SYSK Selects: How Pollen Works

For about 375 million years, plants have been using pollen (aka plant sperm) to propagate their species. And the technique has stuck around because it works. Join Chuck and Josh for a cozy look at the ins and outs of plant reproduction.

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Episode Transcript

Speaker 1 (00:01):
Hello, everyone, It's Saturday, and it's Chuck, and that means
it's time for another Stuff you Should Know. Select we
go all the way back to July to two to
discuss pollen. I'm not sure when this is gonna come out,
but if I'm timing it right, it should be sometime
during pollen season. And that's why I picked it, because
understanding the enemy is the first step toward defeating it.

(00:24):
And so many people have bad problems with allergies and pollen,
and UH, to understand how that really works in your body,
it's kind of cool and it really helps. So I
hope you don't have any problems with pollen. I hope
you're doing okay, but learn all about how pollen works
right here, right now. Welcome to Stuff you Should Know
Fromhouse Stuff Works dot com. Hey, and welcome to the podcast.

(00:51):
I'm Josh Clark and there's Charles W. Chuck Bryant, and
that means it's time for Stuff you Should Know. But
itchy screezy skiez scratchy addition, not scheezy. No, that's not
itchy scratchy sneezy edition. That's what I meant. There you go.
It's funny how you can mix words together come up
with other words. You didn't mean to say, Jerry's eyes

(01:13):
are at Itchen, Yeah, well we should say. We were
just talking about the pollen count here in Atlanta. That's
pretty much all we ever talked about. Ever when the
cameras not on or the mics aren't recording that in
Coca Cola. Oh you know how everyone comes to Atlanta
and they're like, oh, every street's named peach Tree. Let's
go drink a coke because so it's the only two
things we've ever had. Alright, sorry, that's fine. So you

(01:37):
want to talk about Pollentin Moore, Yeah, it's low right
now in Atlanta. Thirty nine that's moderate, Yeah, well low
for us, right, but like according to the pollen scale
they scale that they used to count pollen and then
designated somewhere along the pollen spectrum, thirty nine is considered moderate,
not even low moderate. When it's really bad here in Georgia,

(01:58):
it gets to about nine thousand. Those are the few
weeks that the the streets run yellow with when it
rains with yellow water. Yeah, it looks like p yep.
Your car is totally covered in it. You're covered in it.
It's just everywhere, everywhere. Yeah, but now we're about to
tell everybody we're basically going to turn everybody into a palenologist. Yeah,

(02:20):
to an extent, should be a big fan after this
an amateur palenologists. I think about a third of all
the plants and vegetables and fruits and vegetables we eat
are you know here thanks to pollen. So if you
like eating food doesn't come in a box, thank you pollen.
Is it just a third that pollinate or a third
that are just angiosperms or gymnosperms, a third that that pollinate? Wow,

(02:45):
what's up with the other two thirds? I don't know. Well,
you know, bananas, they are clones of one another. There
you go, there's like there's there's some one. There's like
I think a thousand varieties of bananas. And thanks by
the way to Dama interesting for this information him. But
there's like a thousand varieties or species of bananas, but
each one like if you eat like a type of

(03:06):
just one of those species of bananas, you're eating an
exact clone of every other banana in that species. Because
many thousands of years ago, humans just stumbled upon the banana,
which is the hybrid of two basically inedible fruits that
came together to form the delicious banana, but made um sterile.
All banana plants are sterile, and the only way that

(03:28):
they're allowed to propagate is by human hand. Theous I
did a don't be dumb about that? Yeah, well you
just did it again. Yeah, you can check out Don't
be dumbs on our website Stuff you should know dot com. Wow.
All right, anyway, Pollen, Yes, it's been around for a while. Um.
I know in our b podcast we talked about how
bees and and paulling kind of emerged side by side

(03:49):
a hundred million years ago, but pollen actually goes further
back than that. In this article, it says about three
seventy five million years ago is when the plants started
getting clever and spreading their seed literally using pollen different techniques.
And I think that, um, the gymnot sperms were first,

(04:10):
you think so, I believe so. Uh yeah, And the
author of the article here points out that the reason
why it evolved was so plants didn't have to be
dumb and rely on water to carry their junk to
fertilize other junk. You know, they're like, how about wind
or how about that bat? Or about that beetle? Yeah,

(04:30):
or how about that bird pooping it out? That's right? Yeah? Um,
And like I said, I think pollen grains or plants
spread their seed. Literally, plant pollen is what amounts to
plant sperm. Yeah, it's like I always go to the
kids science pages to research. First off, I mean they're good,

(04:51):
they're they're colorful. Uh yeah, if we want to pollination
very simply, you know, people reproduce. Animals reproduce. They need
male and female parts. Plants and flower you are no different.
They need male parts to connect with the female parts
to make an egg. And in this case, pollination is
how it's done. So basically, how that sperm the pollen
reaches that egg, which is the ovule, right, and once

(05:14):
they get together, magic happens. That's right. But let's talk
about the way it looks first of all. Yeah, there's
like there's a lot of different looks to pollen depending
on the plant um and all of these variations. What
it can be like a cone literally a pine cone. Yeah,
and look at you know, just look up microscope pollen

(05:34):
on Google images and you'll see all sorts of weird,
colorful shapes and sizes. Yeah. Some look like blowfish. Yeah,
others look like sputnick really yeah, I didn't see the spot.
Some have ribbed edges for and all of these adaptations
are um or mutations. I guess they became adaptations allow

(05:56):
that pollen to kind of better ensure that it's going
to be carried to where it needs to go. Yeah,
it's it has a purpose. It's not just like, hey,
this one would look neat if it looks like a
starfish exactly. In the end. Some have wings kind of
what amount of basically wings because they're carried on the wind.
Oh yeah, yeah, like dandelion paulin, it's carried on the wind.

(06:19):
True will dandelions self palling night too. We'll get to
that though. Yeah. They're slippery little guys. Yeah they are.
They're also high and phytonutrients as well. Dandelion greens are
of the stems, No, the leaves, oh, the little leaves,
the yellow part. So here here's the rule of thumb.
There's a New York Times article that came out very

(06:42):
recently about phyto nutrients and how we basically bred them
out of our food and um. The rule of thumb
is the the bitter, the bitterer or more bitter the plant,
the higher it is in phytoonutrients. Phyto nutrients have kind
of the bitterest, stringent taste, and we tend to don't
really like that, so we stopped eating those things over time,

(07:02):
replace them with sweet things that aren't necessarily good for us,
like you know, potatoes and other starches. Yeah, well, bitter
things can also kill you, that's probably why. So you know,
that's that's a pretty good point. But bitter stuff that
you know won't kill you. Dandelion leaves God and needs
them right now. But back in the day, I bet
people are like that tastes bad and it killed tuk tuk,

(07:25):
So let's just not eat it right exactly alright, So
should we talk about pollination. Talked a little bit about pollen.
Now we need to talk about how plants make little
baby plants, right, And it's it's pretty simple, Like I said,
the male part and have you uh, It really helps
to follow along if you go to a handy dandy

(07:46):
little visual aid I found, because they really break down
the male parts and the female parts. The female is
the has the pistol and that's p I S T
I l and within that you have the over, which
you know sits down low in the plant, and the style,
which is a long, ah thin h appendage. I guess

(08:09):
that contains pollen tubes. And then at the top you
have your stigma, which is going to catch the pollen. Yeah,
and that's the female part, right, that's the lady. Don't
be confused because it is phallic in nature. Yeah, true,
but it's still the female part. And the male has
to filament, which is a long stem, and then the
anther at the top which holds all the pollen. And
that's pretty much the long and short of the parts.

(08:32):
And is that just angiosperms that you're describing or is
that all all pollinating? I think these are just the angiosperms. Well,
we should say quite explicitly that there's basically two ways
that plants compollinate. There's gymnas sperms and angiosperms. And the
big difference between the two is that gymnasperms literally that
means naked seed, which, by the way, gymnasium is means

(08:55):
place to be naked canasium and German did you know that, Yeah,
this so gymnasperms naked seed. There's nothing protecting the seed
once it's once it's produced, and a seed is just
a germ, a fertilized ovum or ovule, right yeah, um,
and just sperms produce something to protect that seed, whether
it's a shell like a nut or fruit like an

(09:17):
apple with the seeds inside, right, because an apple is
just a an enlarged ovule ovary and the seeds are
the fertilized though. Yes, Well, you can also pollinate, across
pollinate or self pollinate, right, those are the other two differences.
So you were saying, what what dandelions self pollinate, Well,
they can do both, um, But they do have a

(09:39):
little a cool little feature. They basically grow up. You know,
this is when there's still the little yellow flower. They
have these little florets that grow up and if you look,
well you probably can't see if you look really really close.
So these little florets that grow up, and as it grows,
it carries uh the pollen on its little stem and
then eventually gets to a point where it doesn't start

(10:01):
grow growing up anymore, and it splits and then starts
curling back on itself to uh, you know, no way.
It picks up its own pollen from its own style.
But it's self pollination. It's not gross or like perverted.
There's a there's a lot of them. There's a lot
of plants out there, though, that have mechanisms to prevent

(10:24):
them from self pollinating. It couldn't can't be good or bad.
That's what I couldn't figure out. Well, the plants somewhere
along the way figured out like, hey, the wider the
gene pool, the better off we are, because the more
room there is for adaptation, mutations and than adaptations. Right. Yeah,
But in here the author said ideally it cross pollinates,
But I don't think that's the case always. Well, it's

(10:45):
not ideal, it's just some doing some don't write. I mean,
if you look at it like from just an animalistic
or an organism viewpoint, right, like with us, if you
just get a bunch of Mennonites together and they just
reproduce with one other, there's going to be defects that
just are propagated throughout this this little gene pool. But

(11:05):
if the Mennonites spread out into the you know, larger
country as a whole, those defects are going to you know,
I guess be kind of watered down by the size
of the gene pool. I think it's the same thing
with self pollinating and cross pollinating. Yeah, because it's interesting
because things like peanuts or self pollinators and that's why
they thrive. But corn has a mechanism to not allow

(11:30):
itself to self pollinate. Like there, I think the sperm
is ready at a different time than the ovule is
ready to accept it, So it's it's a timing thing.
The thing is, peanuts would probably be able to talk
if they didn't self pollinate, and they sound like Jimmy
carter um. So there's a lot of mechanisms that plants

(11:51):
have to prevent themselves from self pollinating. UM. Some or
some might have either just male plants and just female ants.
UM some maybe uh where the male part if the
plant has both male and female flowers, for example, yes,
they they the the male flower might come out before

(12:14):
the female flower on the same plant, so that they're
not the timing is off a little bit. Um. And
then there's some they're just like they'll they'll signal a
biochemical marker. If pollen from the same plant gets near
the ovule, it'll just basically turn barren. So it just
is incapable of fertilizing itself, or like corn where the
timing is thrown off, so they rely on cross pollination, right,

(12:38):
which is pretty cool. So let's let's get explicit again here,
gymnasperms naked seed. How does the happened? Like, We'll use

(13:01):
the example of a pine, a lob lolly pine. It's
fun to say, um, but that's a conifer kind of
furs are ancient. I believe they were the first pollinating plant. Yeah,
I think so. Nice. So let's talk about it. Well,
the pine cones, they're they're little male pine cones, a
little female pine cones. You might not realize that you've

(13:21):
got quite a show going on in your backyard at
certain times of the year, right, Um. And basically, if
once you get the two together, you get a male
pine cone and a female pine cone together. The male
pine cone fertilized, well, the pollen comes in contact with
an ovule, and the pollen starts to go to town.
It absorbs a bunch of water. Well, the female pine

(13:43):
comes little sticky too. That helps, by the way, it does,
helps collect the pollen. Um. So the female or the
the pollen, the male, the male part of the pine
cone germinates and it starts growing. It's called a pollen tube,
which basically allows this pollen to directly for lies the ovule.
Once that happens, the ovule basically becomes a seed and

(14:05):
the seed is released from the pine cone. They go
everywhere and then they're eaten by birds and pooped out elsewhere,
carried along in the there trampled by a rhinoceros who
knows which just got loose from the zoo. But then
that seed is carried along, but it's not protected by anything.
It's just a seed and hence a naked seed. Hence gymnasperms.

(14:28):
So angiosperms they have kind of like a similar process
whereas there's a pollen tube that's grown and the male
pollen has to come in contact with the female pollen
and all that. And we're talking about flowers in most
cases here with andrew sperms, they're the only ones that
flower and produce fruit. So when you think about your
garden with the honey bee and all, that's angiosperm, right,

(14:50):
So that's a non naked seed and that's the that's
where the fruit comes in or the shell comes and
there's area sperms have developed a met achanism to protect
the seed, to better ensure its survival, and if you
think about it, to entice the things that transport these
seeds to go ahead and do their thing. Yeah, there's

(15:12):
like every flower has some sort of cool shape or
scent or color or something that matches with some little
insect or bird or bat that's gonna be enticed. Like
the bumble bee in the fox glove, they go hand
in hand because it fits up there just perfect, and
it has a little colorful landing strip on the bottom

(15:33):
pedal to guide the bumble bee in and it's just
like nature's it's just like harmonious. Yes, there's that one
orchid that I believe Darwin predicted the existence of a
type of hummingbird that had a very long curled beak
right that it co evolves with it and he was
absolutely correct. Remembers in that movie adaptation. Yeah, that's a

(15:54):
great movie. Um, and then, uh, you can learn a
lot from that movie. Yeah, yeah, anything that what's his name,
Charlie Kaufman writes, Yeah, well researched agreed. Um. The fruit
is another thing too. Animals love to eat fruit. The
fruit is basically once the fruit piece of fruit drops
to the ground. That means those seeds are ready to go.

(16:16):
They're ready to become seedlings. But first they need a
fox to eat the apple carried in its stomach over
you know, several meters or miles or whatever, and then
poop it out. And then you have seeds that are
basically just planted. That's amazing. They take purchase and a
new tree begins where his seed her insides where a

(16:38):
rocky place where seed you could find no purchase. So
pollen grains um are actually created. I guess we should
step back a second and talk about myosis. That's the
cells are dividing and growing. Eventually you get a little pollen. Uh.
It looks like a little dust speck to our eyeball,
but it's contains the sperm is not actually the sperm.

(16:59):
It contains into the sperm therein and uh, the pollen
is in pollen sacks at the end of the stamen,
which we talked about, and that little two loabed ant
uh almost aid antler antherer. And then eventually it'll find
its way to the stigma and travel down to the ovary.
And and in the case of angiosperms, there are two

(17:22):
sperm that are used. I don't think we said in
the case of gymnosperms, it's only one of the sperm
is used, right, Yeah, in a in a pollen sect,
there's two sperm, but you just need one for the
gymna sperm for the antio sperm unit to Yeah, because
one is actually fertilizing the egg and the other is
developing into endo sperm together alongside and what will eventually

(17:42):
be the seed. And if you think that sounds gross,
like the gymnos sperm, I'm sorry. The endosperm is like
a protein basically to keep it all alive. Yeah, that
keeps the seedling happy. So when you're eating corn, you're
actually eating the endo sperm. Each corn kernel is actually
you know, it's like that starchy indos form, which the

(18:03):
seed loves to eat itself. And that's true. Um. So
we talked about bees, we talked about birds, foxes, mentioned
poopa a couple of times. Yeah, and you were saying
that like basically every every flowering plant, especially has some
sort of mechanism to attract at least one kind of

(18:25):
um bug or animal that's been proven to help pollinate,
transport this pollen and so I mean for the most part,
we enjoy them, like you like the scent of you know,
a good flower, right, sure, but you might not like
the Devil's Tongue, yeah, which is a sumatran plant that

(18:47):
apparently reaks so badly it smells like a decomposing flash. Basically, basically,
did you see this thing? I've seen it before. You
actually remarkable like two feet and it's like it it
basically um flowers or blooms like once every like ten
years or twenty years something like that. Right, I'm not
sure if it's the same one. I'm thinking of things.

(19:08):
But it's stinky, right, And the reason why it's stinky
is because it pollinates with the help of a type
of carrion beetle that's attracted to decomposing flesh. So the
plant attracts this beetle that likes to eat decomposing flesh
by putting out the smell of decomposing flesh. That's so gross, yeah,
but it's pretty spectacular, it is, you know. Yeah, in

(19:30):
the philodendron, something you might have in your house. It
actually does the same thing, but it doesn't stink always. Um.
There's actual chemical reaction that takes place and heats it
up to omit this odor that the beetle is attracted to,
which sounds pretty gross too, but it all works, and
I would google that um the sumatra and devil's tongue.
It's pretty cool looking. Like the flower itself is two

(19:52):
feet It's not like, oh, what a long stem, It's
just this huge flower. It's amazing. And then you're also
saying like, was it fox glove that provided a landing
strip for bumblebees? Yeah, So flowers in general typically have
certain types of um like their color will be based
on the kind of creature that um that that helps

(20:13):
pollinate it, whether it's diurnal meaning it it's awake during
the day or nocturnal meaning it's awake at night. Right, right,
I guess that's in case of like bats and stuff
like that. Yeah, and then our old friend nectar is
a big lure and basically nectar is around right, just
because it tastes delicious and is enticing from what. Yeah,

(20:34):
it's basically like a little enticement like you said, for
like a bee or something or a bird. Yeah, come
get it. Because it's placed by the stamen that's right,
or the way that the the anthers are situated just
the way they're placed in the flower. If it gave
it an advantage to bump up against that bee, then
it's gonna be successful in the long run and live

(20:56):
out as a species as nice stuff that is pretty good. So, chuck,
we've reached a point where, um, I mean, ever since
we started selectively breeding plants, domesticating crops like hey, that's
pretty right, or hey I like this banana um or
that's hardy and it grows in my awful hot area
that I live in, many reasons to do so, right, Um,

(21:20):
you know, we we wanted to keep plants, we wanted
to keep the bad stuff out, keep the good ones
we wanted in. But it never became more crucial, um
until we started genetically modifying crops. And now all of
a sudden, not only are the corporations saying like, hey man,
you can't cross pollinate with our stuff for else that's

(21:41):
patent infringement, and nearby farmers says, I'm not using your
seeds as the bees, you can't blame me, and the
farmers who don't want GMO stuff in their crops say,
hey man, you need to keep your crops over there
because I don't want your GMO creud in here. I
have an organic farm exactly, and you're just blowing by

(22:02):
the wind. It's a touchy subject. We should do that
as the GMOs. I agree. The idea of like patenting
jeans in general and alone like crops is it's really interesting. Um,
but there's been some pretty clever, simple ways of getting
around this problem. It's posed by pollination of GMO crops
with non GMO crops. Yeah. Well, distance is obviously one thing.

(22:28):
Don't put my farm near your farm. But they have
to do all kinds of studies to see how the
wind reacts and how like how far does that be fly? Yeah,
and they found in uh, in certain parts of Africa,
these will go about four miles three kilometers. That's their
range for food. That's you know, that's a lot. Yeah.
But I mean just using that kind of thinking with

(22:48):
all process though, like okay, well this you know, there's
this guy's growing this over here, so I can't grow
this here, right, That will prevent that kind of pollination though. Yeah.
Another thing they can do is uh, sort of like
with the corn, they can time their crop rotation to
time out so where they're flowering at different times and
not interfering with one another. But um, it's a touchy subject.

(23:10):
Like from what I understand, there's a lot a lot
more going on then you know, is preferred by like
the organic farmers of the world, and in't the GMOs.
They can then say that you're infringing just because they
cross pollinated to their crop, even though you didn't buy

(23:30):
their seeds or even want their seeds. If a bee
carries there, it's there's seeds, there's crops falling over to
your crops. And you start to develop plants that have
the GMO characteristics that's patented. According to the corporations, you're
infringing on their pat It's very tricky ground, there isn't it.

(23:50):
I don't think it's tricky ground. If you ask me,
you should not be allowed to have a patent on
any living organism. Oh well, yeah, you know what I mean, though,
that's my opinion. It gets tricky, uh in courts and
studies and corporations and the course to tend to side
on the corporation's side. Typically. Let's do that one though

(24:11):
soon g MS. Yeah all right, Um, so let's say
for Paullen, if you're interested in how pollen causes allergies
and you should listen to our how Allergies Work episode
That was pretty good. Yeah, I was gonna recommend that.
Nice work. Um, thanks man. So, uh, if you want
to learn more about pollen in the meantime, you can
type that word in the search bar how stuff works
dot com. Since I said search bar, it's time, of

(24:32):
course for a message break. And now how about some

(24:56):
listener mail. Yeah, we have correction. It's been blowing up lately.
Oh man, I'm sorry. You know it's crazy. Is that's
the second time I've done that and a podcast on
that same same thing. I don't remember what the other
podcast was, but I've mentioned it before and we've gotten
tons of corrections about it and I didn't learn my lesson. Well,

(25:16):
this guy was really nice about it, so I'm gonna
read his. And it's an important correction because anytime you're
talking about drugs, so to recap in the PTSD podcast,
we got the two drugs beta blocker called propan and
all which helps with PTSD, confused with propofol, which is
what killed Michael Jackson. And so this is from Chris.

(25:39):
He's a big fan. He's listened to every episode on
his commute in southern California, which we know stinks. So
he said what we just said about the getting the
drugs confused, He seconds, see how you guys can mix
it up because the names are very similar, but they're
significantly different. Obviously, propan and all is relatively mild and um,

(26:00):
I'm only prescribed and very little potential for overdose, while
a propofile is a very powerful drug, extremely high potential
for overdose, and rarely administrated outside of strictly monitored medical settings.
It is actually a hypnotic agent that must be administered
intravenously because we talked about Michael Jackson's drip, and is
often used in conjunction with general anesthetics. Like most general anesthetics,

(26:22):
it's steep dose response curve significantly increases the risk of overdose,
where the effective dose is only slightly below a lethal dose.
That's kind of scary, Yeah, it really is. I mean,
like when you're when you're on that, like you're right
along the border. Yeah. Well, he says, Michael Jackson's case
is extremely rare, as he was essentially exposing himself to
risk similar to those associated with general anesthetics used during

(26:46):
surgery with a higher potential for overdose and death on
a daily basis for a relatively trivial purposes, which were
in this case is insomnia. Yeah, but from what I understand,
he had like years long insomnia. Like this guy was
not sleeping at all, Like they would they wouldn't, They
would give him everything first, and then they try that

(27:07):
last resort and like sometimes it's still wouldn't work. Really, Yeah,
he was really in bad shape at the end. Well,
he probably had a resistance to certain ship things like that.
So Chris goes on to say, I'm not certain about
the exact amount of risk posed by propofile administration, but
I believe the risk of death is something on the
order of tenths of a percent, meaning he would have

(27:30):
died according to the statistical model, within a couple of
years of daily use, like British guaranteed. Frankly, he would
have been better off using heroin that whole time, in
spite of his ironically strict yet poorly informed anti drug stance.
So that's from Chris. Thanks Chris. I was a genuinely
awesome email. That was good, um, and I'm sorry everybody
freaking so wrong. Well, I mean the names are just confusing. Yeah,

(27:53):
but I mean one's like a blood pressure medicine. The
other one's like pretty much a general anesthetic. I know.
But what gets me is that half of the emails
were like, well, yeah, they just sound alike, so you
goofed it in. Half of them were like those drugs
couldn't be anymore different, like you really thought of it,
you know. It's just it's like a verbal TYPEO. Thank you, chuck. Yeah,
thanks for letting me off anyway. Uh, if you have

(28:16):
a correction for us, we really do like to get those.
We like to know what we're talking about. Sometimes we
get we get things wrong. Sometimes I get things wrong,
but we do want to be corrected. Happens in the
nicest way possible, because that's usually who gets their letter
read right exactly. Yeah. You can tweet to us at
s Y s K podcast. You can join us on

(28:38):
Facebook dot com, slash Stuff you Should Know if you
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(29:03):
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