The secret of the bat genome
-
0:00 - 0:03What I want you all to do right now
-
0:03 - 0:07is to think of this mammal that I'm going to describe to you.
-
0:07 - 0:10The first thing I'm going to tell you about this mammal
-
0:10 - 0:14is that it is essential for our ecosystems to function correctly.
-
0:14 - 0:17If we remove this mammal from our ecosystems,
-
0:17 - 0:20they simply will not work.
-
0:20 - 0:22That's the first thing.
-
0:22 - 0:27The second thing is that due to the unique sensory abilities
-
0:27 - 0:31of this mammal, if we study this mammal,
-
0:31 - 0:34we're going to get great insight into our diseases
-
0:34 - 0:39of the senses, such as blindness and deafness.
-
0:39 - 0:44And the third really intriguing aspect of this mammal
-
0:44 - 0:49is that I fully believe that the secret of everlasting youth
-
0:49 - 0:53lies deep within its DNA.
-
0:53 - 0:55So are you all thinking?
-
0:55 - 0:58So,
-
0:58 - 1:01magnificent creature, isn't it?
-
1:01 - 1:04Who here thought of a bat?
-
1:04 - 1:07Ah, I can see half the audience agrees with me,
-
1:07 - 1:10and I have a lot of work to do to convince the rest of you.
-
1:10 - 1:14So I have had the good fortune for the past 20 years
-
1:14 - 1:19to study these fascinating and beautiful mammals.
-
1:19 - 1:23One fifth of all living mammals is a bat,
-
1:23 - 1:25and they have very unique attributes.
-
1:25 - 1:28Bats as we know them have been around on this planet
-
1:28 - 1:32for about 64 million years.
-
1:32 - 1:35One of the most unique things that bats do
-
1:35 - 1:38as a mammal is that they fly.
-
1:38 - 1:42Now flight is an inherently difficult thing.
-
1:42 - 1:45Flight within vertebrates has only evolved three times:
-
1:45 - 1:49once in the bats, once in the birds,
-
1:49 - 1:51and once in the pterodactyls.
-
1:51 - 1:55And so with flight, it's very metabolically costly.
-
1:55 - 1:59Bats have learned and evolved how to deal with this.
-
1:59 - 2:03But one other extremely unique thing about bats
-
2:03 - 2:05is that they are able to use sound
-
2:05 - 2:10to perceive their environment. They use echolocation.
-
2:10 - 2:13Now, what I mean by echolocation --
-
2:13 - 2:16they emit a sound from their larynx out through their mouth
-
2:16 - 2:20or through their nose. This sound wave comes out
-
2:20 - 2:24and it reflects and echoes back off objects in their environment,
-
2:24 - 2:27and the bats then hear these echoes
-
2:27 - 2:30and they turn this information into an acoustic image.
-
2:30 - 2:35And this enables them to orient in complete darkness.
-
2:35 - 2:39Indeed, they do look very strange. We're humans.
-
2:39 - 2:42We're a visual species. When scientists first realized
-
2:42 - 2:46that bats were actually using sound to be able to fly
-
2:46 - 2:49and orient and move at night, we didn't believe it.
-
2:49 - 2:52For a hundred years, despite evidence to show
-
2:52 - 2:55that this is what they were doing, we didn't believe it.
-
2:55 - 2:59Now, if you look at this bat, it looks a little bit alien.
-
2:59 - 3:02Indeed, the very famous philosopher Thomas Nagel
-
3:02 - 3:06once said, "To truly experience an alien life form
-
3:06 - 3:09on this planet, you should lock yourself inside a room
-
3:09 - 3:14with a flying, echolocating bat in complete darkness."
-
3:14 - 3:17And if you look at the actual physical characteristics
-
3:17 - 3:20on the face of this beautiful horseshoe bat,
-
3:20 - 3:22you see a lot of these characteristics are dedicated
-
3:22 - 3:26to be able to make sound and perceive it.
-
3:26 - 3:30Very big ears, strange nose leaves, but teeny-tiny eyes.
-
3:30 - 3:34So again, if you just look at this bat, you realize
-
3:34 - 3:37sound is very important for its survival.
-
3:37 - 3:42Most bats look like the previous one.
-
3:42 - 3:46However, there are a group that do not use echolocation.
-
3:46 - 3:49They do not perceive their environment using sound,
-
3:49 - 3:51and these are the flying foxes.
-
3:51 - 3:54If anybody has ever been lucky enough to be in Australia,
-
3:54 - 3:57you've seen them coming out of the Botanic Gardens in Sydney,
-
3:57 - 4:00and if you just look at their face, you can see
-
4:00 - 4:04they have much, much larger eyes and much smaller ears.
-
4:04 - 4:07So among and within bats is a huge variation
-
4:07 - 4:10in their ability to use sensory perception.
-
4:10 - 4:12Now this is going to be important for what I'm going
-
4:12 - 4:14to tell you later during the talk.
-
4:14 - 4:19Now, if the idea of bats in your belfry terrifies you,
-
4:19 - 4:22and I know some people probably are feeling a little sick
-
4:22 - 4:25looking at very large images of bats,
-
4:25 - 4:28that's probably not that surprising,
-
4:28 - 4:30because here in Western culture,
-
4:30 - 4:32bats have been demonized.
-
4:32 - 4:35Really, of course the famous book "Dracula,"
-
4:35 - 4:38written by a fellow Northside Dubliner Bram Stoker,
-
4:38 - 4:40probably is mainly responsible for this.
-
4:40 - 4:43However, I also think it's got to do with the fact
-
4:43 - 4:45that bats come out at night, and we don't
-
4:45 - 4:48really understand them. We're a little frightened by things
-
4:48 - 4:51that can perceive the world slightly differently than us.
-
4:51 - 4:54Bats are usually synonymous with some type of evil events.
-
4:54 - 4:57They are the perpetrators in horror movies,
-
4:57 - 4:59such as this famous "Nightwing."
-
4:59 - 5:02Also, if you think about it, demons
-
5:02 - 5:05always have bat wings, whereas birds, they typically --
-
5:05 - 5:08or angels have bird wings.
-
5:08 - 5:13Now, this is Western society, and what I hope to do tonight
-
5:13 - 5:18is to convince you of the Chinese traditional culture,
-
5:18 - 5:21that they perceive bats as
-
5:21 - 5:25creatures that bring good luck, and indeed, if you walk
-
5:25 - 5:29into a Chinese home, you may see an image such as this.
-
5:29 - 5:31This is considered the Five Blessings.
-
5:31 - 5:34The Chinese word for "bat" sounds like the Chinese word
-
5:34 - 5:37for "happiness," and they believe that bats
-
5:37 - 5:41bring wealth, health, longevity, virtue and serenity.
-
5:41 - 5:45And indeed, in this image, you have a picture of longevity
-
5:45 - 5:47surrounded by five bats.
-
5:47 - 5:50And what I want to do tonight is to talk to you
-
5:50 - 5:54and to show you that at least three of these blessings
-
5:54 - 5:57are definitely represented by a bat, and that if we study bats
-
5:57 - 6:02we will get nearer to getting each of these blessings.
-
6:02 - 6:07So, wealth -- how can a bat possibly bring us wealth?
-
6:07 - 6:10Now as I said before, bats are essential for our ecosystems
-
6:10 - 6:14to function correctly. And why is this?
-
6:14 - 6:18Bats in the tropics are major pollinators of many plants.
-
6:18 - 6:21They also feed on fruit, and they disperse the seeds
-
6:21 - 6:25of these fruits. Bats are responsible for pollinating
-
6:25 - 6:29the tequila plant, and this is a multi-million dollar industry
-
6:29 - 6:32in Mexico. So indeed, we need them
-
6:32 - 6:34for our ecosystems to function properly.
-
6:34 - 6:37Without them, it's going to be a problem.
-
6:37 - 6:42But most bats are voracious insect predators.
-
6:42 - 6:45It's been estimated in the U.S., in a tiny colony
-
6:45 - 6:47of big brown bats, that they will feed
-
6:47 - 6:51on over a million insects a year,
-
6:51 - 6:54and in the United States of America, right now
-
6:54 - 6:57bats are being threatened by a disease known as white-nose syndrome.
-
6:57 - 7:00It's working its way slowly across the U.S. and wiping out
-
7:00 - 7:04populations of bats, and scientists have estimated
-
7:04 - 7:09that 1,300 metric tons of insects a year are now
-
7:09 - 7:13remaining in the ecosystems due to the loss of bats.
-
7:13 - 7:15Bats are also threatened in the U.S.
-
7:15 - 7:19by their attraction to wind farms. Again, right now
-
7:19 - 7:21bats are looking at a little bit of a problem.
-
7:21 - 7:23They're going to -- They are very threatened
-
7:23 - 7:27in the United States of America alone.
-
7:27 - 7:28Now how can this help us?
-
7:28 - 7:32Well, it has been calculated that if we were to remove bats
-
7:32 - 7:34from the equation, we're going to have to then use
-
7:34 - 7:37insecticides to remove all those pest insects
-
7:37 - 7:40that feed on our agricultural crops.
-
7:40 - 7:44And for one year in the U.S. alone, it's estimated
-
7:44 - 7:47that it's going to cost 22 billion U.S. dollars,
-
7:47 - 7:51if we remove bats. So indeed, bats then do bring us wealth.
-
7:51 - 7:54They maintain the health of our ecosystems,
-
7:54 - 7:56and also they save us money.
-
7:56 - 7:59So again, that's the first blessing. Bats are important
-
7:59 - 8:02for our ecosystems.
-
8:02 - 8:06And what about the second? What about health?
-
8:06 - 8:11Inside every cell in your body lies your genome.
-
8:11 - 8:13Your genome is made up of your DNA,
-
8:13 - 8:16your DNA codes for proteins that enable you to function
-
8:16 - 8:19and interact and be as you are.
-
8:19 - 8:24Now since the new advancements in modern molecular technologies,
-
8:24 - 8:28it is now possible for us to sequence our own genome
-
8:28 - 8:32in a very rapid time and at a very, very reduced cost.
-
8:32 - 8:35Now when we've been doing this, we've realized
-
8:35 - 8:38that there's variations within our genome.
-
8:38 - 8:42So I want you to look at the person beside you.
-
8:42 - 8:44Just have a quick look. And what we need to realize
-
8:44 - 8:48is that every 300 base pairs in your DNA, you're a little bit different.
-
8:48 - 8:51And one of the grand challenges right now
-
8:51 - 8:53in modern molecular medicine is to work out
-
8:53 - 8:58whether this variation makes you more susceptible to diseases,
-
8:58 - 9:01or does this variation just make you different?
-
9:01 - 9:03Again, what does it mean here? What does this variation
-
9:03 - 9:07actually mean? So if we are to capitalize on all of this
-
9:07 - 9:11new molecular data and personalized genomic information
-
9:11 - 9:13that is coming online that we will be able to have
-
9:13 - 9:17in the next few years, we have to be able to differentiate
-
9:17 - 9:20between the two. So how do we do this?
-
9:20 - 9:23Well, I believe we just look at nature's experiments.
-
9:23 - 9:28So through natural selection, over time,
-
9:28 - 9:33mutations, variations that disrupt the function of a protein
-
9:33 - 9:36will not be tolerated over time.
-
9:36 - 9:40Evolution acts as a sieve. It sieves out the bad variation.
-
9:40 - 9:42And so therefore, if you look at the same region
-
9:42 - 9:45of a genome in many mammals that have been
-
9:45 - 9:49evolutionarily distant from each other
-
9:49 - 9:52and are also ecologically divergent, you will get a better
-
9:52 - 9:56understanding of what the evolutionary prior of that site is,
-
9:56 - 10:00i.e., if it is important for the mammal to function,
-
10:00 - 10:02for its survival, it will be the same
-
10:02 - 10:07in all of those different lineages, species, taxa.
-
10:07 - 10:10So therefore, if we were to do this,
-
10:10 - 10:12what we'd need to do is sequence that region
-
10:12 - 10:15in all these different mammals and ascertain if it's the same
-
10:15 - 10:19or if it's different. So if it is the same,
-
10:19 - 10:22this indicates that that site is important for a function,
-
10:22 - 10:26so a disease mutation should fall within that site.
-
10:26 - 10:30So in this case here, if all the mammals that we look at
-
10:30 - 10:33have a yellow-type genome at that site,
-
10:33 - 10:35it probably suggests that purple is bad.
-
10:35 - 10:39This could be even more powerful if you look at mammals
-
10:39 - 10:42that are doing things slightly differently.
-
10:42 - 10:44So say, for example, the region of the genome
-
10:44 - 10:47that I was looking at was a region that's important for vision.
-
10:47 - 10:51If we look at that region in mammals that don't see so well,
-
10:51 - 10:55such as bats, and we find that bats that don't see so well
-
10:55 - 10:58have the purple type, we know that this is probably
-
10:58 - 11:01what's causing this disease.
-
11:01 - 11:05So in my lab, we've been using bats to look at two different
-
11:05 - 11:08types of diseases of the senses.
-
11:08 - 11:11We're looking at blindness. Now why would you do this?
-
11:11 - 11:16Three hundred and fourteen million people are visually impaired, and
-
11:16 - 11:2045 million of these are blind. So blindness is a big problem,
-
11:20 - 11:24and a lot of these blind disorders come from inherited diseases,
-
11:24 - 11:26so we want to try and better understand
-
11:26 - 11:30which mutations in the gene cause the disease.
-
11:30 - 11:34Also we look at deafness. One in every 1,000
-
11:34 - 11:37newborn babies are deaf, and when we reach 80,
-
11:37 - 11:40over half of us will also have a hearing problem.
-
11:40 - 11:45Again, there's many underlying genetic causes for this.
-
11:45 - 11:47So what we've been doing in my lab
-
11:47 - 11:50is looking at these unique sensory specialists, the bats,
-
11:50 - 11:53and we have looked at genes that cause blindness
-
11:53 - 11:54when there's a defect in them,
-
11:54 - 11:57genes that cause deafness when there's a defect in them,
-
11:57 - 12:02and now we can predict which sites are most likely to cause disease.
-
12:02 - 12:05So bats are also important for our health,
-
12:05 - 12:09to enable us to better understand how our genome functions.
-
12:09 - 12:12So this is where we are right now,
-
12:12 - 12:14but what about the future?
-
12:14 - 12:15What about longevity?
-
12:15 - 12:19This is where we're going to go, and as I said before,
-
12:19 - 12:22I really believe that the secret of everlasting youth
-
12:22 - 12:24lies within the bat genome.
-
12:24 - 12:28So why should we be interested in aging at all?
-
12:28 - 12:31Well, really, this is a picture drawn from the 1500s
-
12:31 - 12:34of the Fountain of Youth. Aging is considered
-
12:34 - 12:38one of the most familiar, yet the least well-understood,
-
12:38 - 12:41aspects of all of biology, and really,
-
12:41 - 12:45since the dawn of civilization, mankind has sought to avoid it.
-
12:45 - 12:48But we are going to have to understand it a bit better.
-
12:48 - 12:52In Europe alone, by 2050, there is going to be
-
12:52 - 12:56a 70 percent increase of individuals over 65,
-
12:56 - 13:00and 170 percent increase in individuals over 80.
-
13:00 - 13:02As we age, we deteriorate, and this deterioration
-
13:02 - 13:07causes problems for our society, so we have to address it.
-
13:07 - 13:12So how could the secret of everlasting youth actually lie
-
13:12 - 13:14within the bat genome? Does anybody want to hazard
-
13:14 - 13:18a guess over how long this bat could live for?
-
13:18 - 13:21Who -- put up your hands -- who says two years?
-
13:21 - 13:25Nobody? One? How about 10 years?
-
13:25 - 13:29Some? How about 30?
-
13:29 - 13:33How about 40? Okay, it's a whole varied response.
-
13:33 - 13:37This bat is myotis brandtii. It's the longest-living bat.
-
13:37 - 13:39It lived for up to 42 years,
-
13:39 - 13:41and this bat's still alive in the wild today.
-
13:41 - 13:44But what would be so amazing about this?
-
13:44 - 13:49Well, typically, in mammals there is a relationship
-
13:49 - 13:51between body size, metabolic rate,
-
13:51 - 13:53and how long you can live for, and you can predict
-
13:53 - 13:57how long a mammal can live for given its body size.
-
13:57 - 14:00So typically, small mammals live fast, die young.
-
14:00 - 14:03Think of a mouse. But bats are very different.
-
14:03 - 14:06As you can see here on this graph, in blue,
-
14:06 - 14:09these are all other mammals, but bats
-
14:09 - 14:11can live up to nine times longer than expected
-
14:11 - 14:14despite having a really, really high metabolic rate,
-
14:14 - 14:16and the question is, how can they do that?
-
14:16 - 14:20There are 19 species of mammal that live longer
-
14:20 - 14:23than expected, given their body size, than man,
-
14:23 - 14:26and 18 of those are bats.
-
14:26 - 14:31So therefore, they must have something within their DNA
-
14:31 - 14:33that ables them to deal with the metabolic stresses,
-
14:33 - 14:37particularly of flight. They expend three times more energy
-
14:37 - 14:39than a mammal of the same size,
-
14:39 - 14:42but don't seem to suffer the consequences or the effects.
-
14:42 - 14:46So right now, in my lab, we're combining
-
14:46 - 14:50state-of-the-art bat field biology, going out and catching
-
14:50 - 14:53the long-lived bats, with the most up-to-date,
-
14:53 - 14:56modern molecular technology to understand better
-
14:56 - 15:01what it is that they do to stop aging as we do.
-
15:01 - 15:04And hopefully in the next five years, I'll be giving you a TEDTalk on that.
-
15:04 - 15:07Aging is a big problem for humanity,
-
15:07 - 15:10and I believe that by studying bats, we can uncover
-
15:10 - 15:13the molecular mechanisms that enable mammals
-
15:13 - 15:16to achieve extraordinary longevity. If we find out
-
15:16 - 15:20what they're doing, perhaps through gene therapy,
-
15:20 - 15:22we can enable us to do the same thing.
-
15:22 - 15:27Potentially, this means that we could halt aging or maybe even reverse it.
-
15:27 - 15:31Just imagine what that would be like.
-
15:31 - 15:34So really, I don't think we should be thinking of them
-
15:34 - 15:39as flying demons of the night, but more as our superheroes.
-
15:39 - 15:43And the reality is that bats can bring us so much benefit
-
15:43 - 15:46if we just look in the right place. They're good for our ecosystem,
-
15:46 - 15:49they allow us to understand how our genome functions,
-
15:49 - 15:52and they potentially hold the secret to everlasting youth.
-
15:52 - 15:54So tonight, when you walk out of here and you look up
-
15:54 - 15:58in the night skies, and you see this beautiful flying mammal,
-
15:58 - 16:02I want you to smile. Thank you. (Applause)
- Title:
- The secret of the bat genome
- Speaker:
- Emma Teeling
- Description:
-
In Western society, bats are often characterized as creepy, even evil. Zoologist Emma Teeling encourages us to rethink our attitude toward bats, whose unique and fascinating biology gives us insight into our own genetic makeup. (Filmed at TEDxDublin.)
- Video Language:
- English
- Team:
- closed TED
- Project:
- TEDTalks
- Duration:
- 16:25
Morton Bast edited English subtitles for The secret of the bat genome | ||
Morton Bast edited English subtitles for The secret of the bat genome | ||
Thu-Huong Ha approved English subtitles for The secret of the bat genome | ||
Thu-Huong Ha edited English subtitles for The secret of the bat genome | ||
Morton Bast accepted English subtitles for The secret of the bat genome | ||
Morton Bast edited English subtitles for The secret of the bat genome | ||
Joseph Geni edited English subtitles for The secret of the bat genome | ||
Joseph Geni edited English subtitles for The secret of the bat genome |