our time on this planet, we humans have been very
Amy Martin:good listeners, tuning in carefully to the movements of
Amy Martin:water, changes in the weather, the voices of other animals. But
Amy Martin:now many of us move through our days or even our entire lives
Amy Martin:hearing almost nothing but the sounds of just one species. Our
Amy Martin:own. If the planet is a dinner party, we're the guests who are
Amy Martin:ruining the conversation, talking over everyone, assuming
Amy Martin:that our voices are the most important ones in the room.
Amy Martin:We're drowning out essential communication between other
Amy Martin:creatures, forcing them to spend their lives shouting to each
Amy Martin:other in order to be heard, or worse, we're silencing them
Amy Martin:forever. And our noise doesn't only threaten other beings.
Amy Martin:We're endangering ourselves, and we know things are out of
Amy Martin:balance. We feel isolated and cut off because we are.With
Amy Martin:multiple ecological crises mounting around us, many of us
Amy Martin:feel desperate to help, and there is unquestionably so much
Amy Martin:work to be done, but maybe the first step is slowing down and
Amy Martin:letting the voices of our planet mates back in.
Amy Martin:What if being useful starts with being quiet? What if saving the
Amy Martin:world begins with listening to it? What changes when we
Amy Martin:remember to listen to the more than human world? That's the
Amy Martin:question at the heart of this season of our show. Despite all
Amy Martin:the damage that's already been done, there is still a vast
Amy Martin:planetary choir singing around us. It's right there waiting for
Amy Martin:us, if we turn our attention to it.
Amy Martin:All over the world, people are hearing those voices and
Amy Martin:responding. We are in the midst of a listening emergency, but
Amy Martin:also a listening Renaissance. In this season, we'll meet people
Amy Martin:who are devoting their lives to listening, reconnecting with old
Amy Martin:traditions, or creating new ones, and building tools that
Amy Martin:might someday allow us to comprehend what other animals
Amy Martin:are saying in ways we've only dreamed of in the past. It's
Amy Martin:going to be a fun journey and a fascinating one, but I'm going
Amy Martin:for something deeper than the wow factor of cool nature
Amy Martin:sounds. I chose to make this season now because I think all
Amy Martin:of our ecological crises, climate, extinction, pollution,
Amy Martin:are essentially breakdowns in relationship, and the first step
Amy Martin:in healing any broken relationship is listening. So
Amy Martin:what happens when we do that? Welcome to threshold. I'm Amy
Amy Martin:Martin, and this is season five. Hark.
Amy Martin:It's seven o'clock on a sunny morning, and I'm on a boat
Amy Martin:heading into Shark Bay, a huge marine reserve off the Western
Amy Martin:Australian coast. This is Malgana country, one of hundreds
Amy Martin:of Aboriginal groups in Australia, and in malgana, the
Amy Martin:name of this place is Gathaagudu, which means "two
Amy Martin:waters."
Amy Martin:Dr. Stephanie King: Dolphins straight ahead.
Amy Martin:We've barely left the jetty, and Dr. Stephanie
Amy Martin:King has already spotted a dolphin. It surfaced and
Amy Martin:disappeared again in a flash, but that was enough time for her
Amy Martin:to identify it. It was a female named Gindy.
Amy Martin:You knew who it was that fast?
Laura Palmer:Yeah, she does.
Amy Martin:Wow.
Laura Palmer:She's great.
Amy Martin:That's Laura Palmer, she's working on her PhD, and
Amy Martin:the other person with us is research assistant Amelia Clark.
Amy Martin:All three of these scientists are from the University of
Amy Martin:Bristol in the UK. Stephanie is the leader of the expedition and
Amy Martin:the current captain of the boat.
Amy Martin:How did you know?
Amy Martin:Dr. Stephanie King: Because of the markings on the dorsal fin.
Amy Martin:She has an uncle who has a similar fin to her. You can see
Amy Martin:the three small nicks, the little break marks at the top.
Amy Martin:Each nick is kind of similarly spaced along the fin, almost
Amy Martin:equidistant from each other. So each dolphin has a unique dorsal
Amy Martin:fin, like we say, like a fingerprint, but it's far more
Amy Martin:obvious than that, I guess, like a human face. So they're very
Amy Martin:distinctive. If you've been working with them a long time,
Amy Martin:then then you recognize all the individuals.
Amy Martin:Shark Bay and its surrounding coastal areas are
Amy Martin:listed as a UN World Heritage Site, and it's easy to see why.
Amy Martin:The water is a clear turquoise blue and huge sea grass meadows
Amy Martin:provide food and shelter for an abundance of wildlife. Sea
Amy Martin:turtles, dugongs, and more than 300 species of fish, including
Amy Martin:the namesake sharks. But the superstars here are the
Amy Martin:dolphins. The scientists of Shark Bay Dolphin Research have
Amy Martin:been studying them continuously since 1982, making this one of
Amy Martin:the most carefully observed communities of dolphins on the
Amy Martin:planet. Stephanie is one of the current co directors.
Amy Martin:Do you know how many dolphins are here, roughly?
Amy Martin:Dr. Stephanie King: Two to 3000 I mean, there's about 1800 that
Amy Martin:we have in our catalog that we work on, and that's just in our
Amy Martin:core study area, in the eastern Gulf. There's far more than
Amy Martin:that.
Amy Martin:And of those 1800 how many of them can you
Amy Martin:identify on site like you just identified that one in two
Amy Martin:seconds?
Amy Martin:Dr. Stephanie King: I've never tested myself, but maybe we
Amy Martin:could do that. I know a lot. More, way more than 200.
Amy Martin:And when did you first come here?
Amy Martin:Dr. Stephanie King: I first came to Shark Bay in 2014, so 10
Amy Martin:years ago now.
Amy Martin:And have you been coming almost every year since
Amy Martin:then?
Amy Martin:Dr. Stephanie King: Every year. I think 2020 was the only year
Amy Martin:because of COVID, but I come every year, and it's a really
Amy Martin:important part of my, I guess just part of my life, coming
Amy Martin:here, spending time with the animals, being inspired for the
Amy Martin:next questions that we want to answer, seeing who's still
Amy Martin:around, who's had a calf, how are the males doing, who's
Amy Martin:allying with who? I think this is certainly where I'm at my
Amy Martin:most happiest as a field biologist. It's where I'd like
Amy Martin:to be most of the time, if I could.
Amy Martin:Yeah.
Amy Martin:Stephanie studies these dolphins using every non invasive tool,
Amy Martin:she can find: drone videography, DNA sampling, and especially
Amy Martin:bioacoustics. Recording and analyzing the sounds the
Amy Martin:dolphins make.
Amy Martin:Dr. Stephanie King: Sounds is the primary way that they
Amy Martin:communicate, and a lot of our research now is starting to
Amy Martin:uncover exactly what some of these sounds mean and how
Amy Martin:they're used.
Amy Martin:Bioacoustics is the name for a fast growing field of
Amy Martin:science, or really an approach to scientific research that's
Amy Martin:being used across many fields. Sometimes it's also called
Amy Martin:ecoacoustics, or acoustic ecology. All of these labels
Amy Martin:have slightly different meanings, but they're all based
Amy Martin:around listening to the more than human world, and they're
Amy Martin:all booming right now. Over the course of this season, we're
Amy Martin:going to meet bioacoustics researchers working with all
Amy Martin:kinds of different creatures, but we're going to dive deep
Amy Martin:with dolphins. Pun intended. We'll be returning to Shark Bay
Amy Martin:in several episodes in hopes of really getting to know this team
Amy Martin:and the way these remarkable animals are using sound
Amy Martin:Stephanie says that starts with learning about the dolphins
Amy Martin:world overall, their habitats, their relationships, their needs
Amy Martin:and preferences.
Amy Martin:Dr. Stephanie King: So we look at behavioral complexity in
Amy Martin:bottlenose dolphins, and that can take the form of foraging
Amy Martin:specializations and tool use, which is a great example of
Amy Martin:animal culture, but we also spend a lot of time looking at
Amy Martin:cooperation. This is really where my passion lies,
Amy Martin:understanding how animals use communication to mediate complex
Amy Martin:social behaviors like cooperation.
Amy Martin:Highly social animals like dolphins, elephants
Amy Martin:and people have special needs for communication. We make
Amy Martin:decisions together, like where to find food or how to respond
Amy Martin:to a threat. We maintain long term relationships that we
Amy Martin:depend on in times of need, and we pass on information to our
Amy Martin:young. All of this cooperation demands that we develop complex
Amy Martin:communication skills.
Amy Martin:Dr. Stephanie King: And in Shark Bay, we have male dolphins that
Amy Martin:form long term alliances. So these are really significant
Amy Martin:relationships for these animals. They're investing heavily in
Amy Martin:these cooperative relationships with each other, and I'm really
Amy Martin:fascinated by the ways that they do that. So what vocal signals
Amy Martin:are they using to mediate these relationships? How do they keep
Amy Martin:track of each other? How do they coordinate their behavior? So
Amy Martin:these are all the types of questions that we aim to answer
Amy Martin:in our work in Shark Bay.
Amy Martin:Is the cooperation that they're engaged in, how
Amy Martin:much of that is happening through sound?
Amy Martin:Dr. Stephanie King: It's mostly happening through sound, and
Amy Martin:that's because it's a species that lives underwater, right? So
Amy Martin:vision is restricted because light doesn't travel that far.
Amy Martin:They have good visual acuity, they've got good vision, but
Amy Martin:they don't rely on vision because they can't see that far
Amy Martin:underwater. But sound travels really far.
Amy Martin:Dolphins use other forms of communication too, of
Amy Martin:course.
Amy Martin:Dr. Stephanie King: They can be quite tactile with each other,
Amy Martin:so they'll spend time petting and rubbing each other, and
Amy Martin:that's a way of reaffirming or establishing or maintaining
Amy Martin:relationships.
Amy Martin:But Stephanie says sound is central.
Amy Martin:Dr. Stephanie King: They use sound for all important aspects
Amy Martin:of their life, to navigate their environment, to find food, and,
Amy Martin:importantly, to communicate with each other. So it's their
Amy Martin:primary modality, it's sound, it's not vision, it's not
Amy Martin:gestures. And by sharing information through vocal
Amy Martin:signals, they can let each other know where they are, maybe if
Amy Martin:they plan to move, if they want to reunite this type of
Amy Martin:information.
Amy Martin:When I visited the team in May of 2023, they were
Amy Martin:just getting started for the year. Amelia, who goes by
Amy Martin:Millie, is a recent master's graduate who's here to get
Amy Martin:experience as a research assistant. Laura is a PhD
Amy Martin:student collecting data for her thesis work.
Laura Palmer:This is my first time in Shark Bay, so I've only
Laura Palmer:been here a week now. We've had lots of amazing days on the
Laura Palmer:water, so certainly very lucky. It was a good time to come.
Amy Martin:Laura and Millie are under some pressure because they
Amy Martin:only have a few weeks with Stephanie, then she has to
Amy Martin:leave, and they'll do everything on their own. One of the key
Amy Martin:things they need to learn is how to take a survey of every
Amy Martin:dolphin they meet.
Amy Martin:Dr. Stephanie King: By survey, I mean, we photograph the group,
Amy Martin:and we stay with them for at least five minutes, and we write
Amy Martin:down their predominant behavior. So are they socializing,
Amy Martin:traveling, resting, and then we look at who are they with. And
Amy Martin:by doing that throughout the season, over multiple years, and
Amy Martin:we've been doing it for 40 years now, we have this incredible
Amy Martin:picture of who associates with who, who has strong friendships,
Amy Martin:which dolphins avoid each other. And we can, like, map the social
Amy Martin:network, if you like, and we can look at the structure and maybe
Amy Martin:link some of that information to fitness measures, like, does
Amy Martin:being more sociable mean that you're more successful and you
Amy Martin:have more offspring, for example.
Amy Martin:You got dolphins, Laura?
Laura Palmer:No, not yet. But there's splashing basically at
Laura Palmer:zero degrees.
Amy Martin:While I've been peppering Stephanie with
Amy Martin:questions, Laura and Millie are scanning the water for anything
Amy Martin:that looks remotely dolphin-ish. Laura said she saw some splashes
Amy Martin:at zero degrees, meaning straight ahead. So she moves to
Amy Martin:the bow with a boat to get a better look.
Amy Martin:Dr. Stephanie King: If we see splashes, we'll check just to
Amy Martin:make sure it's not dolphins foraging anything that looks
Amy Martin:like it could be a dolphin, or indicate dolphin behavior we'll
Amy Martin:check with the binos and maybe even go a bit closer.
Amy Martin:I quickly get obsessed with dolphins spotting
Amy Martin:myself, which was a little dangerous. Stephanie told me
Amy Martin:that if someone says they see a dolphin and it turns out to be a
Amy Martin:bird, they have to bake something for the rest of the
Amy Martin:group back at the Research Station.
Laura Palmer:Yeah, yeah.
Laura Palmer:Dr. Stephanie King: Yeah?
Amy Martin:But then Laura calls from the bow, there's definitely
Amy Martin:dolphin activity up ahead.
Amy Martin:We're in business!
Amy Martin:The dolphins are constantly in motion, and they are fast.
Amy Martin:Stephanie needs to move us quickly or we'll lose them. But
Amy Martin:she also wants to maintain some distance so we don't disturb
Amy Martin:them. It's a bit of a dance to find that just-right spot.
Amy Martin:Ooh, I just saw a fin.
Amy Martin:Everyone has a job to do. Stephanie's in the captain's
Amy Martin:chair, Laura will try to get clear photographs of every
Amy Martin:dolphin we see. Millie will write down notes, and I'll just
Amy Martin:try to stay out of the way.
Amy Martin:Dr. Stephanie King: We have Zeppelin and Blimey.
Amy Martin:Hands on the steering wheel and eyes on the
Amy Martin:water, Stephanie calls out the name of each dolphin to put into
Amy Martin:the notes.
Amy Martin:Dr. Stephanie King: Z-E-P, and B-L-M. Yeah, you got them. They
Amy Martin:might come again they're still just beneath the surface.
Amy Martin:They're so close!
Amy Martin:Stephanie is mindful of keeping some distance, but the dolphins
Amy Martin:aren't as concerned about the rules. They swim close to the
Amy Martin:boat, zipping around and seeming to check us out. When they swim
Amy Martin:over dark patches of sea grass, they can all but disappear, and
Amy Martin:then all of a sudden, they pop up again to grab a quick breath.
Amy Martin:Even though I can see them coming, it's delightfully
Amy Martin:startling every time they crest the surface. These are
Amy Martin:Indo-Pacific bottlenose dolphins, smaller than some
Amy Martin:other species, but still big. They average around two and a
Amy Martin:half meters long, or more than eight feet, with a maximum
Amy Martin:weight of about 230 kilograms, or about 500 pounds. But all
Amy Martin:that bulk doesn't limit their grace. It's actually hard to
Amy Martin:call what they do swimming. It looks more like dancing or
Amy Martin:flying. Their smooth, shiny bodies roll past us in a
Amy Martin:heartbeat as Laura tries to get a clear portrait of each one.
Laura Palmer:I'm going to try to get Blimey one more time.
Amy Martin:As if she heard Laura's request, Blimey pops up
Amy Martin:and looks right at us, and Laura presses down on the shutter.
Laura Palmer:Thanks, Blimey!
Amy Martin:With the visuals taken care of, it's time to move
Amy Martin:on to sound.
Amy Martin:So Laura's pulling out her recorder, plugging in the
Amy Martin:hydrophones.
Amy Martin:A hydrophone is just a waterproof microphone attached
Amy Martin:to a long cable. This team has four of them. As Laura gets
Amy Martin:everything connected and ready to record, Stephanie keeps the
Amy Martin:boat following the dolphins from a distance, they seem to be on
Amy Martin:the move towards something or someone.
Amy Martin:Dr. Stephanie King: We have another dolphin up ahead, I
Amy Martin:think it's Juicy. Blimey's on the bow. Hey guys. Both on the
Amy Martin:bow.
Amy Martin:Oh wow, right under the surface.
Amy Martin:And then they're gone again. It's shocking how quickly a
Amy Martin:group of 500 pound animals can just disappear. The four of us
Amy Martin:stand in the boat looking in four different directions,
Amy Martin:waiting, watching. We know they're nearby, but we don't
Amy Martin:know exactly where or when they might pop back up to take a
Amy Martin:breath. Stephanie uses the temporary pause in activity to
Amy Martin:look over Millie's notes and tell her what needs to be added.
Amy Martin:Dr. Stephanie King: So the five minute information would be
Amy Martin:travel. There are two other animals here.
Amy Martin:They're back. Stephanie interrupts herself to
Amy Martin:call to Laura, telling her that Juicy is not the only dolphin
Amy Martin:that has joined this group. There's another one, so far
Amy Martin:unidentified. Then she quickly turns back to Millie.
Amy Martin:Dr. Stephanie King: Travel, regular, straight, slow, tight.
Amy Martin:There's a lot happening all at once, with
Amy Martin:dozens of these kinds of teachable moments every hour.
Amy Martin:And Stephanie has to find a balance between making sure the
Amy Martin:data get collected correctly and giving the younger researchers
Amy Martin:freedom to do things themselves.
Laura Palmer:So there's just going to be cables running on
Laura Palmer:the back as well.
Amy Martin:Okay.
Amy Martin:Laura is about to start recording.
Amy Martin:Dr. Stephanie King: Blimey just ahead. Juicy's here.
Amy Martin:So are there four here?
Amy Martin:Dr. Stephanie King: Yes, so that's Juicy. She's got a really
Amy Martin:gnarly peduncle, like an old shark bite wound, makes it very
Amy Martin:scarred.
Laura Palmer:Love juicy. Juicy showed up on a few days now,
Laura Palmer:becoming a firm favorite.
Amy Martin:How old is she, roughly?
Amy Martin:Dr. Stephanie King: Juicy was born in 2001, so she's about 22
Amy Martin:years old, and her calf is about three and a half, so she's still
Amy Martin:quite young, you know?
Amy Martin:Yeah, Twenty-something. Oh, wow, three
Amy Martin:just all came up.
Amy Martin:Young dolphins like this calf, named Jungle, usually stay with
Amy Martin:their mothers for around four years. At first they depend on
Amy Martin:mom for milk, but even after they're weaned, they usually
Amy Martin:stick around perfecting their hunting skills and learning how
Amy Martin:to fit in to dolphin society. I can't help but notice some
Amy Martin:parallels between the animals in the water and us humans up in
Amy Martin:the boat. All together, we're a total of eight mammals working
Amy Martin:in two teams using acoustic communication to learn from our
Amy Martin:leaders. And then for me, came one of the more magical moments
Amy Martin:of this experience.
Amy Martin:We have a speaker! So we're hearing in the hydrophone.
Amy Martin:Laura has flipped on a speaker in the boat, so we can hear, in
Amy Martin:real time, the conversations the dolphins are having in the water
Amy Martin:around us. Suddenly, we're with them in a completely different
Amy Martin:way.
Laura Palmer:I love these guys.
Amy Martin:I'd heard recordings of dolphin sounds before this
Amy Martin:trip, and you probably have too, but this was the moment I
Amy Martin:learned the enormous difference between hearing a random
Amy Martin:recording of some anonymous dolphins and being with actual
Amy Martin:living individual creatures and hearing their voices as they fly
Amy Martin:through the water all around me.
Amy Martin:Dr. Stephanie King: Juicy.
Laura Palmer:Juicy. Juicy is at 230 degrees.
Laura Palmer:Dr. Stephanie King: That might be the calf.
Amy Martin:That high-pitched swoop is called a whistle, and
Amy Martin:it's one of the most important sounds in dolphin communication.
Amy Martin:Laura is overjoyed to hear it, because whistles are at the
Amy Martin:center of her research for this trip. She wants to learn more
Amy Martin:about how they're used between mothers and calves, like Jungle
Amy Martin:and Juicy are doing right now.
Laura Palmer:Juicy at 20 degrees. With calf in BP.
Amy Martin:BP stands for "baby position," meaning right next to
Amy Martin:mom and moving in tandem with her. It's another quick way of
Amy Martin:noting how the dolphins are grouped and relating to each
Amy Martin:This is so cool, you guys, it's making me cry!
Amy Martin:other.
Laura Palmer:I could cry with joy as well. This is a great
Laura Palmer:recording for me.
Amy Martin:I brought my own hydrophone on this trip, and I'm
Amy Martin:eager to get it in the water. But soon this group of dolphins
Amy Martin:disperses, and Laura pulls her gear back up into the boat.
Amy Martin:What do you call those kinds of sounds?
Laura Palmer:Oh, so they were buzzes. So when they're
Laura Palmer:foraging, it's very rapid rate echolocation. They're basically
Laura Palmer:using it to gain a lot of information on their
Laura Palmer:environment, right and potentially the prey items that
Laura Palmer:they're tracking. And we also heard a lot of whistles, which
Laura Palmer:are predominantly social signals as well, so it's likely they're
Laura Palmer:communicating with each other, or, you know, potentially the
Laura Palmer:other animals that we've initially saw that are not with
Laura Palmer:us right now.
Amy Martin:We head off to a new spot across the bay, and as the
Amy Martin:boat picks up speed, it's harder to talk. So I settle in and
Amy Martin:watch the waves for a while. This team has been gracious
Amy Martin:enough to let me tag along for several days, so there'll be
Amy Martin:time for more of my questions later, and I have a lot of them.
Amy Martin:I want to know everything about these whistles, what they mean,
Amy Martin:why they matter. I want to ask Stephanie a lot more about the
Amy Martin:male alliances that she studied and how they use sound, but
Amy Martin:right now, it's time to take a deep breath and appreciate where
Amy Martin:I am and what I'm getting to witness. I don't have to
Amy Martin:understand at all to know that I have just been visited by
Amy Martin:wondrous beings, creatures full of beauty and power and
Amy Martin:intelligence, and they've survived on this planet for
Amy Martin:millions of years by listening to each other. We'll have more
Amy Martin:after this short break.
Amy Martin:Hey, I want to take a minute to thank you for listening to
Amy Martin:Threshold and to explain how important you are in getting the
Amy Martin:show made. Most podcasts raise money by selling advertising,
Amy Martin:and that pushes them to make a lot of episodes as quickly as
Amy Martin:possible. But that's just not who we are. Our show is about
Amy Martin:thinking deeply about how humans are fitting into the rest of the
Amy Martin:web of life. We take you places and craft stories that are
Amy Martin:intellectually challenging and emotionally rich. That's the
Amy Martin:kind of show we want to make, and that's the kind of show
Amy Martin:you've told us you want to hear. That's why we created an
Amy Martin:independent, non profit media company, and why nearly all of
Amy Martin:our funding comes from listeners like you. This is not the
Amy Martin:easiest way of funding a show, but it is the way that's most
Amy Martin:aligned with our mission, and it's worked so far thanks to
Amy Martin:people who decide to support it. Our year-end fundraising
Amy Martin:campaign is happening now through December 31 and each
Amy Martin:gift will be matched by our partners at NewsMatch. That
Amy Martin:means, if you can give $25, we'll receive 50. You can make
Amy Martin:your donation online at thresholdpodcast.org. Just click
Amy Martin:the donate button and give what you can and again, thank you so
Amy Martin:much for listening.
Dallas Taylor:I'm Dallas Taylor, host of 20,000 Hertz, a
Dallas Taylor:podcast that reveals the untold stories behind the sounds of our
Dallas Taylor:world. We've uncovered the incredible intelligence of
Dallas Taylor:talking parrots.
Dallas Taylor:Basically, "bird brain" was a pejorative term, and here I had
Dallas Taylor:this bird that was doing the same types of tasks as the
Dallas Taylor:primates.
Dallas Taylor:We've investigated the bonding power of music.
Dallas Taylor:There's an intimacy there in communicating through the medium
Dallas Taylor:of music that can be really a powerful force for bringing
Dallas Taylor:people together.
Dallas Taylor:We've explored the subtle nuances of the human voice.
Dallas Taylor:We have to remember that humans, over many hundreds of thousands
Dallas Taylor:of years of evolution, have become extremely attuned to the
Dallas Taylor:sounds of each other's voices.
Dallas Taylor:And we've revealed why a famous composer wrote a piece made
Dallas Taylor:entirely of silence.
Unknown:I think that's a really potentially quite useful and
Unknown:quite profound experience to have.
Dallas Taylor:Subscribe to 20,000 Hertz right here in your
Dallas Taylor:podcast player. I'll meet you there.
Amy Martin:Welcome back to Threshold, I'm Amy Martin, and
Amy Martin:for the rest of this episode, we're gonna do some time travel.
Amy Martin:We're going back to a world long before dolphins, before
Amy Martin:dinosaurs, before there were any animals or plants. If we could
Amy Martin:transport ourselves back to the very early Earth, we would find
Amy Martin:a barren world blanketed in toxic gas. The atmosphere had
Amy Martin:almost no oxygen in it. There was no life at all. The only
Amy Martin:thing making sound was the planet itself, storms,
Amy Martin:earthquakes, ocean waves, volcanos. And that's how things
Amy Martin:were for a really long time. The Earth is around four and a half
Amy Martin:billion years old, and for about 90% of those years, nothing
Amy Martin:existed that was capable of intentionally making a sound or
Amy Martin:receiving it. So how do we get from that world to this one? How
Amy Martin:did the Earth transform itself from a place of such
Amy Martin:unfathomable quiet into a non stop symphony of sound? We're
Amy Martin:going to spend the rest of the season telling that story,
Amy Martin:tracing the sonification of the Earth roughly in the order in
Amy Martin:which life evolved. It all started with a silence too long
Amy Martin:for us to truly comprehend, but I wanted to try, and it turns
Amy Martin:out one of the best places to do that is just down the Western
Amy Martin:Australian coast from where I met the dolphin researchers.
Amy Martin:Okay, I'm just in the parking lot. Pardon me, just in the
Amy Martin:parking lot for the Hamelin pool.
Amy Martin:I leave behind one talkative Australian Raven and a small
Amy Martin:flock of chiming wedgebills and walk the short distance out to
Amy Martin:the edge of Hamelin pool, a big bay with a surface smooth as
Amy Martin:glass.
Amy Martin:I just want to try to listen here for a little while. The
Amy Martin:water is so still. There's not a ripple, there's not a there's no
Amy Martin:birds landing on it. There's no bubbles or any sign of movement.
Amy Martin:It's early, and I'm alone. But those aren't the only reasons
Amy Martin:this place is so silent. Hamelin Pool has an inner stillness.
Amy Martin:It's extremely salty, twice as salty as the open ocean, which
Amy Martin:means it's hard for plants and animals to survive here and
Amy Martin:against this canvas of quiet, every sound made by a living
Amy Martin:thing pops out, a bird peep, a fly buzz. For most of our
Amy Martin:planet's history, this kind of silence reigned supreme.
Amy Martin:Just think about the entire earth being that quiet. There
Amy Martin:was nothing, breathing, flying, walking, crawling, a whole
Amy Martin:planet with nothing that had a voice.
Amy Martin:But although Hamelin Pool may be a profoundly quiet place, it
Amy Martin:isn't actually as lifeless as it seems. There's a lot of
Amy Martin:mysterious blackish gunk carpeting the beach in front of
Amy Martin:me, almost like a bathtub ring of slime growing where the water
Amy Martin:meets the shore. These are communities of microbes. They go
Amy Martin:by sexy names like gelatinous microbial mats or pustular
Amy Martin:sheets, and they built a bridge between the barren early Earth
Amy Martin:and the lush, loud, fruitful world we enjoy today. Ancient
Amy Martin:microbes were the inventors of what is arguably the most
Amy Martin:important technology of all time, photosynthesis. A couple
Amy Martin:of billion years ago, they started to tap into the sun's
Amy Martin:energy and produce oxygen, and that changed everything. Bit by
Amy Martin:bit, they pumped that oxygen into the sea.
Amy Martin:Dr. Erica Suosaari: You know, and after a while, then all that
Amy Martin:oxygen created by photosynthesis from microbes, eventually
Amy Martin:saturates the ocean, the ocean can't hold anymore. Where does
Amy Martin:the oxygen go? It goes into the atmosphere.
Amy Martin:This is Dr. Erica Suosaari.
Amy Martin:Dr. Erica Suosaari: The atmosphere becomes oxygenated,
Amy Martin:which essentially that allows for evolution, which then here
Amy Martin:we go, and finally get to us.
Amy Martin:The slimy mats I saw growing in Hamelin Pool were
Amy Martin:microbes still performing these ancient rituals, doing the work
Amy Martin:that led to all other life on Earth. They don't look like much
Amy Martin:at all, but they hold the origin story of every call, cry,
Amy Martin:squawk, or song ever heard.
Amy Martin:Dr. Erica Suosaari: This is a living system still doing this,
Amy Martin:still doing these same processes that were happening billions of
Amy Martin:years ago. There is no place else on the planet that
Amy Martin:represents that in its entirety. It is really this window into
Amy Martin:the ancient.
Amy Martin:I'm curious about you, like, what, what stage in
Amy Martin:your development did you realize, I really want to learn
Amy Martin:a whole lot more about goo?
Amy Martin:Dr. Erica Suosaari: I guess technically I'm a marine
Amy Martin:geologist. I'm a carbonate sedimentologist, but I look at
Amy Martin:marine rocks.
Amy Martin:Erica is based at the Smithsonian Institution's
Amy Martin:National Museum of Natural History in Washington, DC. She
Amy Martin:first visited Hamelin Pool while working on her PhD, and she was
Amy Martin:so blown away by the glimpse it provided into the early Earth
Amy Martin:that she moved to Western Australia and lived close by for
Amy Martin:several years, just so she could continue studying the place.
Amy Martin:Dr. Erica Suosaari: So I have sort of this obsession with
Amy Martin:time. I've always had this obsession with time and kind of
Amy Martin:infinity and what it means and the big picture and how
Amy Martin:significant our lives are and what we do, because the time is
Amy Martin:so big, and it's like, you know, kind of figuring out the puzzle
Amy Martin:of what life means on huge scales.
Amy Martin:And key pieces of that puzzle can be found in
Amy Martin:these communities of microbes at Hamelin. Erica is one of the
Amy Martin:world's leading experts on them and the stony structures they
Amy Martin:create, which are called-
Amy Martin:Dr. Erica Suosaari: Microbiolites, which are basically rocks
Amy Martin:created by microbes.
Amy Martin:We don't tend to think of microbes as creating
Amy Martin:anything except infections, maybe, but at some point, way
Amy Martin:back in time, they started to make rocks: clotted
Amy Martin:thrombolites, branched dendrolites and layered
Amy Martin:stromatolites. The world's oldest fossilized stromatolites
Amy Martin:found in Western Australia are almost three and a half billion
Amy Martin:years old, and the microbes at Hamlin pool are still making
Amy Martin:these rocks today. It's the largest known collection of
Amy Martin:living marine stromatolites in the world.
Amy Martin:Dr. Erica Suosaari: What Hamelin represents is, is, I don't even
Amy Martin:have a word for what Hamelin represents. It's just, it's a
Amy Martin:really spectacular place. It's a living laboratory.
Amy Martin:The stromatolites are kind of like the Machu
Amy Martin:Picchu or Egyptian pyramids of the microbial world. These are
Amy Martin:structures made by communities of living things with a story to
Amy Martin:tell. They grow close to the edges of Hamelin pool in the
Amy Martin:shallow water, maybe a foot or two high. Some of them look a
Amy Martin:little bit like toadstools, others resemble stubby fingers
Amy Martin:or brainy mounds. But whatever form they take, there's
Amy Martin:something about them that signals life. You can see
Amy Martin:familiar, organic patterns in them, you can sense that they
Amy Martin:grew, and this is how it all began, even though the microbes
Amy Martin:themselves are very quiet, without them, there would be no
Amy Martin:voices to speak or ears to listen. Erica says one of the
Amy Martin:essential ingredients in this process is a coding the microbes
Amy Martin:make and cover themselves with.
Amy Martin:Dr. Erica Suosaari: It's called EPS. It's exo-polymeric
Amy Martin:substance.
Amy Martin:Exo-polymeric substance. I asked her to
Amy Martin:translate that into non-sciency language.
Amy Martin:Dr. Erica Suosaari: It's like a, it's this. It's this. It's the
Amy Martin:slime of life. You know? It's like a, it's a goo.
Amy Martin:It's a goo. We've got a microbe that makes a goo.
Amy Martin:Dr. Erica Suosaari: Yeah.
Amy Martin:As sediment in the water floats by, some of it
Amy Martin:sticks to this goo, kind of like dust sticking to fly paper. It
Amy Martin:builds up layer after layer into stone.
Amy Martin:Dr. Erica Suosaari: And you build up kind of this laminated
Amy Martin:structure. So that's a stromatolite.
Amy Martin:The EPS can actually do all kinds of cool stuff. It
Amy Martin:helps the microbes communicate with each other. It acts as a
Amy Martin:sunscreen. It even changes the chemistry of the water, which
Amy Martin:helps in the stromatolite building process.
Amy Martin:So it's a it's a self produced goo that does chemistry.
Amy Martin:Dr. Erica Suosaari: Yes, or has chemistry happening. Yeah, all
Amy Martin:around it.
Amy Martin:Okay, there's like, a lot going on.
Amy Martin:Dr. Erica Suosaari: Oh yeah, there's a lot going on.
Amy Martin:I like to think of these microbial communities as
Amy Martin:the world's first cities, with the bacteria in them bustling
Amy Martin:around, working as architects and engineers, carpenters and
Amy Martin:chemists. They farmed sunlight and produced oxygen, the oxygen
Amy Martin:that led to me talking to you right now.
Amy Martin:Dr. Erica Suosaari: These lineages of bacteria, life
Amy Martin:persisting for billions of years.
Amy Martin:While everything changed around them again and
Amy Martin:again and again, these microbes carried life forward, passing it
Amy Martin:on and on and on, one generation after another.
Amy Martin:Dr. Erica Suosaari: It's not a timeline that I still think I
Amy Martin:can wrap my mind around, but I find it sort of comforting that
Amy Martin:there is this long stretch of time that these rocks represent,
Amy Martin:and I am drawn to that.
Amy Martin:What do you think the world sounded like when the
Amy Martin:only living things were these microbes.
Amy Martin:Dr. Erica Suosaari: Cashing waves. I don't know. A lot of
Amy Martin:water. But underwater,there's something about silence. I can't
Amy Martin:imagine. I mean, silence. What does that sound like for oxygen
Amy Martin:bubbles to rise to the surface, crashing waves? Kind of
Amy Martin:meditative and calm, which is crazy, because it's a time in
Amy Martin:Earth's history where it's very chaotic, and, and yet, you know,
Amy Martin:there's like the kind of the peace that life brings.
Amy Martin:As I stood on the beach at Hamelin Pool, I tried
Amy Martin:to imagine more than 3 billion years of that silence. Eons of
Amy Martin:ear splitting emptiness. And rhen finally, the planet began
Amy Martin:to sing. Every song or call or cry made on Earth happened in
Amy Martin:just the last tenth of the planet's existence. The
Amy Martin:cacophony of life that we take for granted is actually
Amy Martin:exceptional. Silence is the norm on our planet, or any planet
Amy Martin:that we know of. Erica's work is being used in the search for
Amy Martin:life on Mars, and maybe someday we'll receive communication from
Amy Martin:some extraterrestrial being. But so far, we Earthlings are
Amy Martin:singing together into the void. The only voices we've ever heard
Amy Martin:are each others'.
Amy Martin:This episode of Threshold was written, recorded and produced
Amy Martin:by me, Amy Martin, with help from Erika Janik and Sam Moore.
Amy Martin:Music by Todd Sickafoose. Post-production by Alan Douches.
Amy Martin:Fact-checking by Sam Moore. Special thanks to Tim Lamont and
Amy Martin:Miles Parsons. This show is made by Auricle Productions, a
Amy Martin:non-profit organization powered by listener donations. Deneen
Amy Martin:Weiske is our executive director. You can find out more
Amy Martin:about our show at thresholdpodcast.org.
