Hank introduces us to the relatively new field of evolutionary developmental biology, which compares the developmental processes of different organisms to determine their ancestral relationship and to discover how those processes evolved. Also, fruit flies with eyes on their legs and chickens with teeth!

Chapters:
1) EVO/DEVO -
2) Developmental Regulatory Genes -
3) Gap Genes -
4) Homeobox / HOX Genes -
5) Messed-Up Experiment -
6) EVO/DEVO & Evolution -
a) Chickens with teeth -

In which John Green, Hank Green, and Emily Graslie teach you about evolution. So, in the last 3.8 billion years, life on Earth has evolved from single-celled prokaryotes to the dizzying array of life we have today. So how did all this happen? We'll talk about Darwin, evolution, natural selection, and how we got from there to here, and from then to now.

Humans may have been around for a long time, but life has existed for way longer. In this episode of Crash Course Biology, we’ll journey through deep time to uncover the history of life on Earth. We’ll explore the big, game-changing leaps where life diversified, changed, and just plain persisted.

Introduction: How Life Began
Macroevolution
RNA & DNA
The Timeline of Life
Stromatolites & Fossils
Dr. Meeman Chang
Drivers of Macroevolution
Review & Credits
Credits

Hank takes us on a fascinating journey through our excretory system to learn how our kidneys make pee.

Chapters:
1) Homeostasis & Osmoregulation
2) Urea & Uric Acid
3) Kidneys
4) Nephron
5) Glomerulus
6) Bowman's Capsule
7) Proximal Convoluted Tubule
8) Biolography
9) Loop of Henle
10) Distal Convoluted Tubule
11) Collecting Ducts
12) Ureters, Bladder & Urethra
Review

We’re finally to the end of our time together here on Crash Course Study Skills, so this week we’re taking a more holistic approach to being the best learner you can. Part of taking care of your brain is taking care of your whole body, of which your brain is a part. We’re wrapping up this course by outlining some good tips and tricks for maintaining a healthy body, and why it’s such an important part of being a great student.

Today Phil explains that YES, there are other planets out there and astronomers have a lot of methods for detecting them. Nearly 2000 have been found so far. The most successful method is using transits, where a planet physically passes in front of its parent star, producing a measurable dip in the star’s light. Another is measuring the Doppler shift in a star’s light due to reflexive motion as the planet orbits. Exoplanets appear to orbit nearly every kind of star, and we’ve even found planets that are the same size as Earth. We think there may be many billions of Earth-like planets in our galaxy.

Chapters:
Introduction: Exoplanets
Reflexive Motion
Discovering the First Exoplanets
51 Pegasi b
Exoplanets in Transit
Detecting Exoplanet Transits
Photographing Exoplanets
Kinds of Exoplanets
Earth-like Exoplanets
Review

European exploration had a lot of side effects. When the Old World and the New World began to interact, people, wealth, food, animals, and disease began to flow in both directions. In the New World, countless millions were killed by smallpox, measles, and other Old World diseases. Old World animals changed life in the New World irrevocably, and the extraction of wealth and resources from the Americas ultimately contributed to the development of the Atlantic Slave Trade. So, it was an exchange with a lot of downside, especially for non-Europeans.

In 19th century Europe, with nation building well under way, thoughts turned outward, toward empire. This week, we're looking at how Europeans expanded into Africa, Asia, and Oceania during the 1800s. You'll learn about China and the Opium War, British India, and the Scramble for Africa.

So we’ve learned a lot of strategies to fight off failure. But we could be doing all this right and still fail if we straight-up run out of money.

Expenses can pop-up, supplies can suddenly be hard to find, or delivering the most value to customers can involve some expensive choices. Businesses can run out of money -- it happens. But it doesn’t have to happen to us.

Take a 360-degree virtual tour of our Solar System, with the help of Crash Course Astronomy host Phil Plait!

In which John Green, Hank Green, and Emily Graslie teach you about what happened in the Universe after the big bang. They'll teach you about cosmic background radiation, how a bunch of hydrogen and helium turned into stars, formed galaxies, created heavy elements, and eventually created planets.

Join us here, in the darkness. Our theater journey takes us into the heart of expressionism today, as playwrights in the late 19th and early 20th centuries explored the limits of human beings' tolerance for a mechanized, industrial world. Spoiler alert: those playwrights didn't think humans fared very well in the industrialized world. They EXPRESSED that concern about modernity through some pretty dark plays, with pretty dark sets, and pretty dark content.

We're off to fact-checking school. This time, John Green is teaching you how to fact-check like the pros. We're going to walk through the steps that professionals follow, including figuring out who is behind the information we read, why they're sharing that information, and what kind of evidence exists to back up the claim. We'll also talk about the difference between skepticism and cynicism.

The aftermath of the collapse of the Soviet Union and its Warsaw Pact had a huge impact on the countries of Eastern Europe. As the former satellite states turned away from communism and Soviet influence, some of them shifted toward democracy in an orderly way, and some descended into violence and bloodshed and ethnic recrimination. In many ways, this collapse is still playing out today. In this video you'll learn how countries like Czechoslovakia, Yugoslavia, Poland and many others moved into the post-Soviet world.

In which John Green teaches you about the fall of the Roman Empire, which happened considerably later than you may have been told. While the Western Roman Empire fell to barbarians in 476 CE, the Byzantines in Constantinople continued the Eastern Empire nicely, calling themselves Romans for a further 1000 years. Find out what Justinian and the rest of the Byzantine emperors were up to over there, and how the Roman Empire dragged out its famous Decline well into medieval times. In addition to all this, you'll learn about ancient sports riots and hipster barbarians, too.

Chapters:
Introduction: The Fall of Rome
Why Did the Roman Empire Fall? Barbarians at the Gates
Why Did the Roman Empire Fall? Barbarians Inside the Gates
An Open Letter to Pants
Constantine and the Eastern Roman (Byzantine) Empire
Comparing the Eastern & Western Roman Empires
Emperor Justinian
The Orthodox and Catholic Churches Split
Credits

Today we are investigating our moral obligations to our parents and our families. Do we owe our parents anything as adults? Would it be a good idea to license parents? We’ll explore these questions as well as the ethics of care, and some potential problems that type of approach to morality carries with it.

In which John Green teaches you about one of the least family-friendly family dramas in the history of family dramas, Oedipus Rex. Sophocles' most famous play sees its main character, who seems like he's got it all together, find out that he's killed his father, married his mother, had a bunch of incest children, and brought a plague down on his adopted hometown. He doesn't take this news well. John touches on all the classic Oedipus themes, including hamartia, fate, and the wrath of the gods, and even gets into some Freud, although Oedipus was notably not a sufferer of an Oedipus complex. In any case get ready for mystery, incest, bird entrails, and self-inflicted blindness. Very dramatic.

The 1930s in the United States were pretty bad for employment in all industries, and the theater was no exception. As part of Roosevelt's New Deal, the Works Progress Administration created a division called the Federal Theatre Project. The agency created theater companies across the country to put actors and crew back to work in the theater industry. The shows were free, and thanks to forward thinking administrators, a lot of them were pretty interesting. You'll also learn about the Group Theater today. They're the super-influential troupe, with the totally lame name.

In which Craig Benzine teaches you about federalism, or the idea that in the United States, power is divided between the national government and the 50 state governments. Craig will teach you about how federalism has evolved over the history of the US, what powers are given to the federal government, and what stuff the states control on their own. And he punches an eagle, which may not surprise you at all.

In this episode of Crash Course Psychology, Hank talks about these things called "Emotions". What are they? And why do we need them?

Chapters:
Introduction: Emotions
Theories on Emotions
Cognition & Emotion
The Spillover Effect
Top-Down vs Bottom-Up Approaches to Cognitive Processing
The Autonomic Nervous System
Optimal Arousal
Review & Credits
Credits