As the science of life, biology is about everything that lives, grows, poops, and dies.

If you’re breathing right now—and I sure hope you are—that’s biology at work! And it’s not just happening inside of you, but also above you, below you, and all around you.

Basically, biology’s got you surrounded. It’s in the medicine you take when you’re sick and the vaccines that keep you from severe illness. It’s in your dog, selectively  bred to be your best friend.

It’s in your body’s 30 trillion cells, working hard behind the  scenes as you belt out some Beyonce in the shower [to the tune of Beyonce’s Halo]  “I can see your Bio! Bio! Bio!

Bioooo!” And in the 40 trillion microbes treating your guts like an apartment complex as you digest last night’s pizza. It’s also in last night’s pizza. We owe the wonders of tomato, bread, and cheese to the power of soil, sun, and photosynthesis.

Biology is behind the pineapple as well, though I’m not sure who’s to blame for putting pineapple on pizza. And I know that this is like a big argument these days but my hot take is: eh, it’s all right. No shade.

So, really, biology is about everything alive and what makes life worth living. Now I know some of you might be thinking: “Didn’t you already do a Biology series?” Yes, we did. And Hank’s goatee won’t be back for this one.

But we’re using everything that we’ve learned over the past decade of Crash Course to make you an even better series. Biology 2.0, if you will. Extra-shiny.

Hi. I’m Dr. Sammy, your friendly neighborhood entomologist, and I’ll be your host.

I’m the Endowed Professor of Entomology at  the University of Colorado Boulder,   where I study honey bees and teach about  symbiosis and science communication. My work focuses on how creatures form super  close, amazingly complex relationships, like the ones between pollinators and flowers that are responsible for much of our food, or the parasites munching on the bees' liver that threaten that intricate balance of pollination. We’ll talk about lots of fascinating stuff like this and more  in this series: our NEW Crash Course Biology.

Over the next 50 episodes--wait, 50?! So we're gonna...50 of 'em? It's fine, we got this.

We got this! 50 episodes *clears throat* Over the next 50 episodes, we’ll find out  just how connected life really is. We’ll zoom between itty-bitty cells and vast, global cycles. We’ll discover how species evolve, how genes work, and what the heck happens inside a cell anyway,   and what sends nutrients ricocheting  from soil to your stomach and back again.

We’ll also take a look behind the science, through the stories of biologists – both past and present – that you might not have heard before. Like, how Dr. Anurag Agrawal found out that chewed-up radish plants fight back against Very Hungry Caterpillars.

Or how Dr. Jane Cooke Wright proved that a chemotherapy drug still in use today could work, at a time when chemotherapy was thought taboo or absurd. At the same time, we’ll see how biology can help us respond to our global challenges like hunger, access to clean water, and climate change. We’ll find it’s not so easy to pin down exactly what life is.

But that one little word–life–connects living, breathing you to every bug, bat, and barnacle that has ever, well, lived. So join me as we explore our place in a big, diverse family tree, about 4 billion years in the making. I’m so excited to discover it with you.

This series was produced in collaboration with HHMI BioInteractive. If you’re an educator, visit BioInteractive.org/CrashCourse for classroom resources and professional development related to the topics covered in this course. Thanks for watching this episode of Crash Course Biology, which was made with the help of all these nice people.

If you want to help keep Crash Course free for everyone, forever, you can join our community on Patreon.