WEBVTT

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Prof: I want to start
today with some stories from the

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newspapers: to set a tone.

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It was over the last few years.

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Tehran: one afternoon Fatima
Eskandari opened the front metal

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gate of the shelter she runs for
runaway girls in central Tehran

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and was confronted with two men,
armed with knives and rifles.

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"Who are you?"

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She asked.

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"We are the uncles of a
girl named Ranach,

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we are told that you are
keeping Ranach,"

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and indeed that was true.

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Ranach was 16 years old,
and she was inside,

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recovering from the bruises
that she suffered at the hands

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of these same uncles.

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She had run away from home to
escape them.

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The uncles had driven from
Sanandaj in the northwest corner

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of Iran, hundreds of miles away;
they demanded to see their

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niece.

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The uncle said she had shamed
the family by leaving home a few

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days before.

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They had come to behead her.

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They were very open about this.

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There was no secret.

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Staten Island,
New York: A 17-year-old girl

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worked as a cashier in a
convenience store.

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The store owner said that the
girl was stealing from the

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register and he was going to
fire her.

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The girl went to her father and
said that the store owner had

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groped her.

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The father flew into a rage,
grabbed a baseball bat and a

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gun, went down to the store,
and killed two people.

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Islamabad, Pakistan Zahida
Perveen, 21-years-old was

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pregnant in 1998 when her
husband, Mehmood Iqbal,

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bound her hands and feet with a
rope.

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First he shoved a rod in one of
her eyes, blinding her,

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then cut off her nose and ears.

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He SUSPECTED her of seeing
another man.

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Tuscaloosa, Alabama:
Felicia Scott already had two

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sons, but she had an obsessive
desire to have another baby.

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She convinced her boyfriend to
help her get one,

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so they went out,
shot a pregnant woman,

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and cut the full term fetus
from her womb.

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Saudi Arabia:
New York Times--A young

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woman was raped by seven men.

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She pressed charges.

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The Saudi Court sentenced HER
to 200 lashes--200 lashes is

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almost a lethal dose.

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Dominican Republic:
Crucita Medina is 18,

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she's been married for a year
in which her husband Jose beat

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her constantly.

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She had the courage to separate
from him but she met with Jose

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after their separation when he
asked her to talk.

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He took her to a desolate
street on his motorcycle and

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they had an argument.

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He grabbed a container he had
filled with - what they call the

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devil's acid,
- a mixture of gasoline,

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hydrochloric acid,
car battery acid,

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urine and other chemicals.

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He threw it at Crucida.

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The liquid disfigured her
permanently.

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It burned her face,
her arms, the right side of her

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chest, and a portion of her
legs.

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She is still trying to bring
her ex-husband to justice.

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Gosarigaon, Bangladesh:
I'm almost done with this.

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The village elders met under a
lychee tree to put a value on a

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Payara Bigum's grotesquely
ruined face.

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A young man had become obsessed
with her;

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she was married and he was
turned away.

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He took his revenge with
sulfuric acid to erase the

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beauty that had once enchanted
him and to empty her life of

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happiness.

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Her cheeks melted,
her right eye was blinded and

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hollowed to a crater.

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The husband had to bribe the
prosecutors before they would

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even take up the case.

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Eventually the perpetrator's
family had to pay a fee of

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$3,000.

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In one year,
the year I have statistics for,

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1999, there are 174 acid
attacks in Bangladesh and those

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are the ones that were
officially reported.

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Of course, probably the vast
majority of these never get

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reported.

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The article mentioned a
13-year-old girl who was

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attacked as she slept.

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Some victims die,
some are forced to marry their

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attacker, another was forbidden
to come home until she allowed

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her husband to take a second
wife.

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Well these stories are
obviously at the extreme of

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human behavior,
but the purpose of giving you

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all that is to explain that
human sexual behavior has

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extremely deep roots,
very emotional,

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and very hard to change or
manipulate.

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Male/female relationships are
very difficult for humans to

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cope with.

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I think it shouldn't
particularly surprise you that

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human sexuality is not
particularly driven by rational

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calculation.

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The few stories that I've
pulled out of the newspapers are

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just the tip,
clearly just the tip,

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of an iceberg,
of a very widespread

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phenomenon.

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In the long course of human
history across cultures you see

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are the--
I gave you everything from

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Brooklyn to Bangladesh--
these very similar sorts of

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things happen.

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Females, through the long
course of history and in most

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cultures, where most humans have
lived, females are treated very

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badly.

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There's a huge amount of
battering.

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Battering is the prime human
version of violence,

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and females are so
discriminated against that

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statistics indicate that there's
something now,

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right now, something like a
hundred million missing females.

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That these females are either
aborted before they're born,

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killed by infanticide,
pretty much as soon as they're

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born,
or neglected so that they don't

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get the food,
or they don't get the medical

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care that their brothers get.

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There's a dearth of something
like a hundred million women in

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the world today.

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These are extreme incidents but
it's an extremely common thing.

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One of the purposes of this
course is to try to get you to

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understand what is causing all
of this.

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From a biological point of view
this abuse of females is

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extremely weird.

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Males, as you know,
can only reproduce via a female

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and so--
and evolution is--the name of

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the game is reproducing,
so almost all species--what

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kind of female do the males
want?

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They want the healthiest,
most well protected,

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the best fed female,
and you'll see some examples of

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the extremes to which males will
go to provide this so that that

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female can produce offspring for
that male and carry on the

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evolution game.

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In humans, we find that it's
very general that females are

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treated atrociously,
and it just doesn't make sense

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that human males should keep
many of their females hungry,

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sick, and abused.

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In childbirth,
if a woman does give birth to a

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child they can often be
underweight, sickly,

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and it's because the mother is
not in great health.

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This is all a biological
disaster the way human males

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treat human females and we don't
know--

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I mean we do--we have some
idea, why humans do that and the

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first part of the course we'll
talk something about that.

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That's on the individual level,
and evolution works on an

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individual level,
but if you think on a species

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level,
missing a hundred million of

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your breeders,
that does not sound like a

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great tactic for survival of the
species.

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I spent some time,
when I started getting

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interested in this whole topic,
reading the anthropological

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literature,
the sociological literature,

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the feminist literature,
and basically I thought all

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those explanations were a crock.

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I don't think they came close
to an answer.

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In my own studies I had to go
back to the very beginning and

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understand what sex was really
all about.

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I'm going to tell you a few
important things about sex and

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reproduction.

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The first one is that
reproduction turns out to be

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very difficult.

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One day I was sitting over in
our botanical garden under a

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beautiful big oak--
huge oak tree that they have,

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and the ground was just covered
with acorns under this tree,

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and I asked one of the forestry
people,

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because that's the kind of
things that they know,

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I asked them how many acorns
has this tree produced?

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They said, well the wind--this
spread is so much and this line,

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and you know it's so deep,
and they came up with probably

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750,000 acorns a year.

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I thought wow,
so I checked the literature and

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found that people that collect
these notes for commercial

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purposes,
a good oak tree can produce

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five hundred pounds of acorns a
year,

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and many sources say that an
oak tree produces millions of

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acorns in its lifetime.

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Wow, a lot of reproduction
right, there's got to be sex

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before it.

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Then I asked myself,
how many of these million

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acorns survive to make a tree
like their parents?

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What's the answer?

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Basic biology question,
you might know it.

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Well, what if each tree on
average,

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taking an average of tree made
two acorns,

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how many acorns would there
be--how many oak trees would

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there be in the--
made two acorns that made

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trees--how many oak trees would
there be in the next generation?

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Twice as many as now;
what if they only did--and so

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that can't continue because then
the Earth would immediately fill

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up with oak trees and we'd be
this deep in acorns.

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Similarly, if the trees
produced less on average,

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less than one,
what will happen to the oak

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species?

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It goes extinct.

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So, over the long time,
on average, each oak tree has

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only one acorn that grows up to
be an acorn producing tree

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itself.

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That's an amazing fact--it puts
out millions of acorns and only

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one survives.

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Of course this is true not only
for trees but fish,

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which spew out--fish
females--huge numbers,

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hundreds, tens of thousands,
hundreds of thousands of eggs;

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or males of many,
many species that spew out

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billions of sperms that,
in a sexual species,

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the way mammals are,
two parents on average,

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two children.

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If two parents for a species
average more than two children,

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the world fills up with
squirrels or whatever animal

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we're talking about.

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If they have less than two over
a long run, they've gone

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extinct.

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Most species,
in fact, in the history have

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gone extinct.

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The average of current species
has got to be 1:1 or 2:2

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depending on how you count,
but for most species it's less

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than that because most species
have gone extinct.

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So, the answer is,
it is brutally difficult to

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reproduce.

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If any given individual in a
species produces a lot of

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children,
more than one or two,

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depending on how you're
counting,

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then that means that some other
individuals are having less,

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again, unless the species are
humans,

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which are about the only
species that are increasing

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continuously over the long time.

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As an example,
they now, by this genetic

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testing have tested:
how many descendants does

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Genghis Khan have?

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The answer is 16 million
descendants, this one guy,

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so that's an awful lot.

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Guess how he did it?

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By killing a lot of men and
raping their women.

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So he has that many descendants
because an awful lot of men,

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all the men he killed,
don't have any descendants.

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That's just Genghis Khan,
the Mongol Horde had a lot of

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males and I think they spread
their seeds quite widely,

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and a lot of males and
conquered people just didn't

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survive.

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Of course every army in the
world has done--

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essentially all--have done a
huge amount of raping,

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and it's a wonderful instrument
of gene flow in the human

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population.

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Because reproduction is
actually so difficult,

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species have evolved all kinds
of fantastic mechanisms for

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trying to be successful at
reproduction,

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so that's Point One.

12:56.389 --> 12:59.769
Point Two is that sex is not
fair.

12:59.769 --> 13:02.459
It's not only difficult but
it's not fair.

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Sex goes way back in evolution
and even bacteria do it.

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This is--the biologists here
are laughing.

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This is the bacteria that are
in your colon and they have sex

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in this manner,
and so right now billions of

13:20.398 --> 13:24.568
sexual acts are taking place in
your unspeakable parts,

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and this is the way they do it.

13:27.750 --> 13:34.740
Now, in something like this,
actually the exchange of DNA

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can be either way and this is--
even though the hairy guy on

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the left is producing that long
pilus,

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as it's called,
there's more or less equality

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of sexuality here.

13:49.298 --> 13:52.048
But when it comes to higher
organisms you get quite a

13:52.048 --> 13:52.998
different story.

13:53.000 --> 13:54.950
You all know the story the
chicken and the egg.

13:54.950 --> 13:58.020
Well the way I tell it is the
poor chicken,

13:58.019 --> 14:01.909
the chicken has to build this
big egg,

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it has to eat like crazy,
put all that protein and fat

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into the egg which are--
if you're not fed in the

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barnyard--which are hard to come
by,

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and then once the chicken is
hatched guess who sits--

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once the egg comes--out guess
who sits on the egg?

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The female.

14:15.799 --> 14:17.499
Guess who protects the young?

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The female.

14:19.090 --> 14:20.340
So that's chickens.

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You can go all the way up to
humans;

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females have to spend nine
months pregnant and then in most

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societies and most times females
are the ones that have the

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burden of responsibility for the
children.

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Meanwhile in all this,
males just produce a little

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speck of protoplasm,
insert it into the female,

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say, 'bye-bye,
I've had my quickie and I'm

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off,' and--
not in all species--but in most

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species,
the male has a very minimal

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part in reproduction and the
female has this huge burden.

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Now why does that come about?

14:57.220 --> 15:00.060
You'd think evolution would
require that females just

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wouldn't play this game in
evolution and they would require

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a more equal distribution of the
labor.

15:05.580 --> 15:11.110
Well it turns out it
is--starts--as a division of

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labor.

15:12.028 --> 15:15.048
The first animals to evolve,
first of anything,

15:15.048 --> 15:17.898
were probably--were almost
certainly in the sea,

15:17.899 --> 15:22.589
and stuck down on the bottom or
floating around and so they

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couldn't move.

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How do you mate if you can't
get up and find your mate?

15:27.658 --> 15:30.648
Well you just spew out your
sperms into the ocean;

15:30.649 --> 15:33.949
you spew out your eggs into the
ocean, and you hope that they

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meet.

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Not a very efficient mechanism,
but at that stage,

15:38.437 --> 15:43.617
the male has produced zillions
of sperms, and the female has to

15:43.624 --> 15:46.054
produce zillions of eggs.

15:46.048 --> 15:49.628
If you're an animal and you
have to produce so many of

15:49.628 --> 15:53.608
anything, gametes in this case,
each one is going to be very

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tiny.

15:54.220 --> 15:58.130
Two tiny things meet and fuse;
you've still got a tiny thing.

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The odds of survival of a tiny
thing are not very great.

16:01.350 --> 16:05.650
Evolution doesn't like that
idea of the male and the female

16:05.650 --> 16:09.730
both spewing out lots and lots
of these tiny gametes.

16:09.730 --> 16:14.680
What happens eventually is that
the two sexes separate,

16:14.678 --> 16:17.368
that the female's job is to
make a big enough egg,

16:17.370 --> 16:20.210
with enough nutrients in it,
so that the organism can

16:20.208 --> 16:23.348
survive,
and the male's job is to go

16:23.349 --> 16:24.759
find that egg.

16:24.759 --> 16:28.489
What do males have--what have
the sperms evolved?

16:28.490 --> 16:33.570
Tails, to take them swimming.

16:33.570 --> 16:37.730
They find--their job is to find
the egg, so there still has to

16:37.726 --> 16:41.466
be lots of those and they have
to expend a lot of energy

16:41.474 --> 16:42.364
swimming.

16:42.360 --> 16:47.160
It's still an equal amount of
investment.

16:47.158 --> 16:50.978
Then the whole animal--once
evolution proceeds,

16:50.980 --> 16:54.260
the whole animal can now get up
and walk over and find a female,

16:54.259 --> 16:57.569
or vice versa,
and now they can copulate or do

16:57.573 --> 17:01.113
some sort of insemination very
close together.

17:01.110 --> 17:05.640
This now does not require
zillions and zillions of sperms.

17:05.640 --> 17:08.760
If you're--if the eggs they
already laid,

17:08.759 --> 17:12.049
like a fish in a nest,
the male just lays the sperms

17:12.051 --> 17:15.871
right on top of the eggs,
and you need some surplus over

17:15.871 --> 17:19.961
the number of eggs but nothing
to compensate for the amount of

17:19.961 --> 17:22.511
energy she's putting into her
eggs.

17:22.509 --> 17:24.359
You start getting an inequality.

17:24.358 --> 17:32.798
As soon as animals can find
each other and mate in a more

17:32.803 --> 17:39.593
spatially enclosed way,
then you start getting

17:39.587 --> 17:41.847
inequality.

17:41.848 --> 17:44.158
Evolution goes down that path
because it's turned out to be a

17:44.161 --> 17:45.991
very,
very effective path,

17:45.992 --> 17:49.882
and what you get is that
females make a few eggs,

17:49.880 --> 17:53.940
her eggs are very expensive,
they are expensive and rare.

17:53.940 --> 17:57.020
Males still make many,
many sperms;

17:57.019 --> 18:01.379
his sperms are plentiful and
cheap.

18:01.380 --> 18:05.320
This is what we call a sexual
dimorphism that males and

18:05.318 --> 18:09.038
females are taking different
evolutionary routes.

18:09.038 --> 18:13.628
Once they take different
evolutionary routes then

18:13.625 --> 18:18.495
different reproductive
strategies come into play for

18:18.498 --> 18:20.598
males and females.

18:20.598 --> 18:23.228
A male, through the first
billion years of evolution has

18:23.230 --> 18:26.140
been producing a lot of sperm,
and now all of sudden he

18:26.141 --> 18:29.631
figures out how to swim over to
a female and he doesn't need all

18:29.634 --> 18:32.724
those sperms but he's still--
evolution is conservative,

18:32.715 --> 18:34.975
it's still--
he's still producing all these

18:34.980 --> 18:35.410
sperms.

18:35.410 --> 18:39.230
What is evolution going to do
with all those sperms?

18:39.230 --> 18:42.690
One thing they can do is--he
can evolve backwards and just

18:42.693 --> 18:43.853
make fewer sperm.

18:43.848 --> 18:45.798
That would save him energy,
it would be good for him a

18:45.803 --> 18:48.273
little bit,
but it wouldn't really get him

18:48.267 --> 18:51.707
an awful lot more children,
which is the name of the

18:51.714 --> 18:52.764
evolution game.

18:52.759 --> 18:55.079
Now what he can do with those
excess sperms,

18:55.082 --> 18:56.272
find another female.

18:56.269 --> 19:00.789
That his limit--there stops
being a limit on the number of

19:00.789 --> 19:05.629
females that he can inseminate
he spreads his sperm to as many

19:05.627 --> 19:07.767
females as he can find.

19:07.769 --> 19:12.469
This dimorphism that sperm are
cheap and plentiful,

19:12.470 --> 19:15.810
while eggs are expensive and
rare, leads to different

19:15.814 --> 19:19.034
strategies of reproduction in
males and females.

19:19.028 --> 19:21.268
It also sets up some odd
situations where,

19:21.273 --> 19:23.303
for instance,
males are expendable.

19:23.298 --> 19:27.838
If one male can fertilize a lot
of females, females don't need a

19:27.843 --> 19:29.433
lot of males around.

19:29.430 --> 19:32.380
For instance,
there's a certain female wasp

19:32.380 --> 19:34.980
that lays its egg in a
caterpillar.

19:34.980 --> 19:37.730
Wasps are one of the major
predators of caterpillars;

19:37.730 --> 19:40.920
they lay the egg in,
the egg hatches and starts

19:40.917 --> 19:42.857
eating up the caterpillar.

19:42.858 --> 19:47.248
All of the eggs that are laid
in a single caterpillar compete

19:47.253 --> 19:51.433
with each other for the food,
that is, the caterpillar.

19:51.430 --> 19:55.730
What happens is evolution has
arranged that the females hatch

19:55.733 --> 19:59.683
first and they eat up all their
brothers except one,

19:59.680 --> 20:04.230
and then that one male can
fertilize all his sisters and

20:04.229 --> 20:05.469
things go on.

20:05.470 --> 20:08.400
The males are expendable in
that case,

20:08.400 --> 20:11.030
and if the females just ignored
them and let them live,

20:11.028 --> 20:14.178
the males would be competing
with the females for food,

20:14.180 --> 20:15.840
the females would grow less big
and healthy,

20:15.838 --> 20:22.378
and they would have less eggs
and evolution doesn't like that

20:22.378 --> 20:24.448
kind of a system.

20:24.450 --> 20:27.390
We'll--all of these things,
if you think,

20:27.394 --> 20:31.594
it's not very difficult to find
human examples of this.

20:31.588 --> 20:35.448
Who goes off to war and gets
killed?

20:35.450 --> 20:38.900
Males, and very often you don't
very any reproductive--any

20:38.900 --> 20:41.870
change in rate;
the females manages to get

20:41.868 --> 20:43.658
inseminated, in humans.

20:43.660 --> 20:49.600
In lots and lots of species,
the number of males is really

20:49.603 --> 20:55.863
not a critical factor in the
amount of reproduction that goes

20:55.859 --> 20:56.589
on.

20:56.588 --> 20:59.788
Males can inseminate many
females,

20:59.788 --> 21:03.528
but females want to worry about
the survival of each egg,

21:03.528 --> 21:07.208
and similarly again,
this is pretty obvious in

21:07.208 --> 21:10.338
humans that a female,
if she gets pregnant,

21:10.339 --> 21:12.959
is going to be spending nine
months pregnant,

21:12.960 --> 21:15.810
and then breast feeds and won't
get pregnant again,

21:15.808 --> 21:18.718
so it's at least a year and
probably at least a year and a

21:18.719 --> 21:21.219
half before that female can get
pregnant again.

21:21.220 --> 21:25.540
We almost always bear only one
child with an occasional twin or

21:25.542 --> 21:28.042
so forth,
so a very low rate of

21:28.038 --> 21:32.308
reproduction where a male
doesn't have any such kind of

21:32.307 --> 21:33.017
limit.

21:33.019 --> 21:36.859
This does not mean that females
are monogamous,

21:36.857 --> 21:41.777
because there are many other
reasons why a female might want

21:41.779 --> 21:43.699
to have many mates.

21:43.700 --> 21:45.890
First of all,
we'll see, she might want to

21:45.890 --> 21:47.600
get resources from many males.

21:47.598 --> 21:51.838
You'll see she sometimes will
not mate with a male unless that

21:51.836 --> 21:53.986
male gives her some resource.

21:53.990 --> 21:58.290
She might want to mate with a
variety of males because she

21:58.289 --> 22:01.459
can't tell which one has the
best genes.

22:01.460 --> 22:04.640
She many want to mate with many
males if her environment is

22:04.637 --> 22:06.387
unpredictable,
and even if she can tell

22:06.391 --> 22:08.201
something about his genes,
she doesn't know what the

22:08.202 --> 22:09.982
environment for her children are
going to be like,

22:09.980 --> 22:12.630
so she wants to shake up the
deck and try--

22:12.630 --> 22:17.580
have a variety of children with
a variety of different genes.

22:17.578 --> 22:20.318
She might want each male to
think that he's the father of

22:20.318 --> 22:22.858
the children so that he
doesn't--that he protects and

22:22.862 --> 22:24.332
doesn't kill the children.

22:24.329 --> 22:26.329
There are species who do that.

22:26.328 --> 22:29.918
There's something called sperm
competition where she may want

22:29.917 --> 22:33.327
to have a whole variety of
different sperms from different

22:33.327 --> 22:36.017
males in her and then the sperms
compete.

22:36.019 --> 22:40.309
Even though this sort of comic
book presentation says,

22:40.308 --> 22:43.858
all males are promiscuous and
males want to go around and have

22:43.858 --> 22:46.628
a lot of sex,
and the females want one,

22:46.625 --> 22:50.955
there's many species with many
reasons why a female may also

22:50.960 --> 22:52.870
want to be promiscuous.

22:52.868 --> 22:56.718
It used to be believed that
many species were in fact

22:56.718 --> 22:57.678
monogamous.

22:57.680 --> 23:01.620
Birds are a very good example:
what you observe is that a male

23:01.617 --> 23:05.167
and a female meet at the
beginning of mating season,

23:05.170 --> 23:07.320
they stay together all mating
season,

23:07.318 --> 23:10.098
she maybe sits on the eggs,
and he brings worms or some

23:10.096 --> 23:12.306
combination thereof,
and people thought,

23:12.309 --> 23:13.449
'Well this is great.

23:13.450 --> 23:17.420
This is monogamy and what
wonderful animals they are.'

23:17.420 --> 23:22.660
Now we can do DNA testing and
it isn't so--apparently--so they

23:22.662 --> 23:27.732
call that now social monogamy
and distinguish it from sexual

23:27.731 --> 23:28.851
monogamy.

23:28.848 --> 23:33.038
While social monogamy is as
we've always believed it to be,

23:33.039 --> 23:35.929
sexual monogamy is almost
nonexistent.

23:35.930 --> 23:40.360
In species--when they
measured--it turns out 10% to

23:40.355 --> 23:45.575
70% of the progeny had been
sired by someone other than what

23:45.578 --> 23:48.588
they called the resident male.

23:48.588 --> 23:52.588
One article I read claimed that
there's only one species where

23:52.594 --> 23:56.734
it is known for sure that they
are 100% sexually monogamous,

23:56.730 --> 23:59.850
and in that case the male and
female physically fuse together,

23:59.849 --> 24:05.359
so neither can go anywhere.

24:05.358 --> 24:14.458
Males have the job of finding
and gaining access to females.

24:14.460 --> 24:18.050
They have basically two
strategies.

24:18.048 --> 24:21.368
One is to let their sperms
compete.

24:21.368 --> 24:25.328
In that case they make just
more and better sperm,

24:25.328 --> 24:30.398
and the sexual system in a
species like that will be

24:30.398 --> 24:33.618
promiscuous,
that the females will mate with

24:33.615 --> 24:36.905
many males,
they'll have a lot of semen in

24:36.913 --> 24:41.323
their vagina,
or spermatheca or sac for this,

24:41.315 --> 24:46.335
and then the sperms will
compete with each other.

24:46.338 --> 24:49.148
Some scientists believe that in
humans also,

24:49.150 --> 24:52.640
we have a variety of sperm,
including killer sperm,

24:52.640 --> 24:56.870
and other kinds of sperm that
go in and facilitate this.

24:56.868 --> 24:59.938
These killer sperm are supposed
to kill sperm that have a

24:59.938 --> 25:02.458
different genotype,
and it's very controversial

25:02.458 --> 25:04.538
about whether this is true or
not.

25:04.538 --> 25:08.358
The data starts when you look
at sperm they have--human

25:08.358 --> 25:11.258
sperm--they have very different
shapes.

25:11.259 --> 25:14.149
And one version is,
well, all these other shapes

25:14.145 --> 25:16.225
are just damaged,
they're just bad,

25:16.233 --> 25:19.983
they're not effective and
there's some evidence for that.

25:19.980 --> 25:24.140
The other story is that,
no, these are doing different

25:24.144 --> 25:27.764
jobs then fertilization,
and it's a hot area of

25:27.758 --> 25:28.778
research.

25:28.778 --> 25:32.278
That's strategy Number One,
to engage in sperm competition,

25:32.278 --> 25:38.208
and you'll see if we get time
that in our related species,

25:38.210 --> 25:42.180
Bonobos, chimps,
our group of species generally

25:42.175 --> 25:44.845
engages in sperm competition.

25:44.848 --> 25:48.358
What you get is very large
testes, so you can determine

25:48.361 --> 25:52.391
this by taking the measure--the
weight of testes--as a fraction

25:52.394 --> 25:54.024
of total body weight.

25:54.019 --> 25:57.229
If it's very large,
you know there's sperm

25:57.229 --> 25:59.029
competition going on.

25:59.029 --> 26:02.699
The other strategy of course is
males can compete with each

26:02.702 --> 26:04.922
other for control of the
females.

26:04.920 --> 26:09.080
This happens of course in
motile--motile animals--

26:09.078 --> 26:12.248
sperm competition is the
original thing where you spew

26:12.253 --> 26:15.253
zillions of sperms and then the
best ones find--

26:15.250 --> 26:17.770
are the ones that find the
females,

26:17.769 --> 26:21.049
but once they're motile,
the males can come into contact

26:21.054 --> 26:24.584
with each other and they can
fight in some way and control a

26:24.577 --> 26:26.247
territory, for instance.

26:26.250 --> 26:30.410
Coral reef fish control
territories in the coral and the

26:30.413 --> 26:34.203
females cruise around,
find a male who's got a good

26:34.198 --> 26:37.528
territory, then come and mate
with them.

26:37.529 --> 26:41.549
Well generally the males will
actually fight with each other

26:41.549 --> 26:45.499
for dominance and then use that
dominance to gain access to

26:45.501 --> 26:46.321
females.

26:46.318 --> 26:48.928
How does this--what are some
examples of how this all works

26:48.930 --> 26:49.200
out?

26:49.200 --> 26:53.130
The females have also two basic
strategies.

26:53.130 --> 26:59.490
One is to get the males to
provide resources other than

26:59.491 --> 27:07.151
sperm, and those resources allow
her to build big healthy eggs.

27:07.150 --> 27:11.660
One of the really cute examples
of this is in the jungle,

27:11.657 --> 27:15.037
protein, nitrogen,
is very, very scarce.

27:15.038 --> 27:18.438
The soils are thin and the
rains wash everything away so

27:18.436 --> 27:20.596
it's really hard to get
nitrogen.

27:20.598 --> 27:23.218
Guess what's a great source of
nitrogen?

27:23.220 --> 27:24.210
Dung.

27:24.210 --> 27:28.100
Any animal takes a dump in the
rain forest, immediately there's

27:28.098 --> 27:31.738
all kinds of--especially insects
that come and are going to

27:31.738 --> 27:33.368
utilize that nitrogen.

27:33.369 --> 27:35.389
It's a really scarce resource.

27:35.390 --> 27:39.290
Beetles have--are ones that are
very good at this and there's a

27:39.288 --> 27:42.118
whole group of beetles called
dung beetles.

27:42.119 --> 27:43.309
What do they do?

27:43.308 --> 27:47.078
They--as soon as they detect
this--by odor probably,

27:47.077 --> 27:51.067
they come in and start rolling
it up into little balls,

27:51.067 --> 27:53.947
because it's much too big for
them.

27:53.950 --> 28:05.410
Let me show you a picture
of--this is a dung beetle,

28:05.410 --> 28:07.010
and what he has done--there's a
big pad--

28:07.009 --> 28:12.259
a big animal pad nearby and
he's cut off with his cutting

28:12.261 --> 28:16.151
claws this big ball,
and that's what he's going to

28:16.153 --> 28:17.413
present to a female.

28:17.410 --> 28:20.190
A whole lot of dung beetles
come in,

28:20.190 --> 28:23.130
they make these balls,
then in the species I'm talking

28:23.133 --> 28:26.523
about they put it on their back
and sort of parade around with

28:26.520 --> 28:26.910
it.

28:26.910 --> 28:30.780
Meanwhile, the females are on
the outside, and they're

28:30.775 --> 28:34.855
watching all this go on and what
males do they choose?

28:34.859 --> 28:38.579
The ones with the biggest balls.

28:38.578 --> 28:45.418
She wants resources and that's
her resource.

28:45.420 --> 28:51.110
Now the most extreme case of
this is in praying mantises.

28:51.108 --> 28:54.298
So a praying mantis is a
beautiful animal,

28:54.297 --> 28:57.017
as you may know,
here's one of them,

28:57.017 --> 28:59.347
but they're very solitary.

28:59.348 --> 29:01.948
They have to actually catch
insects.

29:01.950 --> 29:04.970
They sit on the ends of
branches and--with these

29:04.968 --> 29:07.788
claws--and they wait for an
insect to fly by,

29:07.792 --> 29:10.172
and then they grab it and eat
it.

29:10.170 --> 29:13.090
It's not an easy way to make
your living.

29:13.089 --> 29:14.909
They're poised;
they're very quiet,

29:14.914 --> 29:16.874
and they want to capture a
meal.

29:16.868 --> 29:19.568
They have just a few
milliseconds of something

29:19.568 --> 29:20.348
buzzing by.

29:20.348 --> 29:24.298
Now a male comes up and wants
to mate with this female but

29:24.299 --> 29:27.419
she's ready to eat,
so he's got the problem of

29:27.419 --> 29:30.329
approaching her and not getting
eaten.

29:30.328 --> 29:36.028
In evolution they sometimes get
eaten and that has led to a very

29:36.029 --> 29:40.009
interesting form of reproductive
strategy.

29:40.009 --> 29:44.199
That what you see is that the
male will come on and you can

29:44.202 --> 29:48.682
see--now that's the male on top
and look how much smaller he is

29:48.683 --> 29:50.133
then the female.

29:50.130 --> 29:52.620
In many species the male is
bigger, but he's smaller,

29:52.616 --> 29:55.386
and that's a sign that the
males are not fighting with each

29:55.391 --> 29:55.871
other.

29:55.868 --> 29:57.878
You'll see later that if the
male is bigger that means

29:57.878 --> 29:59.698
they're--almost always means
they're fighting.

29:59.700 --> 30:01.650
She's big because he only has
to make sperm,

30:01.647 --> 30:02.687
she has to make eggs.

30:02.690 --> 30:08.470
Notice he has his head still
on, she has her head on.

30:08.470 --> 30:11.020
That's the way it starts,
and you think that something

30:11.020 --> 30:13.620
normal is going to take place,
when actually in fact,

30:13.621 --> 30:15.231
she reaches around and grabs
him,

30:15.230 --> 30:16.410
she's bigger and stronger than
him,

30:16.410 --> 30:20.550
pulls him off and starts eating
his head.

30:20.548 --> 30:24.388
What then happens is she allows
him to go back,

30:24.387 --> 30:28.057
but now you can see she's still
got her head,

30:28.059 --> 30:30.229
there's no head there.

30:30.230 --> 30:33.740
The way the insect nervous
system is put out;

30:33.740 --> 30:38.060
all the circuits to coordinate
the copulation are down here.

30:38.058 --> 30:41.168
What the head actually does is
inhibit that,

30:41.170 --> 30:43.310
unless it goes and says--well
most situations--

30:43.308 --> 30:45.448
no this isn't right to start
copulating,

30:45.450 --> 30:48.360
but only in the very special
situation where it's a female,

30:48.358 --> 30:53.088
when she eats off his head that
releases those circuits from

30:53.090 --> 30:56.940
inhibition and he copulates her
to completion.

30:56.940 --> 31:00.270
Now--and then she can--when
he's done she can eat the rest

31:00.265 --> 31:00.785
of him.

31:00.788 --> 31:05.768
Now what's really interesting
is--and he doesn't object,

31:05.771 --> 31:08.401
he doesn't try to get away.

31:08.400 --> 31:10.450
What's going on?

31:10.450 --> 31:14.890
The key thing is that this is a
sparse species.

31:14.890 --> 31:18.080
How many of you have seen a
praying mantis?

31:18.078 --> 31:21.048
How many of you have seen a lot
of praying mantis?

31:21.048 --> 31:23.408
One person, you must study them
or something.

31:23.410 --> 31:25.230
They're not hard--they're not
easy to find,

31:25.230 --> 31:26.400
there's not many of them.

31:26.400 --> 31:29.620
If a male is lucky enough to
find a female and get in this

31:29.624 --> 31:31.384
situation,
man he's in heaven,

31:31.384 --> 31:34.624
and it's unlikely if he leaves
her he's going to find another

31:34.622 --> 31:35.002
one.

31:35.000 --> 31:36.760
That's just an unlikely event.

31:36.759 --> 31:39.439
How does he maximize his
reproduction?

31:39.440 --> 31:43.010
Well in my one chance I've got
to have that female produce as

31:43.007 --> 31:46.367
many eggs with my genes in it,
so he wants her to produce a

31:46.368 --> 31:48.988
lot of big,
very healthy eggs and so his

31:48.994 --> 31:52.794
body is the food for her,
including a lot of protein so

31:52.785 --> 31:55.315
that she can make a whole lot of
eggs.

31:55.318 --> 31:59.428
In evolution it's worked out
that males who sacrifice their

31:59.429 --> 32:03.609
bodies to this have more
offspring then males who don't,

32:03.608 --> 32:07.238
so you see the evolution from
him being prey just because he's

32:07.244 --> 32:11.064
prey to it being an actual part
of the whole sexual situation.

32:11.058 --> 32:13.998
The next time someone tells you
that evolution is the survival

32:14.000 --> 32:15.980
of the fittest,
what are you going to tell

32:15.976 --> 32:16.406
them?

32:16.410 --> 32:20.400
Fitness has--survival has
nothing to do with the price of

32:20.397 --> 32:21.037
cheese.

32:21.039 --> 32:25.609
That's only one of the ways.

32:25.608 --> 32:30.008
Now, the next strategy of
females--

32:30.009 --> 32:34.029
the first is to get resources,
the second strategy is for

32:34.027 --> 32:38.467
females to try to find the male
with the best genes and so that

32:38.473 --> 32:42.543
she--
her offspring have good genes

32:42.535 --> 32:45.475
and are very successful.

32:45.480 --> 32:50.150
There's a whole lot of aspects
to this and one is she has to be

32:50.145 --> 32:54.205
able to control which male is
fertilizing her genes.

32:54.210 --> 32:57.450
The more separated the male and
the female, when you spew out

32:57.445 --> 33:00.785
into the ocean eggs and sperm
there's no control whatsoever.

33:00.788 --> 33:06.278
The closer that you come--the
male and the female come to each

33:06.278 --> 33:10.328
other the more control that the
female has.

33:10.328 --> 33:15.328
One of the interesting ways of
looking at this is internal

33:15.327 --> 33:17.957
fertilization,
as in humans.

33:17.960 --> 33:24.450
It is among other things a
strategy for female control.

33:24.450 --> 33:27.820
Internal fertilization and
internal growth of the fetus has

33:27.820 --> 33:29.100
a lot of advantages.

33:29.098 --> 33:31.748
It protects the fetus,
allows the mother to provide

33:31.752 --> 33:33.882
nutrition and waste removal
continuously,

33:33.875 --> 33:34.295
etc.

33:34.298 --> 33:40.908
There are also these aspects to
the female control strategy.

33:40.910 --> 33:44.360
Generally, if a female won't
allow a mating,

33:44.363 --> 33:45.973
it doesn't happen.

33:45.970 --> 33:48.260
If a female doesn't allow it
then rape has to happen.

33:48.259 --> 33:50.489
We'll talk about rape later.

33:50.490 --> 33:53.860
In humans, as you know,
females have a vulva and that's

33:53.855 --> 33:55.535
the Latin word for valve.

33:55.538 --> 33:58.098
She can open it,
she can close it,

33:58.104 --> 34:00.284
and that's the whole idea.

34:00.278 --> 34:05.118
If the female wants to mate she
gets excited and she lubricates,

34:05.117 --> 34:08.497
and the purpose of the
lubrication is to ease

34:08.496 --> 34:11.566
penetration and ease the sexual
act.

34:11.570 --> 34:15.260
Behaviorally she's also--aside
from the beginning she's

34:15.257 --> 34:18.057
receptive, she assumes the
proper posture,

34:18.056 --> 34:20.376
and everything goes just fine.

34:20.380 --> 34:22.510
But if these things--if she
doesn't want to do it and these

34:22.505 --> 34:24.565
things don't happen,
there's no lubrication,

34:24.574 --> 34:27.294
there's no assumption of the
proper posture which is

34:27.288 --> 34:29.468
necessary for internal
fertilization,

34:29.469 --> 34:34.979
then it's very hard for the
male to intermit and probably

34:34.981 --> 34:38.331
sexual intercourse won't happen.

34:38.329 --> 34:40.859
In a real rape,
say among humans,

34:40.858 --> 34:45.598
the vagina does not lubricate,
and that's why there's so much

34:45.597 --> 34:49.387
lacerating and tearing of the
vaginal walls.

34:49.389 --> 34:53.129
That's why it's so dangerous
because it's part of the human

34:53.125 --> 34:57.045
female strategy to control what
males inseminate her is to not

34:57.052 --> 35:01.292
lubricate,
but if she's forced there can

35:01.289 --> 35:04.899
be a lot of damage done to her.

35:04.900 --> 35:08.430
How does a female know which
male has the best genes,

35:08.425 --> 35:11.135
which male to allow to
inseminate her?

35:11.139 --> 35:14.979
She has to either watch a
competition or see the male in

35:14.981 --> 35:17.111
some way,
or know the outcome of some

35:17.108 --> 35:18.778
competition that she doesn't
see,

35:18.780 --> 35:23.910
by say, detecting a male's
position in a status hierarchy.

35:23.909 --> 35:25.869
In some birds,
like flamingos,

35:25.865 --> 35:29.635
there's a beautiful movie of
flamingos doing this which I

35:29.643 --> 35:33.853
don't have time to show,
there can be 100 or so males

35:33.851 --> 35:36.991
can gather together and start
dancing.

35:36.989 --> 35:39.359
It's what's called a lek,
and many of you may have heard

35:39.358 --> 35:41.468
of it or seen it in National
Geographic movies.

35:41.469 --> 35:43.979
The males dance back and forth,
back and forth,

35:43.980 --> 35:46.980
they show their coordination,
they show how perfect their

35:46.981 --> 35:49.321
feathers are,
they show their stamina because

35:49.318 --> 35:51.368
they're doing this for quite a
long time,

35:51.369 --> 35:54.329
and again, the females stand
around on the outside and try to

35:54.331 --> 35:56.161
notice a male who's a good
dancer,

35:56.159 --> 35:59.399
a good strong well coordinated
dancer,

35:59.400 --> 36:02.650
and then she chooses him and
goes off and mates.

36:02.650 --> 36:08.280
By choosing these males that
are not creeping around,

36:08.275 --> 36:14.765
she presumes that she's getting
a male with a good--with good

36:14.768 --> 36:15.848
genes.

36:15.849 --> 36:24.209
Another way that the females
get to choose a good male is by

36:24.211 --> 36:30.621
choosing males who have--
in species where males fight as

36:30.615 --> 36:35.515
part of male strategy then the
females choose the winners.

36:35.518 --> 36:37.658
Males may fight,
and you set up a dominance

36:37.664 --> 36:39.544
hierarchy,
but there's nothing that says

36:39.536 --> 36:41.156
the female has to choose the top
dog,

36:41.159 --> 36:44.129
maybe she wants to choose the
middle dog or a bottom dog,

36:44.130 --> 36:47.520
but in general in species,
females choose the top dog.

36:47.518 --> 36:52.148
They know the result of--in a
variety of ways--the dominance

36:52.146 --> 36:56.066
fights, and the female then
chooses the top dog.

36:56.070 --> 37:00.050
In the male fights,
the winner gets the female,

37:00.050 --> 37:05.070
or maybe gets the whole harem
of females, and the loser may

37:05.072 --> 37:07.412
get absolutely nothing.

37:07.409 --> 37:10.979
Well the females are very happy
to join the winner's harem.

37:10.980 --> 37:12.700
Why is that?

37:12.699 --> 37:16.749
Because once that starts in a
species that means that male has

37:16.753 --> 37:20.013
some genes which allow him to
win these fights.

37:20.010 --> 37:22.150
He's big, he's strong,
he's vicious,

37:22.150 --> 37:25.140
he has sharp teeth,
he's a violent character,

37:25.139 --> 37:29.469
and therefore he is successful
in these battles and the female

37:29.465 --> 37:32.685
wants her young to also--
wants being in this

37:32.688 --> 37:36.478
evolutionary sense of if she
does that she passes on her

37:36.480 --> 37:38.910
genes--
the female wants her offspring

37:38.913 --> 37:42.463
to have these characteristics of
being able to win a fight,

37:42.460 --> 37:44.360
i.e., of being very violent.

37:44.360 --> 37:46.800
She will choose the most
violent male,

37:46.800 --> 37:51.260
the winner of these battles to
father her children because then

37:51.264 --> 37:53.944
they--
then the odds are that they

37:53.943 --> 37:57.923
will also become these big,
strong, violent males.

37:57.920 --> 37:59.970
What happens,
in this case,

37:59.969 --> 38:04.699
is in evolution males may start
fighting and once the females

38:04.701 --> 38:09.281
select the fighter's then both
male and female reproductive

38:09.275 --> 38:13.925
strategy colludes in increasing
the violence a little bit in

38:13.927 --> 38:15.897
every generation.

38:15.900 --> 38:20.630
It's very interesting that
males and females are colluding

38:20.628 --> 38:24.278
in the evolution of male on male
violence.

38:24.280 --> 38:26.070
What else does evolution do?

38:26.070 --> 38:29.720
Well if the males are fighting
each other and reproductive

38:29.722 --> 38:33.762
success depends on winning these
fights, then males will tend to

38:33.757 --> 38:34.717
get larger.

38:34.719 --> 38:38.409
You get a large male,
humans, chimpanzees,

38:38.409 --> 38:43.359
males larger than the female,
and that helps them in the

38:43.360 --> 38:44.350
fights.

38:44.349 --> 38:49.109
It also opens up a second
strategy for reproductive

38:49.112 --> 38:51.582
success--
a second strategy for

38:51.579 --> 38:55.899
reproductive success and that is
that the male is now bigger than

38:55.902 --> 38:59.352
the female and he can start
coercing the female.

38:59.349 --> 39:02.309
He may not have to fight the
males;

39:02.309 --> 39:08.169
he can just coerce,
fight with and coerce this

39:08.173 --> 39:10.393
smaller female.

39:10.389 --> 39:12.109
Then guess what happens?

39:12.110 --> 39:16.660
If that gets into a species
that the males start coercing

39:16.657 --> 39:20.877
the females, what is an
evolutionarily wise female to

39:20.880 --> 39:21.450
do?

39:21.449 --> 39:25.709
She chooses a male who is most
successful at coercing females,

39:25.710 --> 39:28.510
because again,
her children will then inherit

39:28.505 --> 39:31.995
those genes which will allow
them to successfully coerce

39:32.000 --> 39:34.920
females and get more
reproduction and have more

39:34.922 --> 39:35.942
offspring.

39:35.940 --> 39:40.600
Again, we see that not only are
male and female reproductive

39:40.597 --> 39:44.697
strategies cooperating in an
increase in male on male

39:44.704 --> 39:47.984
violence,
they also cooperate in

39:47.978 --> 39:51.528
increasing male on female
violence.

39:51.530 --> 39:55.740
It's really quite an
interesting way of looking at

39:55.735 --> 40:00.795
things and explains--starts to
explain some of this violence

40:00.797 --> 40:04.057
that we see in human
interactions.

40:04.059 --> 40:08.559
Now the great--we belong to the
great ape line of evolution,

40:08.556 --> 40:13.196
and it seems that our line of
evolution seems to specialize in

40:13.204 --> 40:15.344
male on female violence.

40:15.340 --> 40:18.040
Consider rape,
so a lot of political

40:18.041 --> 40:22.521
correctness about use of the
word rape, but I'm going to do

40:22.516 --> 40:25.446
it in a straight biological
sense.

40:25.449 --> 40:29.139
Rape is the coercion of an
unwilling female into

40:29.139 --> 40:30.239
intercourse.

40:30.239 --> 40:33.949
Outside of mammals there are
only a very few species where

40:33.949 --> 40:34.859
rape occurs.

40:34.860 --> 40:38.720
Scorpion flies are one of the
best known examples.

40:38.719 --> 40:42.729
Normal sex occurs when a male
offers a female a dead insect or

40:42.726 --> 40:45.726
other food mass;
she's getting resources from

40:45.733 --> 40:46.063
him.

40:46.059 --> 40:52.259
After she accepts she allows
copulation to proceed,

40:52.257 --> 40:55.107
and it goes smoothly.

40:55.110 --> 40:57.480
Sometimes, however,
sex happens in quite a

40:57.483 --> 40:58.413
different way.

40:58.409 --> 41:02.249
A male without an offering can
ambush the female and she

41:02.248 --> 41:05.738
clearly is trying to escape and
the whole time,

41:05.739 --> 41:08.669
he's got genital claspers to
try to grab onto her,

41:08.670 --> 41:12.220
and she's trying to get away
and push him away,

41:12.219 --> 41:13.309
fly away.

41:13.309 --> 41:16.479
In your reading,
there's a description of this

41:16.480 --> 41:20.430
rape of scorpion flies so I
don't have to go further with

41:20.425 --> 41:20.915
it.

41:20.920 --> 41:25.030
In vertebrates,
rapes occur in several species

41:25.030 --> 41:30.240
of ducks and in mammals there
are only three species where

41:30.239 --> 41:33.069
rape is routine:
elephant seals,

41:33.070 --> 41:35.630
orangutans and humans.

41:35.630 --> 41:39.240
Rape occurs occasionally in
three other mammal species:

41:39.244 --> 41:41.864
chimpanzees,
howler monkeys and gorillas

41:41.856 --> 41:46.106
when they're captive;
it has not been observed in the

41:46.110 --> 41:46.610
wild.

41:46.610 --> 41:48.970
This is really quite striking.

41:48.969 --> 41:53.179
Of the six species,
mammalian species,

41:53.184 --> 41:59.224
in which rape has been
observed, five of those are the

41:59.221 --> 42:01.501
great--are apes.

42:01.500 --> 42:07.140
I'm sorry one is a monkey--of
the five species of primates

42:07.144 --> 42:12.894
where rape's been observed,
four are great apes like us.

42:12.889 --> 42:16.739
Those statistics are way out of
the range of chance.

42:16.739 --> 42:21.529
There is something special
about ape evolution that has led

42:21.525 --> 42:26.225
to this emphasis on violent
relationship between males and

42:26.228 --> 42:27.218
females.

42:27.219 --> 42:32.249
Most likely it is the extreme
unavailability of eggs,

42:32.250 --> 42:36.720
so it's an extremely rare--in
the great apes it's extremely

42:36.722 --> 42:41.272
rare to find a female who has an
egg ready to be fertilized,

42:41.273 --> 42:41.893
why?

42:41.889 --> 42:46.559
Well first, primates take many
years to become sexually mature.

42:46.559 --> 42:52.159
In chimps and humans it's
around 12 to 13 years before a

42:52.159 --> 42:55.009
female can ovulate an egg.

42:55.010 --> 42:58.270
Then primate mothers have these
long gestation periods,

42:58.268 --> 43:01.688
eight months in chimps,
nine months in humans,

43:01.690 --> 43:04.360
and so just counting gestation
and the recovery from

43:04.364 --> 43:06.664
childbirth,
females can have at most one

43:06.655 --> 43:09.905
young a year,
which means one egg available

43:09.914 --> 43:12.844
for fertilization in a whole
year.

43:12.840 --> 43:16.200
Then the females lactate and
you probably know about

43:16.197 --> 43:20.217
lactational amenorrhea that when
a female is lactating and the

43:20.215 --> 43:25.235
baby is sucking on the nipple,
hormones are released and the

43:25.235 --> 43:29.485
female does not lactate--
does not ovulate again.

43:29.489 --> 43:33.349
The average for a chimpanzee is
about another four years in

43:33.349 --> 43:37.469
which the female feeds--
breastfeeds the infant and so

43:37.467 --> 43:40.677
she doesn't come into fertility
again.

43:40.679 --> 43:44.569
Then they can sometimes stay
with their young even longer

43:44.570 --> 43:48.600
time, so the average birth
interval for chimpanzees is five

43:48.599 --> 43:50.059
and a half years.

43:50.059 --> 43:53.609
That means for any female
there's one egg every five and a

43:53.614 --> 43:55.864
half years ready to be
fertilized.

43:55.860 --> 44:00.530
That's Jane Goodall's number,
a Japanese group says it's six

44:00.527 --> 44:02.757
years,
for orangutans it's eight

44:02.760 --> 44:06.290
years, and gorilla females have
a baby about once every ten

44:06.291 --> 44:06.841
years.

44:06.840 --> 44:13.090
There's an extreme dearth of
eggs to get fertilized.

44:13.090 --> 44:14.980
You have a chimp community,
there's say 40,

44:14.980 --> 44:18.330
45-55 individuals,
something like that,

44:18.329 --> 44:20.739
maybe 10 or 12--this is a big
community--

44:20.739 --> 44:24.509
10 or 12 sexually mature males,
about the same number of

44:24.505 --> 44:28.615
females,
non-mature males and females,

44:28.621 --> 44:32.631
and of those then,
given the very long period,

44:32.632 --> 44:36.402
there's probably going to be
one or two females in that whole

44:36.396 --> 44:40.286
year who are going to be fertile
and in estrus and ready to get

44:40.286 --> 44:41.286
fertilized.

44:41.289 --> 44:43.869
These males spend the whole
year, in terms of their

44:43.867 --> 44:47.447
reproductive evolution,
spend the whole year setting

44:47.445 --> 44:51.665
themselves up to have that one--
to inseminate that one egg

44:51.668 --> 44:53.928
that's available in that whole
year.

44:53.929 --> 44:58.199
You can imagine there's going
to be a huge amount of

44:58.197 --> 45:02.967
competition, a huge amount of
violence among the males.

45:02.969 --> 45:09.049
As we've seen that male/male
violence then spills over into

45:09.048 --> 45:11.458
male/female violence.

45:11.460 --> 45:16.510
Within this group--we belong to
an order called primates,

45:16.510 --> 45:19.990
as you know,
and within this group monkeys

45:19.990 --> 45:25.260
are fairly distant relatives but
the rest of the great apes are

45:25.255 --> 45:26.695
fairly close.

45:26.699 --> 45:30.679
You can see there are a lot of
similarities,

45:30.682 --> 45:36.062
these are some jokes about the
singles bar, even in biology

45:36.056 --> 45:40.036
there's some sense of humor
still left.

45:40.039 --> 45:44.889
Now, this is another professor
at Yale and I always ask

45:44.891 --> 45:49.571
students--you have too many
advisees--so I asked them

45:49.565 --> 45:53.065
wouldn't you rather go to this
guy?

45:53.070 --> 45:56.870
He looks very fatherly and kind
and everything.

45:56.869 --> 45:58.489
Well that's an orangutan.

45:58.489 --> 46:03.039
Of the great apes,
it's as far a distance from

46:03.043 --> 46:06.283
humans as--
the most distant species and

46:06.282 --> 46:10.772
yet looks pretty much--
you can empathize with that as

46:10.773 --> 46:12.863
almost a human being.

46:12.860 --> 46:16.840
It doesn't take a lot of
evolution to go between these

46:16.838 --> 46:17.288
two.

46:17.289 --> 46:22.089
There are five species of great
apes.

46:22.090 --> 46:26.070
That's a young guy.

46:26.070 --> 46:30.240
This is a time scale,
about 15 million years ago

46:30.242 --> 46:35.662
there was one line of evolution
coming up from a long time ago

46:35.657 --> 46:41.337
and the first event was that
orangutans split off the tree,

46:41.340 --> 46:44.290
that the tree split and one
branch became orangutans.

46:44.289 --> 46:47.899
Then about ten million years
ago another--there was another

46:47.898 --> 46:51.318
split and gorillas went off,
a group went off and became

46:51.320 --> 46:52.130
gorillas.

46:52.130 --> 46:56.260
Then about six million years
ago another group came off and

46:56.257 --> 46:58.177
they evolved into humans.

46:58.179 --> 47:02.469
The most recent split is about
two million years ago and gave

47:02.469 --> 47:05.969
two species, very similar
species: chimpanzees and

47:05.972 --> 47:06.832
Bonobos.

47:06.829 --> 47:10.649
The farther distant the split
is the more there's been time to

47:10.650 --> 47:13.760
evolve differently,
so an orangutan who as that

47:13.762 --> 47:18.312
nice guy,
is very distant from the other

47:18.307 --> 47:19.457
species.

47:19.460 --> 47:27.060
That's our family tree and the
difference--this is a fairly

47:27.059 --> 47:29.679
recent split here.

47:29.679 --> 47:33.209
The genetic difference between
these three species,

47:33.208 --> 47:37.228
between any pair of those three
species, is about 1.5%.

47:37.230 --> 47:41.060
If you draw out the DNA
sequence for a chimpanzee and a

47:41.056 --> 47:43.606
human and look at the base
pairs,

47:43.610 --> 47:47.420
out of every hundred,
98 or 99 will be identical and

47:47.422 --> 47:49.742
one or two will be different.

47:49.739 --> 47:55.589
We're extremely similar
genetically.

47:55.590 --> 47:58.010
Now, what does this difference
mean?

47:58.010 --> 48:01.460
1.5% or 2%, we don't have the
foggiest idea of what it means.

48:01.460 --> 48:04.010
Obviously, you can look at a
chimpanzee and say,

48:04.010 --> 48:06.200
hey it isn't human,
and their behavior is different

48:06.204 --> 48:08.904
and they can't speak,
and all kinds of things,

48:08.900 --> 48:12.590
but genetically there's not
that big of a difference.

48:12.590 --> 48:16.260
I wouldn't draw any particular
conclusions from the genetics

48:16.257 --> 48:16.627
yet.

48:16.630 --> 48:21.600
This is a rapidly evolving
field and we're going to learn

48:21.597 --> 48:25.717
an awful lot very quickly,
and one doesn't know what the

48:25.722 --> 48:27.922
conclusions are going to turn
out to be.

48:27.920 --> 48:31.570
One thing which may be solid is
that if you look between a man--

48:31.570 --> 48:36.250
females have two X chromosomes
and males have an X and Y

48:36.248 --> 48:38.108
chromosome,
so you can ask,

48:38.108 --> 48:40.468
well what is the genetic
distance between a human male

48:40.469 --> 48:41.449
and a human female?

48:41.449 --> 48:46.289
Guess what, 1.5%.

48:46.289 --> 48:49.029
Whatever you think of the
difference,

48:49.030 --> 48:52.350
genetic distance of those
species, you pretty much at this

48:52.353 --> 48:55.803
current stage of our knowledge
have to think the same as the

48:55.795 --> 48:59.465
genetic difference between a
human male and a human female.

48:59.469 --> 49:05.569
That's just for your thinking.

49:05.570 --> 49:11.070
Each of the great ape species
has evolved a different social

49:11.070 --> 49:14.240
system to organize reproduction.

49:14.239 --> 49:18.159
All but one have an awful lot
of violence associated with it.

49:18.159 --> 49:21.799
Orangutans are the least social
of apes.

49:21.800 --> 49:26.660
The males and females generally
stay apart, and the mother and a

49:26.661 --> 49:29.751
child are the only stable social
unit.

49:29.750 --> 49:33.150
The offspring stay with the
mother until adolescence,

49:33.154 --> 49:37.284
very much like the chimpanzee
story and like the human story.

49:37.280 --> 49:41.130
It's about ten years before the
young separates.

49:41.130 --> 49:43.700
For most of the eight years
between births,

49:43.701 --> 49:46.271
the mother has no interest in
males at all,

49:46.273 --> 49:50.973
no interest in sex at all;
she doesn't really come very

49:50.974 --> 49:52.514
close to them.

49:52.510 --> 49:54.350
There are two kinds of
orangutan males.

49:54.349 --> 49:56.989
There's a large one and a small
one.

49:56.989 --> 50:01.219
The big males are about 200
pounds, the females and the

50:01.219 --> 50:05.919
small males are less than half
that size, about 90 pounds.

50:05.920 --> 50:10.740
The small male develops
normally up to adolescence and

50:10.742 --> 50:14.112
then just stops developing
further.

50:14.110 --> 50:17.890
Doesn't develop the
characteristics of the full

50:17.889 --> 50:21.669
male, doesn't grow a beard,
crests of the hair,

50:21.668 --> 50:23.638
throat pouches,
etc.

50:23.639 --> 50:26.319
They remain looking like
adolescents.

50:26.320 --> 50:28.400
But, they are completely
fertile, have a normal

50:28.396 --> 50:31.176
complement of testosterone,
they're sexually totally

50:31.184 --> 50:34.774
capable, and they can stay in
this adolescent stage for up to

50:34.771 --> 50:37.111
18 years,
maybe longer but that's the

50:37.114 --> 50:39.204
most that anyone has observed
them.

50:39.199 --> 50:43.509
They probably don't grow into a
big male until the dominant male

50:43.510 --> 50:47.480
in the region has died or is too
weak to defend himself.

50:47.480 --> 50:51.850
The females always want
to--When they have a choice they

50:51.851 --> 50:56.861
always want to mate with the big
males because the big males are

50:56.860 --> 51:00.130
more successful,
and it's the old story that

51:00.126 --> 51:03.666
females mate with males of a
type that are already successful

51:03.672 --> 51:07.222
because that is good for the
genes that her children get.

51:07.219 --> 51:11.249
In the mating between a female
and a big male,

51:11.248 --> 51:15.188
sex is very relaxed,
it takes on a languorous

51:15.186 --> 51:20.286
quality, an erotic quality,
there's not a great rush.

51:20.289 --> 51:24.629
Matings can begin with oral or
manual manipulation of the

51:24.628 --> 51:27.768
partner's genitalia,
and it can be initiated by

51:27.773 --> 51:29.613
either the male or by the
female,

51:29.610 --> 51:34.700
and when they finally do engage
in intercourse they do it often

51:34.697 --> 51:37.047
face to face,
missionary style,

51:37.054 --> 51:39.824
and it takes about as long as
it takes humans:

51:39.820 --> 51:43.140
an average of 11 minutes and up
to a half an hour,

51:43.139 --> 51:47.859
just in case you want to
compare.

51:47.860 --> 51:50.150
Now these big males are
ponderous,

51:50.150 --> 51:53.820
they can't move fast,
whereas, the females are lithe

51:53.818 --> 51:56.828
and they can go pretty fast,
so you know the female is

51:56.833 --> 51:59.173
choosing the male,
because if she didn't want him,

51:59.166 --> 52:02.576
she could be gone and there's
no way that he could catch her.

52:02.579 --> 52:06.059
What about the small males?

52:06.059 --> 52:09.879
They are not attractive to
females but they have one

52:09.878 --> 52:12.948
advantage, they're small and
they're fast,

52:12.949 --> 52:16.919
and they can run fast and they
can catch females.

52:16.920 --> 52:20.220
That's what mother evolution
has done.

52:20.219 --> 52:24.629
They try to catch and rape the
females.

52:24.630 --> 52:26.990
The females are usually,
as I said,

52:26.989 --> 52:31.539
alone with their young and if
they're found by a single--

52:31.539 --> 52:34.569
by one of these small males
they're chased and sometimes

52:34.565 --> 52:37.655
they get caught,
and then the females show fear

52:37.659 --> 52:41.539
and they struggle to escape,
and the males sometimes strike

52:41.539 --> 52:43.779
them or bite them,
and the females scream and the

52:43.777 --> 52:46.207
young--
they're dependent--the young

52:46.213 --> 52:48.683
scream,
the females bite back,

52:48.679 --> 52:53.589
they hit, they pull the hair of
the males while the copulation

52:53.585 --> 52:59.365
is going on and that lasts --
not more than ten minutes.

52:59.369 --> 53:01.709
How common is this?

53:01.710 --> 53:04.010
Different--orangutans are very
hard to see.

53:04.010 --> 53:07.380
They live in a part of Borneo
that's hard to get to and

53:07.376 --> 53:09.056
they're very hard to see.

53:09.059 --> 53:12.279
There are different studies
coming to different conclusions.

53:12.280 --> 53:16.320
One ethologist found that about
a third, 1/3 of orangutan

53:16.322 --> 53:20.802
copulations involve some degree
of forcing of the female by the

53:20.800 --> 53:21.450
male.

53:21.449 --> 53:25.049
Japanese observers reported
that 88% of the copulations were

53:25.050 --> 53:27.920
rapes and that these were of the
severe kind.

53:27.920 --> 53:31.810
A Dutch observer judged half
the copulations to be rape,

53:31.813 --> 53:34.013
so these are not rare events.

53:34.010 --> 53:39.740
They're a standard part of the
orangutan sexual strategy.

53:39.739 --> 53:44.199
There's a lot of examples where
orangutans are close enough to

53:44.197 --> 53:48.577
humans that apparently a lot of
those same sexual signals are

53:48.583 --> 53:49.463
passing.

53:49.460 --> 53:55.340
A woman primatologist who ran
primatology research in Borneo

53:55.338 --> 54:01.318
talked about an orangutan who
had lived with humans for a lot

54:01.315 --> 54:04.485
of his life,
so he was very acculturated to

54:04.485 --> 54:04.875
humans.

54:04.880 --> 54:08.030
One day apparently he raped one
of the female cooks,

54:08.025 --> 54:10.055
the orangutan,
the male orangutan,

54:10.061 --> 54:13.271
raped one of the human female
cooks at the camp.

54:13.268 --> 54:17.488
Apparently it was a complete
rape with penetration and

54:17.492 --> 54:18.532
everything.

54:18.530 --> 54:23.160
As you know,
rape is a big embarrassment for

54:23.161 --> 54:26.031
the female,
as well as the male,

54:26.034 --> 54:29.204
but in this case,
and this was in Indonesia,

54:29.202 --> 54:31.432
the husband,
very unusually,

54:31.425 --> 54:33.205
took it quite easily.

54:33.210 --> 54:36.280
The husband said that since the
rapist was not human,

54:36.275 --> 54:38.865
the rape should not provoke
shame or rage.

54:38.869 --> 54:42.389
He said, "Why should my
wife will or I be concerned;

54:42.389 --> 54:45.749
it wasn't a man."

54:45.750 --> 54:52.630
There are all kinds of stories
that I don't have time to tell

54:52.632 --> 54:54.012
you about.

54:54.010 --> 54:57.450
Okay, now why doesn't evolution
just keep the big males and the

54:57.454 --> 54:58.514
females together?

54:58.510 --> 55:02.110
Probably food density because
food is hard to get and

55:02.110 --> 55:05.920
individuals have to forage alone
to find enough food;

55:05.920 --> 55:09.510
if they foraged in pairs what
they found would not be enough

55:09.512 --> 55:10.612
for two of them.

55:10.610 --> 55:14.220
Now gorillas live in a region,
and have an ecology that they

55:14.224 --> 55:16.434
have more food available to
them,

55:16.429 --> 55:21.669
so they live in somewhat larger
groups and in gorillas the

55:21.666 --> 55:24.786
females stick close to the male.

55:24.789 --> 55:30.099
Each male, big silverback male
can have a harem of say three to

55:30.103 --> 55:31.393
four females.

55:31.389 --> 55:34.139
In these harems,
they spend most of their time

55:34.141 --> 55:36.101
just the few of them together.

55:36.099 --> 55:38.109
They're quiet;
they're relaxed;

55:38.110 --> 55:40.590
they're affectionate with each
other;

55:40.590 --> 55:44.360
the troop is stable with the
one silverback,

55:44.360 --> 55:49.360
the three or four females and
whatever young they have.

55:49.360 --> 55:53.120
Very little aggressiveness
of--between the males and the

55:53.121 --> 55:56.681
females, or female to female,
just hardly happens.

55:56.679 --> 56:00.029
But, as I said before,
if one male is controlling

56:00.030 --> 56:04.430
three to four females that means
there's two to three males that

56:04.427 --> 56:06.937
don't have any mates whatsoever.

56:06.940 --> 56:10.360
What is evolution going to do
with those bachelor males?

56:10.360 --> 56:12.810
Again, it isn't nice.

56:12.809 --> 56:15.889
The males--so the gorillas
travel through the jungle,

56:15.889 --> 56:17.369
resting some,
eating some,

56:17.369 --> 56:19.209
they eat fruits,
they eat roots,

56:19.206 --> 56:20.506
they eat shoots.

56:20.510 --> 56:24.890
These bachelor males follow the
troop on the uphill side and

56:24.885 --> 56:28.515
just wait until the silverback
is not watching.

56:28.518 --> 56:30.698
Then they charge down,
they can make a fair amount of

56:30.702 --> 56:32.932
noise,
so often the silverback notices

56:32.932 --> 56:36.642
and goes over and beats the hell
out of the guy and he retreats

56:36.641 --> 56:37.181
again.

56:37.179 --> 56:41.169
Every so often he's successful;
the male is with another female

56:41.172 --> 56:44.882
or off--never very far away,
but a little away.

56:44.880 --> 56:46.350
He goes down and what does he
do?

56:46.349 --> 56:48.849
He charges downhill,
so he gets up a lot of speed,

56:48.849 --> 56:52.209
he charges right at a female
with a young,

56:52.210 --> 56:57.100
he grabs the young immediately
smashes it on the ground and

56:57.101 --> 57:00.321
kills it;
runs away and doesn't try to do

57:00.322 --> 57:04.022
anything, but just kills the
young of the female.

57:04.019 --> 57:04.689
Now what does the female do?

57:04.690 --> 57:07.420
The female's are-- these are
very smart, they're great apes

57:07.420 --> 57:09.790
so they're very smart;
they recognize each other as

57:09.786 --> 57:11.896
individuals;
they have long memories,

57:11.896 --> 57:15.736
so you would expect that this
female would remember this male

57:15.737 --> 57:18.487
the rest of her life and fear
him, hate him,

57:18.489 --> 57:19.449
avoid him.

57:19.449 --> 57:21.659
In fact the opposite happens.

57:21.659 --> 57:25.269
What happens is the female
within a few days generally

57:25.268 --> 57:29.418
leaves the silverback that was
supposed to be guarding her and

57:29.420 --> 57:32.890
goes with the single male and
they go off and have a

57:32.893 --> 57:34.123
consortship.

57:34.119 --> 57:38.019
What the message that the male
is delivering to the female is,

57:38.023 --> 57:41.483
'Look you've put a huge
investment into this infant and

57:41.480 --> 57:42.760
now it's wasted.

57:42.760 --> 57:45.120
That guy can't protect you.

57:45.119 --> 57:47.099
He has too many females;
he's too old,

57:47.101 --> 57:50.091
he's too big and slow,
he can't protect you.

57:50.090 --> 57:52.920
I can--you can stay with him,
get pregnant again and I'm

57:52.918 --> 57:55.488
going to come down and kill your
next baby too,

57:55.489 --> 57:57.959
so if you want to reproduce you
come off with me.'

57:57.960 --> 58:00.490
Of course none of this is
verbal, this is an evolutionary

58:00.485 --> 58:02.105
story, I hope you understand
that.

58:02.110 --> 58:06.540
They're not mentating this
stuff that I'm saying.

58:06.539 --> 58:10.949
What you notice is in a few
days this female leaves and goes

58:10.945 --> 58:14.975
with the male that has just
killed her young and starts

58:14.978 --> 58:17.218
reproducing with that one.

58:17.219 --> 58:22.159
That may be stable and last a
long time, or another male may

58:22.161 --> 58:27.021
come by and in a few months
separate him--separate them.

58:27.018 --> 58:30.758
Again, these are not isolated
incidents.

58:30.760 --> 58:36.890
Diane Fossey had data on about
50 infants;

58:36.889 --> 58:41.729
38% of them died before they
were three, and 37% of those

58:41.733 --> 58:43.813
were from infanticide.

58:43.809 --> 58:47.439
About one infant in seven dies
from infanticide,

58:47.438 --> 58:51.998
and each of the female gorillas
she studied had at least one

58:51.996 --> 58:55.236
infant that was killed by
infanticide.

58:55.239 --> 58:57.969
In the gorillas,
the females are trapped in this

58:57.974 --> 59:00.074
vortex of male initiated
violence.

59:00.070 --> 59:03.680
At any moment a male may come
crashing through the forest and

59:03.681 --> 59:06.211
kill her young,
and the best way for her to

59:06.210 --> 59:08.920
prevent this is to go off with
that male.

59:08.920 --> 59:12.980
She needs protection,
she lives in a world of baby

59:12.983 --> 59:17.133
killers and she needs some
protection from them.

59:17.130 --> 59:19.980
Chimpanzees--so we're going
down the list of species,

59:19.980 --> 59:24.220
and we won't get time to
finish, but chimpanzees have yet

59:24.219 --> 59:28.839
another solution to this primate
reproductive problem of very,

59:28.838 --> 59:30.428
very scarce eggs.

59:30.429 --> 59:35.139
Unlike orangutans and gorillas,
the males are not solitary,

59:35.139 --> 59:39.279
but related males spend their
lifetime together as a

59:39.282 --> 59:40.422
community.

59:40.420 --> 59:44.750
Chimps live in groups of about
40 individuals,

59:44.750 --> 59:50.530
with a dozen or so adult males,
and a similar number of adult

59:50.525 --> 59:51.675
females.

59:51.679 --> 59:54.989
As with the orangutans,
the chimp females spend most of

59:54.990 --> 59:57.260
their time alone with their
young,

59:57.260 --> 1:00:01.250
and they're not separated from
their young until the young are

1:00:01.246 --> 1:00:03.986
several years old,
really into adolescence.

1:00:03.989 --> 1:00:06.229
First they hold them,
they're not physically

1:00:06.231 --> 1:00:09.141
separated for several years,
and then for several years

1:00:09.144 --> 1:00:11.854
they're not out of sight,
and then for several more years

1:00:11.847 --> 1:00:13.377
they're not out of voice
contact,

1:00:13.380 --> 1:00:16.780
so it's really very,
very tight bonding between

1:00:16.782 --> 1:00:18.412
mother and children.

1:00:18.409 --> 1:00:21.119
The males defend a rather large
territory,

1:00:21.119 --> 1:00:25.459
numbers of square kilometers,
in which they range and which

1:00:25.458 --> 1:00:28.678
the females range,
and the males spend their time

1:00:28.677 --> 1:00:31.667
searching for food,
patrolling the borders,

1:00:31.670 --> 1:00:34.890
the territory,
and they're often with other

1:00:34.893 --> 1:00:35.383
males.

1:00:35.380 --> 1:00:39.470
This patrolling is often--is a
bunch of males together and they

1:00:39.474 --> 1:00:43.114
go around checking on the
females to see which ones have

1:00:43.108 --> 1:00:46.608
come into estrus or if any have
come into estrus.

1:00:46.610 --> 1:00:49.360
As I mentioned,
the females come into estrus

1:00:49.355 --> 1:00:53.565
only about once every six years
after their last young was born.

1:00:53.570 --> 1:00:57.190
They have a 35-day cycle,
very similar to humans,

1:00:57.190 --> 1:01:01.720
and are sexually receptive for
about 15 of these days in each

1:01:01.717 --> 1:01:03.827
of their monthly cycles.

1:01:03.829 --> 1:01:08.499
Her fertility increases during
these 15 days and she's most

1:01:08.498 --> 1:01:13.488
fertile the last two or three
days of this receptive period.

1:01:13.489 --> 1:01:17.019
The females do an interesting
thing, have you ever been to a

1:01:17.023 --> 1:01:19.363
zoo and looked at chimpanzee
females?

1:01:19.360 --> 1:01:21.850
What do you see?

1:01:21.849 --> 1:01:23.809
Big red rump if they're fertile.

1:01:23.809 --> 1:01:26.249
It looks rather disgusting to
humans,

1:01:26.250 --> 1:01:27.520
and I've been looking for a
picture of it,

1:01:27.518 --> 1:01:29.048
and amazingly it's such a
striking thing,

1:01:29.050 --> 1:01:31.520
I cannot find a really good
picture of this.

1:01:31.518 --> 1:01:35.778
You go to a zoo it's very,
very obvious they--they're

1:01:35.775 --> 1:01:38.225
called ano-genital swelling.

1:01:38.230 --> 1:01:40.220
They advertise their estrus.

1:01:40.219 --> 1:01:42.939
Oppositely to humans;
humans keep their estrus secret;

1:01:42.940 --> 1:01:46.090
neither the male nor the female
knows whether they're in estrus.

1:01:46.090 --> 1:01:48.800
Chimpanzees advertise it,
everybody knows.

1:01:48.800 --> 1:01:50.810
Now why do they do that?

1:01:50.809 --> 1:01:53.319
Well what happens is when a
female comes into estrus,

1:01:53.320 --> 1:01:55.720
the males have been waiting all
year for this,

1:01:55.719 --> 1:01:58.629
the males congregate together
and what do the males start

1:01:58.632 --> 1:01:59.052
doing?

1:01:59.050 --> 1:02:00.700
Competing for the female.

1:02:00.699 --> 1:02:03.899
They're fighting,
the dominant male arrives,

1:02:03.902 --> 1:02:08.302
and it's clear whose dominant,
so the females advertise as a

1:02:08.297 --> 1:02:10.827
way of inciting male violence.

1:02:10.829 --> 1:02:13.019
That they want to be able to
choose the dominant male,

1:02:13.018 --> 1:02:15.758
the ones that are in great
fighting form,

1:02:15.760 --> 1:02:17.300
so they say,
'Hey I'm in estrus,

1:02:17.295 --> 1:02:21.815
all you guys come and fight,
and I'm going to sit there and

1:02:21.815 --> 1:02:27.485
choose the best of you,' which
in this case means the most

1:02:27.487 --> 1:02:29.277
violent of you.

1:02:29.280 --> 1:02:30.760
Unfortunately,
in this situation,

1:02:30.755 --> 1:02:33.335
all these males are not only
fighting with each other but

1:02:33.340 --> 1:02:35.280
they're trying to get at the
females,

1:02:35.280 --> 1:02:38.080
so the females are herded about.

1:02:38.079 --> 1:02:42.559
They have to run around to
escape the clashes with the

1:02:42.563 --> 1:02:43.243
males.

1:02:43.239 --> 1:02:47.479
They regularly receive quite a
lot of wounds when they're

1:02:47.480 --> 1:02:51.340
chased they try to climb up
trees to escape this and

1:02:51.342 --> 1:02:54.222
sometimes they fall out of
trees,

1:02:54.219 --> 1:02:57.029
and they have their young with
them,

1:02:57.030 --> 1:02:59.720
and the young sometimes cling
to them and then if they--

1:02:59.719 --> 1:03:01.399
the mothers fall, the kids fall.

1:03:01.400 --> 1:03:07.570
It's a very,
very dangerous unpleasant time.

1:03:07.570 --> 1:03:13.430
The violence is so great that
when a male approaches a female,

1:03:13.429 --> 1:03:17.239
she doesn't know whether he's
coming to be--

1:03:17.239 --> 1:03:20.529
to try to mate with her or to
be violent toward her because as

1:03:20.532 --> 1:03:23.882
you'll read in the reading how
the males have a long history of

1:03:23.878 --> 1:03:25.658
being violent to the females.

1:03:25.659 --> 1:03:29.299
It's a way of cowing them so
that when they're in this melee,

1:03:29.295 --> 1:03:32.385
when they're in estrus and the
male approaches them,

1:03:32.385 --> 1:03:33.715
they don't resist.

1:03:33.719 --> 1:03:38.959
If they do try to resist he
does a lot of violence on them.

1:03:38.960 --> 1:03:41.570
The male has to--when the male
comes and wants to mate with

1:03:41.570 --> 1:03:43.590
female,
he has to signal to her don't

1:03:43.592 --> 1:03:46.522
run away,
I'm not going to try to beat

1:03:46.516 --> 1:03:51.376
you up and he has--
this is--orangutans,

1:03:51.376 --> 1:03:57.126
gorilla, chimpanzee with her
young.

1:03:57.130 --> 1:04:01.930
This is the--this male is
inspecting the female,

1:04:01.929 --> 1:04:04.519
not only is there a red rump
but there's odors,

1:04:04.518 --> 1:04:09.488
chemicals, and he's trying to
see what the status of her cycle

1:04:09.490 --> 1:04:12.060
is,
and this is a male

1:04:12.061 --> 1:04:18.311
displaying--letting a female
know that this is a sexual

1:04:18.309 --> 1:04:19.929
engagement.

1:04:19.929 --> 1:04:22.629
Humans have been known to do
the same thing.

1:04:22.630 --> 1:04:26.580
This is a picture from ,
the same sort of advertising,

1:04:26.579 --> 1:04:30.079
with pretty much the same
message, and here's an

1:04:30.081 --> 1:04:32.021
incredible photograph.

1:04:32.018 --> 1:04:36.228
I don't know should I leave
that on the board for you?

1:04:36.230 --> 1:04:42.960
I get in trouble leaving things
like that on the--up for too

1:04:42.960 --> 1:04:43.760
long.

1:04:43.760 --> 1:04:46.920
Okay, now, so in this great
melee, this great violent melee,

1:04:46.920 --> 1:04:50.080
there's all the males there
trying to get at this female.

1:04:50.079 --> 1:04:53.969
If a male does--let's say that
alpha male is off fighting with

1:04:53.974 --> 1:04:57.364
someone else and the female is
alone for a minute,

1:04:57.360 --> 1:05:00.840
the male--any male that's
around rushes in.

1:05:00.840 --> 1:05:03.710
He's not going to have a lot of
time before the other males

1:05:03.713 --> 1:05:06.393
notice what's going on and rush
into separate them,

1:05:06.389 --> 1:05:12.279
because they're all competing
to inseminate that egg.

1:05:12.280 --> 1:05:16.080
The males have a very short
time in which to complete the

1:05:16.083 --> 1:05:19.893
copulation, and ejaculation
occurs after just 15 seconds,

1:05:19.887 --> 1:05:22.127
with only 8.8 pelvic thrusts.

1:05:22.130 --> 1:05:25.230
I think those are very
important numbers you should

1:05:25.230 --> 1:05:29.140
know, but the females make up in
quantity what they don't get in

1:05:29.135 --> 1:05:29.875
quality.

1:05:29.880 --> 1:05:32.180
They appear--and there's a
story behind this,

1:05:32.177 --> 1:05:34.837
but they appear to be quite
promiscuous in their sex

1:05:34.840 --> 1:05:35.520
partners.

1:05:35.518 --> 1:05:37.678
In the community followed by
Jane Goodall,

1:05:37.679 --> 1:05:40.639
in each estrus cycle,
each female had at least one

1:05:40.641 --> 1:05:43.001
bout of intercourse with every
male,

1:05:43.000 --> 1:05:46.090
so all the males are getting
some chance at having

1:05:46.094 --> 1:05:46.984
intercourse.

1:05:46.980 --> 1:05:49.890
They average six encounters a
day.

1:05:49.889 --> 1:05:52.579
Don't get excited,
it's still only a minute and a

1:05:52.577 --> 1:05:55.467
half at their rate,
and in each monthly sexual

1:05:55.469 --> 1:05:58.979
cycle they have about 100 or so
bouts of intercourse,

1:05:58.980 --> 1:06:02.070
so there's a lot of sexuality.

1:06:02.070 --> 1:06:04.310
Do females have orgasms?

1:06:04.309 --> 1:06:07.519
Not known;
there are debates about it,

1:06:07.519 --> 1:06:08.459
but not known.

1:06:08.460 --> 1:06:12.840
All right, I guess our time is
running out.

1:06:12.840 --> 1:06:19.900
We will continue on Thursday
and I'll set up sections in

1:06:19.903 --> 1:06:23.633
between, and any questions?

1:06:23.630 --> 1:06:26.610
I stay after every lecture for
as long as necessary if people

1:06:26.605 --> 1:06:28.485
want to come down and ask
questions.

1:06:28.489 --> 1:06:33.999