[SWOOSHING] We're all human. And yet we all look different. Now, a lot about the way
we look is down to our DNA, as we can see so brilliantly
with these identical twins. From eye colour to hair
colour to dimples to height, each pair of twins
looks very similar. But look a little more
closely, and you'll see that each person
here is unique. In this lecture, we'll explore
how much of the differences between us are down
to genes and how much is due to everything else. We'll be looking at
what makes you unique. [BUBBLING] [GROANING] [CRINKLING] [APPLAUSE] I am Professor Alice Roberts. Welcome to the third of this
year's Royal Institution Christmas Lectures. And this lecture is all
about us as a species. It's all about human diversity. But first, let's start off
with a different species which is very diverse indeed. You stand here. So we've got an amazing
range of different dogs here. And the astonishing thing about
this is that they are all dogs. They all belong to
the same species. And yet they look so incredibly
different from each other. We've got to we've got a Great
Dane, got a little Shih Tzu, and a tiny little
miniature dachshund. Now, isn't it amazing that
there's all that variation in one species? Humans first started
domesticating dogs about 30,000 years
ago, when our ancestors were hunter-gatherers. And then over
thousands of years, we've somehow moulded
all of these changes. So we've bred dogs
that are really good at going down burrows
and chasing animals, like the dachshund. And this is all down
to us interacting with this other species. Now, to explore this diversity
and how it comes about in more detail, I
need to introduce one more species and, my friend,
geneticist Professor Aoife McLysaght. [APPLAUSE] It wasn't entirely clear
if you were referring to me as the additional species
or this beautiful chihuahua in my arms. But this Chihuahua, of course,
was bred as a companion dog. And you can see,
he's very, very cute. And dogs are especially
interesting in terms of genetics because
this huge diversity that we can see in
front of us is actually down to quite a small
amount of genetic diversity. They are, after all,
just one species. And that makes it
much easier to be able to figure out how the
genes contribute to the changes that we can actually
see on the outside. And so for example,
this little Chihuahua, and other miniature
dogs like this, the size variation is
largely down to just changes in just one gene. Now, we are actually able to
understand the genetic basis of some of this? Yeah. So many of the origins
of these traits has been traced genetically. So we can get a real handle
on how variation in our genes contributes to the kind of
variance that we can see. So let's have a think about
how all of this variation comes about. But for now, let's say
"thank you very much" to our brilliant dog lineup. [APPLAUSE] Here we go. So all those
differences have been bred into different
breeds of dogs by breeders choosing
dogs of particular traits and then breeding them on
to the next generation. That's something called
selective breeding. It's what Charles Darwin
called artificial selection. And he imagined how
he could continue thinking about
this to see, well, does this happen
in nature, as well? How do we get natural selection? And to really
explain this, we're going to play a
game with this demo. And we need two volunteers. OK. Let's see. Yes? You there in the lovely jumper. Lovely Christmas jumper. Come on down. And also put one
down there, as well. Great. [APPLAUSE] So are you excited? Freddy. Freddy. Lovely to meet you, Freddy. And what's your name? Rebecca. Rebecca. So what you see beside
you here are two habitats. And you can see very
quickly that this is mainly orange habitat. The floor is orange. And it's filled with these
balloons, which are mostly what we're calling "orange pebbles." And over there, we've got a
grey habitat with grey floor and grey pebbles. But in amongst the pebbles,
there is something else. So here we have a mouse. And there's orange and grey
mice in each of these habitats. And so we're going to
put these in there. And Freddy, what
we didn't tell you is that your job is to
actually be a predator. You need to catch some mice. And you need to catch
some mice, as well. So you're going to
have to go in there. And I want you to catch
mice but not pebbles. So you can go around the back. And just the ones
with faces, all right? Yeah. So only the ones with
faces we're interested in. If you go around the
back, they'll let you in. Yeah. So don't start catching
mice yet because that's far too easy, actually. Yeah. Let's make make
them more energetic. Yeah. We need to make something a
bit more difficult for you. [ROARING] So on our marks at--
well, we'll count down. 3-- (ALL) 2, 1. Go. [WHIMSICAL MUSIC] (TOGETHER) 3, 2, 1. Stop. [APPLAUSE] OK. You can come out. OK. You can come back out. Come around and see how you did. [APPLAUSE] How was that? OK. Let's have a look. Well, that's a mouse. These are pebbles. So we'll put those back. And if you've
gotten your rocks-- We've managed to catch four
orange mice and just one grey mouse. Well, Freddy managed
to catch one of each. So what did you think, Freddy? What did you think of trying
to catch the mice in there? What was it like? Hard. Was it hard? Were either colour easier? Not really, no. What about you over there? Oh, it was easy. It was easier to see the
orange on the grey background. Yeah, you were going after
the orange ones, weren't you? Yeah. And this is kind
of what we expect. We see that naturally. In parts of the world where
we have kind of black rocks, you tend to find
more black mice. And in parts of the world
where you have these golden, sandy rocks, we tend
to find these yellow, sandy-coloured mice
because what we expect, especially in the grey
habitat over there, the orange mice were picked
off quite easily by this fierce predator. And the grey mice actually have
survived to live another day and to pass on their genes. But we did ask you
to be a predator. We did. You haven't quite finished
the job, have you? No. Could you stomp on those
balloons for me, please? Go on. Have a stomp. [POUNDING] Yes! Yeah! [APPLAUSE] Thank you so much. So artificial selection has
created all the dog breeds that we see today. Natural selection picks
off some orange mice in that demonstration. And natural selection has also
acted on us humans, as well. So our species originated in
Africa hundreds of thousands of years ago. But then we spread out of
Africa and colonised the globe, so we encountered all sorts
of different environments as we went. And there are lots of
ways that humans can fit into different environments. We're quite clever, so
we can create culture. And that can help us. So if we move into
a cold place, we might make ourselves
warm clothes to put on. There's also a
physiological adaptation. And that means
that your body can get used to an environment
over your lifetime. But you don't pass those kind
of changes on to your children. So natural selection is when
there is a genetic difference generation by generation. And we can see some great
examples of that in us humans. And one really good example
comes through the variation that we can see in skin colour. And it tends to
map onto geography. Now, most of us tend to have a
fairly consistent skin colour that we've inherited from
our parents and from earlier ancestors. So over most of your body, your
skin colour is fairly similar. But I want to introduce you
to somebody now who's got very striking differences in
skin colour across his body. And he is fashion
model Bashir Aziz. [APPLAUSE] Bashir, hello. Much respect. Fantastic. Bashir, you've got a
really striking look. You've got two completely
different colours of skin and hair, as well. So how long have you had that? Were you born like it? Yeah, all my life. So that's what I've known. So across your body,
you've got areas-- and obviously, we
can see on your face, you've got areas quite pale skin
and then dark skin, as well. I mean, look at your arm there. Yeah. So you've got a real mixture. Yeah. So we can actually have a look
and see how much skin pigment you've got in different areas. So we can use this
instrument here. So yeah. Have look at the back
of your hand there. And there we go. So that says you've got 70%
skin pigment on that area. Let's have a look at areas of
your skin that's pale, then. Can I try it on that area there? If I just pop it on there,
it should just work. Yeah. See, look at a different there. That's astonishing. So where you've got pale skin,
there's only, what, about 9%-- 9%. --pigment. So really, really
big difference. So Bashir, we've got slides
here of pale skin-- rather like the pale areas you've got--
and then dark skin, as well. And you can see that they're
very different when you first look at them. And this difference is all to do
with the skin pigment melanin. And there are very few granules
of melanin in this skin. But you can see, in
this section here, all of those cells completely
packed full of lots and lots of melanin granules. I'm going to try on me, as well. Go on. Go on. And let's see what-- let's see what I've got. There's a little bit
of melanin in there. 19. 19. There you are. Well it is my hand,
though, so it is exposed to the sun quite a bit. That's all right. So do you notice any difference
between your dark skin and your light skin? What, as in like naturally? When you're exposed to the sun,
do you notice any difference? Do I see any difference? I don't feel a difference. I don't notice a difference. I just walk the walk
and talk the talk. I would like, say,
put a little sunscreen if it was very,
very, very sunny. So-- So it's interesting because
the difference in pigment and the kind of pigment that's
there to begin with anyway gives us a clue as to why we've
got this colour in our skin. And it is to do
with sun protection. So in fact, your dark
skin is giving you some pretty significant
sun protection here. And Bashir's dark
skin is coming out as about factor 20 sunscreen. Naturally. So you've got your own
natural sunscreen there. Oh, perfect. Lovely. And if you have got very
pale skin, of course, you have to put sunscreen on if
you go out into bright sunshine because you could
burn your skin. And every single
episode of sunburn means that you have a higher
risk of developing skin cancer. That's the seriousness
of it a bit later on. Bashir, thank you so much. Thank you for having me. Thank you. [APPLAUSE] See, that connection between
skin colour and sun protection gives us a clue as to how this
evolved in humans, as well. So our ancestors who
expanded out of Africa would have all had dark skin. So the first Asians,
the first Europeans would all have had dark skin. And in fact, it's not until
much later that some mutations started to pop up in genomes so
that skin started to get a bit paler, particularly in very,
very northern areas where the sun just isn't as bright
as it is in the tropics and around the Equator. And in fact, we still see these
patterns of skin colour today. So we still see that people
whose ancestry is predominantly from those sunnier places of the
world tend to have darker skin. And people who've got more
ancestry in the far north tend to have paler
skin, as well. Well, next we're going to
look at another adaptation, another way that natural
selection has acted on humans. But this time, it isn't
to do with interacting with the environment
as we find it. It's about interacting
with an environment that we've actually changed. And it's about the
beginning of farming. I'd like you to gently give
a round of applause for Jade the cow and her calf, Hazel,
who are going to come on now. Aw, she's lovely. Hello, Jade. (SOFTLY) Hello. So Jade is a Dexter
cow, isn't she? And this is her little calf. Yes. Yeah. So obviously, calves
drink their mother's milk. And when our ancestors
started farming and they started
domesticating cattle, they could keep cattle
for their meat, of course, but also for their milk. Now, we want to
demonstrate some milk here. So I want a volunteer
from the audience who's going to come
down and milk Jade. Let's see. Who shall we have? Another fantastic
Christmas jumper, I think. Just there, yes. Come down. [APPLAUSE] Yeah. And what's your name? Nam. Nam. Do you want to come and
have a go at milking, then? Yes. I think Felicity will help you. We've got a milking stool here. So you can either sit on the
stool, or you can lean down. And you gently squeeze
and pull, like that. OK. So this is what
our ancient farming ancestors had to
learn to do, just what Nam's doing right now. There's a bit of a
problem here because it isn't so easy to drink milk. And there's a clue
to that in genetics. Yes, there is. So the main sugar that we find
in milk is called lactose. You see this lactose here. And that's actually quite
a hard sugar to digest. It's a very big sugar. And in order to be
able to digest that, it needs to be broken down. And that gets broken
down by an enzyme. And I need a volunteer to help
me demonstrate what's going on. So let's see. Yes. You at the back with
a beautiful jumper. You have the red stripe on it. Come on down. [APPLAUSE] Catherine. Lovely to meet you. So Catherine, you are not
going to be an enzyme, because we have enzymes
which break down these things that we eat. So you're going to
wear this, please. And if you could come around
here, what the enzyme does-- come over here. What the enzyme does is
it breaks the lactose into smaller sugars. So you can do that
by turning this. Yeah. So that's the way it works. But stop for a second because
the enzyme doesn't just come from nowhere. The enzyme is
produced by a gene. That's me. And the enzyme is only produced
when the gene is switched on. So when you're a baby,
this gene is switched on. And in this baby calf,
this gene is switched on. So the enzyme can go ahead. Yeah, keep-- so now the enzyme
is working, working, working. And it's breaking
down this lactose into smaller, simpler
sugars that we can actually digest without any problem. So this is what this
lovely little calf has. And it's what all
baby mammals have. But then at a certain
point, what happens is the gene switches off,
and the enzyme switches off. Very good. And so this is what
normally happens. But is there
anybody in this room who can drink milk and
it's not a problem? Lots of you. Lots of you, and including
some adults, as well. But that's because,
in many humans, there's an adaptation
to dairy culture, which means that the gene stays on,
and the enzyme keeps going, and you're still able to break
down this lactose sugar well into adulthood-- in fact,
for the rest of your life. And when we look at what parts
of the world this happened in, it happens in parts of the world
where we have dairy culture. It happened in dairy cultures
in Africa and in Europe. So thank you so much. I'll switch off the gene
now so you can have a rest. [MOO] Thank you so much. You're a wonderful volunteer. Thank you. Thank you. Thank you, Nam. [APPLAUSE] Oh my goodness. It's wonderful. Nam did an absolutely
brilliant job. Thank you very much, Nam. Well done. Thank you. [APPLAUSE] I have never milked a cow. Have you ever milked a cow? I don't think I have. Well done. Nam just did. That's impressive. Thank you. Thank you very much,
Jade and Hazel, as well. Thank you. [APPLAUSE] So this adaptation
to drinking milk that appeared in our
farming ancestors then spread so that most
of us in Europe can now drink fresh milk. And the way that
that gene spread is through people moving
through migrations. And what we know is
that, throughout history, there have been big
migrations of people, and people have
just kept moving. And that has spread
different characteristics around the world. And that spreading
keeps on going. It's interesting that the ethnic
groups that we can spot today-- and we can sort of
say, one population looks a bit different
from another population, but it's just a snapshot
in the "here and now." And those ethnic groupings
are different from what they were a few thousand years ago. And they'll keep changing
because we humans keep moving, and we keep mixing
ourselves around. So we've got an illustration
here of just some of the global connectedness of everyone
in this theatre tonight. When you got your
tickets, we asked you where your parents and your
grandparents came from. And we've mapped those
connections here. So the centre of it
all is, of course, this lecture theatre in the
Royal Institution in London. This is just a snapshot of
where you are this evening. But here are all your family
connections around the world-- to North America,
to South America, to West Africa, over here to
Southeast Asia and East Asia, and down to Australia, as well. So what a wonderful image
of global connectedness. Thank you very much. [APPLAUSE] We've looked at some
variation in humans that we can explain
through adaptation and that we can
experience ourselves. We can look at our
own skin colour. We can see differences
in skin colour around us. But there's another adaptation
or another gene variant that we want to
introduce to you now, which is a bit more hidden. And we'll need some volunteers
to help us show it, as well. Yes. So this is something
that is very much hidden. So let's see--
we'll pick somebody. Yes. You. Very enthusiastic there. Yep, boy with the
lovely Christmas jumper. Yeah. How many do you want, Aoife? We need six. So you pick three. I'll get three. I've got two. Good. Yeah. You all get close together,
into a line, shoulder to-- yeah. What a lovely group
of volunteers. [APPLAUSE] Alice, I'd like-- Alice, I'd like you to
join in this one, as well. You can be our
seventh volunteer. Yeah, yeah. I owe you one. So what I'm going to do
now is I'm going to ask you to taste something, OK? So you're going to
get a piece of paper. If you just stick
out your hand, you're going to get a piece of paper. Just hold it in your
hand for a moment. And then I'm going to ask you
to just place it on your tongue. You're not to chew it, or
swallow it, or anything. There's going to be
a mix of flavours. So some of you are going
to taste something, and some of you are not
going to taste something. OK. Let's see. (EXCITED) There's a nasty
reaction over there. Oh my god. What do you think? You can take it out
of your mouth again. That was disgusting. Yeah. So who else thought
it tasted disgusting? [GROAN] Did you get any taste? Yeah. You got a taste? What did it taste like to you? I don't know, like broccoli. Like broccoli, interesting. What did you think? I didn't taste anything. No taste. But you thought it
tasted horrible. I thought it tasted like soap. It's like soap. So this is interesting
because we actually have genetic variation in one
of our taste receptor genes. You all got the
same piece of paper. But some of you could
taste it, and some of you couldn't taste it. And that's because we have
different versions of a gene that allows us to taste
this bitter flavour or not. But you seem to think it was
particularly horrible, did you? So I mean, maybe
there's something I can show you here that
might cause you some dread. [LAUGHTER] What do you think? Do you like sprouts? (TOGETHER) No. Because you can taste
the bitterness in them. But thank you very much. Wonderful volunteers. [APPLAUSE] Yeah. So we've seen, now, a few
examples of genetic variation. Geneticists, in
particular, are totally obsessed with variation. We want to understand how
the differences that we see between us are related
to differences in our genes. This works quite differently
in different cases. So for example, for
height, the height that you will grow
to as an adult is really strongly
determined by your genes. It's really a strong effect. Of course, what you eat
and how much you eat is going to contribute to that. But if I wanted to guess
your height as an adult, I would look at your parents. And that would be a
fairly good guess. But there are
other things which, even though there's
a genetic influence, it's really not that strong. There's something else
comes in, as well. So can you please
raise your right hand if you are right-handed? OK. That's really a lot of people. Can you please raise your left
hand if you are left-handed? There's a few. OK. So when did you decide
to be left-handed? You never decided. It's a trick
question, of course. So it's a strange
one because, even though it's only partly genetic,
you are also born that way. So in terms of whether you're
left-handed or right-handed, this is a really
good example of where genes and chance come together
to make you what you are. And we're going to
represent that here with this kind of
obstacle course. So this obstacle
course we've got here is representing the
process of development. So that's you
growing in the womb. And if we imagine you'll
get the start here, which is the start
of development. And at the end, you either end
up right-handed or left-handed. So if this one individual
went through this process of development-- I have one individual-- So they might end up
left-handed or right-handed. Now, we can't tell
at the beginning. But let's see what happens. Let's see. And watch it go down. So we can actually predict
what side it will end up on. But this one ended
up on the left. So this individual ended
up, let's say, left-handed. But if we have somebody else
with exactly the same genetics, they might turn out differently. So this person ended
up right-handed. We can do a few more. And we can do a few more. Aw, I'm going to be
tipping all these balls in, we'll see what happens. [CLATTERING] Nice and easy. OK. So in this case, even
though everybody here has the same genetics, it's
got the same obstacle course, a lot more turned out
right-handed than turned out left-handed. So on average in the population,
90% of people are right-handed. And only 10% of people
are left-handed. And so the genetics
works a bit like this. So your genes set
up a probability. But they don't determine exactly
how you're going to end out. No, they don't. You know, we might
think about something as normal or something
as not normal, but that's really
not the way it is. Yeah. You've got two outcomes here. One of them is more
probable than the other one. But you can't say that
being right-handed is normal and being left-handed
is abnormal. No. But there's other things that
have similar genetics to this. And one of those is
sexual preference. So usually, men are
attracted to women, and women are attracted to men. But sometimes it's not that way. And the genetics actually
is very, very similar. The percentage is very similar. And we have a similar situation
that the genes determine the shape of this
obstacle course. And sometimes it'll go one way. And sometimes it'll
go the other way. So your genes aren't
completely in control. There's a lot of room
for chance, as well. Yeah. And in fact, in
our own bodies, we see the way that having the
same genome, for instance, on both sides of
your body can produce slightly different effects. Yes. And you can see an example of
that by looking in the mirror. And for this, I will
need another volunteer. And I'll need somebody who is
very good at staying still. Who can be very,
very, very still? So here's somebody who's
very nice and still. Yes. And with a beautiful jumper. Yes. You. [APPLAUSE] OK. So I'm going to ask
you to do something. Come around this
side of the table. So what's your name? Cam. Cam. It's lovely to meet you. So we are going to ask
you to sit your head in your hands like that, right? I want you to keep your
head as straight as possible and looking straight
at that camera. Now, we all have quite symmetric
faces, don't you think? But there are little
asymmetries that we can't even notice most of the time. And those asymmetries are
just that kind of chance in development that we
just mentioned earlier. So if we look at
this picture of Cam, we can see she looks very
symmetric, like all of us do. But she probably has some
small little asymmetry. So if we just take the
left-hand side of Cam's face, and flip it over, and make a
magic mirror image, and then we move that over to the
left here of the picture. And we'll do the same
thing with the right. So we take the right-hand
side and flip it over. OK. So now keep looking
exactly straight. And so you can see
here, on the left, we have the left-hand side
of Cam's face made symmetric and the right-hand side of
her face made symmetric. And they look a bit
different, don't they? So it almost looks like Cam
is her own identical twin or something. But just look at me
without moving your head-- without moving your head. And can you look at Alice
without moving your head? [LAUGHTER] OK. Look back at me. And look back at Alice. OK. Thank you very much. You're wonderful, Cam. [APPLAUSE] Aoife, was an example of
how a genome can play out slightly differently in
one side of your face compared to the other. But sometimes we
get the same genome in different individuals. --otherwise known as-- --(TOGETHER) identical twins. And we have some
twins who are here this evening who have kindly
agreed in advance to do some experiments with us. So if you could
please come down. We have Ronnie and Ritchie,
and Noah and Harris, and Rosanna and Caitlin. [APPLAUSE] OK. OK. So which one of you is Ronnie,
and which one's Ritchie? I'm Ronnie. He's Ritchie. OK. Thank you. So what we're going
to ask you to do is to put your hand into
this bucket of ice water and to keep it there just until
it feels uncomfortable, OK? So you're going
to take it out as soon as it feels uncomfortable. And because we
want to compare you and because we don't
want you to know what's happening with the
other twin, we're going to ask you to put
on those ear defenders so you can't hear
what's happening around. So I'm going to go
behind you and I'm going to start
these stopwatches. And you can see me
starting the stopwatch. And that's when you're
to put your hand in, OK? So put the ear defenders on. And we'll get ready. OK, ready? Go. Well, Aoife, you time
the twins, seeing how long they can keep
their hands in the ice, I've got Noah and Harris here,
and Helen Earwaker, who's a fingerprint researcher. And so Helen, you're going
to be looking at the twins' fingerprints and seeing just
how similar and different they really are. Yes, I am indeed. I'm going to take prints
from both of them. Should we start with
one of them, then? Fantastic. Are you Noah or Harris? I'm Noah. You're Noah. OK. OK. So we're going to take
Noah's right thumb. And we're going to
very carefully move the thumb round all the way from
one end of the fingernail all the way to the other-- To get lots of ink on it. --ink on all of the
ridges of Noah's thumb. And then we're going to
create a record of that thumb by popping it down on the paper
and rolling all the way across. Ah. Look at that. That's a beautiful thumbprint. Excellent. And up. Perfect. Helen, I'll leave you to
do the same with Harris. Thank you. And I'll move over here
because we've got Omar Mahroo. He's an eye doctor. And then we put another pair
of twins, Rosanna and Caitlin. Who's Rosanna? I'm Rosanna. Hi, Rose. You must be Caitlin. And Omar is going to have
a look at your irises. So Rosanna, if you'd
like to sit down there, we're going to have a
look at the fine structure of these twins' eyes. Are you comfortable, love? And Omar, what are
you doing there? So this allows us to take a
detailed picture of the iris of Rosanna's left eye. And what are you interested in? Are you interested in the
colour or the structure? No. Actually, the fine details
of the structure, which you can't normally see
with the naked eye. But with a camera
like this, you can. Lovely. Oh, that's great. Oh. The ice has stopped. Yes. Well, actually, I didn't want
to let them go past two minutes. And they both got
that far, so they did the maximum amount of time. Wow, that's amazing. Oh my goodness. You're very strong. You can take your
ear defenders off. [APPLAUSE] But I wonder if it-- was it really not
uncomfortable before then? Did you just keep
going, even though-- Yeah. You did? Oh, you're so bad. Yeah. But they're both very
strong, obviously. And they're both the
same as each other. Between twins, we see
this pain resistance is quite similar between
twins, but very strong. And possibly very
competitive, as well. And possibly quite competitive. Now, Helen, what about Noah and
Harris and their thumbprints? They're beautiful thumbprints. They are, indeed. We've managed some excellent
prints here from both of them. So if we start by
looking at Noah's print, then we're going to start
by looking at something called first level detail, which
is the type of overall pattern that we can see. So the question is, are
they broadly similar, then? So we would expect to see
a level of similarity, each of you, to some of the
genetic ways in which those fingerprints are formed. But also, we'll expect
to see some differences due to the exact conditions in
which that friction ridge skin, those fingerprints are
formed within different areas of the womb. OK. So what can you see? So you can see here,
in Noah's print, that we have lines coming
up and going round. Yeah, there's a loop. There's a loop, indeed. And we look at Harris's print,
and we can see, similarly, a loop coming up and round. But if we look carefully, we
can also see another loop-- That heads back up. Indeed. So Harris has something that
we would call a twinned loop. And then-- But Noah doesn't have that. No. Noah has what we would an
ulnar loop coming round here. Yeah. Just a single loop. That's fascinating. I mean, it's very
interesting, isn't it, that you've got
similar fingerprints, but you're both individuals. You've both got something
special, and different, and unique about
your fingerprints. Brilliant. Thank you, Helen. How are you doing over here? Great. Omar with Rosanna and Caitlin. We've got some very nice-- How's their eyes look? --very nice pictures of the iris
of Roseanne and Caitlin here. And here, you can see
superficially they do look very similar-- similar colours. But if you look at
the fine detail, you can see that Caitlin has a
couple of small depressions-- we call them crypts-- that Rosanna doesn't
have in the same place. And that's highlighted here. What's really interesting
is that when you look at their irises
like that, I mean, they are strikingly
similar in terms of colour. Yes. Absolutely. Yeah. But it's this structure. It's the fine structure
that's actually different. Yes. And then another
difference is this ridge. It's a raised area we
call the collarette. And I've just highlighted
them in both twins. And you can see the
shape's subtly different. And if you superimpose
them, again, they're not identical at all. Yeah. They're quite different. Isn't that interesting,
that when we really get into this level of detail,
again, you are each unique. Thank you very much, twins. Thank you, Omar. Thank you, Helen. [APPLAUSE] So Ronnie and Ritchie
have stayed around because, last week, they
did something else for us, and that was this. So what they're doing
there is they're taking a sample from
inside their mouth, but it's not a sample
of their own DNA. It's a sample of things that
are living in and on all of us. We all have bacteria that
are growing on our skin and inside our mouth
and our intestines. And Ronnie and
Ritchie very kindly agreed to give us
samples so that we could have a look at us. And here to talk
to us about that is Arwyn from the
University of Aberystwyth. [APPLAUSE] Hi. Arwyn Edwards. It's so lovely see you. Thank you for doing this. So you have here
something that has grown from inside their mouths. Yeah. So we have the bacteria from
Ronnie in Ritchie's mouths that have been plated
out on nutrient media. So this nice nutrient tallied
up is basically bacteria food. But you can see some
differences between you. Which one of you is Ronnie? Him. OK. Ronnie, I need to give you give
bacteria back for a second. So you can see some
differences there. But it's all kind of little
spots of this and that. So it's a bit difficult to tell. And that's because only 1% of
bacteria will grow on a cup. So to really get in touch with
our microbiomes, what we have to do is do DNA sequencing. So this is really a small
sample of what Ronnie and-- Yes. Yeah. --Ritchie are carrying
around, and all of us are carrying around. Everyone's carrying around right
now, everybody in this room. Yeah. So how do you then sample
the rest of the diversity? Well, that's a good question. So as well as collecting
those swabs, what happened was their samples of
spit then had their DNA in that sample extracted. And we amplified
bacterial genes in there to do a sort of DNA
fingerprint of the microbes that are present. So you have something here. Ronnie and Ritchie,
come over here beside. We'll have a look. So now you're loading
the sample in-- I'm just preparing for
a sample to just go in. OK. That's-- And this is the sample going in
here, this kind of milky liquid here. OK. And how long does it take before
this sequencer starts actually generating some sequence? It's already started. It's already started? Wonderful. That's incredible. So we've gone from the dark
green colours here with nothing going through the machine. And now we've got the
light green colour. And you can see numbers
here flashing up saying that it's sequencing. But this is going
to take a while. I don't think we can
wait for this to finish. No. So here's one we made earlier. Yes. So it takes a-- it's very fast,
but it still takes a few hours. So we did the DNA
sequencing earlier. And we sequenced 2
million DNA molecules from both of you put together. And from that, we have numbers
of the types of species that we have there from
bacteria growing in your mouths. You're twins, obviously. So you have more in common
than you have apart. So 116 species of bacteria
growing in your mouth right now that you both have
and you're both sharing. But then, Ronnie, you've got 18
species that are unique to you. And your twin brother
doesn't have those species. And then Ritchie, you've
got slightly more. You've got 25 species
that are unique to you. So even though your
genomes are identical and your daily habits
are very, very similar, you have some bacteria
that make you unique. Yeah. And so these are totally
separate from the genome we've been talking
about until now. So it's not your genome. It's the genome of little
things living on your skin and in your mouth. Yeah. So if somebody had a pet, would
that influence what's growing? Yeah. So if you have a
pet dog at home, you're likely to share
many, many bacterial species between you and the dog. So next time you have
dogs in the audience there, give them a good pat
because you're picking up friendly bacteria from them. So would somebody be
more like their twin or more like their pet? That's a good question. It depends how much you
like your twin brother. OK. Well, thank you so much, Arwyn. And thank you so much,
Ronnie and Ritchie. You can keep those. And you've been
wonderful volunteers. [APPLAUSE] Thank you. Aoife, that was
incredible, I mean, I think that it's
interesting to see how many different
species of bacteria we've got living in our mouths. But also, the fact
that the sequencing is so quick and so miniaturised
now, that amazing technology. It's incredible. Yeah. So I want to test
you a bit now-- Oh, yeah? --because we've been talking
about various characteristics that we can map on
to our genetics. But if you didn't know
what somebody looked like and you didn't know who
somebody was, how much could you tell about them if you
had their DNA sequence? So now you're talking about
basically the Holy Grail of genetics. Can you take a DNA sequence
and describe the person? Well, it's quite hard
because we've already talked about examples where you
might have particular genes. And it gives you a chance of
being one thing or another. But it doesn't totally
fix the outcome. And then there's another side
to it, as there's lots of stuff that we just don't know yet. There's lots of examples
where we just don't know how, exactly, the genes work. But-- So I've got somebody's
DNA results here. Yes, yes. So we have a mystery guest. And honestly, I don't know who
this guest is, nor does Alice. But I have been looking
at some of their DNA. So this mystery guest
is going to come in. And don't say
anything that might let us guess who it is because
we have no idea who this is. And we're going to make
some predictions of some of this person's traits just
based on the DNA sequence analysis. So please come
in, mystery guest. [APPLAUSE] OK. Mystery guest, you don't
have to say anything to me because I don't even
want to hear your voice. But thank you very
much for coming. So the mystery guest
over there has two bells. And they can use one of them for
"yes" and one of them for "no." So the first thing
that I'm going to talk about with
regard to this guest is that this person
has two X chromosomes. These are the sex chromosomes. So usually when somebody
has to X chromosomes, then they're female. It's not 100%, but
it's most of the time. So I'm going to go for that
we have a female guest. Am I correct? [RINGING] Yes. OK. One right. OK. You're doing well, Aoife. Thank you. Now, let's see. So we also know that skin
colour is highly genetic. But we don't know all
the variants very well. So based on the
genetic variants, I'm relatively confident
that this person has skin on the darker scale,
so a brown to darker brown. Am I correct? [RINGING] OK. Good. Yes. OK. I wasn't certain about that one. Perhaps you might have
detached earlobes. So we have earlobes that can
be-- my earlobes are detached. And Alice's are-- Mine are attached. --attached. So do you have
detached earlobes, yes? [RINGING] Oh, OK. So we talked earlier about
lactose tolerance, as well. And so this person does
not carry the variant that we normally see in
European individuals that allows them drink milk. I'll go for that this person
is lactose intolerant. [RINGING] OK. There we go. And so some people-- you know the herb, coriander--
the green herb, coriander? So for me, that
tastes really nice. But for about 13% of
people, it tastes like soap. And this person
might be one of them. I'm not confident, but I will
say for soapy coriander, yes? [HONK] Oh. OK. There we go. Interesting. So finally-- and
this one, I'm quite confident that this person
has either dark brown or hazel eyes. [RINGING] OK. All right. Well, that's as much
as I'm going to do. But what was
interesting about this is you know some
of these traits are better predictors than others. But it's never going to be 100%. So you might be right
sort of, you know, 7, 8, 9 times out of 10. But there are some
people that you're not going to guess right by
knowing their genetics. OK. I think we just need
to end the suspense and see who actually
is our mystery guest. Do you think we
should reveal it? I think we should reveal
our mystery guest. Let's see. [GASPS] Hello. Hi! How are you? One for you and one for you. Thank you so much for coming. [INAUDIBLE] So it was a surprise. Were you impressed
that Aoife managed to guess so much about you? Yeah. And I feel so bad
that I love coriander. You love coriander? I love coriander. But your genes say that you
should taste a soapy taste. That's not right, then. Tastes delicious to me. I don't know. So that one didn't work. Oh. That was amazing. Ruby, star baker,
thank you very much. Aw. Thank you so much. Thank you. [APPLAUSE] So this is fascinating. We do seem to be able
to make some reasonably good predictions about people
based on their genetics. But that was a bit of fun. It was a lot of fun,
and I got a cupcake. But there's a more
serious side to this, too, because we can use genetics to
predict our risk of disease. I mean, you just
think really carefully about how we do
that and whether we want to know this information. So to help us think through
some of these issues, I'd like you to welcome my
friend, bioethicist Professor Heather Widdows. Heather. [APPLAUSE] Now, Heather, first of
all, what is a bioethicist? Well, my job is to think
not about what we can do, but about what we should do. So I think about
the implications for all the stuff you've heard. And now that we can predict
risk of some diseases-- some better than others-- what are the
advantages to knowing that kind of information? Well, some of it is
disease specific. So if there's a
treatment, for instance, then you need to know. But there are general
things that people think that maybe you
have a right to know, that you should know. And that will help
you plan your future. So that could be things
like lifestyle choices. So if you have a disposition,
say, to something like a form of
cancer, then you might want to plan your life
a bit differently. So when you're
thinking about things like when you want
to have children, if you want to
have children, you might want to have
children earlier. You might want to maybe
do your "bucket list." You don't want to wait till
you're retired to go and climb Mount Everest. Yeah. So it can kind of
help with planning. Right. You could change your
lifestyle and hopefully lessen your risk there. But what are the
negatives when it comes to knowing your disease risk? So just like some people
think you should know, other people feel very
strongly that other way. They think that you should have
an open future, that knowing is going to make you
think that you're ill when, in fact,
you're very well still. So even though
you're not ill, you might start behaving
as if you are. And you kind of
wish your life away. So for very many
other people, they think that, in fact, we
really have a duty or a right not to know that's important. So we'd like to explore some
of these areas with you. And at your feet,
you've got voting cards. So when we ask you to vote,
what I'd like you to do is hold up your answer
with the answer facing us. So we're going to talk
about a number of diseases and see what you think,
see how you feel about it. Have a good think about
whether you'd really want to know if you had a
higher risk of developing such a disease. So should we have a think
about early-onset Alzheimer's disease? Yeah. So Alzheimer's is
one form of dementia. And usually, the tests will
only tell you susceptibility and risk. And it's more about a cluster
of genes in the environment. So this is something which
would cause memory loss, eventually makes it difficult
for you to be independent and to look after yourselves. At the moment, there's
no treatment for it. So would you like to know if you
had a higher risk of developing early Alzheimer's? I think there's a-- I think there's a majority
of yeses, actually. But there's quite
a lot of people who wouldn't like to know. So let's think about
another disease. OK. So the next one we want to
think about is type 2 diabetes. So this is where your
body responds to sugar. It can affect your eyesight. And it can gradually
get more severe. It is a disease where
you can manage it very well by lifestyle changes. So obesity is a key
factor in the disease. So knowing means that you
really can change your lifestyle to address it. So who would like to know if
they had a slightly higher risk of developing type 2 diabetes? That's really different. Even more. Yeah. So the vast, vast majority
of you are saying yes. It's important to remember, with
these kind of ethics questions, there is no right
or wrong answer. It's what's right
and wrong for you. So let's think about
one final disease. And let's think about cancer. Now, there are lots of
different types of cancer. Some of them are treatable. Some of them are more
difficult to treat. But if you could test for a
high risk of a particular cancer where there was a treatment
option, what would you feel about that? Would you want to know if
you were going to develop this particular type of cancer? I think it is about 2/3. Yes. And about a third "no." Yeah. I think that looks-- now, our roving
reporter, Aoife, is going to come and ask you some
of your opinions about this and why you voted-- Is there anybody-- --in various ways. Is there anybody who'd like
to tell me what they voted and why they voted? So I'll come around to you. Oh, sorry. I fall on the stairs, as well. And what way did you vote
on the Alzheimer's one? I voted no. And why did you vote no? I think you shouldn't
live knowing in fear. You should make
your own choices. Yeah. Very interesting. Anybody else who wants to tell
me about one of their answers? Yeah? But which one? I voted yes on Alzheimer's-- Yes? --because I think it'd be
nice to warn your family-- OK. Very interesting. --and to share. Yeah. Yeah. Let's see if there's
somebody up here. You voted no? OK. Do you want to tell us what
did you vote no to and why? I voted no to the
first one because-- Alzheimer's. Yes, because I didn't
want to know because then it would make me feel scared. And then I won't enjoy my
life as much as I would have. I mean, it's very
sophisticated opinions coming from our audience here. So give yourselves
a round of applause. [APPLAUSE] Thank you very much
for doing that with us. There was some really, really
thoughtful answers there, I thought, Heather. Absolutely. Lots of the answers
you came up with are exactly the answers
that ethicists talk about. Really? One really interesting
thing, of course, about DNA is that it connects
us with other people. So this is something you've
thought about long and hard, Heather-- that, in fact, when
you have your DNA sequenced, it's not just your genes
that you're looking at. Yeah. Absolutely. The two key things that
make genetic information so different are that it is
shared and it is identifying. So it's shared with other
members of your family. And we don't really know
how to balance that. So if we think about
something like, you know, testing for the
indicators for breast cancer-- if you are 15, and
you want to be tested, and your mother is
35, 40, and doesn't want to know, and you know
that there's kind of cancer in the family, if you go,
and get tested, and turn out to be positive,
then you will have information about your mother
that she does not want. And we need to think about
how we ethically manage that. It feels like we're
only just catching up with the ethics of this
whole area of biology. It feels that we're not
really kind of grasping how to deal with that
information quite yet. Yeah. No. I don't think we are at all. I think that's exactly right. You know, the science has
moved on quite dramatically. This is all about
unknowns in the future. Who will want your information? Will it change what you
can do employment-wise? Will insurers want it? And of course, there
is one particular area when a genetic test
is carried out, it's actually not
on your own DNA, but very much on the DNA
of another individual. And that's when we test
babies in the womb, when we do antenatal testing. And we're able to test for
more and more things now. But again, some really difficult
decision-making when parents are presented with results. Absolutely. So you know, perhaps the
one that's most well known is a test for Down syndrome. That happens very routinely. So that means that nearly
every pregnant woman in the UK will have that test. And they will be
offered it routinely. And they may just
think, oh, well, this is just part of getting
ready to have the baby. And what they may not realise
is that once that result comes back, if that's a
positive result, then the only thing to
do is either continue-- so the tests can
help to prepare-- or you can end the pregnancy. And that may be something that
they hadn't quite realised was happening. So very difficult decisions. I want to introduce
you to somebody who did have an antenatal
test for Down syndrome. and her daughter. So please, will you
welcome Donna and Frankie. [APPLAUSE] [BABY COOS] Oh, she gave us a lovely wave. [BABY HUMMING] Are you excited to be here? Yeah. So Donna, you had
an antenatal test. So you knew that
Frankie was going to be born with Down syndrome. We had a blood test. And she came back as a high
chance of having Down syndrome. We didn't know
until she was born that she had Down syndrome. But we knew that there
was a high chance of it. Yeah. And did it help you prepare? Yeah, definitely. I mean, I think I went through
my pregnancy, in my head, thinking, baby
has Down syndrome. It wasn't anything that
was negative for me. I was quite happy,
quite excited. I've had my first baby. It didn't matter
how she came out. She was Frankie, weren't you? And she's different,
but she's lovely. Yeah. You know, no child's the same. She is so unique
in so many ways. But I wouldn't change
a thing about her. She's perfect. Yeah. And we're all unique. Exactly. Thank you very much-- Thank you for-- --Donna, Frankie, and Heather. [APPLAUSE] So Aoife, we've been
looking at what we can do with this new technology. You know, it is new. And it's getting faster,
and faster, and cheaper, and cheaper. And we can read DNA, and we
can make some predictions about what we're going to be. But we can actually
change DNA now, as well. Yeah. And we have a really
wonderful example of this. So if you could please
welcome a leader in this field of gene therapy,
from Great Ormond Street Hospital, Professor
Bobby Gaspar. [APPLAUSE] Thank you so much for coming on. So you've been working in
the area of gene therapy-- so being able to change
genes to help patients-- for quite a number of years now. Yes. Well, I actually I started
right at the beginning, when I was a junior doctor
at Great Ormond Street Hospital about 25 years ago. And really, what we're trying
to do is, in some diseases, it comes about because a
gene is defective or missing. And what we want
to try and do is put a working copy of the
gene back into those cells so they now have
the correct gene. The gene works. It makes the right signals to
be able to correct that disease. So it's a very fundamental
way of correcting diseases. So you're really getting
to the root cause. And you helped the
first ever patient to be helped with the gene therapy. First worldwide. And he's the first
successfully-treated child by gene therapy. And our team at University
College and Great Ormond Street helped treat him back in 2001. And he's here this evening
to come and show off how strong and healthy he is. Please welcome Rhys. [APPLAUSE] Hello, Rhys. I must say you are
looking very healthy. We have a picture of you
from about one-year-old, I think, up there. What you can just
about see, there is a plastic bubble around Rhys. So you spent a lot of
time in that bubble. Well, when I was born, I had
to be put into this bubble because I wasn't born
with an immune system. And so any sort of bacteria
or viruses in the atmosphere that I would inhale
or breathe in, it would then harm
me because my system wasn't very strong at all. And Professor Bobby
Gaspar was your doctor. Yes. Yeah. So what did you do for Rhys? Well, Rhys, as he says,
there was a single gene that was missing in his bone
marrow, not working properly. He couldn't make immune cells. And so my colleague
and myself, we were working on a new way
of treating this condition through gene therapy. And that meant taking
Rhys's own cells. So he went to the
operating theatre. And we took out your
bone marrow stem cells. And in the lab, we put a
working copy of that gene-- that gene that was missing-- we put a working copy of that
back into his bone marrow cells and then gave those gene
modified cells back to Rhys. And then over a few months, his
immune system starts to grow. And this was the first time we'd
seen it in any child in the UK. And then after
about six months, it was growing and
working really well. So we were really, really
delighted how well it worked. And so Rhys, this has
totally changed your life. Yeah. No, I don't think I'd
be alive, honestly. It's such a wonderful
example of how genetics can transform medicine. And we have these new therapies. Well, now that we're
able to identify all of these different
genes that cause diseases, now we'll see genetic
treatments for eye diseases. Certain leukemias can be
treated by genetic therapies. And there'll be other
conditions, as well, that will be treated
by gene therapy. It's such a positive story. So thank you so
much, Rhys and Bobby, for coming in and
telling us that. Thank you. Thank you. [APPLAUSE] Aoife, Rhys's story,
it was just amazing. It's incredible. And this does feel like a
new frontier in medicine, being able to fix faulty genes. And I wonder how
far we go with this because fixing disease seems
like a very positive thing to do. But you could make
other changes. I mean, parents could be
choosing, I don't know, eye colour, skin
colour of their babies. And that, I think, is a
very, very different issue. Definitely. I mean, I have a
personal view on that, and that is that that
shouldn't be done. I just don't think it's a
suitable use of the technology. And it's something
that should be avoided. And this science
and this technology is moving really fast. So all of you will have to think
about this really carefully over the course of your lives. Science is fantastic. It tells us so much
about the world around us and about ourselves. And it provides us with
amazing technological tools. But we have to work out how
we're going to use these tools. And that's not just a question
for scientists and ethicists. It's a question for everybody
because this science and this technology
belongs to all of us. And just because
we can do something doesn't mean that we should. But one thing that we do see in
all of this is that each of us is a total one-off. Even the twins were
a unique parcel of talents, strengths,
weaknesses, foibles, and charms. We started out
wondering who we were, what makes us unique,
what makes you "you." And we found an answer to that. But it's your past. It's all your ancestors who have
passed down their genes to you. But it's also your own past. What happened to you
in the womb and what's happened to you since
you've been born combined with a lot of chance, as
well, makes each one of you a unique individual. And there is no such
thing as a perfect human. There is no normal human. Humanity is all of us. Everyone is different. And everyone has
something special to give. Thank you. [APPLAUSE]
