right okay right so hello everyone thank
you for joining us for this live quick
Q&A question-and-answer session with dr.
Brooke Johnson today and I would like to
briefly introduce Brooke before I
actually tell you about the format that
we're going to follow for today's
session so Brooke had completed his
geology degree it's University of London
and then moved to Oxford to University
of Oxford to do his doctoral research on
understanding environmental changes that
happened 1.4 billion years ago during
the mesoproterozoic era (that
is quite long, we need to find a lay
terminology for that!) so he's passionate
about public engagement and he has been
involved in several events and he's
particularly interested in working with
pupils who might not consider further
education or usually have access to
earth sciences or higher education so
before we start our discussion I would
like to remind everyone about our
structure or introduce you if you're new
to live with scientists Q&A sessions so
the structure of the session will start
with a discussion where I will be asking
group some questions for about 40
minutes and then we will have a
10-minute break to give our audience an
opportunity to submit their questions
through the comments log on the
right-hand side of the YouTube page so
after the break we will resume and we'll
have a further Q&A session for another
20 minutes during which I will be asking
your questions on your behalf so
Brooke thank you very much for joining
us today it's really nice to be able to
host you during his session and yeah if
you're ready I would like to start with
other questions though yeah yeah so I
have got a list of technical questions
though so obviously you do separate you
have got several geological era so can
you please
tell us what's the importance of the
mesoproterozoic era relative to others
and why you decided to focus on that
and if we can find a shorter or a lay
terminology I would really appreciate it
age fantastic thank you
it's the middle age so if you imagine
if you imagine it like you hold your arm
out yeah one of your arms out at arm's
length and if you imagine that earth
formed four-and-a-half billion years ago
and that's the middle of you chin yes
all of the animals and fossils and
things that we can see they only appear
round about the bottom of your wrist so
the Earth's middle age is most of your
forearm from like your elbow to your
forearm the rocks there this
will also might help you understand how
old they are they're far about five
times older than the oldest dinosaur so
the earth back then one and a
billion years ago all of the continents
were joined together into a continent
called nuna there was one giant ocean a
lot of the the land surface was flooded
by shallow seas there was nothing alive
on land except maybe some bacteria and
the ocean was completely dominated by
bacteria there was as far as we know a
very little oxygen in the atmosphere so
if we went back in time there if we stood
on this desolate landscape there's no
ozone layer so we'd need lots of Sun cream
you'd need an oxygen mask because
there's also a lot of carbon dioxide the
whole planet would have been really
really warm as well there's no ice at
the poles and if you'd have gone to
northern Australia then the area that I
look at which is now the desert was a
shallow sea nice warm shallow sea and it
would have probably been green with
piles and piles of bacteria that we're
living there because no animals to eat
them so you've been stood on this
desolate landscape with this green sea
in front of you and the moon would have
been bigger and volcanoes and everything
you'd imagine that the primordial the
ancient ancient earth would have looked
like but the reason this period of time
saw
so special is because this is when
complex life first appeared so all life
that we know of falls into two groups
you've got bacteria which it is
basically like a little capsule or a
little pill full of soup and they're
alive they can wiggle around they can
reproduce by splitting off and well
they're not very complex they can join
together to do bigger tasks and things
although the kind of life is called a
eukaryote and that's everything from
an amoeba a single-celled amoeba or an
algae all the way through to us to the
biggest whales and trees fungus is
everything that you can think of there
isn't the bacteria our cells are quite
complex
they have little little engines inside
them and little organs that do
specialized tasks we we don't just
reproduce by splitting although we can
do that we can also have like sexual
reproduction and swap genetic material
and the leap between a simple bacteria
that's basically a capsule or a can
full of soup and this really complex cell
structure is again that it's like a
mind-blowing thing it's it's a bigger
gap than going from stone age technology
to spacecraft it's such a huge gap and
the time I study is when that that
happened and we don't know why it
happened that was a bigger mystery
because when eukaryote cells appear they
then do nothing for a billion years
so they're basically just that they're
kind of existing they're not
diversifying they're not evolving
they're just kind of plodding along for
a billion years we don't know why so
that's what that's that's kind of what I
look into and that what was special
about this time period okay all right so
we knew that then there was some form of
life present at that time you know we
definitely know that there were plants
around there was micro organisms around
but nothing complex nothing more to
cellular it's what you're saying apart
from plants so not even plants okay no
plants at all flat alright come along
I think animals actually turn up before
plants plants as we think of them don't
exist so there are bacteria that
photosynthesize around now that do the
same kind of jobs as plants if you think
of like it call it why animals do in an
ecology is like a job then there are
things that do that job of
photosynthesize I call them
cyanobacteria and whenever you seem like
a pond or a lake or a stream that
they're the kind of green mushy stuff
that you see they make all of our oxygen
so they were around but there's nothing
modern around at all
nothing that you would recognize okay
great thank you so then I would like to
ask then you know it is obviously so
long ago so can you tell us a bit more
about in layman's terms what techniques
do you use to study things that happened
you know 1.4 billion years ago of
drawing and coloring in I literally draw
the rocks and color them in which sounds
facetious
sounds like I'm being a bit silly I'm
not so when we get these rocks they're
underground and we have a huge drill
that pulls them out in a tube and
this tube of rock comes out in
sections but it could be like thousands
of meters long if you look on the
website that photograph of rock those
tubes of rock of ones we've pulled out
and the scene have got all different
kinds of colors and textures and those
colors and textures tell us of our
records of the environment and of what
life was doing at that time so by
recording those colors and textures by
drawing them and coloring them in and
making what we call a graphic log we can
actually look we can actually record how
going along this tube of rock we can
record how the environment is changing
so that's the first thing we do we just
use our eyes and we don't usually need
any fancy technology or of terminology
you're just kind of going well that gets
bigger than that bit that bits green
bits red that's moves and that's Wiggly
and maybe so you'll use like a
magnifying glass so that's the first
thing we do and we can get a huge amount
of information
where next thing we do is take those
rocks and cut them in half and polish
them and look at them with a binocular
microscope and that's basically just
like a very fancy kind of magnifying
glass you have one on each eye and so
you can look at the rock really closer
and that gives us another layer of
information and then we all take one of
those chunks of rock and I'll slice it's
about the size of a domino and then i'll
grind it down so it's about as thin as
one of your hairs and then I'll look at
it under a different microscope that
shines polarized light through it and
I'll polarize is a fancy way of good
saying goes in a straight line so light
bounces all over the place and is all
jazzy and very excitable but if you have
a polarizer it's like a gate that forces
all of the light to go in one direction
and when polarizing light passes through
an object it interacts with that object
it'll get bent and twisted a little bit
because the structure of the of the
crystals in the rock the electromagnetic
and the gravity of them the forces will
pull the light ever since slightly and
that lets us see change there I'm
getting too excited and what that does
if it changes the color of the crystals
in predictable ways that we've
catalogued and we know so we know which
minerals were looking at and it lets us
see textures we couldn't see otherwise
that has no what was happening happening
on the scale of microns so a micron is
like a thousandth of a millimeter so
giving a grain of rice is maybe two
millimeters long so imagine the various
tiny tip of a grain of rice that's the
size of things that will look at with
this microscope and we can see things
like fossil bacteria for example oh yeah
fossil bacteria okay I mean you know if
we if you have any of these videos we
would be interested to see this just
before our Q&A session if you have them
available yes I do
I've got all of the pictures and videos
oh that's great so I think it would be
nice or if they're handy we can maybe
have a look at them now sure yeah we
can keep talking and I can take
them out I did wonder if I should do any
in advance but that's fine that's fine
or like to say we can do it right before
the Q&A session
as well whichever you prefer so
obviously you mentioned about fossils
though so can you tell us a bit more
about how do they form yeah so a fossil
is the remains of a living organism
that's preserved in the rock record and
they can form in a lot of different ways
and they could preserve a lot of
different things so I think everyone's
probably been on on the beach at some
point or by a lake and they may have
some shells or bits of plants well if
those shells and bits of plants get
covered by mud and successively buried
by getting more wood piled on top of
them that will eventually turn into rock
and it will preserve the 
organism as a fossil and that can have
happened by preserving the original
material that it's made of so things
like shells they're actually only made
of minerals they're made of stone same
as bones and that they preserve quite
nicely things like plants plants are
actually quite resistant so don't 
preserves the original material but you
preserve all of their details in carbon
and sometimes it can be preserved so
well that you can see individual cells
so there's a place in Scotland
underneath the golf course I believe
where there are some of the oldest
plants in the world are preserved and
you can see their cells and how they
were arranged yes and most of the time
you just get hard parts but there are
very special occasions where you get
soft parts as well and then we can see
things as things like eyes and guts and
brains and they get preserved by clay
sticking to the to the organs and making
like a template out of it and some clays
are antibacterial as well but sometimes
the bacteria help by precipitating by by
basically pooping out minerals that
preserve the organism it's it's really
complex the study it's called taphonomy
and it's like super fascinating and
sometimes you can even get fossils
preserved by say volcanic eruptions like
a Pompeii okay
there are even in ancient versions where
south american
rhinoceroses were preserved by a
volcanic eruption like Pompeii
most of the time you're going to get
hard parts it turns out bacteria are
quite resistant in in natural
environments as long as you're not
cleaning them with bleach and an
antibacterial they'll survive quite well
and like I said some bacteria basically
excrete minerals and so they'll
accidentally fossilized themselves in
certain circumstances and that's why I
find in my rocks these little things
that look like tiny tiny tiny wee polo mints
little loops made of a mineral
called apatite and apatite is what
your bones and teeth are made of and so
we know it's generally made by living
organisms and for a long time I couldn't
figure out what they were they're about
a quarter of the width of one of your
hairs so these things are tiny tiny
until I looked at them on an electron
microscope and then I was able to see
them close up and see that they had
structure and then in a carbon organic
carbon call and then I compared them
with other other people who found
similar things and we all had a
different bit of the puzzle and then went oh the bacteria okay great
thank you so the other thing that I was
wondering obviously you're seeing
these structures in the rocks but can
you actually as from a biologist's point
of view obviously I'm excited about can
you actually extract ancient animal DNA
from fossilized let's say rocks from
fossilized amber and do some analysis on
it or is it is it too you know too long
then it won't preserve for such a long
period yeah so DNA it turns out is
really unstable things that have a lot
of proteins in them full of energy and
bacteria and other organisms will be
straight on that at the point like when
an organism dies so it tends not to
survive that first level it gets
filtered out quite quickly that's why
for example in oil what you tend to get
are the the resistant materials the
carbon-based materials from
plants and bacteria and algae because
all of the proteins and fat from animals
gets eaten really quickly so
amber is especially interesting because
it gives you a perfectly
preserved what's on the outside of the
organism but actually it desiccates and
dehydrates the inside so when you see
those beautiful and like in Jurassic
Park where people drill in and extract
the blood there's actually nothing
inside there they're empty it's just
dust
Amber's also not it doesn't perfectly
seal them it's kind of breathable so gas
and liquids can get in and out of a very
long time skills but you can get some
very strange things preserved recently
this is something I never thought I
would say but recently someone showed me
an insect in amber that had farted while
it died and the fart bubble had been
preserved if it's not died some of the
gas coming out the the back end of the
animals okay
however some people claim to have found
fragments of DNA from dinosaurs that
died in arid conditions and were
mummified so there's not enough DNA
there to to bring them back to life our
or analyze or understanding any kind of
where but there is a no there was enough
there for them to say this was probably
DNA at one point the other thing that
you've got to contend with is when as
rocks are buried at the temperature goes
up and the pressure increases so some
rocks if they if they're only shallow
ordinary shallow they'll be about 150
degrees centigrade for thousands if not
millions of years and then thousands of
times the earth is pressure so a lot of
salt and fragile biological material
doesn't survive that kind of treatment
okay so you know in your field of
research then can you tell us obviously
you're seeing lots of different fossils
and you're being able to actually do
some research on them how often do you
think a scientist would have a chance to
discover
new species of extinct animals 300
fossils is it as common or other as rare
as we anticipate it to be or you know
can you give us some insights into that
well it's not rare at all we've we've
probably only really know a very small
percentage of animals that are alive
today and the percent of extinct animals
that we know is even tinier and I mean
less than 1% of all life that's ever
existed on earth so it can be quite
common to discover new species a lot of
times people will do a bulk collection
with a new site and then they'll go in a
museum collection and then they'll
forget to work on it and people won't
know about it until decades or even
centuries later when a grad student
comes along and says oh what's in this
drawer so that's really common the other
thing is you have to define what a
species is and this is this is a bit of
a contentious point is that people don't
really understand what a species is for
living organisms it's even harder if he
all you've got is a bit of shell so
where I grew up in North Yorkshire there
are lots of ammonites and an ammonite is
busy a squid with a fancy curly shell
and people like to divide them up into
lots of different species because there
are lots of different varieties and some
of them you can look at them and say in
the same way that you would look at a
tiger and a lion and say well they're
related but they're obviously different
and some of them you would look at them
and it would be as different as looking
at say like a tiger and a house cat
they're fed very different
but some of them you would be looking at
like a two different types of tiger and
going well how can I tell which ones
which if all of you got the shell or a
borne it's really difficult think about
how much variation there are between
humans how much of that variation is
then lost when humans are just the
skeleton yes imagine in my case for
example I've had broken bones and I've
got metal plates and I've got all kinds
of like where I've fallen over and hurt
myself when someone in the future looks
at those and go oh this is a separate
species because look it's got a metal
jaw or what have you
why would they say actually no these are
all the same species and it's a same
with fossil
creatures like the ammonites the splitters
which of people that like to divide
things up have divided them up into lots
and lots of species but the lumpers have
said oh these are all pretty much the
same they're probably one species some
are probably males from a female some
had injuries some are pensioners and some
are just young babies that's why you've
got all this variation in them it's
quite a big argument and sometimes
people discover that a new species is
basically like what's called
sexual dimorphism and  it's the female or the
male version of one creature or it's the
juvenile or adult stage of one organism
and sometimes in some famous cases
people discover that that's several
separate species at different parts of
the same organism so there's a very
famous ancient crustacean ancient
astronaut so creature related to things
like crabs and insects lived about 500
million years ago called anomalocaris
which means mystery shrimp because
people found it's two front claws
first and they look like a shrimp
missing its head and then they found
this thing called the Toya which looked
like a jellyfish and then they found
this other thing they thought was a
sponge and I can't remember the name of
it and so they classified them as
three new species and then about 50 or
so years later someone found a complete
one and realized the shrimps were
the front claws the sponge was actually
the body of this big flapping creature
that had lots of flaps to swim and the
jellyfish was its mouth parts and had this
circular mouth for grabbing and crushing
so that's often what could happen you can
never be sure if you've actually found
the whole animal or the whole organism
or just a little wee bit of it yeah okay
well that's very interesting thank you
very much and it was very informative as
well so so for a budding geologists then
where would you think would be able
place to start looking for interesting
rocks or fossils that depends on where
you live and what I have available to
you okay the easiest place to maybe look
at that is if you're in if you're in a
big city is the buildings around you
so just thinking of Oxford Oxford's got
lots of buildings made a lot of
different types of building stone so
that about three billion years worth of
history just in the building stones of
Oxford an Oxford in terms of its
building materials is typical of most
big cities glass epic cities most older
cities in the UK you've got all
different types of rocks sedimentary
metamorphic igneous you've got lots of
fossils in those rocks as well to look
at and most people will walk by them
every day
for example Tesco's in oxford town
centre has a building stone called larvikite
and it's really common across the
world as a decorative building stone and
larvikite contains these big crystals of
a mineral called labradorite which is
actually which is also a gemstone and
people walk past it every day and never
notice it and occasionally I'll go and
look at it and someone I'll ask me why
you're staring at that wall but when
they notice it you think about labradorite is it has mother-of-pearl
effect it has rainbow colors on it when
you tilt
ahead and there are certain people
notice that this is wall made out of all
this shimmering rainbow colored material
so the best thing to do is that haven't
have a look around of the buildings
around you if you've got that available
if you're in the UK the British
Geological Survey and all of their
things free their Maps their the digital
maps and you can find out what the rocks
are like around you and I know the USGS
has a similar thing but they don't think
they have an app yet also the internet
there are lots of websites dedicated to
different locations where you can go and
check out and see what the the geology
is is literally everywhere if you just
have you just scratch the surface and
you'll start once you start seeing it
you won't be able to wouldn't see it
it'll be everywhere lovely so maybe you
can drop these links on your website
here on the your space on our website so
anyone who is interested you can
actually have a look at it yeah so one
of the things I did on my youtube
channel sorry for the shameless plug if
there's an episode where I walk around
Oxford and show up the different kinds
of building stones so you can see common
and they're all very common
building stones in the UK and even and
even in the rest of Europe and North
America so there so that'll give you an
idea of the things to look for and the
kinds of things you can see that's
actually quite interesting and we would
be interested to include the link for
your YouTube channel as well for those
who are interested Thank You lovely it's
all it's all in common language as well
it's designed with my dad to watch it so
that's quite good yeah we would be
really interested to do that for our
audience so going back to the technicalities though can you tell us how do you
know obviously you can't do very much of
analysis on them as we know it let's say
as a biologist as I would know it you
can't do very many analysis on them but
can you tell us at least how do you
think those microorganisms are different
from the ones that we see you know there
won't be modern microorganisms are
different from the ones that you see in
this the past well they're not they're
not different at all that's the thing so
you can do this thing called and this is
one of the big differences between
bacteria and all other life the complex
like it's a bacterial kind of hit their
peak and were like yeah this is that
they could have evolved to fill all of
their niches so to speak and they
haven't really changed in the billions
of years so there's a technique called a
molecular biology
I say technique a field of study and
people can kind of look at the timings
of of DNA I don't really understand it
because it seems like magic to me but I
have friends that do it and I've tried
to explain it to me and you can kind of
look at the rate of how the DNA changes
to trace when different species changed
and evolved and people have done this to
bacteria and what they find is the
bacterial DNA is really really
old so and because we share a lot of
similarity and certain kinds of bacteria
we've incorporated in they know it goes
back a really long wear so most so the
answer back to your I find in my world
pretty much the same as their
equivalents in the modern day
so what I find are things like
cyanobacteria and when you look at cyanobacteria fossils from billions of years
ago they're not pretty much the same and
then chemically and geo chemically with
the bits that you can get out look you
can tell that they're kind of doing the
same jobs and the other big one I guess
all the bacteria who make the phosphorus
and make apatite and that's exactly what
they do
I've looked at solar bacteria I plucked
out of a stream and they're identical to
the ones that I found in my rocks but
bacteria don't have many very many
shapes the important thing is that
they're doing the same sort of jobs
they're producing apatite they're
processing sulfur and cycling it through
the environment so it can be so it
doesn't get stuck in one place too long
okay great and can you I know you'd
mentioned about the methods that you
actually use to get the material to work
on but can you compare the modern
analytical techniques that you are using
in your research to the ones to the more
traditional ones do you think you are in
a better position than you were before
in order to make some more discoveries
so the analytical techniques are just
they're just tools basically and if you
think of instead of thinking of a
scientific and analytical technique you
think about hammer like hammer is really
good for hammering nails into stuff and
pulling nails into stuff it's good for
splitting rocks up and in finding
fossils but it's not very good for other
jobs so what it comes down to is having
you can have a new fancy tool if you're
not using it properly and you don't
understand these limitations then you
might as well just have a brick you know
it's not going to do you much good so
what I found is and what I've tried to
do with my work
is take these traditional techniques
that were starting to kind of get say
traditional they were only like a couple hundred
years old at most these techniques like
looking at the rocks and using
microscopes and then tie them to the to
the modern analytical techniques where
we put things in in a mass spectrometer
and blast it with plasma and and do all
of these like things that to me sounds
still sound like science fiction
and tie the two together and use their
strengths to kind of build a broader
picture because if you were putting up
like if you were building a shed you
wouldn't just use a hammer you would use
other tools as well and you reduce each
tool for the right job but and they've
definitely increased our ability to
under understand what's going on in the
past the new tools
I tend to think of it as like
viewing the past during rocks is like
trying to look at a really complex
picture but all you've got is a keyhole and
then by having these new tools and using
them in the right ways that gives you
another keyhole and by using them in
conjunctions that are just looking
through one keyhole and saying this is
what the whole world was like for a
billion years you can go okay that bits
like that that bits they like that looks
like that and then you can put together
a bigger picture what is going on all
right
great thank you so I have got a couple
more questions if you're not too tired
though I know you've been talking for about
half an hour now
so I yeah I know I know  so I'm also interested in
learning about your personal experiences
as well so I would like to you know can
you tell us if there are any students
out there or students to be who are
listening to that to us so can you tell
us a bit more about how's your time
divided between lab work and fieldwork
how do you manage both and can you tell
us what do you do for each aspect so the
division between lab work field work and
some office stuff varies depending on a
PhD no two PhDs are alike even two
people studying the same rocks aren't
gonna have the same sort of thing the
same kind of time divisions so my
fieldwork was going to Australia to
sample these rocks and so that was very
concentrated I also go and do field
trips with our undergrads and teaching
and things so I also like do that kind
of fieldwork a lot of my time was spent
in the labs so the office work at the
beginning was reading and that got
boring pretty quickly as much as I like
rocks
reading about learning papers can be
quite quite dry so as soon as I got
samples back I would take them into the
lab and for me lab work was cutting up
the rocks polishing them grinding them
down putting them on the microscopes
putting them on the electron microscopes
I had two over 500 samples and then I
had to turn those into powders to go on
different kinds of analytical machines
so I had to do all of that crushing
which was loud and noisy and smelly and
yeah it took a long time but I didn't
really notice it it just kind of went by
yeah and then the rest of time I was
reading and writing or teaching
okay I was able to and I was able to
maintain a work-life balance like my
supervisors didn't demand kind of undue
hours off me I wouldn't have done
that anyway because I worked before I
did my degree and became a scientist so
I'm used to kind of doing 9:00 to 5:00
you being very kind of regimented and
getting work done so for me it was very
much like a day job started work and
finished at like five or six and didn't
work weekends
okay great so in terms of the lab work
though you know or in terms of the
research can you tell us a bit more
about why is this research important and
how it actually applies to the present
or to the future so there's two main
aspects and one of them is kind of like
actually I'll rephrase it so when people
ask about the benefits of science and
then what will happen is people will
tell you about the features of a
particular kind of science so but
there's only really for benefits a
benefit either like saves you time and
money so safety time saves you or makes
you money changes how you see yourself
and changes how you see the world around
you so the benefits of my work is it
changes how we see the world around us
we understand how the earth evolved
how'd you go from a barren planet to one
covered in bacteria and then algae and
then two carbon-based bags of water
having this conversation
right now who've learned to take apart the
universe and put it back together as
laptops and tables and Pokemon and then
change how I see myself is I guess ties
into that because I kind of understand
how the natural world works now and I'm
able to share that with well not how
that's a big thing I don't understand
how the natural world works I have I
understand it better than I did and I
can understand that impact these humans
are having on the natural world so I
used to think maybe like well the
climate has changed quite a lot
over geological time how can I be sure
that humans are causing this well now I
understand how ancient climates work and
change I can say oh yeah there's
literally nothing else that can be
causing this other than people so that's
another benefit of it and in terms of
time and money so these rocks hold
resources and we need those resources
the main one I constant with the things
like iron and phosphorus phosphorus we
need to make fertilizer and phosphorus
reserves around the world a pretty low
because life tends to take it and not
let go but if that life dies in a
shallow sea and then we find it billions
of years later we can maybe look at
ways of extracting that phosphorus
phosphorus also likes to throw up rare
earth metals that we need for building
things like laptops telecommunications
so we need those and then obviously we
need iron and iron deposits tend to be
formed by the action of microbes or life
concentrating the iron so it all ties
into how we understand like how the
world works how we're changing the world
and how and how life has interacted with
the rocks and the atmosphere and such
like to create deposits of the
economic minerals that we need
also it's just really cool yeah I mean you
know it's quite interesting so do you so
do when you do your research then are
there any other research groups who
might be collaborating with companies
who might be helping to find these
reserves for whatever
reason yeah there's a lot of interest in
the northern territories so the the
other side of this is that these rocks
are also full of oil because wherever
something dark when you get a lot of
living things die and buried you get a
lot of hydrocarbons generated so these
rocks are full of oil and gas and the
Australian government are interested in
tapping into this reserve I don't think
it's gonna happen anytime soon because
this base and these reserves are all out
in the desert there's one water that
goes through it and you can only really
get into it a couple of months a year
because in the dry season it's too hot
like literally nothing lives there it's
things not even kangaroos or anything
and then in the wet season it's even
hotter but also it rains so much the
desert turns to swamp okay so it's
really difficult to get any anything out
there so there's lots of groups working
on it from the oil perspective and then
a few people who've been looking at the
iron where the rocks are close to the
surface but otherwise it's actually you
know it's unsure even though it's
effective
technically much easier to get to than
say at the bottom of the sea where most
say oil deposits are it's proving very
difficult for people to get out there
and also there aren't that many
geologists in Australia looking at it
so which is why we get to access to
their stuff and it covers a huge area
the Northern Territory so we're still
mapping out where these rocks are when
do they look under the ground okay
alright great so I'm gonna leave it
there though and anyone who is
interested to ask questions please feel
free to do this from the right-hand side
of the YouTube channel YouTube video and
then we're going to resume in about 13
minutes we will be back by 20 past 7:00
so I will see you all then thank you
very much for your attention so far
I'm just gonna look for some for tours
now hello thank you for joining to back
with us for the question and answer
session we're just waiting on Brooke
which I think will be here in this
second hello there sorry I was talking
to you I didn't realize I had turned my thing off that's fine that's fine
great so Brooke would you like to start
by showing us the pictures that or
videos that you thought you had
yeah am I just looking to share screen
uh yeah we should be a co-host by now
let's start with this one this is called
a zebra stone well notice it has all
kinds of weird patterns in it we don't
really understand why you only find it
in one tiny Valley in the Northern
Territory and it's not found anywhere
else in the world okay
it's a complete mystery so there's
there's something very strange this time
it's basically a moonstone that was
deposited in a river and that's a mud
China clay is the beige bits the
yellowy greeny beers bits and then these
red spots are iron oxide but we don't
know why it forms that pattern because
they have all kinds of different
patterns some of them even look like
writing but I've been writing because
they've been buried under the ground for
hundreds of millions of years yeah
that's so very interesting do you have
one in one of those with what you think
is writing or which looks like writing I
don't know of the know on this drive
it's all my my computer at work that's
fine no let's try another one
okay so here's one of here's one of the
rocks
one of the rocks we found from the drill
core so if you imagine if this is
vertical the top would be this this area
here to the far right of the picture and
that's basically a beach an ancient
beach and then all of these blobs and
globules and wiggles and other weird
shapes are little colonies of bacteria
and they basically secrete snot we call
it EPS if we're being fancy which stands
for extracellular polyamic substance but
I prefer snot because it's easier to say
and things get stuck to it and the
chemical and within the meet within that
slime the bacteria can control the
chemical conditions and that allows
certain minerals to grow really quickly
and then that sticks more things to it
and so they grow outwards as they get
flipped around on the seabed and form
these beautiful little structures and
this is an entirely new type of
lithology that we've not seen before
because normally they're made out of
carbonate calcium carbonate minerals but
these are made out of iron rich
and no one's ever seen it like this kind
of thing before so and also just looks
really cool yeah it does like to me so I
was saying about slicing them up and
looking at them under the microscope so
one of those little globules under the
microscope looks like this it looks like
this Wow
so this is some of the polarizing
microscope so all the white grains are
sand so there's these are a mixture of
quartz feldspar zircon and other
minerals that we call detritals because
they get weathered out of rocks and then
just dropped everywhere and this black
gooey looking stuff is a mixture of
fossilized bacteria their poop and
the clay that they've produced and if you
look there's a spiral so this was
probably on the seabed and then got
ripped up by a storm and then rolled
around and so it's rolled up like a
carpet but the bacteria don't care they
just move up to the next layer so they
can get on sunlight okay
so if you were to imagine how small this
is if you look on the top left there's a
big grin of quartz yeah that's about the
saw half the size of a grain of rice
okay so this is teeny tiny small that's
quite interesting so we can we can
actually zoom in even further as well so
here are some more these are what we
call ooids and these are these are
basically like bacterial bogies that
have accumulated on the seabed and then
got rolled around they form in the
modern-day in places like Caribbean but
they're made out of calcium carbonate
there and they're nice and white that's
what makes the white beaches in tropical
locations but here they're made out of
all of these this bacterial goo and
these green iron clays and they're
green because there's no oxygen around
so even though this was on a beach there
was very little oxygen so it couldn't
get oxidized so we can what we're gonna
do is we're gonna zoom right in on these
layers because these layers accumulate
they're kind of like tree rings so I
take that one away so this one's about
two millimeters across so this one here
for top to bottom about the size of a
grain of rice okay but we can zoom right
into it - look at those tree lit - look
at those tree like the tree ring type
structures the lamina we'll call them
it's just a fancy way of saying lots of
layers and look at them
so if you see those little Wiggly bits
yeah you can see the dark bits between
the layers they look like they're made of little dots those are bacteria so
if you think that this the big view was
the size of a grain of rice we've now
assumed so far in that we can see the
bacteria that we're living in it so
that's that's what we do with the
regular light microscope okay if we
want to look close up at one of the
bacteria we use the electron microscope
and that produces something like this a
picture like this so there that's a a
1.4 billion year old bacteria okay so
the outside of the of the polo would
be the outside the shell of the bacteria
on the outside and then the inside bit
where it's hollow that would be where
the bacteria the inside of the cell
where it's seen was thrown out saying
that they were like a can of soup and
then this is the phosphate which it uses
as food the apatite and it secreted it
around its outside and in accidentally
fossilized itself so the modern ones do
this so if your oxygen level is going up
and down really quickly the bacteria
have different ways of breathing and to
breathe when there's no oxygen around
they have to generate phosphorus the
apatite and if there's if it's without
oxygen for too long they basically
fossilized themselves and that's what
happened here right very interesting
though and then lastly I said we had
those slices of rock that we look at
with the polarizing microscope
so I'll just quickly show you some of
those this ones I'll start with something
familiar this one here's this spiral is
a section through a snail shell and this
is from the Jurassic of North Yorkshire
so this is only about 200 million years
old okay I'm just there we go rotating
it round and then I'll skip it forward a
bit that's a bit of shell
oops
I'm just trying to get the bit where I
switch that yes I look looking around we
can see them all bits of all different
sea creatures and shells that we're
looking at that you wouldn't be able to
see with your naked eye these bits here
like that one that just moved this is a
bit of oyster okay and all of this black
stuff is sulfur all right and if you see
it changes color a little bit yeah okay
stop that and then finally I'll show you
one of the impressive ones this this is
a rock called a gabbro and this is what
forms the crust of the ocean this is
what most of the earth's surface is made
of this is what the sea the deep seabed
is made of and in the middle we've got a
mineral called olivine and this mineral
comes from the Earth's mantle it's come
from hundreds if not thousands of
kilometers down and then when the ocean
plates are spread it gets erupted onto
to the surface and forms the ocean
or the ocean bed and when I said it
changes color this is it go up on the
screen yeah that's it changing color so
this these patterns and colors they're
unique to olivine so whenever we see
this in a rock we know we're looking at
olivine okay and if you see these grey
stripes we know that's a feldspar
mineral all right so this is how we can
identify minerals yeah you see the
one at the bottom with the pinstripes
yeah I always like it when we show the
under grads how to do this for the
first time because they'll sit there
looking at it and it's transparent and
then they swap the polarizer and they
get all the colors and the whole glass
just goes oh wow yet if you looked at this rock  in your hand it would
be a dull black and it may be able to
see some shiny crystal faces but it
would just be black but by looking at
this where we can see all of these
textures and this tells us about this
was originally liquid rock deep under
the ground and by looking at all of
those different textures we can see how
the rock is 'cause we can't live
in a magma chamber
so we can see how all of the rock has
cooled and crystallized and what
first and and that kind of thing we can
just read it like it's a book yeah great
fantastic very interesting thanks very
much for sharing though if that's okay
with you
I would like to move on to questions
from the audience we have got a couple
of these but thanks a lot you know the
those rocks and what you have shown us
the showing us it's very interesting so
I would like to start one of the
questions that I've received though I
was wondering can you tell us how long
does it take you you know from finding
the sample to actually ending up with
the images that you showed us what is
this timescale for that how much effort
so the longest part of it is shipping
them back from Australia huh so let's
just say I went outside and picked up a
rock
so around Oxford there's lots of
beautiful middle jurassic limestone's
follow the fossils and cool things so if
I go outside and pick one of them up and
bring it back to the lab then I can have
it under the microscope within a couple
of hours the the longest step is waiting
for the glue to dry when you stick it to
the glass that takes about an hour but
otherwise it's just like you have to
polish it by you cut it up and then you
polish it on a polishing wheel and then
a finer polishing wheel and then you
polish it by hand with like a powder and
water mixture until I get a slurry I
think it has to do like this and then
check it check it and then you put on a
machine that measures it and cuts it
down so it's as thin as one of your
hairs and you have to you have to look
at it and then measure it flat again and
then measure it again and then you look
at it oh yeah a couple of hours I see
okay
the other thing that I was wondering
though again this is a question coming
from one of our audience so are there
any ideas though why life wasn't
diversifying during this era why did we
only have microorganisms and not even
like plants as we know it so
there are a couple main hypotheses like
ideas why people think it is some
people think that there was a some kind
of barrier in the way either there
wasn't enough food there wasn't enough
oxygen yeah are the two big ones and
some people think it just takes a really
long time to evolve complexity if you
think about it like this life appeared
on earth almost instantly as soon as it
was you could have liquid water on the
surface like turns up and then it took 2
billion years to go from bacteria to
eukaryotes our the cells like us but it
only took a billion years give or take
to go from a single cell organisms
eukaryotes to things like seaweed and
probably jellyfish and sponges and then
half a billion years roll more or less
to go from single-celled amoebas and
seaweeds and sponges and jellyfish to
us having this conversation so every
time it's actually got faster and faster
and faster that's actually kind of a
pattern that you see in other terms in terms of like when you're getting
complexity so if you look at the level
of complexity of say a civilization
starts off slow and I gets really fast
if you look at the development of
computer technology suddenly 
goes really fast so the other argument
says there wasn't enough oxygen and
there wasn't enough food so as well as
oxygen for breathing because oxygen
respiration basically using oxygen to
burn food that gives you the most energy
and one of your cells requires it like
10,000 times more energy to power it
than a bacteria bacteria can just sit
there there are bacteria that living in
the rocks under the ocean under
kilometers of water in kilometers of
rocks and they'll basically breathe once
every couple of hundred years they don't
need much energy but what our cells do
and so if there's not enough phosphorous
around a not enough oxygen then we can't
do that our cells can't do that and that
could hold it back also oxygen does
things like it allows you to build stuff
like collagen and if you've got collagen
which is kind of what makes your skin
stretchy and then lets you stick make
muscles then you can start going
from a single cell to being something
like a jellyfish
with muscles that can swim and move
around so you need oxygen for that also
oxygen controls weathering on the
surface and that's where phosphorus
comes from so if you don't have oxygen
to weather phosphorus out of the rocks
then things like cyanobacteria can't
produce oxygen to weather phosphorus
serve the rocks and get stuck in a loop
so what my research found though was
that there was plenty of phosphorus
there was loads that's why they could
fossilized themselves there was too much
of it not enough to poison but enough
different for them to be perfectly happy
another idea says that there was lots of
sulfide sulfide is really really toxic
to organisms like us because it gets in
your respiratory system and it basically
it has the same kind of shape as as
calcium and it basically blocks up the
calcium where calcium switch should set
in your breathing system and stops you
from taking up oxygen so a tiny bit of
sulfide can make you ill pretty quickly
and some people thought there was a lot
of sulfide in the ocean then but then
the work of myself and other people has
shown actually there wasn't that much
sulfide so without what kind of back to
square one
and those of us who think even just
takes a really long time a kind of going
and now we've also found about modern
organisms that would be perfectly happy
in those environmental conditions and so
we're starting to think like maybe
they were we just don't have
the fossils or the data we just think oh
that they look like bacteria the other
thing is evolution isn't something that
has to happen we tend to think of
evolution because we get taught it in
school where you start off with like the
single cell and then you've got the guy
with a beard at the end because of
Darwin the things are trying to to get
to more complexity well they don't they
don't have to be that's why bacteria
haven't really evolved that's why
something like an earthworm hasn't
evolved beyond what it has it's already
pretty good what it does it doesn't have
any pressure and if there's no pressure
there to evolve then you're not going to
evolve at the end of that billion years
there's a huge amount of environmental
change like gigantic ice ages
 where even the Equator might
have been frozen and so all of a sudden
after a billion years of pretty pretty
steady conditions you start to have all
of these changes happening so maybe
that's got something to do with it
questions still open yeah great thank
you very much for this comprehensive
answer though so going back to the
climate so so do you think I've seen
something here about the climate so yeah
so do you think rocks or fossils can
actually be used indicate to indicate
past climates or temperatures yes yeah
now something we do routinely Paleo
climatology a lot of my colleagues do
that
my supervisor Stu Robinson and his group
do that my colleague Ricky Sengupta she
was able to look at how how much rain
and there was in southern England 90
million years ago through looking at
rocks and fossils so sedimentary rocks
particularly if they're well preserved
they record the situation situation the
environmental conditions at the time of
deposition and it's the same with
creatures who make shells they're recording
the environmental conditions
as they're making their
shells
and so we can we can read that
information and we can combine that with
laboratory experiments to kind of test
how these how these chemical signals
work to test if they're actually
realistic and it takes a lot of
jiggery-pokery but we've got it down to
quite a good science now of being
able to say actually we know what the
temperatures were millions of billions
of years ago the other thing is if you
are in if you are at the South Pole and
then you find a rock full of coral we
know the coral only live in tropical
conditions
so either the South Pole used to be in
the tropics or it was tropical at the
South Pole so it was like there's like a
more practical way or if for example as
some people have done you find
and glacial sediments at the equator
yeah where there glaciers on the equator
or were equatorial land masses 
now at the equator were they at one of
the poles and then the answer to those
questions is yes to all of them because
the continents move around but the
climate changes as well okay all
right great thank you so continuing on the theme of climate
how do you think that obviously we have
seen a great change in our climate
recently because of human activity so
how do you see that change impacts your
field you know obviously fossils are
forming as we are progressing through
our lives so how do you think the
changes that we're seeing today is going
to impact the geology in the future I'll
start by saying that I'm not an expert
on climate I just know enough of it to
to be able to understand it for a
geological point of view so if there are
any experts out there feel free to
correct me in terms of if I was to go
into the future in sample rocks or mud now
what we would see was some would be some
very strange geochemistry so for example
things like the oxygen and carbon
isotopes stored in fossils would be very
very strange we see this happen in the
deep time say for example a giant
volcano erupts and the earth warms up
what we call a hyper thermal event which
is the course that you can get to what
we're doing we see a big spike in the
carbon and oxygen isotopes so an isotope
is where you have an element like carbon
and then you have a slightly different
version of it kind of if you think of
like a carbon and diet carbon or like
carbon light same with oxygen and by
measuring the ratio of the isotopes the
different types of the element they
relate to temperatures water to changes
in like huge global cycles so when we
see ancient hyper thermal events usually
caused giant volcanic eruptions when
an ocean opens the continent splits in
half we see these huge shifts in the
carbon isotopes and that's what we would
see if you looked at sediments and
shells from the modern tier there would
be and there would be a lot
plastic as well in the rock record there
are already rocks now made of plastic
from humans so you would see lots of
plastic and strange metal alloys and
things in the rock record stranger
shell-like organisms might be
incorporating things like heavy metals
that we've released yeah for example if
you go back and look at the ice core
records you can actually see for example
when the Roman Empire changed the type
of coin that they're using where to
start including more thing because it
affects the global system yeah great
thank you very much that's quite
interesting so again there is another
question from our audience they're
asking what's the most exciting species
that you have had opportunity to work on
or to identify yourself oh good grief
whichever one I'm holding in my hand at
the time you asked me finding those
bacteria and like realizing that I was
looking and I was the first human to
ever see them that's pretty exciting but
I get that whenever I split open  a bit
of rock and I know that I'm the first
human to see what I'm looking at all
right all right guys great yeah I've got
to go to a famous fossil site called the
Burgess Shale and I got to have a look
at fossils and stuff there and that a
place where soft tissue gets preserved
so you can see like the eyes and guts
and things and I find I found a
trilobite which it looks like a wood
louse it's like a fancy wood louse and
normally that's just the shell and
they're really cool and beautiful but
this one you could see itslegs and its
gills it's little feelers and stuff and
I was like oh this is so cool but I get
that excited yeah I got excited
yesterday I was making a video about the
coral a fossil reef that's in in Oxford
and I found a shell and I was like oh this is
so cool
I don't think I could pick one alright
okay okay so the novelty is actually
what's is fascinating you about your
research area yeah because you've got
this connection to this thing you're
both alive under the same sky and the
same Sun but just hundreds of millions
of years apart yeah it's like it's
the closest you ever gonna get to
meeting an alien and visiting an alien
world yeah I suppose you're right thank
you very much so it's very again
very
interesting so I was wondering though so
I did have quite a bit of we have got
quite a bit of questions from possibly
prospective PhD students I suppose and
they're asking about your personal
experiences in terms of your PhD so
they're asking what skills have you
gained from your PhD which are now
helping you as a tutor and where did you
get your first teaching experience and
what is your favorite thing about
helping us on the graduates are good
grief skills I've got for my PhD so
there's the obvious technical skills
that I've got in terms of geology yeah
I've also got a lot of people skills so
I had oh I had a weird route in saw into
science because I was I worked for 10
years in call centers I've done
everything from call centers to crisp
factories and so I picked up a lot of
what you call soft skills like people
skills there yeah before I came into to
do my PhD so mostly what I've got for my
PhD is the the technical skills and
thinking like a scientist my first
teaching experience is I used to I would
with people when I was on the beach
looking for fossils people would ask me
about them usually parents with kids and
so I would I would be explained to them
about how to look for fossils and I'm
doing that like I'm like you can see
like that nodule I've just flipped open
with the RNA in it and so that but then
as soon as and then when I was doing my
undergraduate at Birkbeck I would help
if there were things where I'd picked up
on something quicker especially with
fieldwork
I would always help my my classmates if
especially like when they were
struggling so like helping your
classmates when you were undergraduate
is a really good way to understand if
you knew it because if you know
something you can teach it yeah and then
as soon as I got to Oxford I was like
when can I start when can I start
teaching undergrads and what I enjoy
about teaching the undergrads I get to
talk about cool rocks as people that
can't can't escape because they have to
be in class I seriously that I like
they're always asking like really good
questions and it's really fun when you
when you do stuff like show them the
same sections for the first time and
they'll go whoa that's really fun and
then helping them to understand the
world and and what's the point in me
knowing all of this cool stuff if I'm
just going to keep it in my head and
like you know like the dragon with its
gold they always imagine people being
like we who don't want to talk about
their subject areas where they've all
just got it hidden away like it's it's
there to be shared and and utilized and
and to help people understand the world
and themselves so that's what I like
about it
great and another question again from
assuming from a prospective PhD student
so what what do intend to do after your
PhD will you carry on teaching or
researching or look for a job in a
different sector so I've had I've had
normal jobs and I really didn't wasn't
my job I'm not particularly interested
in car insurance so I'm probably not
going to go back to that I like rocks I
like teaching undergraduates and they're
like researching and the easiest way for
me to do that is to continue on as in
academia so that's the current plan
mm-hmm
yeah look for it look for a postdoc and
then go from there
lovely well BrookeI think this is the
end of the questions that we have today
and I would like to thank you for your
time it was an absolute pleasure
pleasure to have you and it's really
nice to see the examples of rocks that
you have showed us it's really
interesting and and it's really nice
that we actually get to hear from you as
well because normally people do assume
that if you want to have a job in
academia you need to go through certain
paths and it's nice to show people that
it's not you know there isn't one way of
doing it there are multiple ways as long
as you know you have the will you will
always find a way around it so I'm sure
it will be an inspiration for younger
people definitely I I failed my GCSEs
and I don't have any A levels I still
did a PhD at Oxford
so it took a bit longer
and I learned a lot of different useful
stuff going through call centers and
things but it's definitely possible it's
like this modern there's more than one
way to get a job done so yeah if you
want to if you want to do science or
whatever is a career you can definitely
do it
yep lovely well thank you very much for
your time though you're welcome thanks
for having me I had so much fun
