Transcriber: Sandra Konopka
Reviewer: Emma G
Good afternoon.
So, what I want you
all to do right now,
is to think of this mammal that
I'm going to describe to you.
The first thing I'm going
to tell you about this mammal,
is that it is essential for
our ecosystems to function correctly.
If we remove this mammal
from our ecosystems,
they simply will not work.
That's the first thing.
The second thing is that due to
the unique sensory abilities of this mammal,
if we study this mammal,
we're going to get great insight
into our diseases of the senses,
such as blindness and deafness.
And the third really intriguing
aspect of this mammal,
is that I fully believe that the secret of
everlasting youth lies deep within its DNA.
So are you all thinking?
So...
magnificent creature, isn`t it?
Who here thought of a bat?
I can see half the audience agrees with me
and I have a lot of work to do
to convince the rest of you.
So, I have had the good fortune
for the past 20 years
to study these fascinating
and beautiful mammals.
1/5 of all living mammals is a bat.
And they have very unique attributes.
Bats as we know them
have been around on this planet
for about 64 mllion years.
One of the most unique
things that bats do
as a mammal, is that they fly.
Now, flight is inherently a difficult thing.
Flight within vertebrates has
only evolved three times.
Once in the bats,
once in the birds
and once in the pterodactyls.
And so, as with flight
it's very metabolically costly.
Bats have learned and
evolved how to deal with this.
But one other extremely
unique thing about bats
is that they're able to use sound
to perceive their environment.
They use echolocation.
Now, what I mean by echolocation.
They emit a sound from their larynx
out to their mouth or to their nose.
This sound wave comes out and it reflects and
echoes back off objects in their environment.
And the bats then
hear these echoes
and they turn this information
into an acoustic image.
And this enables them
to orient in complete darkness.
Indeed, they do look very strange.
We're humans,
we are visual species.
When scientists first realised that
bats were up to using sound
to be able to fly and orient and move
at night, we didn't believe it.
For a hundred years despite evidence
to show that this is what they were doing,
we didn't believe it.
Now, if you look at this bat,
it looks a little bit alien.
Indeed, the very famous philosopher,
Thomas Nagel once said,
"To truly experience an alien
life form on this planet,
you should lock yourself inside a room with
the flying echo-locating bat in complete darkness."
And if you look at the actual
physical characteristics
on the face of
this beautiful horseshoe bat,
you see a lot of these characteristics are
dedicated to be able to make sound and perceive it.
Very big ears, strange nose leaves,
but teeny-tiny eyes.
So again, if you just look at this bat,
you realise sound is
very important for its survival.
Most bats look like
the previous one.
However, there are a group
that do not use echolocation.
They do not perceive their environment
using sound and these are the flying foxes.
If anybody's ever been lucky
enough to be in Australia,
you've seen them coming out of
the botanic gardens in Sydney.
And if you just look at their face,
you can tell they have much
larger eyes and much smaller ears.
So among and within bats is a huge variation
in their ability to use sensory perception.
Now, this is going to be important for what
I'm going to tell you later during the talk.
Now, if the idea of bats in
your belfry terrifies you –
and I know some people probably
are feeling a little sick looking at
very large images of bats.
That's propably not that
surprising because here,
in Western Culture,
bats have been demonised.
Really, of course the famous book "Dracula"
written by a fellow northside Dubliner Bram Stoker
propably is mainly responsible for this.
However, I also think it's got to do with
the fact that bats come out at night
and we don't really
understand them.
We're a little frightened by things that can
perceive the world slightly different than us.
Bats are usually synonymous
with some type of evil events.
They are the perpetrators in horror movies
such as famous "Nightwing".
Also if you think about it,
demons always have bat wings,
whereas birds, they typically,
or angels, have bird wings.
Now, this is western society
and what I hope to do tonight,
is to convince you of
the Chinese traditional culture,
that they perceive bats as
creatures that bring good luck.
And indeed, if you walk into a Chinese home
you may see an image such as this.
This is considered
the Five Blessings.
The Chinese word for "bat" sounds
like the Chinese word for "happiness".
And they believe
that bats bring wealth,
health, longevity,
virtue and serenity.
And indeed, in this image you have
a picture of longevity surrounded by five bats.
Now, what I want to do tonight,
is to talk to you
and to show you that at least
three of these blessings
are definitely represented by
a bat and that if we study
bats we will get nearer to getting
each of these blessings.
So, wealth.
How can a bat possibly
bring us wealth?
As I've said before, bats are essential for
our ecosystems to function correctly.
And why is this?
Bats in the tropics are
major pollinators of many plants.
They also feed on fruit and
they disperse the seeds of these fruits.
Bats are responsible for
pollinating the tequila plant
and this is a multimillion
dollar industry in Mexico.
So indeed, we need them for
our ecosystems to function properly.
Without them it's going
to be a problem.
But most bats are
voracious insect predators.
It's been estimated in the US in
a tiny colony of big, brown bats
that they will feed on over
a million insects a year.
And in the United States
of America right now,
bats are being threatened by a disease
known as white-nose syndrome.
It's working its way slowly across
the US and wiping out populations of bats.
And scientists have estimated that
1300 metric tons of insects a year
are now remaining in the ecosystems
due to the loss of bats.
Bats are also threatened in the US
by their attraction to wind farms.
Again, right now bats are looking
in a little bit of problem.
They are very threatened in
the United States of America alone.
Now how can this help us?
Well, it has been calculated that if we were
to remove bats from the equation,
we're gonna have to then
use insecticides to remove
all those pest insects that
feed on our agricultural crops.
And for one year in the US alone,
it's estimated that
it's gonna cost 22 billion US dollars,
if we remove bats.
So indeed, bats then
do bring us wealth.
They maintain the health
of our ecosystems
and also they save us money.
So again, that's the first blessing.
Bats are important
for our ecosystems.
What about the second?
What about health?
Inside every cell in
your body lies your genome.
Your genome is
made up of your DNA,
your DNA codes for proteins that enable you
to function and interact and be as you are.
Now, since the new advancements
in modern molecular technologies,
it is now possible for us to sequence
our own genome in a very rapid time
and a very very reduced cost.
Now, when we've been doing this we realized
that there's variations within our genome.
So, I want you to look at
the person beside you.
Just have a quick look.
And what we need to realize is that every
300 base pairs in your DNA, you're a little bit different.
And one of the ground challenges
right now in modern molecular medicine
is to work out whether this variation
makes you more susceptible to diseases?
Or does this variation
just make you different?
Again, what does it mean here?
What does this variation actually mean?
So, if we are to capitalise on all of this new molecular
data and personalise genomic information
that is coming online, that we will be able
to have in the next few years,
we have to be able
to differentiate between the two.
So how do we do this?
Well, I believe we just look at
nature's experiments.
So, through natural selection, over time, mutations,
variations that disrupt the function of a protein
will not be tolerated over time.
Evolution acts as a sieve.
It sieves out the bad variation.
So therefore, if you look at
the same region of a genome,
in many mammals they have been
evolutionary distant from each other,
and also ecologically divergent.
You will get a better understanding of
what the evolutionary prior of that site is.
I.e. if it is important for the mammal
to function for its survival,
it will be the same in all of
those different species, taxa.
So therefore, if we were
to do this, what we would do is
sequence that region and
all these different mammals
and ascertain if it's the same
or if it's different.
So, if it is the same, this indicates that
that site is important for function,
so a disease mutation
should fall within that site.
So, in this case here, if all the mammals that
we look at have a yellow type genome at that site
it propably suggests that purple is bad.
This could be even more powerful
if you look at mammals –
They are doing things slightly differently.
So say for example, the region
of the genome that I was looking at
was a region that's important for vision.
If we look at that region in
mammals that don't see so well
such as bats, and we find that bats
that don't see so well have the purple type,
we know that this is probably
what's causing this disease.
So in my lab we've been using bats to look at
two different types of diseases of the senses.
We're looking at blindness.
And why would you do this?
314 million people are visually impaired
and 45 million of these are blind.
So blindness is a big problem.
And a lot of these blind disorders
come from inherited diseases.
So we want to try and better understand
which mutations in the gene causes the disease.
Also we look at deafness.
1 in every 1000 newborn babies are deaf.
And when we reach 80, over half of us
will also have a hearing problem.
Again, there's many underlying
genetic causes for this.
So what we've been doing in my lab is looking at
these unique sensory specialists: the bats.
And we have looked at genes that cause
blindness when there's a defect in them.
Genes that cause deafness
when there's a defect in them.
And now we can predict which sites
are most likely to cause disease.
So, bats are also important for our health, to enable us
to better understand how our genome functions.
So this is where we are right now.
But what about the future?
What about longevity?
This is where we're going to go.
And as I've said before, I really believe that the secret of everlasting youth lies within the bat genome.
So why should we be
interested in aging at all?
Well, really, this is a pictured Rome
from the 1500s of the fountain of youth.
Aging is considered one of the most familiar,
yet the least well understood aspects of all of biology.
And really, since the dawn of civilization,
mankind has sought to avoid it.
But we are going to have
to understand it a bit better.
In Europe alone by 2050 there's going
to be a 70% increase of individuals over 65.
And 170% increase
of individuals over 80.
As we age we deteriorate.
And this deterioration causes
problems for our society.
So we have to address it.
So, how could this secret of everlasting youth
actually lie within the bat genome?
Does anybody want to hazard a guess over
how long this bat could live for?
Who, put up your hands,
who says two years.
Nobody?
One?
How about 10 years?
Some.
How about 30?
How about 40?
Ok, it's a whole varied response.
This bat is myotis brandtii.
It's the longest living bat.
It lives for up to 42 years.
And this bat's still
alive in the wild today.
But what would be
so amazing about this?
Well, typically in mammals there is
a relationship between body size,
metabolic rate
and how long you can live for.
And you can predict how long
a mammal can live for given its body size.
So, typically small mammals
live fast, die young
Think of the mice.
But bats are very different.
As you can see here on this graph,
in blue, these are
all of the other mammals.
But bats can live up to 9 times longer than expected despite having a really really high metabolic rate.
And the question is,
how can they do that?
There are 19 species of mammals that live longer
than expected given their body size than man
and 18 of those are bats.
Therefore, they must have something within their DNA that ables them to deal with the metabolic stresses,
particularly a flight.
They spend 3 times more energy
the mammal of the same size
but don't seem to suffer
the consequences or the effects.
So right now, in my lab, we're combining
state-of-the-art bat field biology –
going out and catching
the long-lived bats –
with the most up-to-date
modern molecular technology,
to understand better what it is
that they do to stop aging, as we do.
And hopefully in the next 5 years
I'll be giving you a TED Talk on that.
Aging is a big problem for humanity.
And I believe that by studying bats
we can uncover the molecular mechanisms
that enable mammals
achieve extraordinary longevity.
If we find out what they're doing,
perhaps through gene therapy,
we can enable us
to do the same thing.
Potentially, this means that we could hold
aging or maybe even reverse it.
And just imagine
what that would be like.
So really, I don't think we should be thinking
of them as flying demons of the night
but more as our superheroes.
And the reality that bats can
bring us so much benefits
if we just look in the right place.
They're good for our ecosystem,
they allow us understand
how our genome functions
and they potentially hold
secret to everlasting youth.
So tonight, when you walk out of here
and you look up
at the night skies
and you see this beautiful flying mammal,
I want you to smile.
Thank you. (Applause)