[Music]
my subject is the future of life on
earth this is a very large and complex
topic it’s the subject of futurology in
fact I am a paleontologist I study
dinosaurs and you might wonder why a
paleontologist would have something to
say about the future however there are
some shared aspects which I will talk
about and this can provide some evidence
to help us in making decisions
I’m paleontologist as I say I decided on
this career when I was 7 years old
I loved dinosaurs at the age of 7 and I
think these days young people still do I
am and I haven’t changed my views since
I love the job teaching students going
to exotic parts of the world to dig up
dinosaurs finding new facts about the
history of life however this kind of
subject studying the past like studying
the future could be said by some not to
be truly scientific and I want to
explore that a little bit first how do
we do this
before we get to the point of beginning
to establish some facts and figures
about life and current threats so and
this has been criticized by other
scientists for example a hundred years
ago Sir Ernest Rutherford a very famous
physicist nobel prize winner said all of
science is physics and the rest is stamp
collecting by which he meant that if it
you cannot make it into mathematics or
physics it doesn’t count that excludes
there in the Natural Sciences Medicine
and a lot of other areas and I think at
the far end of the spectrum would be my
subject paleontology I’d like to give
you an example though to show you how we
apply scientific methods to achieve a
certain level of understanding
uncertainty and this has been something
that has been developing during my
career so that when I started a lot of
what we did would be called speculation
or guesswork
whereas now a lot of what we do can be
tested and we can be called scientific
the example I’m going to take is that
question I asked when I was 7 could
t-rex bite a car
are in half this is a question about the
most famous dinosaur Tyrannosaurus Rex
which was huge five tons in weight
enormous jaws and teeth could it bite a
car in half
well there were no cars in the
Cretaceous but let’s forget that for the
moment when I started you could only
answer that question by guesswork or you
could make some very simple models of
the skull like levers and try to
calculate things if you were going to
make a realistic model that had all the
properties of the original bone and
flesh of the dinosaur you could not do
it but now with the power of computing
we can do this kind of thing
so the way you calculate the bite force
of t-rex and the way people have done it
is they scan a skull and make a
three-dimensional digital model inside
the computer you then divide that model
into a mesh or into a framework of
elements or small components and each of
these elements can be given and physical
properties so that we know the physical
properties of bone of living animals
these are material properties like how
far can you twist the bone before it
breaks
how much compression can that bone take
and so all of those properties are
mapped into the skull and then you apply
imaginary forces and increase those
pressures until the thing breaks and so
the bite force of t-rex is huge let me
lead you to the figure our bite force is
about 800 Newtons at most the biggest
bite force of any living animal is the
great white shark and that is about
5,000 Newtons
t-rex 50,000 Newtons ten times and
that’s equivalent to five tons of weight
acting so it could bite a car in half
why do we believe this method because
this method is a standard in design and
architecture finite element analysis is
used for designing buildings like this
one you don’t simply build it and hope
it doesn’t fall down the thing is
designed in a computer it is stress
tested using
actly this program we apply to the
dinosaur I think we can believe it
but let’s move on so that was just a
brief word about how you can actually
apply science I would argue two
questions that are not happening at our
time in the past or maybe in the future
and in paleontology we don’t just find
fossils we also care about evolution and
diversification how groups have become
diverse how groups go extinct and at the
moment we are crucially concerned about
extinction so let’s have a look at that
let’s explore that what are the current
views and these views are expressed not
by scientists but also the very
important politicians so some of you may
recall a number of years ago Al Gore who
was then vice president of the United
States he quoted a figure of 100 species
are going extinct every day so this is a
very high rate of extinction 100 per day
which is equivalent to 40,000 per year
at the other end other politicians
perhaps in president Trump’s camp would
say don’t worry about it extinction
happens look at the dinosaurs we’ve got
nothing to do so how do you connect
between these two positions because of
course we have to think about these
points the first approach that we use is
to look at history we have recent
history recorded of extinction so many
of you will be familiar with the extinct
bird called the dodo this lived on the
island of Mauritius in the Indian Ocean
the dodo was kind of fat flightless bird
related to pigeons and a very famous
image of the dodo was in the famous
children’s book Alice in Wonderland
where the dodo who is a wise old
gentleman with a walking stick
organisers Alice and all the animals and
says to them we will have a caucus-race
and a caucus-race is one way people
start when they like and they finish
when they like and everybody gets
surprised so that was very nice but
unfortunately the dodo in real life
didn’t get a prize because some of you
may know that the first record
of Dodos was in 1598 when semen reported
they had seen this bird they could go on
the island and catch it very easily and
eat it and within sixty years it was
extinct
another example of recorded extinction
is the Great Auk this was a large bird
that lived in the North Atlantic and the
Great Auk went extinct in 1844 how do we
know that because collectors sent by a
museum shot the last example they were
concerned that their museum did not have
a stuffed specimen of this bird they
heard it was going extinct so they
thought we’d better get one before it
dies out so these are two examples of
data about extinction and indeed through
the last five hundred years mankind has
killed many species which are recorded
like that and this is the basis of the
figure that Al Gore gave let me explain
it he gave that figure of 100 species
per day going extinct this was based on
the bird data but we know something like
a hundred or two or three hundred
species of birds have been killed by
human activity in the last five hundred
years and the figures are debated it’s
something like from half a species to
four species each year on average we
don’t know for sure because of course
people didn’t record everything now how
do we scale this up to get a global
figure from birds on the one hand to all
of life and the way it was done was
simply to say we know how many species
of birds there are alive today there are
10,000 and the initial estimates for the
diversity of all of life were 100
million so you scale from for a day
upwards and that brings you up to this
figure of a hundred per day by
multiplying up many times 40,000 loss
per year a hundred per day based on that
extreme high bird figure at the other
end the lowest estimate is something
like one species per day this is because
we’re not sure about that bird figure so
we could take a lower
estimate and also we’re actually not
sure about the diversity of life today
either some of you will know that you
you might think we would name every we
would have named every species we would
know that we don’t you can look at
Wikipedia there are thousands and
thousands of pages describing all the
living species but there are so many
living species that we have never
discovered never described aren’t there
in wikipedia so there is that
uncertainty 100 million 10 million we
don’t know those are the estimates of
numbers of species going extinct each
day one per day 100 per day do we worry
about that this is where paleontology
comes in first because fossil data
allows us to calculate what would be the
normal rate of extinction species do go
extinct so this this politician over
here was quite right and but was Al Gore
right we don’t know you know he was
giving that high figure maybe somewhere
in between but what is the norm is one a
day okay
doesn’t sound too many if there are
millions and millions of species it is
far too high we know that the average
duration of a species is two million
years they originated they go extinct
two million years and that means as they
come and go on average we would expect
the extinction of five million species
every million years which is five
species per year so that does contrast
remarkably even at the lowest estimate
of human impact five hundred species per
year is 100 times the normal rate of
five per year and at the bottom there is
the dodo just in case you weren’t sure
what it looked like so I want to look at
two other topics briefly one is risk and
so one of the questions we would have
estimating the total numbers is one
thing we have learned that we are
impacting life harder than we should be
human activity is causing extinction
what about risk it’s easy to say of
course the dodo was stupid it lived on
one island it just stood around and
allowed itself to be hit on the head to
an extent we worry about elephants we
worry about pandas we worry about many
individual species many of those have
high risk factors so for example an
elephant is very large this means they
need a lot of food they need a lot of
territory to walk around and so it’s
much harder to keep a sufficiently large
population of elephants breeding and
successfully in the wild we don’t need
to worry about rats for example they’re
small and there’s lots of them so body
size is one risk factor being big is not
a good thing if you want to survive as a
species what about the Panda they’re not
so huge they’re about human sized they
have a specialized diet there they have
evolved into a crazy position as you
know they are eating bamboo without the
real ability to consume it properly if
that food supply disappears they’re
stuck so secondly restricted diet is a
problem the third one is shown by the
dodo
if you live in only a very small
geographic area rather than over the
whole world you are at risk so there are
three things to be medium size or small
if you want to survive a broad diet
willing to eat everything and living
over the whole world so that includes
human beings and rats and cockroaches
they will survive and many other species
will not survive whatever we do so a
risk is something we can determine from
the present day but also we can test
when we look at mass extinctions in the
past so this is where we come back to
paleontology because I think most people
here know that the end of the dinosaurs
was marked by a mass extinction many
millions or thousands of species died
out rather rapidly because of that
extinction definitely was largely the
impact of a meteorite a huge asteroid
maybe ten kilometers across and the
model for extinction of the dinosaurs
sixty-six million years ago was the
asteroid hit the earth this is
unpredictable when this may happen or
not it penetrated into the crust it is
vaporized and all of that rock of the
asteroid plus the crust that it had
penetrated turned into rocks and dust
mainly dust this was thrown up high into
the atmosphere and why
all run the earth blacking out the Sun
and so that you get two effects there
are no light no heat so there was a
cessation of photosynthesis the plants
died there was darkness and cold so this
was not good for dinosaurs and other
groups that enjoyed the warm climates
and so you get extinction and you might
think of course what do we learn from
this yes that’s all very well but that’s
not something we can do anything about
really
and indeed asteroids do come close to
the Earth from time to time earlier this
week one did luckily it didn’t hit the
earth we can’t really prepare but the
key point is that the other mass
extinctions in the history of life were
not caused by impact they were caused by
climate change immediately you can see
now how that matters I’ll briefly
characterize one of them that I have
worked upon at the end of the Permian
period 250 million years ago there was
another major extinction this was before
the dinosaurs and the sequence of events
was that massive volcanoes erupted in
Russia they were so huge that they
poured out enormous amounts of lava of
course but more importantly they’ve
poured out gases into the atmosphere
including carbon dioxide and carbon
dioxide is as famous as a greenhouse gas
meaning it heats the atmosphere we have
primary evidence that around the equator
ocean temperatures warmed up to 40
degrees plus so this is like a very warm
shower you might think that’s okay maybe
for ten minutes but not for day after
day after day and so life had to
progressively flee out of the equatorial
zones it became crowded at the poles and
there was great extinction so we learned
from that that carbon dioxide and global
warming can cause extinction
whatever the cause of that carbon
dioxide whether it comes from volcanoes
or human activity so we’ve learned three
things that we can illustrate and use
for predicting into the future what may
happen to life we’ve learned that we can
calculate the rate of extinction by
looking at historical extinctions and at
that rate of extinction even at the
minimal figures
is at least 100 times what it ought to
be secondly we’ve learned something
about risk which species are most at
risk of extinction and I think that’s
fairly straightforward but we need the
evidence to be able to argue the case
and thirdly we’ve learned that the whole
history of the earth records they’re a
rich record of of climate change we
don’t need to do experiments we don’t
need to imagine what what a world would
be like without the polar ice caps it
has existed and we can study it so to
conclude my aim has not been simply to
spread doom and gloom and but to
indicate that we have the power to
change and in order to change we have to
accept reality along the lines I’ve been
mentioning and we have to ask the right
questions about what we should do and in
order to decide what we should do that
we need to use evidence and the some
great evidence comes from the history of
the earth and the history of life thank
you very much
[Applause]
[Music]
my subject is the future of life on
earth this is a very large and complex
topic it’s the subject of futurology in
fact I am a paleontologist I study
dinosaurs and you might wonder why a
paleontologist would have something to
say about the future however there are
some shared aspects which I will talk
about and this can provide some evidence
to help us in making decisions
I’m paleontologist as I say I decided on
this career when I was 7 years old
I loved dinosaurs at the age of 7 and I
think these days young people still do I
am and I haven’t changed my views since
I love the job teaching students going
to exotic parts of the world to dig up
dinosaurs finding new facts about the
history of life however this kind of
subject studying the past like studying
the future could be said by some not to
be truly scientific and I want to
explore that a little bit first how do
we do this
before we get to the point of beginning
to establish some facts and figures
about life and current threats so and
this has been criticized by other
scientists for example a hundred years
ago Sir Ernest Rutherford a very famous
physicist nobel prize winner said all of
science is physics and the rest is stamp
collecting by which he meant that if it
you cannot make it into mathematics or
physics it doesn’t count that excludes
there in the Natural Sciences Medicine
and a lot of other areas and I think at
the far end of the spectrum would be my
subject paleontology I’d like to give
you an example though to show you how we
apply scientific methods to achieve a
certain level of understanding
uncertainty and this has been something
that has been developing during my
career so that when I started a lot of
what we did would be called speculation
or guesswork
whereas now a lot of what we do can be
tested and we can be called scientific
the example I’m going to take is that
question I asked when I was 7 could
t-rex bite a car
are in half this is a question about the
most famous dinosaur Tyrannosaurus Rex
which was huge five tons in weight
enormous jaws and teeth could it bite a
car in half
well there were no cars in the
Cretaceous but let’s forget that for the
moment when I started you could only
answer that question by guesswork or you
could make some very simple models of
the skull like levers and try to
calculate things if you were going to
make a realistic model that had all the
properties of the original bone and
flesh of the dinosaur you could not do
it but now with the power of computing
we can do this kind of thing
so the way you calculate the bite force
of t-rex and the way people have done it
is they scan a skull and make a
three-dimensional digital model inside
the computer you then divide that model
into a mesh or into a framework of
elements or small components and each of
these elements can be given and physical
properties so that we know the physical
properties of bone of living animals
these are material properties like how
far can you twist the bone before it
breaks
how much compression can that bone take
and so all of those properties are
mapped into the skull and then you apply
imaginary forces and increase those
pressures until the thing breaks and so
the bite force of t-rex is huge let me
lead you to the figure our bite force is
about 800 Newtons at most the biggest
bite force of any living animal is the
great white shark and that is about
5,000 Newtons
t-rex 50,000 Newtons ten times and
that’s equivalent to five tons of weight
acting so it could bite a car in half
why do we believe this method because
this method is a standard in design and
architecture finite element analysis is
used for designing buildings like this
one you don’t simply build it and hope
it doesn’t fall down the thing is
designed in a computer it is stress
tested using
actly this program we apply to the
dinosaur I think we can believe it
but let’s move on so that was just a
brief word about how you can actually
apply science I would argue two
questions that are not happening at our
time in the past or maybe in the future
and in paleontology we don’t just find
fossils we also care about evolution and
diversification how groups have become
diverse how groups go extinct and at the
moment we are crucially concerned about
extinction so let’s have a look at that
let’s explore that what are the current
views and these views are expressed not
by scientists but also the very
important politicians so some of you may
recall a number of years ago Al Gore who
was then vice president of the United
States he quoted a figure of 100 species
are going extinct every day so this is a
very high rate of extinction 100 per day
which is equivalent to 40,000 per year
at the other end other politicians
perhaps in president Trump’s camp would
say don’t worry about it extinction
happens look at the dinosaurs we’ve got
nothing to do so how do you connect
between these two positions because of
course we have to think about these
points the first approach that we use is
to look at history we have recent
history recorded of extinction so many
of you will be familiar with the extinct
bird called the dodo this lived on the
island of Mauritius in the Indian Ocean
the dodo was kind of fat flightless bird
related to pigeons and a very famous
image of the dodo was in the famous
children’s book Alice in Wonderland
where the dodo who is a wise old
gentleman with a walking stick
organisers Alice and all the animals and
says to them we will have a caucus-race
and a caucus-race is one way people
start when they like and they finish
when they like and everybody gets
surprised so that was very nice but
unfortunately the dodo in real life
didn’t get a prize because some of you
may know that the first record
of Dodos was in 1598 when semen reported
they had seen this bird they could go on
the island and catch it very easily and
eat it and within sixty years it was
extinct
another example of recorded extinction
is the Great Auk this was a large bird
that lived in the North Atlantic and the
Great Auk went extinct in 1844 how do we
know that because collectors sent by a
museum shot the last example they were
concerned that their museum did not have
a stuffed specimen of this bird they
heard it was going extinct so they
thought we’d better get one before it
dies out so these are two examples of
data about extinction and indeed through
the last five hundred years mankind has
killed many species which are recorded
like that and this is the basis of the
figure that Al Gore gave let me explain
it he gave that figure of 100 species
per day going extinct this was based on
the bird data but we know something like
a hundred or two or three hundred
species of birds have been killed by
human activity in the last five hundred
years and the figures are debated it’s
something like from half a species to
four species each year on average we
don’t know for sure because of course
people didn’t record everything now how
do we scale this up to get a global
figure from birds on the one hand to all
of life and the way it was done was
simply to say we know how many species
of birds there are alive today there are
10,000 and the initial estimates for the
diversity of all of life were 100
million so you scale from for a day
upwards and that brings you up to this
figure of a hundred per day by
multiplying up many times 40,000 loss
per year a hundred per day based on that
extreme high bird figure at the other
end the lowest estimate is something
like one species per day this is because
we’re not sure about that bird figure so
we could take a lower
estimate and also we’re actually not
sure about the diversity of life today
either some of you will know that you
you might think we would name every we
would have named every species we would
know that we don’t you can look at
Wikipedia there are thousands and
thousands of pages describing all the
living species but there are so many
living species that we have never
discovered never described aren’t there
in wikipedia so there is that
uncertainty 100 million 10 million we
don’t know those are the estimates of
numbers of species going extinct each
day one per day 100 per day do we worry
about that this is where paleontology
comes in first because fossil data
allows us to calculate what would be the
normal rate of extinction species do go
extinct so this this politician over
here was quite right and but was Al Gore
right we don’t know you know he was
giving that high figure maybe somewhere
in between but what is the norm is one a
day okay
doesn’t sound too many if there are
millions and millions of species it is
far too high we know that the average
duration of a species is two million
years they originated they go extinct
two million years and that means as they
come and go on average we would expect
the extinction of five million species
every million years which is five
species per year so that does contrast
remarkably even at the lowest estimate
of human impact five hundred species per
year is 100 times the normal rate of
five per year and at the bottom there is
the dodo just in case you weren’t sure
what it looked like so I want to look at
two other topics briefly one is risk and
so one of the questions we would have
estimating the total numbers is one
thing we have learned that we are
impacting life harder than we should be
human activity is causing extinction
what about risk it’s easy to say of
course the dodo was stupid it lived on
one island it just stood around and
allowed itself to be hit on the head to
an extent we worry about elephants we
worry about pandas we worry about many
individual species many of those have
high risk factors so for example an
elephant is very large this means they
need a lot of food they need a lot of
territory to walk around and so it’s
much harder to keep a sufficiently large
population of elephants breeding and
successfully in the wild we don’t need
to worry about rats for example they’re
small and there’s lots of them so body
size is one risk factor being big is not
a good thing if you want to survive as a
species what about the Panda they’re not
so huge they’re about human sized they
have a specialized diet there they have
evolved into a crazy position as you
know they are eating bamboo without the
real ability to consume it properly if
that food supply disappears they’re
stuck so secondly restricted diet is a
problem the third one is shown by the
dodo
if you live in only a very small
geographic area rather than over the
whole world you are at risk so there are
three things to be medium size or small
if you want to survive a broad diet
willing to eat everything and living
over the whole world so that includes
human beings and rats and cockroaches
they will survive and many other species
will not survive whatever we do so a
risk is something we can determine from
the present day but also we can test
when we look at mass extinctions in the
past so this is where we come back to
paleontology because I think most people
here know that the end of the dinosaurs
was marked by a mass extinction many
millions or thousands of species died
out rather rapidly because of that
extinction definitely was largely the
impact of a meteorite a huge asteroid
maybe ten kilometers across and the
model for extinction of the dinosaurs
sixty-six million years ago was the
asteroid hit the earth this is
unpredictable when this may happen or
not it penetrated into the crust it is
vaporized and all of that rock of the
asteroid plus the crust that it had
penetrated turned into rocks and dust
mainly dust this was thrown up high into
the atmosphere and why
all run the earth blacking out the Sun
and so that you get two effects there
are no light no heat so there was a
cessation of photosynthesis the plants
died there was darkness and cold so this
was not good for dinosaurs and other
groups that enjoyed the warm climates
and so you get extinction and you might
think of course what do we learn from
this yes that’s all very well but that’s
not something we can do anything about
really
and indeed asteroids do come close to
the Earth from time to time earlier this
week one did luckily it didn’t hit the
earth we can’t really prepare but the
key point is that the other mass
extinctions in the history of life were
not caused by impact they were caused by
climate change immediately you can see
now how that matters I’ll briefly
characterize one of them that I have
worked upon at the end of the Permian
period 250 million years ago there was
another major extinction this was before
the dinosaurs and the sequence of events
was that massive volcanoes erupted in
Russia they were so huge that they
poured out enormous amounts of lava of
course but more importantly they’ve
poured out gases into the atmosphere
including carbon dioxide and carbon
dioxide is as famous as a greenhouse gas
meaning it heats the atmosphere we have
primary evidence that around the equator
ocean temperatures warmed up to 40
degrees plus so this is like a very warm
shower you might think that’s okay maybe
for ten minutes but not for day after
day after day and so life had to
progressively flee out of the equatorial
zones it became crowded at the poles and
there was great extinction so we learned
from that that carbon dioxide and global
warming can cause extinction
whatever the cause of that carbon
dioxide whether it comes from volcanoes
or human activity so we’ve learned three
things that we can illustrate and use
for predicting into the future what may
happen to life we’ve learned that we can
calculate the rate of extinction by
looking at historical extinctions and at
that rate of extinction even at the
minimal figures
is at least 100 times what it ought to
be secondly we’ve learned something
about risk which species are most at
risk of extinction and I think that’s
fairly straightforward but we need the
evidence to be able to argue the case
and thirdly we’ve learned that the whole
history of the earth records they’re a
rich record of of climate change we
don’t need to do experiments we don’t
need to imagine what what a world would
be like without the polar ice caps it
has existed and we can study it so to
conclude my aim has not been simply to
spread doom and gloom and but to
indicate that we have the power to
change and in order to change we have to
accept reality along the lines I’ve been
mentioning and we have to ask the right
questions about what we should do and in
order to decide what we should do that
we need to use evidence and the some
great evidence comes from the history of
the earth and the history of life thank
you very much
[Applause]
[Music]
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