The secret powers of flowers

We're waiting impatiently for a science of spring beneath the melting snow. I mean, I haven't been looking for you, crocuses, and daffodils. These colorful blossoms would surely brighten all of our moods. But my next guest argues that flowers are not just beautiful.

They are critical to the diversity of life as we know it.

And to food and agriculture, let's learn all about that with Thukta David George Haskell, biologist and author of How Flowers Made Our World, the story of nature's revolutionaries. He's based in Atlanta, Georgia. Welcome to Science Friday. Thank you, Ira.

It's a delight to be with you. It's a chat about the world changing power of flowers. One of my favorite topics, because I grow a lot of them, so let's get right into this

“because when I think about the evolution of life on earth, flowers are not typically”

front and center in my mind. So tell me what we have been getting wrong all these years. Yes, we think of Earth's evolution often. We think about Tyranosaurus and animals and maybe microbial revolutions millions of years ago.

I think flowers belong in that pantheon of revolutionaries, because they were later rivals

on planet Earth, they evolved maybe 130 million years ago.

After they evolved, they swiftly took over most of the habitats on the planet and are the foundation of most rainforests, prairie, seagrass meadows, mangroves all over the world now. So they truly are revolutionaries, they opened opportunities for other animals and created most of the most productive ecosystems on the planet.

So we think of them as a femoral and nearly ornamental, but in fact, flowers are extraordinarily powerful world changes. Let's talk about that, because I'm wondering does the fact that flowers are pretty in these smell good?

“Does it distract us from seeing them as evolutionary powerhouses?”

Perhaps I mean, there's nothing wrong with enjoying flowers, as pretty as ornamental is enjoying their aromas, it's an important part of our individual and cultural expression. And those aromas and the colours that we're so attracted to are also the source of much of flowering plants, world changing power. It was through experiences of beauty connecting to be aesthetics and butterflies and beetles

and so on that flowers drew other species into cooperative networks and through that cooperation and revolutionize the world. So in a way, we think about revolutions in a human context, often through violence and domination or authoritarianism. Flowers offer an alternative view of how the world can be changed and transformed and that

is through interconnection, often mediated by interspecies experiences of beauty. Now if I remember correctly from my biology, nine flowering plants came first, like ferns.

“So that raises the question, why did flowers emerge and when did flowers first come”

on to this scene? What happened? Yeah, absolutely. There are, I mean, mosses, ferns, cicheds, there are lots of non-flowering plants and they were around building the Earth's forests and creating habitats for hundreds of millions

of years before flowers came along. And then what flowers did was, there's a convergence of innovations. Some of them were about attracting pollinators into the flower itself, using petals and aroma as visual signals, combining male and female into the same flower, which is a much more efficient way of pollinating the flower, transferring pollen from one flower to another.

But they also revolutionized botanical motherhood by enclosing their seeds inside fruits. And some of those fruits are flashy, some are protective, some are wing-like to catch the wind. And so through a series of different innovations, flowers quickly became, some of the dominant creatures are on the planet.

And by some estimates, it only took a handful of million years after they evolved for them

to become the dominant vegetation around much of the planet. And then they catalyze the evolution of whole new animal groups, like bees and butterflies and later grazing mammals. And even humans, we wouldn't be here without flowering plants. So was this evolution quite rapid?

Yes, they exploded onto the scene and in a Darwin back in the 19th century called it an abominable mystery how flowers appeared so late and so explosively in the fossil record. Now, of course, Darwin didn't know anything about modern genetics and so we have some insight now that he didn't that the flowers have these genetic superpowers there, especially genetically

And the earth changed from a planet covered mostly in psychheads and mosses and very forms

“of ferns and other non-flaring plants into one where first the understory and then the”

overstory of most forests were dominated by flowering plants and that's still the world we live in today before flowering plants there were no rainforests, prairies, steps or mangroves. So flowering plants were not only innovative, they were to use some jargon from human economics, they would disrupt us, they came along and overturned many ecosystems and created enormous opportunities for other creatures.

One really interesting idea I learned from your book is that grasses are considered flowers.

I didn't think I ever thought of my lawn as a sea of flowers. Yes, so you know, lawns are kept in a state of perpetual youth, we erase all signs of

“sex and death from them, creating this ecological illusion which of course you go out”

and so forest mostly what you see is sex and death and so we've a lawn is a strange, strange thing reflection of parts of our psyche maybe, but if you were to not mow your lawn or go out to a natural area where the grasses are free to grow, of course later in the season, the grass who had send up flowering stalks and grasses are pollinated by the wind, not generally by bees or other insects, so they have very inconspicuous small flowers, but

anyone with hay fever knows the grasses can make quite a lot of pollen, that pollen drift

through the air and is received by other flowers and then the amazing thing with grasses is

it after fertilization, the little embryo grows and the mother grass supplies an enormous amount of food that goes along with the embryo, which is why grass seeds when you plant them, whether it's grass for your lawn or wheat or maize or rice can explode, it's like rocket ships taking off from the soil because they've got these amazing storehouses of food and that's another innovation of firing plants is to give many of their embryos the whole food hampers to give them

a boost as they start off their lives, after the break the integral role of grasses to human evolution don't go away, how does AI even work? Where does creativity come from? What's the secret to living longer? Ted radio hour explores the biggest questions with some of the world's greatest thinkers, they will surprise, challenge and even change you, listen to NPR's Ted radio hour wherever you get your podcasts. So grasses play this huge role in human evolution then because we're

“talking about rice which is a flower which I didn't really think about and wheat is there grasses?”

Yes, if you count up all the calories that humans eat worldwide, two thirds of those calories come from just three species of grass, wheat, maize and rice and a lot of the rest of the calories come from sugar cane and oats and barley and millet and then if we're eating grass fed beef for example well that if cow is also made from from grass all flesh is grass the sort of the secret text tell us and that's sort of an ecological truth as well as having some

theological overtones and so in the present day we are sustained by grasses but our evolution was also catalyzed by grasses because why did we or our ancestors come down from the trees, our ancestors were living happy lives up in the trees in tropical forests and a few of them decided to come down from the trees and become bipedal primates in grasslands so without the grasslands and the savannas there would be no incentive for early pre-human hominins to evolve and then the diet of those pre-human

ancestors was also mostly grass-based either eating the grass and grass seed directly or eating a lot of the animals that were feeding on that grass so yes we are grass apes homopoacia if we were to name ourselves for the family of plants that sustain and created us that is really interesting you know I'm a big fan of orchids and I know you devoted a large chunk of your book to orchids I grow them on my windowsill what can they tell us about the relationship between

flower and pollinator absolutely orchids are the so the apex of the complexity of relationships

window cell I've got a whole load on my window cell here orchids have magnificently often very

large and conspicuous displayers with that petals and their seepals some of them are aromatic but the sexual parts are actually miniaturized they only produce a tiny little piece of bit of pollen and the the egg is buried sort of right in the center of the flower then the stigma receives the pollen from other orchids and orchids lure and manipulate and bribe all sorts of different insects to come and pollinate them if you think about the orchids on your window cell

that usually there's a central portion which is often too black or a little bulbous lip that encourages the bee or other pollinator to pass in and and receive the pollen now and some of

“the some orchids are doing this quote unquote honestly by offering nectar rewards to reciprocate with”

the pollinator but others are a lot more devious some orchids look like they've got pollen and nectar but in fact have none others look and smell and feel just like female insects there's one the bee orchid that looks and feels and smells just like a female wasp so amorous male wasps try to mate with these orchid flowers and of course just get a little dab of pollen put on their head complete waste of time for the male wasps but the orchids are then pollinated so orchids take a

deliciously varied approach to pollination and it's often very specific to individual pollinators which then relates to sort of a powder cake for evolution when you get specificity between a pollinator and a flower a slight genetic change in the flower or the pollinator could cause that species to split which is why there are tens of thousands of species of orchids around the world more than any other flower I think yeah depends how you count it either them or the the

sunflower you know you talked about specific pollinators and and specifically about the orchid

“I remember getting an orchid I think it was called Darwin's orchid because it had a huge”

bowl but the bottom you know what I'm talking about and there had to be a moth that could stick its nose all the way into the bottom yes this is an orchid from Madagascar the first western scientist only knew about the flower and it had this big long spur that with nectar in the end but no one knew what pollinated and Charles Darwin said I predict that there is a moth out there with a propossess of exactly the right length to fit into this flower and of course this was after

he died he never lived to hear the end of the story but 20 years after he died western scientists

found the moth described the moth and there was an almost perfect match between the moth and the orchid which at the time was sort of a triumph for the predictive power of evolution because there

“was some creationists who at the time were arguing look this moth is disproves Darwin in evolution and of”

course Darwin had the last laugh on that one right so I mean to be so specific for a pollinator that that could only be one pollinator just as an amazing thing yeah and it's you know it's extremely efficient it means that the orchid is not giving nectar to pollinators that that aren't going to be diligent and faithful couriers of it of its pollen but it's also very you know it's a risky strategy in terms of long-term evolution because if your pollinator goes extinct or the habit that changes

and the your aroma doesn't carry quite so well you've put yourself at risk compared to a flower like say a magnolia flower rose right that welcomes all kinds of pollinators to wrap up and looking toward the future is it is it's silly to ask if flowers are endangered by climate change or changing world not at all fifty percent of orchids fifty percent of magnolias as far as as we can tell are threatened with extinction and then on the other hand

there are there are flowering plants that are extremely nimble and are adapting to the various

changes whether it's climate or salty soils or increasing drought so that as flowering plants always

have done they've adapted but we are having such an extraordinarily powerful effect on the planet that we are indeed pushing many flowers towards extinction which is improvident to say the least because flowers made our world created the most productive habitats on the planet including human agriculture

cautious path by pondering with flowers we can find solutions and that's the great genius of

“flowers is to draw animals into cooperative partnerships we can we have been and we can be even more”

one of those cooperators working towards a better future with flowering plants last question do you have a favorite flower oh I've got lots of favorite flowers I mean one really in writing it's asking about your children yeah no one that really shock me I learned a lot

“about in writing this book with the sea grasses these they they look very inconspicuous unremarkable”

these are flowering plants that flower literally under the water in the sea water and they are

in all kidding they're incredible at storing carbon storing sediment stabilizing the edges of

continents providing habitat for marine animals to breed in and to feed in and until recently

“we knew very little about sea grasses and they too are also endangered their populations are”

in decline but there are some amazingly inspiring stories about restoration of sea grasses so I like them because they're obscure they're not very conspicuous and they have this great story about humans working with flowering plants to solve some of the problems that we've created so so they they're one of my many favorites I'm glad I asked you know I learned so much

today Dr. Haskell thank you for taking time to be with us today thank you are always a pleasure

to chat thank you Dr. David Jordan Haskell biologist an author of how flowers made our world the story of natures revolutionaries he's based in Atlanta Georgia if you like flowers you'll love this book even if you don't like flowers show Shana books found produce this episode am I repladot we'll see you again.