Extinctions In Near Time: Biodiversity Loss Since The Pleistocene



The transition 11,700 years ago from the Pleistocene glacial period into the Holocene interglacial witnessed the expansion of humans around the world, climatic warming and the demise of many large vertebrate species. Since that time extinctions have continued on land and in the sea, culminating with the biodiversity crisis we are experiencing today. We explored these prehistoric extinctionsWho? When? Where? and Why?in order to learn more about our planets future. Students then translated their knowledge into a podcast for a general audience addressing the question: Why do we care when species face extinction?


  • Is a Bear Bile Market Necessary? by Isabel Cardenas

    Is a Bear Bile Market Necessary? by Isabel Cardenas

    16/12/2011 Duración: 03min

    Hi everyone, my name is Isabel Cardenas and I’ll be talking about the market for bear bile and what it means to farmed bears, wild bears, and North American bears. In parts of Asia, drinking bear bile is a traditional remedy to cure intestinal and heart illnesses1. This has created an enormous market for fresh bear bile. Poachers have decimated the populations of Asiatic black and brown bears to satisfy the demand. As a result, bear farms emerged throughout Asia so that profiteers have a constant source. The market for bile has had extensive consequences for bears in farms, wild Asian bears, and now wild bears in North America. My name is Isabel Cardenas and I would like to tell you about how the demand for bear bile is threatening bears around the world. Today’s demand for bear bile is large enough to warrant the captivity of twelve thousand bears on farms in China, Vietnam, and Korea5. Typically, Asiatic black bears and brown bears are captive on these farms1. On bear farms, a tube extracts bile f

  • Urban Makeover Advice by Yari Greaney

    Urban Makeover Advice by Yari Greaney

    16/12/2011 Duración: 03min

    It seems so innocent. Pretty houses with manicured lawns, several little parks with small grassy fields bordered by metal fences, a few house sparrows hopping around the picnic tables. We’d call it a beautiful town. Unfortunately, this perception of beauty is deadly (Rosenzweig). Hi. My name is Yari and I’m here to provide some urban makeover tips that will help many different plants and animals. Usually when we think about saving wildlife, we think about rain forests and the wilderness, but lets not forget city wildlife. Of course, some animals – like rats, cockroaches, and pigeons – do great living with us (Marzluff). These animals that are thriving in cities are called generalists, meaning they can survive in lots of different situations (Francis). It’s the creatures who need very specific habitats that are struggling, because we’ve replaced their homes with our towns (Rosenzweig). That means that a few generalists like house sparrows (Shoshat) and house mice (Francis) can live all over the pl

  • Juan Fernandez Island and the Endemic Firecrown Hummingbird by Michael Peñuelas

    Juan Fernandez Island and the Endemic Firecrown Hummingbird by Michael Peñuelas

    16/12/2011 Duración: 04min

    On an island called Isla Juan Fernandez in the Pacific Ocean there lives a hummingbird that I’ll tell you a bit about today called the Juan Fernandez Firecrown. It is a strikingly beautiful little thing, and it lives only on this one island (Hodum). Today it is threatened for a whole host of reasons, all caused in some way by humans, and exacerbated by the remoteness and size of the island on which it lives. Isla Juan Fernandez is an island 400 miles off the coast of Chile (Terrestrial Eco…). It has been 400 miles away from the mainland and therefore any contact with other ecosystems, for 4 million years (Anderson pp1). In that time, the biota, meaning the total complement of animals and plants, that initially settled the island has evolved on its own, independent from outside interference, and formed a totally endemic, native ecosystem (Anderson pp1). Later on as humans began to arrive, which didn’t happen until this century, they brought things with them. Things like invasive plant and animal species,

  • Where did the Dingo go? By Lauren Sweet

    Where did the Dingo go? By Lauren Sweet

    16/12/2011 Duración: 04min

    Hi I’m Lauren and your listening to “Where did the Dingo Go?” We often think of Australia as a land hopping with kangaroos, wallabies, bilbies and other fuzzy critters. What most people don’t realize is that, despite this apparent diversity, in the last 2 centuries Australia has seen 19 of its unique mammal species become extinct (Johnson 2006) –that’s about half of all mammal extinctions worldwide in that period (Johnson et al. 2007). And Australia's mammals are still in great danger because of the slow demise of the wily dingo. About 4000 years ago man brought the dingo to Australia. Since then, the dingo has gone from ancient companion to top predator(Ritchie & Johnson 2009).While you might think the Dingo is a pesky carnivore that eats livestock, gobbles up native animals and is generally the equivalent of the big bad wolf, the truth is that the dusty colored dingo is anything but bad. Since becoming top dog, dingoes have lived in relative harmony with the many small, rare Australian marsupials-you know,

  • The last female just died: A tale from Guam. By Joseph Topasna

    The last female just died: A tale from Guam. By Joseph Topasna

    16/12/2011 Duración: 04min

    Why has the Pacific Island of Guam gone from sounding…like this...to a little more like this... Hello again everyone! My name is Joseph, and today I’m reporting to you all from the always beautiful Stanford University. Before we dive in, first a little about me. You see, I was born on the island of Guam 18 years ago. The silence you got a brief glimpse of is extremely concerning for me. Many species of animals on Guam have disappeared forever- that’s the silence. For my generation of Guamanians, this pestilent silence has nowadays become common place. Sixty years ago my grandfather would have heard all of those beautiful birds. Where.have.they.gone? Why has the island of Guam become a quieter place?! Ope! And it looks like we have caller! You're live caller #1, what do you have to say on the subject? YARRRRRRR Oh goodness me, not again. Make it quick captain yosef. I have the answer to your question!!! NOW... Come with me across the Pacific to peer at the answer in the form of an evolutionarily gifted pred

  • Megafaunal Loss by Mark Valentine

    Megafaunal Loss by Mark Valentine

    16/12/2011 Duración: 02min

    Hello again. Like I said before, I’m Mark Valentine and I’m going to be talking about Megafaunal Extinction and how it affects present and future biodiversity. Before I begin, you probably are going to want to know what exactly Megafauna are. Megafauna are HUGE animals. This would certainly include animals like elephants and giraffes, but also lions, tigers and bears. All these animals, however, are relatively well known and still exist in the world today. What many people don’t know is that there were many incredible Megafauna that existed a few thousand years ago that are now extinct. Around 50,000 years ago, at the end of the last Ice Age, Megafauna worldwide underwent massive and widespread extinctions . Before then, there were all kinds of amazing and enormous animals worldwide: In Eurasia, there were wooly mammoths and saber tooth cats, which you’ve probably heard of, but in North America there were beavers the size of small cars and 9 foot tall Bison with horns that spanned over 6 feet , in S

  • Are Worms Worthy of Conserving? by Jack Werner

    Are Worms Worthy of Conserving? by Jack Werner

    16/12/2011 Duración: 03min

    Me: In the last episode, we talked about efforts to save charismatic animals from extinction. In this episode, we ask a very different question: is it ever ok to MAKE an animal go extinct? Not me: Of course not. It's immoral to just wipe a living creature off the face of the earth. Me: Well, let me tell you about an animal I - and the U.N. - think should be made extinct: the guinea worm. Guinea worms are these tiny little worms found in Asia and Africa. Not me: Nothing wrong with worms. Me: This worm is a parasite. People drink dirty water containing the worm's larvae, and these larvae burrow into their host's stomach and intestines. Photo from Wikipedia Not me: So what? There's plenty of food to go around. Me: I’ll tell you. After growing for about a year, the worm migrates to your feet, causing excruciating pain as it slithers through your leg. Then…a blister forms. Slowly, a worm three feet long and as thick as a spaghetti noodle crawls through your ruptured blister. The process often takes days, b

  • Animal magnetism and conservation by Jack Werner

    Animal magnetism and conservation by Jack Werner

    16/12/2011 Duración: 04min

    Me: Some call it cuteness, some call it charisma, some even call it animal magnetism: Hi, I’m Jack Werner, and today I’ll be talking about why we try so much harder to conserve likeable species and what this means for endangered animals everywhere. With me is my good friend, Not me. Not me: Hello there Me: Let’s get to it. From China’s giant pandas to the elephants of the African savanna to America’s iconic bald eagles, there are some animals that just captivate us. In fact, a study estimated that 54% of all wildlife funding in the United States is devoted to just 1.8% of America’s endangered species. Not me: Why exactly do we value some endangered species so much more than others? Me: Most endangered species aren’t economically valuable, so we usually value them for emotional reasons. Different people are captivated by different animals, but there are some general patterns to what people like. Typically, physical and behavioral similarity to humans is an important factor. Gorillas hold their babi

  • Contents


    16/12/2011 Duración: 02min

    Short intros for each episode Photo: Creative Commons: Matt-80

  • Crops Wild Relatives: Maize and Teosinte by Dylan Sweetwood

    Crop's Wild Relatives: Maize and Teosinte by Dylan Sweetwood

    14/12/2011 Duración: 03min

    The Relationship Between Maize and Teosinte Dylan Sweetwood You probably already know that maize, or corn, is one of the most culturally and commercially important crops in the world, with hundreds of applications in areas from agriculture to energy. But what you may not know is that teosinte, one of corn’s closest genetic relatives, is currently under threat of extinction. Then again, so are a lot of other plants—why is teosinte worth worrying about? My name is Dylan Sweetwood, and I’m going to talk about the relationship between maize and teosinte and why this relationship is important to preserve. Humans have grown maize for thousands of years—so long, in fact, that it can no longer reproduce without human cultivation. This long history has resulted in a genetic bottleneck, which means that all modern varieties of corn are genetically indistinguishable. Traditionally, this was considered advantageous, but now scientists believe that genetic diversity is beneficial for crop persistence. Corn’s limited gen

  • An interview with Nicole Ruiz about orangutans

    An interview with Nicole Ruiz about orangutans

    14/12/2011 Duración: 03min

    Bartholomew: Hey guys. So last week I took my family to the zoo where we watched a show about orangutans. I was a little upset to hear that they’re declining in numbers. Anyway, last night I met up with Nicole Ruiz, a Stanford student interested in orangutan conservation, and she let me in on the little things that make orangutans so special. Tune in to find out what I learned! Interview: B: Hi Nicole, thanks for taking the time out to speak with me. So what can you tell me about orangutans? What makes them so special? N: So I’d like to begin by giving you a little background of where they live. Wild orangs are located on either the island of Sumatra or Borneo. Sumatran orangutans are more critically endangered, though. They have a population of about 7000. Bornean orangutans have a population of about 50000. I don’t know if you know this, but orangutans are one of the great apes. This includes chimps, gorillas, bonobos, humans, and, of course, orangutans. B: Wait--so are you telling me thes

  • Little Brown Bats  White Nose Fungus by Nora Tjossem

    Little Brown Bats & White Nose Fungus by Nora Tjossem

    14/12/2011 Duración: 03min

    Did you hear that? That was the sound of the little brown bat - Myotis lucifugus. They’re everywhere on summer nights, and sometimes if you’re lucky, you’ll get to catch a glimpse of one as it chases mosquitoes through the trees. But go outside right now if you want to, because it’s possible that within the next sixteen years, you won’t be hearing more than a recording. The little brown bats of North America are fighting a losing battle against an enemy we call... Fungi? That’s right. Or, in the scientific world, “Geomyces destructans.” This cold-loving fungus has been ravaging bat caves throughout North America since 2006, wiping out an average of 73% of an infiltrated cave population. How does a fungus take out three out of every four bats? Picture this: It’s late October. You’re a bat, hanging upside down in preparation for winter. This means you’ve eaten your fill of summer insects, you’ve huddled together with your family members, and you’re ready to shut down for the long, cold Northeastern winter a