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  • FISH THAT WALK,

  • MUSHROOMS THATBLEED,”

  • PRIMATES THAT FIND THEIR FOOD JUST WITH THEIR MIDDLE FINGER...

  • THESE ARE REAL THINGS, PEOPLE.

  • WE SHARE OUR PLANET WITH MILLIONS OF INCREDIBLE LIFE FORMS.

  • AND DISCOVERING WHO THEY ARE, WHERE THEY ARE, AND WHAT MAKES THEM TICK IS KEY IF WE WANT

  • TO UNLOCK THE SECRETS OF MEDICINE, ENGINEERING, DESIGN, ECONOMICS,

  • SUSTAINABILITY AND STEWARDSHIP

  • THAT WILL DEFINE THE FUTURE OF OUR SPECIES;

  • REVEAL CLUES ABOUT OUR EVOLUTIONARY PAST;

  • AND JUST CULTIVATE OUR SENSE OF WONDER AT LIFE'S SHEER POTENTIAL.

  • BUT WE NEED TO ACT FAST.

  • - Today we are living in a biodiversity crisis,

  • in which species are going extinct before we even realize their existence, or their

  • potential value.

  • SO, HOW CLOSE ARE WE TO DISCOVERING ALL LIFE ON EARTH?

  • IN THIS EPISODE, WE'LL MEET SOME AMAZING BIODIVERSITY RESEARCHERS

  • WORKING INTERNATIONALLY TO ACCELERATE SPECIES DISCOVERY,

  • DEVELOP DIGITAL CONSERVATION TOOLS,

  • AND MAINTAIN ONE OF THE WORLD'S LARGEST BIOLOGICAL COLLECTIONS

  • THROUGH A PROCESS CALLEDCRYOPRESERVATION

  • THAT IS, LITERALLY, ULTRA-COOL.

  • BUT THIS NETWORK OF RESEARCHERS HAS A HERCULEAN EFFORT IN FRONT OF THEM.

  • - Strangely enough, we know only maybe 10% of the biodiversity that we have on our planet.

  • THAT MEANS THERE'S SOMETHING LIKE 90% OF LIFE ON EARTH LEFT TO DISCOVER.

  • SO LET'S START AT THE BEGINNING.

  • DESCRIBING A NEW SPECIES TYPICALLY REQUIRES COLLECTING A PHYSICAL SPECIMEN OF SOME KIND,

  • WHICH CAN OFTEN MEAN TRAVELING TO HARD-TO-REACH LOCATIONS.

  • - They call them theserapid inventories.” Sometimes they don't have road access so they'll

  • fly in by plane and just parachute in with a team of ecologists that identify the plants,

  • the birds, the amphibians and the butterflies.

  • - If a species is bigger, it's easier to find

  • than a small specimen.

  • If the species has a really colorful pattern, it's easier to see than a species that has

  • a kind of camouflage.

  • ONCE IT'S RETRIEVED, THE SAMPLE WILL BE SENT TO A SCIENTIFIC COLLECTION, WHERE IT

  • MAY HAVE TO WAIT TO BE  DISCOVERED ALL OVER AGAIN.

  • After you collect this specimen in nature,

  • it might take, like, 21 years for that specimen to be discovered in a scientific collection,

  • and have someone process it and describe it as a formal new species.

  • THIS IS BECAUSE THE EXPERTISE REQUIRED TO DO THIS IS PRETTY RARE.

  • A TAXONOMIC EXPERT NEEDS TO STUDY THE SPECIES' SHAPE, STRUCTURE, AND GENETIC MAKEUP, AND

  • COMPARE IT WITH ANY CLOSE KNOWN RELATIVES BEFORE GIVING IT A NAME.

  • We don't have enough taxonomists.

  • We need to have an army of taxonomists to describe all the species

  • that exist in the world.

  • BUT DUBBING A SPECIES OFFICIAL IS JUST THE BEGINNING.

  • TO CREATE A RECORD OF IT THAT OTHER SCIENTISTS CAN STUDY, LET ALONE USE FOR ANY CONSERVATION

  • WORK, WE NEED TO CAPTURE AND PRESERVE ALL THE INFORMATION WE CAN ABOUT AN ORGANISM.

  • THAT'S WHERE COLLECTIONS LIKE THE SMITHSONIAN

  • INSTITUTION'S BIOREPOSITORIES COME IN.

  • SO WE WENT TO VISIT THE NATIONAL ZOO IN DOWNTOWN WASHINGTON, D.C.

  • TO SEE WHAT HAPPENS NEXT.

  • - A biorepository is a specialized facility

  • that really contains a lot of biological materials,

  • that really need to be preserved in a stable state.

  • It's like in a museum when you have paintings that are very sensitive to variation of humidity

  • or temperature.

  • Every day, we have tens to hundreds of incoming samples

  • that are processed and stored for the long term.

  • I would say that we are probably among the largest collections in the world.

  • THAT COLLECTION REPRESENTS AROUND 18,000 SPECIES

  • AND INCLUDES OVER 1 MILLION DNA SAMPLES, SKIN

  • BIOPSIES, BLOOD SAMPLES, SPERM, EGGS, EMBRYOS...

  • YOU NAME IT.

  • CRYOPRESERVATION INVOLVES A SERIES OF METICULOUS STEPS,

  • WHICH I GOT TO EXPERIENCE FIRSTHAND.

  • THE WATER IN A SKIN SAMPLE FROM A NEWLY DISCOVERED RODENT,

  • FOR EXAMPLE, NEEDS TO BE REPLACED

  • WITH A FLUID CALLED CRYOPROTECTANT THAT ACTS AS ANTIFREEZE, EFFECTIVELY PUTTING THE CELLS

  • ON PAUSE WHEN THE SAMPLE IS STORED IN LIQUID NITROGEN.

  • So basically you suspend life entirely and

  • this life suspension can travel through time - for a long, long period of time.

  • - Do you mind if I try? Is that okay?

  • - Sure, go for it.

  • - You have to show me how to do it, though, because I have a feeling this is harder than it looks.

  • - A little.

  • - Okay. So, we've got thethingsand the goal is to put it in the tube, right? Okay.

  • - Mm-hmm, and while keeping everything underneath the liquid nitrogen,

  • as much as possible.

  • - Haha, I don't know if I'm going to be able to do that, okay.

  • Let's try.

  • Ah! Okay, okay. Like this... it's not submerged, it's not submergedoh no.

  • Ha!

  • It's good, right?

  • - Nice!

  • Yaaaaaaas. High five.

  • We preserve also, all the packaging of the DNA but

  • we also preserve the cells that are containing the DNA and beyond the cells, the whole tissue.

  • We want to make sure that everything is still viable when we are thawing the samples.

  • Viable means that the tissue has to be able to recover and to resume normal activities,

  • biochemical, biophysical activities and when we are talking about gonadal tissues like

  • ovaries or testes, we need to make sure that they are still producing germinal cells.

  • YOU HEARD THAT RIGHTTHESE SAMPLES CAN BE USED

  • NOT ONLY FOR FUTURE SCIENTIFIC STUDY, BUT EVEN ARTIFICIAL INSEMINATION

  • TO HELP RECOVER AN ENDANGERED POPULATION.

  • AND WHILE THE ZOO ITSELF SPECIALIZES IN VERTEBRATES AND CARNIVORES,

  • THROUGH SOMETHING CALLED THEPAN-SMITHSONIAN CRYOINITIATIVE,”

  • PIERRE AND HIS TEAM WORK WITH SCIENTISTS AT

  • OTHER ZOOS, MUSEUMS, AND RESEARCH CENTERS TO PRESERVE INVERTEBRATES, PLANTS, AND SOIL

  • SAMPLES, ADDING MICROBES AND FUNGI TO A MORE AND MORE COMPLETE 'LIBRARY OF LIFE.'

  • - So, there are specific parts of the planet that

  • we've barely explored, and there are specific parts of the tree of life, like specific animal

  • groups, that we haven't scientifically explored in the same way.

  • SO HOW DO WE KNOW WHERE TO LOOK NEXT?

  • WHERE MIGHT BE MOST AT RISK, OR MOST RIPE FOR DISCOVERIES?

  • TO CREATE A ROADMAP THAT POINTS US TO WHERE NEW SPECIES MIGHT BE HIDING, WE'LL NEED

  • TO COMPILE EVERYTHING WE KNOW SO FAR ABOUT WHERE SPECIES OCCUR,

  • FROM CONSERVATION DATASETS,

  • TO VINTAGE FIELD GUIDES, TO INFORMATION COLLECTED BY CITIZEN SCIENTISTS

  • ON THEIR MOBILE PHONES.

  • ENTER THEMAP OF LIFE,” A FLAGSHIP PROJECT

  • AT YALE'S CENTER FOR BIODIVERSITY AND GLOBAL CHANGE THAT'S DOING JUST THAT.

  • What we do is compile all types of spatial and non-spatial information

  • about species, to get the best idea of where species occur in the world.

  • Our data teams can standardize millions of records so that we can really easily and

  • quickly get an idea of, 'this is what information we have for this specific region.'

  • AS THE NAME SUGGESTS, THIS DATA, TAKEN TOGETHER,

  • CREATES A VIRTUAL MAP OF LIFE THAT CAN BE USED BY ANYONE ,

  • WHETHER YOU'RE DISCOVERING SPECIES IN YOUR OWN BACKYARD

  • OR PLANNING A FIELD EXPEDITION.

  • We also inform UN-level decision makers, and conservation managers

  • that are working on the ground.

  • It gives an answer to people that are curious to say like, "how can I get involved?

  • How can I help?"

  • And this is showing like, "This is what you're stewarding in your area that you live."

  • Anywhere on the planet.

  • BUT WHETHER RACING TO FREEZE TISSUE SAMPLES THAT IMMORTALIZE A SPECIES

  • OR DRAWING DIGITAL MAPS THAT POINT US TO NEW DISCOVERIES,

  • RESEARCHERS AGREE THAT OUR BEST BET TO PRESERVE AND DOCUMENT

  • LIFE AS QUICKLY AS WE CAN, IS TO ACT LOCALLY AND THINK GLOBALLY.

  • We built a dashboard for Peru, Ecuador, and Columbia

  • for park managers there to figure out what species are in their park, what do

  • we expect to be there, and also what has been actually recorded there.

  • In some cases, a species only occurs in one smaller reserve, and nowhere else on the planet.

  • And many times the park manager doesn't know that.

  • So it's making these really important linkages for them to be able to make decisions at a

  • really small scale.

  • - We've been working extensively with Thailand,

  • with Vietnam.

  • We've been working with countries like Kuwait in the Middle East.

  • To build capacity and to help countries to build their own national gene bank

  • to make sure that they preserve their own biodiversity.

  • - The regions with the most rewarding potential to have new discoveries are the tropical forests.

  • They harbor most of the undescribed species on Earth,

  • amphibians, reptiles, birds, and mammals.

  • SO, IF ALL WE NEED TO DO IS PRESERVE  OUR TROPICAL FORESTS,

  • RECRUIT AN ARMY OF TAXONOMISTS TO EXPLORE THEIR LIVING TREASURES,

  • CLEAN OUT THE SHELVES OF OUR SCIENTIFIC COLLECTIONS

  • TO SEE WHAT MIGHT BE HIDING IN PLAIN SIGHT,

  • AND POUR MORE RESOURCES INTO PRESERVING AND PROCESSING

  • MILLIONS OF SAMPLES AND DIGITAL RECORDS TO BUILD A LIBRARY OF LIFE AND A ROAD

  • MAP THAT POINTS US TO NEW DISCOVERIES,

  • HOW CLOSE ARE WE TO DISCOVERING ALL LIFE ON EARTH?

  • -  In birds, in mammals, we have a better knowledge.

  • In amphibians and reptiles, that knowledge is not that good, but it's something at least.

  • But for invertebrates and marine organisms, that knowledge is really sparse.

  • At the current rate of discoveries it might

  • well take 50 years to describe all vertebrates.

  • So the other groups, like invertebrates or marine organisms -

  • I would say that it will take perhaps another 100 years.

  • Or more.

  • - When you think that there are millions of species on the planet

  • and when I tell you that we only have 18,000 in the biorepositories

  • at the Smithsonian, you can see that it's a very small proportion.

  • But when you think about it, I mean, everything grows exponentially.

  • Because 100 years ago, we had no idea what cryobiology was.

  • Ten years ago, we knew that we could sequence DNA but it was a very, very long process

  • and now it can be done in an hour for a single genome.

  • It's a transgenerational, multigenerational effort  and I think it's pretty encouraging

  • to know that there are good chances for those efforts to be carried on, and probably improve,

  • and go way faster than what we can do right now.

  • - When you're working in biodiversity conservation,

  • it's easy to lose hope because you're just seeing we're in a mass extinction crisis.

  • But we're in this age where technology can really change the landscape of how we operate,

  • in positive ways.

  • So I have a lot of hope that it's not too late,

  • and now is as good a time as any to do something about it.

  • For a complete guide to all things science, subscribe to Seeker.

  • And let us know in the comments below what we should investigate next.

  • This was actually a really special episode for me, because it was my first time

  • getting to travel with Seeker, go in a lab, and investigate

  • what the scientists were doing in real-time, so if you liked that

  • please leave it in the comments below, thumbs up and share this video.

  • Thanks so much for watching. Bye!

FISH THAT WALK,

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B1 中級 美國腔

我們離完整的生命樹有多近? (How Close Are We to a Complete Tree of Life?)

  • 45 3
    劉源清 發佈於 2021 年 01 月 14 日
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