Thank you to Skillshare for supportingÂ
this episode of Journey to the Microcosmos.  If you are one of the first thousandÂ
people to click the link in the description  you can get a free trial ofÂ
Skillshare’s Premium Membership. There’s a lot of green in the world,Â
and that is thanks in no small part  to the microcosmos. Not only did cyanobacteriaÂ
lay the foundation for an oxygenated Earth,  they laid the foundation for chloroplasts whenÂ
they were endosymbiotically consumed helping  their host take on their photosynthetic machinery.
For most of us, the green we are confronted with  every day is a more macroscopic kind, the leavesÂ
you see on trees and grass. And if you’re on a  hike, you might notice some squishy bundles ofÂ
green flush against a tree, or low to the ground. “Oh, a moss,” you might tell yourself. Or “oh, aÂ
lichen!” And then, perhaps, you move on, unsure  of whether you’ve called it the right thing butÂ
distracted by the many other sights around you. But today we’re not going to letÂ
that happen. We’re going to linger  on our non-vascular plant friendsÂ
and look at them a little closer,  learning more about what they are, and whyÂ
only one of those things is actually a plant. …it’s the moss. Moss is the plant.
More specifically, moss is a member of the  plant division called Bryophyta. And when we sayÂ
that moss is a non-vascular plant, what we mean  is that it doesn’t have the vascular tissue like aÂ
xylem and phloem to transport water and nutrients  around the plant. This lack of vasculature keepsÂ
mosses short so that they can still transport  nutrients and water easily. And while they don’tÂ
technically have roots or leaves as defined for  vascular plants, you’ll see the equivalentÂ
structures like their root-like filaments  called rhizoids and also these leafy parts.
And mosses provide a lot of benefits to the  environment around them. They help preventÂ
erosion, and they can provide insulation.  And we’ve seen ourselves how mosses provide aÂ
home to some of our favorite microbial companions. Lichen on the other hand though they areÂ
sometimes called non-vascular plants,  they are very definitely notÂ
plants. So what is lichen? In a 2010 Discovery article, the lichenologistÂ
Trevor Goward described lichen as “fungi  that have discovered agriculture.”
To be more specific,  lichen is a symbiotic union between a fungus andÂ
an algae. The fungus provides access to nutrients,  as well as protection from the elementsÂ
and UV light. And in exchange, the algae  provides its own photosynthetic capabilities.
Now that sounds straightforward enough, especially  when you consider all the symbiotic relationshipsÂ
we’ve learned about in the microcosmos.  Put together the right fungus, and theÂ
right algae, and you get a lichen…right? Well, scientists have attempted toÂ
create lichens in the lab by culturing  the appropriate partners together, butÂ
with little success. And it turns out  that that might be because we’ve underestimatedÂ
the number of partners involved. In one study,  scientists found that there was at leastÂ
one other fungal partner in their lichens.  And it could be that other species have manyÂ
many other members involved, making them  far more complex than we have understood thus far.
For something so strange and complicated,  lichens are amazingly prevalent: they’re estimatedÂ
to cover up to around 6% of our planet’s surface,  whether that’s on the side of a tree or on a rockÂ
or even on dunes. And lichens have this ability  to not only latch on to all sorts of surfaces,Â
but to disrupt them and convert them into a more  habitable environment by releasing minerals andÂ
creating the early ingredients for future soil. And so because lichens are so important toÂ
cultivating the seemingly inhospitable parts of  our world, many have thought lichens were possiblyÂ
one of the first organisms to make it onto land.  But research from 2019 has suggested that lichensÂ
didn’t find their way to land until well after  vascular plants did. In fact, it could be as longÂ
as 100 million years after, raising new questions  about how plants and our own earth evolved.
Now mosses are also part of this story,  as they were likely among the earliest plants toÂ
make it onto land. And their ancient spread may  have played an important role in raisingÂ
oxygen levels to where they are today,  allowing for the evolution of not just other plantÂ
life, but of more complex animal bodies as well. With that said, the trick with evolutionÂ
is to know that creating a whole world  is much more complicated than any oneÂ
step would have you believe. Mosses and  lichens carry their own worlds in their spreadingÂ
masses, not fully invisible like the microcosmos,  but often underfoot and easy to ignore. ButÂ
maybe if you spot some on a walk, take a moment  to look a little closer, and to wonder whatÂ
other secrets they might possibly hide. Thank you for coming on this journey with us asÂ
we explore the unseen world that surrounds us. And thank you again to SkillshareÂ
for supporting this video. After staring at all of this moss,Â
maybe you’re thinking, “You know,  I could use more plants around the house.” ButÂ
you might also be worried that you don’t have the  green thumb necessary to keep those plants alive.
Well, with classes like Happy Houseplants,  hosted by the botanist Chris Satch, SkillshareÂ
can make sure you have everything you need  to pot and care for your plants so that they liveÂ
long, healthy lives. That’s right. Skillshare,  you can learn Python, you can learnÂ
plants. This course can teach you  how to troubleshoot for your plants as well asÂ
more specific skills like how to pot a cactus. Skillshare is an online learning communityÂ
that offers membership with meaning.  With so much to explore, real world projectsÂ
to create, and the support of fellow-creatives,  Skillshare empowers you to accomplish realÂ
growth. It’s curated specifically for learning,  meaning there are no ads to distract you, andÂ
they’re always launching new premium classes,  so you can stay focused and followÂ
wherever your creativity takes you. A Premium Membership will give youÂ
unlimited access, so you can join the  classes and communities that are right for you.
And an annual subscription to Skillshare is  less than $10 a month, and if you’re oneÂ
of the first 1,000 people to click the  link in the description, you can get a freeÂ
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right now? They are our Patreon patrons.  If you like what we do here and you’d like toÂ
join them check out patreon.com/journeytomicro. If you want to see more from ourÂ
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button somewhere nearby.
r/MossMan
Alice Algae and Freddy Fungi took a lichen to each other, and they’ve been on the rocks ever since.