This episode of SciShow is brought to you by Skillshare. [♪ INTRO].

I don't know if you've noticed, but zebras look an awful lot like horses. They're even part of the same equine family, and you can cross-breed them into an animal called a zorse.

But no matter how similar they look, don't be fooled: Thanks to their biology and evolution, you just can't ride a zebra. It's a beautiful, stripey, majestic trap. According to archaeological evidence, humans have been taming horses for at least 5500 years, but our relationship with zebras goes back much farther.

Humans and zebras have spent millions of years together because both species evolved alongside each other in Africa — and that's actually where the problems with zebra riding start. Because even though we've spent millennia together, it's not like humans and zebras were best buddies. For quite a while, early humans saw zebras as food, and not much else.

There's even evidence that we hunted them, so our striped neighbors kind of grew up knowing that people were bad news. According to some researchers, that means they could be predisposed to fear us. Horses, meanwhile, didn't encounter people until much later, and we likely didn't hunt them long enough for them to pick up the same fear.

But even though we totally started our relationship off on the wrong foot, there's actually an even bigger problem with zebras: Their evolutionary history has made them just plain nasty. They spend their whole lives surrounded by large predators like lions, cheetahs, and hyenas, so they have a really well-developed fight and flight response. That means zebras are flightier than horses, and a lot more aggressive.

Corner a zebra, and it will bite and kick and in general try to end you — because those are the kind of skills it needs to survive in the wild. And a zebra's kick is serious business. An adult zebra can kick hard enough to break a lion's jaw, and zebras injure more American zookeepers than any other zoo animal.

This aggressiveness is such a big deal that some researchers have even looked for a genetic component to it, although they haven't found anything conclusive yet. Either way, trying to convince a zebra to let you ride it is just asking to get hurt. And I don't know about you, but I would rather walk somewhere than deal with that.

Finally, temperament aside, zebras aren't built for riding. Even though they're from the same family, they're smaller than domestic horses, and their backs aren't as strong, so they're not able to comfortably carry as much weight. They also have thick necks, so it's not so easy to direct them with reins.

And because they're so ill-tempered, they're a lot more prone to getting fed up when they're tired, and that's likely to end with your swift introduction to the hard ground. This isn't just a hypothesis, either. During the Victorian era, when Europeans were attempting to colonize parts of Africa, taming zebras was a popular idea.

Their horses weren't that useful, because in sub-Saharan Africa, they were susceptible to a fatal disease commonly called animal sleeping sickness, which is carried by tsetse flies. Zebras, meanwhile, almost never catch this disease because they're only rarely bitten by tsetse flies — possibly because the flies are put off by all those stripes, or maybe because they have natural fly repellent in their skin. Whatever the reason, Europeans took note of this and famously attempted to domesticate the horse's striped cousin.

And while there were a few individual successes, this was, for the most part, an abysmal failure. Today, people have mostly given up on riding zebras — partly because we've come to our senses, and mostly because we have jeeps now. Still, it goes to show that no matter what we mighty humans do, nature can sometimes still get the upper hand.

And that's probably okay. Speaking of things getting the upper hand… emails. Whether you're a student who needs to unsubscribe from all of those listservs or a SciShow host waiting for the next script to come in, e-mail inboxes can sometimes feel like black holes.

Or time sinks. Or mountains of chaos. And that's why I'm glad Skillshare exists.

They have a bunch of productivity-related classes, including a Skillshare Original class specifically on e-mails, taught by technology writer Alexandra Samuel. It's full of tips about filters, folders, routines, and it even has a worksheet to help you figure out how to apply everything. Conveniently, Skillshare is offering SciShow viewers two months of unlimited access to all 20,000 Skillshare classes for free!

So whether you want to be a better e-mail manager or learn a new skill like videography or writing, there's plenty to check out. You can learn more at the link in the description. [♪ OUTRO].