So people are more afraid of insects than they are of dying.
(Laughter)
At least, according to a 1973 book of lists survey which preceded all those
online best, worst, funniest lists that you see today.
Only heights and public speaking exceeded the six-legged as sources of fear.
And I suspect if you had put spiders in there, the combinations of insects
and spiders would have just topped the chart.
Now, I am not one of those people.
I really love insects. I think they're interesting and beautiful,
and sometimes even cute.
(Laughter)
And I'm not alone.
For centuries, some of the greatest minds in science from Charles Darwin to E.O. Wilson
have drawn inspiration from studying some of the smallest minds on earth.
Well, why is that?
What is that keeps us coming back to insects?
Some of it of course, is just the sheer magnitude of almost everything about them.
They're more numerous than any other kind of animal.
We don't even know how many species of insects there are because new ones
are being discovered all the time.
There are at least a million, maybe as many as 10 million.
This means that you could have an insect of the month calendar
and not have to reuse a species for over 80,000 years.
(Laughter)
Take that pandas and kittens!
(Laughter)
More seriously, insects are essential. We need them.
It's been estimated that 1 out of every 3 bites of food is made possible
by a pollinator.
Scientist use insects to make fundamental discoveries about everything
from the structure of our nervous systems, to how our genes and DNA work.
But what I love most about insects is what they can tell us about
our own behavior.
Insects seem like they do everything that people do.
They meet, they mate, they break up.
And they do so with what looks like love or animosity.
But what drives their behaviors is really different than what drives our own,
and that difference can be really illuminating.
There's nowhere where that's more true than when it comes to one of our most
consuming interests -- sex.
Now, I will maintain and I think I can defend what may seem like
a surprising statement.
I think sex in insects is more interesting than sex in people.
(Laughter)
And the wild variety that we see makes us challenge some of our own assumptios
about what it means to be male and female.
Of course, to start with, a lot of insects don't need to have sex at all to reproduce.
Female aphids can make little, tiny clones of themselves without ever mating.
Virgin birth, right there. On your rose bushes.
(Laughter)
When they do have sex, even their sperm is more interesting than human sperm.
There are some kinds of fruit flies whose sperm is longer than the male's own body.
And that's important because the males use their sperm to compete.
Now, male insects do compete with weapons, like the horns on these beetles.
But they also compete after mating with their sperm.
Dragonflies and damselflies have penises that look kind of like Swiss Army knives
with all of the attachments pulled out.
(Laughter)
And they use these formidable devices like like scoops, to remove the sperm
from previous males that the female has mated with.
(Laughter)
So, what can we learn from this?
(Laughter)
Alright, it is not a lesson in the sense of us imitating them or of them setting
an example for us to follow.
Which given this, is probably just as well.
And also did I mention sexual cannibalism is rampant among insects?
So, no that's not the point.
But what I think insects do, is break a lot of the rules that we humans have
about the sex roles.
So people have this idea that nature dictates kind of a 1950s sitcom version
of what males and females are like.
So that males are always supposed to be dominant and aggressive, and females
are passive and coy.
But that's just not the case.
So for example, take katydids, which are relatives of crickets and grasshoppers.
The males are very picky of who they mate with because they not only transfer
sperm during mating, they also give the female something called a nuptial gift.
You can see two katydids mating in these photos.
In both panels, the male's the one on the right and that sword like appendage
is the female's egg-laying organ.
The white blob is the sperm and the green blob is the nuptial gift, and the male
manufactures this from this own body and it's extremely costly to produce.
It can weigh up to a third of his body mass.
I will now pause for a moment and let you think about what it would be
like, if human men -- everytime they had sex
had to produce something that weighed 50, 60, 70 pounds.
(Laughter)
Okay, they would not be able to do that very often.
And indeed, neither can the katydids.
And so what that means, is the katydid males are very choosy about who they
offer these nuptial gifts to.
Now, the gift is very nutritious and the female eats it during
and after mating.
So, the bigger it is, the better off the male is because that means
more time for his sperm to drain into her body and fertilize her eggs.
But it also means that the males are very passive about mating, where as the females
are extremely aggressive and competitive, in an attempt to get as many as these
nutritious nuptial gifts as they can.
So, it's not exactly a stereotypical set of rules.
Even more generally though, males are actually not all that important
in the lives of a lot of insects.
In the social insects -- the bees and wasps and ants
the individuals that you see everyday, the ants going back to your sugar bowl,
the honey bees that are flitting from flower to flower.
All of those are always female.
People have had a hard time getting their head around that idea for millennia.
The ancient Greeks knew that there was a class of bees, the drones, that are
larger than the workers, although they disapproved of the drones' laziness
because they could see that the drones just hang around the hive
until the mating flight -- they are the males.
They hang around the hives until the mating flight, but they don't
participate in gathering nectar or pollen.
The Greeks couldn't figure out the drones sex, and part of the confusion
was that they were aware of the stinging ability of bees, but they found it
difficult to believe that any animals that bore such a weapon could
possibly be a female.
Aristotle tried to get involved as well.
He suggested, OK, well if the stinging individuals are going to be the males,
then he got confused because that would have meant that males were also taking
care of the young in the colony and he seemed to think that would be
completely impossible.
He then concluded that bees had the organs of both sexes in the same individual,
which is not that farfetched.
There are some animals that do that, but he never really did get it figured out.
And you know, even today, my students for instance call every animal they see
including insects, a male.
And when I tell them that the ferocious army ant soldiers with their giant
jaws, used to defend the colony are all always female, they seem to not
quite believe me.
(Laughter)
Certainly all of the movies -- Antz, Bee Movie
portray the main character in the social insects as being male.
Well, what difference does this make? I mean, these are movies.
They're fiction.
They have talking animals in them, what difference does it makes if they talk
like Jerry Seinfeld?
(Laughter)
I think it does matter and it's a problem that actually part of a much deeper
one that has implications for medicine, and health and a lot of other aspects
of our lives.
You all know that scientists use what we call model systems,
which are creatures -- white rats or fruit flies
that are kind of stand-ins for all other animals including people.
And the idea is, that what's true for a person will also be true
for a white rat.
By in large, that turns out to be the case.
But you can take the idea of a model system too far.
And what I think we've done, is use males, in any species, as though they are
the model system.
The norm. The way things are supposed to be.
And females as a kind of variant -- something special that you only study
after you get the basics down.
And so back to the insects.
I think what that means, is that people could not see what was in front of them.
Because they assumed that the world's stage was largely occupied by male players
and females would only have minor, walk-on roles.
But when we do that, we really miss out on a lot
of what nature is like.
And we can also miss out on the way natural, living things incudling people
can very.
And I think that's why we've used males as models in a lot of medical research,
something that we know now to be a problem if we want the results to apply
to both men and women.
Well, the last thing I really love about insects is something that a lot of people
find unnerving about them.
They have