Thanks to Skillshare for supporting this  episode of Journey to the Microcosmos.

The   first 1,000 people to click the  link in the description can get   a free trial of Skillshare’s Premium Membership. You've probably gone through something like this  before.

You have a loaf of bread sitting around,   waiting to be eaten. And you fully intend to eat  it, you might even have had the perfect sandwich   in mind. But then you go grab some slices and you  notice that someone…or something…got to it first.  It’s the mold, the dreaded  hairy patches of black, blue,   green, and gray expanding like a circular  lawn intent on taking over your bread.   It seems to come out of nowhere, but once  it arrives, there is no getting rid of it.  If you’ve been following our journey through the  microcosmos for a while now, you might remember   that we talked about slime molds before.

So maybe  it seems to you that we have covered mold already.  Except that when it comes to nature, it  turns out that historically, humans have   not been so great at naming things, which is not  entirely our fault. We have, for obvious reasons,   tended to use similar names to describe  organisms that look similar to each other.  And slime molds kind of resemble bread mold,  with the way they both fly around the world   as small spores, and the way that they both  creep and spread across surfaces. But this   resemblance hides some pretty big differences.

For example, a slime mold is a protozoan,   which means that the large organism you  see is actually a single-celled eukaryote   able to push the boundaries of its one  cell further and further and further.  Mold, regular old mold, like  the kind you see on bread,   are not anything like that. They are an entirely  different kingdom, in fact. They... are fungi.  And there are a few fungal species that are  known to make up bread mold specifically,   the most common of which are the multicellular  Rhizopus, Penicillium, and Cladosporium2.  As we said, fungi are their own kingdom of  life, just like protozoans and plants.

But   while their growth and way of life might make  them sometimes resemble members of other kingdoms   like plants and protozoans, it turns out fungi  are the animal’s kingdom’s closest relations3  Of course, family relations mean nothing  when there’s food on the table. And fungi   are not like us. They can’t just go to the  store to pick up a loaf of bread.

They can   however travel, flying through air or swimming  through water as spores. These spores are kind of   like seeds, waiting for the right combination of  temperature, acidity, and moisture to take root.  And for some lucky spores, bread can  potentially provide those conditions.   Especially pre-sliced bread, which has all  those nutritious nooks and crannies to grow in.  And mold are very good at growing. Starting from  the spore, the fungus begins to expand in the   form of threads called hyphae.

The hyphae grow at  the tips, their walls made out of the tough but   flexible chitin that allows them to get creative.  Sometimes the hyphae form branches of their own,   and sometimes they will fuse with one another. The result is a web of hyphae called the mycelium.   But the mycelium is not just a matter  of spreading. It’s a network that acts   as a feeding apparatus.

The hyphae will secrete  enzymes into the bread around it, breaking down   its nutrients so that the fungus can eat. It’s  basically just a really large network of mouths.  This makes for a frustrating sight  when we’re looking at our despondent,   gross slices of bread. But when you see a piece of  mold growing and eating away at a piece of bread,   you are seeing a loose approximation of the  same processes that made our world possible.  We’ve seen this before with lichen, a  collaboration between fungi and algae that   breaks down rocks into the mineral components  that sustain other forms of life.

And fungi   can break down so much more. There are  even species in Chernobyl, eating away   at radioactive material like hot graphite Fungi, they could eat the world, if they   wanted to. But their path is much more subtle  than their fuzzy appearance might suggest.   Because fungi don’t just tear things apart.  They also form relationships—significant,   essential relationships—with other organisms.

A plant’s roots, for example, might become   intimately entwined with a fungi’s hyphae,  forming a bond we call the mycorrhiza.   And as fungi hook themselves up to different  plants, they can connect the plants themselves,   serving as living bridges to exchange everything  from nutrients to chemical warning messages.  So it is tempting, when writing about fungi,  to treat them as something that needs to be   redeemed. After all, for many of us, fungi  are the thing that rots. They put an end   to our bread, our fruits, and our snacks.

And It’s so easy to redeem them when they   clear the world for us. When the bread mold  that disgusts us also famously supplied us with   penicillin, an antibiotic that after  its accidental discovery in mold   went on to save countless lives. But fungi, however prevalent they may be,   are a challenge to pin down.

In his book Entangled  Life, the mycologist Merlin Sheldrake writes,   “I have tried to find ways to enjoy the  ambiguities that fungi present, but it’s   not always easy to be comfortable in the space  created by open questions. Agoraphobia can set in.   It’s tempting to hide in small rooms built from  quick answers. I have done my best to hold back.”  Ambiguity is not difficult to find in  nature, especially when we’re venturing   into the microcosmos.

These are organisms  that speak to a world that long pre-dates us,   and in their enduring nature, they suggest a  bit of what the world may look like after us.  Thank you for coming on this journey with us as  we explore the unseen world that surrounds us.  And we’d like to also say thank you to  Skillshare for supporting this video.  If you’re looking for a more aesthetically  pleasing way to bring fungus into your home,   you can check out the “Sculpt your  Own Mushrooms” course on skillshare.  Host Stephanie Kilgast will guide you along as  you use polymer clay to sculpt and then paint   three different kinds of fungus for a fantastic  desktop display. It’s a fun project that can   be done in a couple of hours and there are no  special skills required so you can start making   your own mushrooms right now! And there are tons  of easy to start classes like this on Skillshare.  Skillshare is an online learning community that  offers membership with meaning.

With so much to   explore, real world projects to create, and the  support of fellow-creatives, Skillshare empowers   you to accomplish real growth. It’s curated  specifically for learning, meaning there are no   ads to distract you, and they’re always launching  new premium classes, so you can stay focused   and follow wherever your creativity takes you. And an annual subscription to Skillshare   is less than $10 a month.

If you’re one  of the first 1,000 people to click the   link in the description, you can get a free  trial of Skillshare’s Premium Membership.  The people on the screen right now, well they are  our Patreon patrons. Every single one of them is   like a delightful little fungal spore implanting  itself in the fertile ground of the microcosmos   and then stretching their mycorrhizae out and  secreting digestive enzymes into our creative   brains so that we can continue to pump out  good microcosmos content. If you want to   become one of those delightful spores, I don’t  know if this is a good pitch or not, regardless,   you can go to patreon.com/journeytomicro If you want to see more from our master of   microscopes James Weiss, check out Jam & Germs on  Instagram.

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