Jonathan Drori: The beautiful tricks of flowers

http://www.ted.com/talks/jonathan_drori_the_beautiful_tricks_of_flowers.html

Do you know how many species of flowering plants there are? There are
a quarter of a million -- at least those are the ones we know about --
a quarter of a million species of flowering plants. And flowers are a
real bugger. They're really difficult for plants to produce. They take
an enormous amount of energy and a lot of resources. Why would they go
to that bother? And the answer of course, like so many things in the
world, is sex. I know what's on your mind when you're looking at these
pictures. And the reason that sexual reproduction is so important --
there are lots of other things that plants can do to reproduce. You
can take cuttings; they can sort of have sex with themselves; they can
pollinate themselves. But they really need to spread their genes to
mix with other genes, so that they can adapt to environmental niches.
Evolution works that way.

Now the way that plants transmit that information is through pollen.
Some of you may have seen some of these pictures before. As I say,
every home should have a scanning electron microscope to be able to
see these. And there is as many different kinds of pollen as there are
flowering plants. And that's actually rather useful for forensics and
so on. Most pollen that causes hay fever for us is from plants that
use the wind to disseminate the pollen. And that's a very inefficient
process, which is why it gets up our noses so much. Because you have
to chuck out masses and masses of it, hoping that your sex cells, your
male sex cells, which are held within the pollen, will somehow reach
another flower just by chance. So all the grasses, which means all of
the cereal crops, and most of the trees have wind-borne pollen. But
most species actually use insects to do their bidding. And that's more
intelligent in a way, because the pollen, they don't need so much of
it. The insects and other species can take the pollen, transfer it
directly to where it's required.

So we're aware, obviously, of the relationship between insects and
plants. There's a symbiotic relationship there, whether it's flies of
birds or bees, they're getting something in return, and that something
in return is generally nectar. Sometimes that symbiosis has led to
wonderful adaptations -- the hummingbird hawk-moth is beautiful in its
adaptation. The plant gets something, and the hawk-moth spreads the
pollen somewhere else. Plants have evolved to create little landing
strips here and there for bees that might have lost their way. There
are markings on many plants that look like other insects. These are
the anthers of a lily, cleverly done so that when the unsuspecting
insect lands on it, the anther flips up and whops it on the back with
a great load of pollen that it then goes to another plant with. And
there's an orchid that might look to you as if it's got jaws. And in a
way, it has; it forces the insect to crawl out, getting covered in
pollen that it takes somewhere else.

Orchids: there are 20,000, at least, species of orchids -- amazingly,
amazingly diverse. And they get up to all sorts of tricks. They have
to try and attract pollinators to do their bidding. This orchid, known
as Darwin's orchid, because it's one that he studied and made a
wonderful prediction when he saw it. You can see that there's a very
long nectar tube that descends down from the orchid. And basically
what the insect has to do -- we're in the middle of the flower -- it
has to stick its little proboscis right into the middle of that and
all the way down that nectar tube to get to the nectar. And Darwin
said, looking at this flower, "I guess something has coevolved with
this." And sure enough, there's the insect. And I mean, normally it
kind of rolls it away, but in its erect form, that's what it looks
like.

Now you can imagine that if nectar is such a valuable thing and
expensive for the plant to produce and it attracts lots of
pollinators, then, just as in human sex, people might start to
deceive. They might say, "I've got a bit of nectar. Do you want to
come and get it?" Now this is a plant. This is a plant here that
insects in South Africa just love. And they've evolved with a long
proboscis to get the nectar at the bottom. And this is the mimic. So
this is a plant that is mimicking the first plant. And here is the
long-probosced fly that has not gotten any nectar from the mimic.
Because the mimic doesn't give it any nectar. It thought it would get
some. So not only is the fly not got the nectar from the mimic plant,
it's also -- if you look very closely just at the head end, you can
see that it's got a bit of pollen that it would be transmitting to
another plant, if only some botanist hadn't come along and stuck it to
a blue piece of card.

(Laughter)

Now deceit carries on through the plant kingdom. This flower with its
black dots: they might look like black dots to us, but if I tell you,
to a male insect of the right species, that looks like two females who
are really, really hot to trot. (Laughter) And when the insect gets
there and lands on it, dousing itself in pollen, of course, that it's
going to take to another plant, if you look at the
every-home-should-have-one scanning electron microscope picture, you
can see that there are actually some patterning there, which is
three-dimensional. So it probably even feels good for the insect, as
well as looking good.

And these electron microscope pictures -- here's one of an orchid
mimicking an insect -- you can see that different parts of the
structure have different colors and different textures to our eye,
have very, very different textures to what an insect might perceive.
And this one is evolved to mimic a glossy metallic surface you see on
some beetles. And under the scanning electron microscope, you can see
the surface there -- really quite different from the other surfaces we
looked at. Sometimes the whole plant mimics an insect, even to us. I
mean, I think that looks like some sort of flying animal or beast.
It's a wonderful, amazing thing.

This one's clever. It's called obsidian. I think of it as insidium
sometimes. To the right species of bee, this looks like another very
aggressive bee, and it goes and bonks it on the head lots and lots of
times to try and drive it away, and, of course, covers itself with
pollen. The other thing it does is that this plant mimics another
orchid that has a wonderful store of food for insects. And this one
doesn't have anything for them. So it's deceiving on two levels --
fabulous.

(Laughter)

Here we see ylang ylang, the component of many perfumes. I actually
smelt someone with some on earlier. And the flowers don't really have
to be that gaudy. They're sending out a fantastic array of scent to
any insect that'll have it. This one doesn't smell so good. This is a
flower that really, really smells pretty nasty and is designed, again,
evolved, to look like carrion. So flies love this. They fly in and
they pollinate. This, which is helicodiceros, is also known as dead
horse arum. I don't know what a dead horse actually smells like, but
this one probably smells pretty much like it. It's really horrible.
And blowflies just can't help themselves. They fly into this thing,
and they fly all the way down it. They lay their eggs in it, thinking
it's a nice bit of carrion, and not realizing that there's no food for
the eggs, that the eggs are going to die, but the plant, meanwhile,
has benefited, because the bristles release and the flies disappear to
pollinate the next flower -- fantastic.

Here's arum, arum maculatum, lords and ladies, or cuckoo-pint in this
country. I photographed this thing last week in Dorset. This thing
heats up by about 15 degrees above ambient temperature -- amazing. And
if you look down into it, there's this sort of dam past the spadix,
flies get attracted by the heat -- which is boiling off volatile
chemicals, little midges -- and they get trapped underneath in this
container. They drink this fabulous nectar and then they're all a bit
sticky. At night they get covered in pollen, which showers down over
them, and then the bristles that we saw above, they sort of wilt and
allow all these midges out, covered in pollen -- fabulous thing.

Now if you think that's fabulous, this is one of my great favorites.
This is the philodendron selloum. For anyone here from Brazil, you'll
know about this plant. This is the most amazing thing. That sort of
phallic bit there is about a foot long. And it does something that no
other plant that I know of does, and that is that when it flowers --
that's the spadix in the middle there -- for a period of about two
days, it metabolizes in a way which is rather similar to mammals. So
instead of having starch, which is the food of plants, it takes
something rather similar to brown fat and burns it at such a rate that
it's burning fat, metabolizing, about the rate of a small cat. And
that's twice the energy output, weight for weight, than a hummingbird
-- absolutely astonishing. This thing does something else which is
unusual. Not only will it raise itself to 115 Fahrenheit, 43 or 44
degrees centigrade, for two days, but it keeps constant temperature.
There's a thermoregulation mechanism in there that keeps constant
temperature. Now why does it do this? I hear you ask. Now wouldn't you
know it, there's some beetles that just love to make love at that
temperature. And they get inside, and they get it all on. (Laughter)
And the plant showers them with pollen, and off they go and pollinate.
And what a wonderful thing it is.

Now most pollinators that we think about are insects, but actually in
the tropics, many birds and butterflies pollinate. And many of the
tropical flowers are red, and that's because butterflies and birds see
similarly to us, we think, and can see the color red very well. But if
you look at the spectrum, birds and us, we see red, green and blue and
see that spectrum. Insects see green, blue and ultraviolet, and they
see various shades of ultraviolet. So there's something that goes on
off the end there. "And wouldn't it be great if we could some how see
what that is," I hear you ask. Well yes we can. So what is an insect
seeing? Last week I took these pictures of rock rose, helianthemum, in
Dorset. These are little yellow flowers like we all see, little yellow
flowers all over the place. And this is what it looks like with
visible light. This is what it looks like if you take out the red.
Most bees don't perceive red. And then I put some ultraviolet filters
on my camera and took a very, very long exposure with the particular
frequencies of ultraviolet light and this is what I got. And that's a
real fantastic bull's eye.

Now we don't know exactly what a bee sees, any more than you know what
I'm seeing when I call this red. We can't know what's going on in, let
alone an insect's, another human being's mind. But the contrast will
look something like that. So standing out a lot from the background.
Here's another little flower -- different range of ultraviolet
frequencies, different filters to match the pollinators. And that's
the sort of thing that it would be seeing. Just in case you think that
all yellow flowers have this property -- no flower was damaged in the
process of this shot; it was just attached to the tripod, not killed
-- then under ultraviolet light, look at that. And that could be the
basis of a sunscreen, because sunscreens work by absorbing ultraviolet
light. So maybe the chemical in that would be useful.

Finally, there's one of evening primrose that Bjorn Rorslett from
Norway sent me -- fantastic hidden pattern. And I love the idea of
something hidden. I think there's something poetic here. That these
pictures taken with ultraviolet filter, the main use of that filter is
for astronomers to take pictures of Venus -- actually the clouds of
Venus. That's the main use of that filter. Venus, of course, is the
god of love and fertility, which is the flower story. And just as
flowers spend a lot of effort trying to get pollinators to do their
bidding, they've also somehow managed to persuade us to plant great
fields full of them and give them to each other at times of birth and
death, and particularly at marriage, which, when you think of it, is
the moment that encapsulates the transfer of genetic material from one
organism to another.

Thank you very much.