Beyond Words | Animal Communication || Radcliffe Institute


– Welcome, everybody. I want to just jump right in. Because we have so much
interesting material today to talk about in our panel
on animal aesthetics, and how gender and
aesthetics are not limited to the human world. My two colleagues that are
here to present today– by the way, I’m Ani Patel. I’m a fellow here at the
Radcliffe Institute this year. And I’m a professor of
psychology at Tufts University. Anyway, so my colleagues
here are my colleague from Tufts, Zarin Machada, an
assistant professor of Tufts at the Department of
anthropology and biology. And research director of
the long-term research project on chimpanzees, the
Kibale Chimpanzee Project. Zarin has spent the past 17
years studying wild chimpanzees in Uganda. And is especially committed
to their conservation. Her research revolves
around social relationships in chimpanzees and
wild chimpanzees. Machada has also
conducted several studies in chimpanzee
communication that have helped shape our understanding
of human language. She’s also on the
board of directors of this really great
project called the Kalial? – Kasiisi. Kasiisi Project, an
organization that works with more than 10,000
schoolchildren in Uganda implementing conservation
and education programs. And the other colleague here
is Professor Richard Prum, professor of Ornithology
at Yale and curator of Ornithology at the Peabody
Museum of Natural History there. He’s researched many
topics in biology, including feather
development and evolution, sexual selection, and the
dinosaur origins of birds. He’s the author of a book
called The evolution of Beauty: how Darwin’s Forgotten
Theory of Mate Choice Shapes the Animal
World and Us, that was published in 2017, which was
included in the New York Times 10 best books of 2017 and a
finalist for the 2018 Pulitzer Prize for general nonfiction. I read it last winter. And I highly recommend
it to you all. He’s been awarded many
fellowships, including the Guggenheim, and the
MacArthur, and the Fulbright. And he has directed
Yale’s Frank program for science and humanities. So he’s used to crossing these
boundaries that we so much like to cross here at Radcliffe. So just the briefest of
introductions into a concept that will be important today. Many of you will be familiar
with Darwin’s theory of natural selection, his
great idea about the mechanism of evolution, of how species
change over time, which involves some key
things like there has to be variation in traits. Let’s say, like, how long
your bill is if you’re a bird. Some of that variation
has to be inherited by the next generation. And that variation
has to be related to differential survival
and reproductive success. So for example, a longer bill
might help you find more food. And therefore, survive
better and pass on your genes to the next generation. So that has to do with how you
survive in the environment, finding food, escaping
predators, and so on. But there’s a second
mechanism that he proposed in his great
book The Descent of Men, about human evolution. Actually, a lot of that book was
spent on talking about animals. And his other
principle of evolution called sexual
selection, which is also a variation in traits,
which is inherited, which leads to differential
reproductive success. But this time it’s
about traits that help you compete for mates. Things that maybe a display
that helps attract a mate, or something that helps
you fight off a competitor in the battle for
finding a mate. So these two ideas, natural
selection and sexual selection, are different
mechanisms of evolution. And today we’re going to
hear about how they play out in terms of animal aesthetics. So with that, I
will invite Richard to give our first presentation. [APPLAUSE] – Thank you to Ani. And thanks to the
Radcliffe Institute for this marvelous opportunity. When the invitation came to
address Beyond Words, gender and the aesthetics
of communication, it was like a dream come true. That means I have way too many
aspirations for my 15 minutes. So what is an
ornithologists doing here? I have been working on the
evolution of courtship display, and the physics and chemistry
of color of feathers, avian display, and through– evolving through sexual
selection for a long time. And that has led me to some
really revelatory things about the agency in the world. So what I want to do is
give away my punch line. I think that we
can scientifically establish that birds are
beautiful because they are beautiful to themselves. That they are agents
in their own evolution. That subjective
experiences actually are the core of what sexual
communication is about. In addition, having understood
or recognized the agency– aesthetic agency
in birds that leads us to understand for
the first time what it means when
agency is infringed by sexual conflict
or sexual violence. And that leads to the
conclusion that sexual autonomy matters to animals. That there is something it is
like to have freedom of choice. And that the
capacity to reinforce your freedom of choice,
or to earn and create sexual autonomy,
evolves in the wild. And that this has
real implications for how we think and
understand our own evolution. So I have spent a
lot of time looking at what I call beauty
studies, the deep aspects of the courtship of birds. And I could go on about
the physics of this blue and the chemistry
of that purple. But I’m just going
to shamelessly use animal video to– this is an image, a video,
of a male superb bird of paradise in New Guinea. It was filmed by my student, Ed
Scholes, a number of years ago. [BIRD SCREECHING] Yeah. So this is a
[INAUDIBLE] species. The female does all
the reproduction and chooses among
available males. What we’re going to see here
is an incredible performance of an amazingly transformative
communication event. The female is regarding
this male at inches away. And that blue is a photonic
structure– a structural color. And around that blue are
super black feathers. The physics of which we’ve just
described in the last year. Now interestingly, this
raises a lot of questions. And I want to just go
straight into the controversy in evolutionary biology, which
is that most of my colleagues believe that sexual
selection operates to select for characters
that actually provide objective information
about quality. And there’s the alternative is
that this is purely aesthetic. That it’s about subjective
pleasure in the act of choice. So in the science
that I recommend, the subjective
experience of animals should be moved to the
center of our science. Not explained away as merely
a path toward adaptation, but as it’s right in itself. And here we have the– imagine the olfactory
world of the mall, or the sonar world of the
bat, or the electrical world or the more mirrored
fish, would sing songs in electrical pulses that
vary in tempo and frequency, like music but an
entirely different wave. Right? Well, of course I’ve
studied the bird sound here, which we can much
more easily relate to. Right? In sound effect. But I want to propose
that there is a– [BIRD TWIRPING] That’s a little land probably. There is a mode of
evolution, that I’ll call aesthetic
evolution, that is an emergent consequence
of sensory perception, cognitive evaluation,
and choice. And then what this choice,
either sexual, or social, or ecological choice, happens
on a heritable substrate, you get the evolution
of aesthetic features that function not in
the physical world, but in the cognitive
domain, in the evaluation– the aesthetic evaluation
of con-specifics or other organisms. And this applies to
both sexual signals, but also to flowers, and
to the scents of flowers. So part of this research is
to try to bring beauty back into the sciences– as a legitimate topic
for the science. And so to define beauty
in a way that, I think, is scientifically productive,
I say that beauty is not merely attraction. Beauty is a core
evolved attraction in which the form of
preference or desire is shaped to match
the object of desire. And that this
shaping as happening through a mutual
entrainment of interactions. I won’t spend time on
how to differentiate between the adaptive
and non-adaptive view, but I express my view
as beauty happens. And what that means
is that when there is choice and a
heritable substrate that beauty will arise. That’s an expectation of nature. And that mate choice
in this regard is kind of like a spinning top. It creates normativity. But that normativity
is unstable over time. And then if you spin the
top millions of times it will go to different places. And that is why nature
looks the way it does. Now I haven’t been able to
defend any of those assertions, but I’m going to move on. [LAUGHTER] Well, what this does
is focus the science on the aesthetic
agency of animals. The fact that animal
choices are really at the heart of the science. Now for accidental
reasons, really, I moved from this area
in sexual selection to start working on duck sex. Now duck sex is a
problematic topic. [LAUGHTER] And when Patricia Brennan,
now at Mount Holyoke, came to my lab with an interest
in working on the evolution of avian genitalia. I thought, well, I’ve never
worked on that end of the bird before. I’m sure I’ll learn a lot. But what I learned
transformed, really, my understanding of biology
in a fundamental way. Now duck sex is problematic
because there are– well, much of duck sex
is what we imagine. Females, like this
female mallet, choosing males on the
base of their core evolved preferences for
traits, like the green head and the quack, quack, quack. Right? But in ducks there’s a problem
that high breeding density also leads to many males not
being paired, leading to forced copulation, or
essentially rape in the ducks. And what that is made possible
as a consequence of the fact that birds have a penis. That the penis evolved in a
common ancestor of reptiles and mammals, but was
lost in most birds, but still retained in ducks. So this is fascinating
and also troubling. Because this
animal, for example, the penis of birds or
ducks is very unusual. This is the largest penis for
any animal of its body size. It’s actually longer
than the duck. And so it took patty
Brennan, a female biologist, to come to my lab and
say, what is with that? Where is that? And how is that functioning? So a bit of introduction
to the avian penis. It is homologous,
but very weird. It has a counter
clockwise spiral. It has an open groove
instead of a closed urethra, called the sulcus. And it comes in smooth,
ribbed, and toothy varieties. And– most of which
have co-evolved with forced copulation,
or with force. Now in science we
aim to change lives. And the next video
will change your life if you’ve never seen a slow-mo
video of a duck penis erecting. But– and so, here we have it. If you don’t want
to change your life, then keep your eyes closed. This is a video taken. And the erection of the penis
takes a third of a second. It unfurls from outside in. And that is a– well, you can see,
16 centimeter there. And I want to point
out that we’re using the metric side of the ruler. So that means that this
is actually science. [LAUGHTER] Although ducks are
common barnyard animals, it took until 2010 to
actually describe something that all farmers, or all people
around waterfowl, have known. Right? So this is a new
and unknown biology. So what’s going on? Well, what Patty
discovered is that there is a co-evolution
between the penis and the vaginal
morphology in ducks. On the left we
have a small penis at a simple virginal tract in
a species that has very little forced copulation. But on the right
we have a species with advanced or frequent
force copulations with a convoluted and
complex vaginal tract. Well, those– that
complexity matters. Here we say that
females have evolved anatomical countermeasures
against forced fertilization. On the inside of the vaginal
tract the first set of things are a set of blind pouches,
or dead end cul de sacs. And above that is
a clockwise spiral. So female ducks have literally
evolved an anti-screw device in their anatomy. Right? Which they can
behaviorally deploy during forced copulation. And we know this is effective
because in species where 40% of the copulations
are forced, only 2% to 5% of the eggs in the nest
are fathered by males other than the social partner. So this is a 98% successful
birth control method. Right? That is FDA approvable. Right? So how do the ducks do it? How do they evolve such a thing? We were able to actually
demonstrate that vaginal– or demonstrate that
the shape of the track affects the success
of intramission by having ducks erect their
penises into these glass tubes. Male-like on the right, and
female-like on the left. And they failed
over 80% of the time to completely intrimate,
or to enter the female– or to enter the glass tube
that was shaped like a female. What this means is that sexual
autonomy matters to animals. Right? That– as I said,
there is something it is like to have
freedom of choice, and there’s something that is
like to be have that infringed. So how could these
structures evolve? Well, when the female chooses
the male that she prefers, her offspring will
inherit the traits that she and other
females have evolved to prefer through the
aesthetic co-evolution. But if she’s
forcibly fertilized, then her offspring
will more likely inherit either a random
trait, or a trait that she’s specifically rejected,
which means that they’re less likely to be recognized
by other female ducks as attractive. That is the indirect
genetic cost of sexual violence to females. And so anything
the female could do behaviorally or anatomically to
reinforce her freedom of choice will be rewarded
by other females. So these anatomical
structures grow as a consequence of the power
of aesthetic normativity. Females who agree on
what is attractive can use that to advance
their freedom of choice in the face of persistent
sexual violence. Right? Now that is a kind of
statement that as a scientist I never thought that I would
be in a position to make. And I think it is a
scientific statement that is– we’ve led to
specifically because of recognizing the
aesthetic agency of the aesthetic position. Right? Now duck sex is a
co-evolutionary arms race played out in the genitalia. But there are other
kinds of birds that show other sorts of responses. Here is a Bower bird. The Bower bird is– a male builds this
structure, which is not a nest, but
a seduction theater. Right? And it has one seat. And that one seat is
occupied by the female. OK. So I think I got 2:40. Yeah. So what we see here
is the female is– or this is a male. And the Bower have various
kinds of architecture. So here we see, for example,
a male with his ornaments. And in the front
of the ornaments, those ornaments are
actually fossil clam shells. So this is a
paleontological Bower bird. As a curator, I kind
of relate to this guy. So that’s actually the male,
but he’s sitting in the position where the female sits. So when the female
sits there the male is out front displaying to her. But now we see the
male makes the Bower, because the females prefer it. They’re the agents that have
shaped the architecture. But now we see
the other feature, which is that when the
male approaches the female to copulate, he has to
go back around the walls of the barrel– of the Bower, providing
her with the opportunity to pop out the front if she
doesn’t like the way things are going. So the Bower is aesthetic. It has architecture. But it also has
this extra feature, that it protects her
from sexual coercion. Right? And so she can intimately
regard the male at this intimate distance
for as long as she likes. Right? And to make her
[INAUDIBLE] choices and have that freedom
without threat. Right? And I call this
aesthetic remodeling. Mate choice has
remodeled maleness in a way that furthers
female sexual autonomy. So then lastly, what do
females do with their freedom? They choose beauty. And so freedom
autonomy in nature creates an explosion–
an aesthetic explosion in the Bower birds
with elaboration of all kinds of
architecture and all kinds of ornamental structure. Right? So that is the second
profound discovery that I never thought I’d be
in a position that has been made possible by the aesthetic. Right? This sort of phenomena is
going on not just in sexuality, but in other choices,
like ecological choices, like pollinators, and frugivory,
or coral snakes, which are kind of a genre of
horror in the natural world. Right? Another kind of art. And so I see my time is up. And I– if you like
this, there’s more. And please check out
Evolution of Beauty. Thank you very
much for your time. [APPLAUSE] – Great. – OK. You go get them. – OK. Duck penises are a very
tough act that follow. [LAUGHTER] I will do my best. I will say, just
as I’m starting, that I was teaching a
class and once needed a picture of a duck
corkscrew penis and made the mistake of googling
corkscrew penis in Google. Don’t do it. I forgot the duck part. It was really terrible. OK. So I’m here to tell you about
chimpanzee communication. It’s something that I have
studied for many years. And I’m particularly
interested in sex differences in chimpanzee behavior, and how
they manifest in communication. And I would be remiss
today if I didn’t all teach you how to find your
inner chimp a little bit. So chimpanzees give at least
60 distinct vocalizations that we generally have a good
idea of what each of those mean, not every single one. And if you spend time
with chimps in captivity or the wild one of the
most commonly heard sounds that you will
experience is the pant-hoot. Now this is pretty
much the loudest call that a chimpanzee could give. We can hear it in the forest
for up to two to three miles. So imagine being able to make
a sound that you could hear– that someone could hear
you three miles away. So the call actually has
four different components. And let me actually just say,
this is in many ways a way that chimpanzees
give a greeting. It’s kind of a
hello, I’m over here, I’m really excited to see you. It’s a call they give when
they’re socially excited. Before two groups
of chimps meet up they often call– give
this vocalization as a way to say, hey, come over to me. I’m really excited. So that’s why I think this is
appropriate for this venue. So the call comes in
kind of four parts. The first is called the pant. So it’s– [PANTING]. And then they’re excited. So it gets louder and faster. And it’s called the build up. [CHIMP NOISES] And then
they have the hoot. And the hoot is the loud part. So this is the part we
hear from very far away. And the other thing
I love about the hoot is that it’s very
individually distinctive. So when I hear hoots
of different chimps I can usually tell
who is hooting just based on that sound. So the hoot, as you’re thinking
about your inner chimp the hoot could be something like– it’s going to be loud. The hoot could be something
like, [SCREAMING].. OK. It could be like that. It could be a little
bit more melodious. It could be like
[CHIMP NOISES] OK. So think about you as a chimp. And then, this is very
important if you’re going to teach small
children this call, you have to stop
screaming eventually. At some point you
stop screaming. And you kind of relax. And you have this let down. [PANTING] OK. So let’s put it all together. This is my pant-hoot. [CHIMP NOISES] Hello. OK. [APPLAUSE] Now you’re all going
to do your pant-hoots to say hello back to me. So are you ready? – Yeah. – Remember this is loud. So how many times
a professor’s told you to be as loud as possible? Never. They should hear us
in Porter Square. OK. You ready? [CHIMP NOISES] Wonderful. Now here is an actual
chimp giving a pant-hoot. This is a chimp named Johnny. [PANT-HOOT] – So I could tell
you that is Johnny. Johnny’s hoot is
like [PANT-HOOT].. It’s amazing. OK. So there is a lot of
information encoded in that one vocalization. So through many studies
by many different people we know that the pant-hoots
are mostly given by males. So the males give
this call much more come much often than females. Males who are high ranking tend
to give this call more often. So alpha males pant-hoot more. Interestingly, we also
know that individuals who have higher
levels of testosterone give more pant-hoots. And the actual hoot
has a higher pitch when their testosterone is higher. But there’s also a lot
of social information encoded by this call. We know individuals who are
good friends with each other tend to pant-hoot
together more often. So they chorus. And when you see chimps in
the wild pant-hooting a lot of times those first
parts, that [BREATHY OOH],, they’ll actually extend
that so that they wait for other
individuals to join in. And what’s interesting is
that not only do these calls kind of indicate or
give us a sense of who– which chimps have strong
bonds, but they also facilitate more cooperation
with the chimps. So if they chorus
together you’re more likely to see other
cooperative behaviors between those individuals. And interestingly,
they also give us information about
group membership. So different groups
of chimpanzees have different
dialects of pant-hoots. And my favorite– one
of my favorite studies is that a group of Dutch
chimps got moved to Scotland. And the Dutch chimps actually
learned the Scottish dialect of the chimps that they now
had to be roommates with. So there is a lot of meaning
in these vocalizations. But one of the things that
we often have trouble with is trying to figure out
what these calls mean, and really trying to
understand different aspects about these calls. And we can take a lot of data in
the wild just observing things. But another way that animal
scientists have collected data on the meaning of calls
is through the use of experiments in the field. And so I’m going to
tell you about one that I love that we
did about nine– oh, six years ago now, where we
were trying to understand the vocalizations that
chimpanzees give in response to things that scare
them, like snakes. So we found a Python skin. We stuffed it to
make it look real. And then we hit it on a path. And we covered it with leaves
so they couldn’t see it. This is– this is obviously
the illustration of this. And then a chimp came by we
would reveal a snake to them. [CHIMP CALLING] And we would then
record what happened. So here is what happens. This is a chimp named Nambi. She’s about to get
exposed to the snake. Nambi’s seeing the snake. – Hoo-ing. Hoo-ing. Hoo-ing. So that voice is my colleague,
Anna [INAUDIBLE],, who collected the data for this. So that first
response, [HOO-ING].. Very kind of–
it’s probably what we would do if we saw a snake. Now here’s the interesting part. Now this is a view from behind. That’s Nambi. And this is Nambi’s son. So she’s just hoo’d. And you’re going to
see her look back. And she’s giving this
call called a waa bark. [WAAING] She looks back. She sees who behind her. Here’s the most amazing thing
about this study, we had– we did 40 trials, different
chimps, different groups. When chimpanzees saw the snake,
that hoo, that hoo-hoo, that seemed to be just
automatic, a reflex, kind of a fear response. But that waa bark,
that [WAAING].. What they would do, they
would look behind them. They’d see who it
was behind them. And if it was a friend or a
relative they would waa bark. And if it was anybody else
they would keep walking. So what does this mean? Two profound
implications of this. One, chimpanzees are jerks. We know that. But I think more interestingly
from a scientific point of view, chimpanzees, at
least in this particular call, are showing signs
of intentionality. Signs that they can control the
sounds that they make and give them in different contexts. And they don’t have– they
can choose not to communicate. So I think that’s a
really important aspect. And that’s something that
really puts chimpanzees in kind of the sphere of humans. Right? One of the hallmarks
of human language is our intentionality
in speaking. But chimpanzees also do
a number of other types of communication. Obviously we focus
on vocalizations because we can hear
them, but as you get to know
chimpanzees more you’ll see lots of different
kinds of communication. So here are two
of our male chimps just sitting around grooming. This is something that we think
they do to relieve stress. We know that
chimpanzees– we know that males are much
more likely to groom each other than females. So in a two year study we
did we had 2,000 grooming events between males and– I’ll just wait for the
horn bells to pass– and 32 between females. So a huge difference. We also know that grooming
just facilitates a lot of other cooperative behavior. So this is a way of
saying, I like you. I’m not going to beat you up. Let’s have fun together. We also can do things about
looking at the initiation of these kinds of events. This is Stout. This is Kakama. And you’ll see they
scratch each other. They’re scratching. We think that may
be a signal to, hey, I want someone to groom me. Look how itchy I am. And then they start grooming. This is a particularly
fascinating behavior where, when they
groom, sometimes they just hold their hands
up above their head. We have no idea why. We’ve done– we’ve
done studies on this. We still don’t know
why they’re doing this. And not every chimpanzee
group does it. So this is something that
we think is really cultural. Some groups hold
hands, others don’t. Lots of unanswered questions
in chimpanzee communication. Is this a signal? It’s a debate. Why do this kind of grooming? Chimpanzees, especially males,
often have communication just by trying to be big and strong. So when we watch
male chimpanzees we’ll sometimes see them like
lift all of their hair up. It’s called piloerection. Of course, we think
this is to make them bigger than they actually are. We have this vestigial response
when we get goose bumps. It’s kind of just a stimulus
where we’re kind of stimulated. And that’s what’s
happening here. Now chimpanzee males are
especially interested in kind of being bigger than they are. And rank and hierarchy
matter a lot for males. So this is Kakama, the same
chimp that you see here. He’s going to walk by
a lower ranking chimp. And you’ll kind of see
his swagger, his bravado. And he really intimidates
the little chimp. [CHIMPS HOO-ING] And that vocalization,
called a pant-grunt, is a, I know I’m not as
dominant as you. Please don’t beat me up. OK. And I think you can
hopefully see that swagger that Kakama has. Now when chimpanzee males–
when you’re watching them, you’ll often see
them displaying. So it’s not just that
kind of everyday swagger, but a lot of times
during the day they’ll actually puff
up all of their hair, and just run around
and throw things. And just act a little crazy,
but act strong and powerful. [CHIMP CALLING] So that was Mikoku. Working in the jungle
is a little crazy so there’s a lot of
foliage in the way. [CHIMP CALLING] There are four
chimps displaying. And this is something
we see on a daily basis. Males making themselves
look big, and scary, and intimidating. Now this is a product
of sexual selection. But unlike the birds
of paradise where we see the evolution of
ornaments, what we’re seeing here is more
of the evolution of armaments, things that are
good for fighting abilities. And what happens
in chimpanzees is that males are competing
with each other to have access to females. So we see things like males
are bigger in body size. They have bigger canine teeth. They have bigger
bodies, more muscles. But interestingly, we also
see that they’re more social. Just like we saw those
two males grooming. And that’s because what happens
with male chimpanzees is that a lot of times the
way they get to the top is through their friends. So an alpha male often gets
to the top by having friends. So that kind of sociality is
very important for those males. Females are much more kind
of concerned with raising their offspring. Once a female chimp becomes
an adult and has a baby she nurses them till
they’re four or five, and then has another one. And over her lifetime she
probably has about five or six. And so the daily lives
of female adult chimps are very much about mothering. And I will say
just to highlight, I don’t have anything
about chimp penises, but they are actually
extraordinary, as well. The fun fact to take
home with you today is that male chimpanzees not
only compete with their bodies, but they compete
with their sperm. So male chimpanzee–
a female chimpanzee will mate with every male in the
community when she’s ovulating. And so there’s– people’s faces. OK. So chimpanzee sperm has evolved
to compete with each other, to be very fast. And they have to
make a lot of sperm. And so chimpanzee testicles– chimpanzee testicles are giant. They hang down to their knees. And the size of one
chimpanzee testicle is the same size as their brain. And they have two testicles. OK? So– – Zarin, you’re
almost out of time. – Yes. I know. OK. So just– I just want to kind
of echo something that Richard said, which is, when
we see females– I want to just focus on
females for maybe one minute. When we see females
they often do approach males for copulation. I’ll show a quick video. And here you’re going to see
Tongo approaching Kakama. Kakama has his erection. And this is Tongo. This is Kakama. And you’ll see her
approach him eventually. He’s scratching. He’s drawing
attention to himself. This is why we can get so much
more intimate detail on chimps than human. And she goes up to him. They copulate. The average copulation
is seven seconds. So don’t be too impressed. And I think one of
the questions that we can discuss with Richard is
this idea of female choice. I think a lot of you might think
that Tongo is choosing Kakama as a mate, when actually,
a lot of our studies show that what’s happening
here is a form of conditioning coercion. And male chimps are so
aggressive to females on a daily basis
that when it is time to copulate the females
approach the males more out of a fear of retaliation
than as a choice. And so in fact, what
we see are probably aspects of male choice. Males have preferences for
older females, mate with them, aggress against them more often. And as I’m getting
off, I do want to just say we tend to
focus on male communication, but female communication
is interesting. It’s more subtle. And as I’m walking away
I’ll show you a little video of a mom and her baby. And this is mom who’s
trying to sleep, and a baby who’s
sitting on her face. [LAUGHTER] So thank you very much. I’m sorry I went over. [APPLAUSE] – Thank you very
much, both of you. So to launch in, I wanted
to start just quickly, Richard, with this idea
of aesthetic remodeling. And if you could just quickly
remind us what that idea is, and how you think it might
apply to human evolution. – All right. So aesthetics
remodeling is a way in which female
choice can evolve to change maleness in
a way that furthers their freedom of choice. And so it means
that preferences are correlate with something else. They’re correlated
with actually more females being able in the
future to have more choices. And in the book I
have the opportunity to apply both arbitrary
female choice– or Beauty Happens, and sexual autonomy
evolution to human beings. And I have proposed– it’s probably about as grandiose
a theory as you can get. Though, it’s a bit embarrassing. But in fact, I propose that
one of the biggest ways to overcome the kind of
environment of coercion that we see in chimpanzees
is through female choice. Taking coercion
apart bit by bit. So I propose that the reduction
of canine weapons in males– male humans– or male primates
have weapons in their faces that human males lack. And it’s an important question
to ask, how do you get males to give up their weapons? That’s actually a quite potent
question in America today. But the answer an evolution
sense is you make them unsexy. And I think that’s
been one of the roles– and also the reduction
of size, that morphism. We’re a lot bigger
than chimpanzees. That would mean that we
predicted to get very much different in body size. And yet, we’re
much more similar. It turns out the famously
peaceful Bonobos are actually a lot more different in
body size than humans are. – Hmm. Interesting. – And I think one of
the other aspects, instead of just thinking
about canines, is that– I don’t know if you noticed. But Tongo, when
she was ovulating, chimpanzees have this
very visual pink signal, which is a swelling of
the labia tissue, which is about 10 days around ovulation. It’s, hey, I’m ovulating. I’m ready to mate. And obviously, one of
the things that humans have lost in the
course of our evolution is this sexual swelling. I’m very happy about that. But it does mean
that what humans have is concealed ovulation. And I think that has
allowed human females to change the interactions that
they have with males in ways that chimpanzee
females can’t do. – Hmm. Zarin. I wanted to ask you about– you talked a lot
about the binaries between male and female
chimps, but what about– one of the themes of this
conference is the continuum. And one thing you
mentioned to me is that there are different
ways of being an alpha chimp. It’s not always about
being the tough guy. Right? And could you talk a little
bit about the continuum. Kind of– – Yeah. I mean, I think one of the
things that’s lacking sometimes when we talk about
animals is the variation that we see within a sex. And so, for being
an alpha male we have examples from my study
site where we have kind of Kakama, who is just a jerk. Just a despotic male. All– you could tell all
the other chimps just were like– he’d show up
and they’d be like, oh. Because he was going
to beat everyone up. And in contrast,
we had Big Brown, who is actually still alive. And he was the politician. Kissing– he still
plays with babies. And he really had success by
being friendly with everyone, conceding matings when he needed
to, building relationships. And I would say they were, in
many ways, equally successful. So, yeah. I think you can have
different forms. – That’s fascinating. It looks like it’s
running down to zero, which means we’re about to
go to audience questions. Right? OK. So we’d like now open it up
to members of the audience. There should be a mic
appearing pretty soon. And then please do lineup. And make sure your
question is a question. And we’ll try and
honor everybody who comes to the microphone. – So my question is, if the
female birds are selecting for the beautiful
male birds, how come in the history of fashion– although in world
historical terms, human males have
been at least as fashionable and colorful
as females, if not more so. For the past few 250 years
it switched completely to the other side. Can you offer me a
scientist’s hypotheses about why it’s the
females of Homo sapiens that now are the colorful ones. – I Would say that
the scientific answer is patriarchy. And actually, one of the
conclusions of the book is that patriarchy is the
appropriate scientific way to describe that situation. I will also talk just a
little bit about birds. I focused on female
choice in birds because those are the
aesthetically most extreme birds on the planet. And that happens to be where I
started with my own fieldwork. However, there is a huge
variety of that in birds. Lots of mutual mate choice. You think about
puffins and penguins where males and females
have identical ornaments, and identical preferences,
and long-term pair bonds. And then there is
polyandra species, where a female will
acquire a territory and defend it with weapons
and large body size. And attract multiple females. She lays the eggs. The males take care of the nests
and eggs entirely on their own. So there’s lots of other kinds
of variation within birds as well. And I would also say that with
human fashion, whether it’s male or female, I
think we possibly can also interpret that as
a way of displaying status. Right? So not just beauty,
but also our status. – Thank you. Lucia? – So my name’s Lucia Jacobs. And I would like to tie
this morning’s talks to these talks, which
is the role of olfaction and the sense of smell. In fact, in bird– there’s new studies
showing birds are actually using odor to choose
mates and zebra finches. And I think it’s– of course, and mate choice– odor and mate choice
is kind of universal in insects and invertebrates. And what’s interesting is, tying
into your Bower bird example is that in mice there’s this
complex signal that females are using to decide whether
or not to approach a male. And there’s a long
distance olfactory signal, and then there’s a
contact olfactory signal. And the long
distance ones is very similar to what you
said about the Bower, where the female can make a
decision from a safe distance. And I think the whole question
of male aggression, which we know is important
for many animals, females always
have that problem. Like, who is it? How good is he? And– but– and is
he going to hurt me? And I think that there might
be a very interesting parallel in mice that I would like to
hear what you think about it. – Well, olfaction is
probably the least studied sensory modality in birds. The idea is that they don’t
have a very good sense of smell. But there are lots of
exceptions that are being known. For example, parakeet
auklets, which live in the Aleutian Islands,
smell exactly like tangerine. It’s not actually
just like tangerine. It is tangerine. It’s the exact molecule
that makes tangerine smell like tangerines. And they– but however, they
rub each other all over with it. They call it the riff– the sniff rough, where
they’re rubbing each other with tangerine oil. And so they’re using at
a very intimate distance. But we don’t really know much
about pheromones or olfactory communication in
the lives of birds. – Thank you. Let’s move on to
the next question. – Thank you very much. – Hi. I have a question for Zarin
about the transferring of cultures between
the chimpanzees. So I’m wondering if you
can speak a little bit more about how those
cultures are observed, and then how you observe
them being transferred. So is their a dominant male in
one group whose decides, well, we’re going to use the Scottish
call, or the Dutch call. Or is it the
transference exactly like they were already
there, and the Dutch– – It’s probably a combination
of a lot of things. I would say in many ways
the transfer of culture among chimpanzee communities is
going to be driven by females. Because females
are the ones that transfer to new
communities at adolescence. So they’re the ones
that bring things from the culture they’re
born into into a new place. And one of the
interesting things we saw about that
hand clasp study is that they actually clasp
hands in different ways. So they can go, you
know, palm to palm– all sorts of different ways. And the way they do it is
the way their mother did it. – Hm. – Wow. – So a lot of times there is
a lot of female influence, I think, in chimpanzee culture. But I think you’re right though
that with some vocalizations we see dominant individuals
kind of being the ones who everyone else copies. – Thank you. We have two minutes,
and two questions. So let’s– – Hi. Professor Machanda, I
was curious first of all whether female chimpanzees
are exempted from sex when they’re raising their children? First of all. – No. – And then secondly, I was
curious about the snake example that you gave, and whether
it was entirely binary, the results. Because I would’ve assumed
that you would actually see greater evidence
of evidenciality– or intentionality if
one or two of the chimps had actually indicated
to strangers, as opposed to just one or the other. If you saw kind of a range of– – Sure. There always a range. I mean, so the result– you know, there were
certainly chimps that would give calls to– none of them were strangers. It was either, are they
related or good friends? So there were certainly
chimps that would call to people– to people. To chimps that
weren’t good friends. But the majority– it
was kind of a majority. We did not see a difference
between males and females. So that’s also kind
of interesting. And just about your sex
comment, female chimps don’t generally have swelling
while they’re lactating. Sometimes they do. And female chimps when
they have a little infant tend to separate
themselves from the group. So we don’t really see
that many interactions. So they in many ways protect
themselves and their offspring from some of that. – Thank you. Can we do one last
quick question? Oh. Oh, great. Well, we’re done. Well, thank you very much. [APPLAUSE]

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