Why Are Mules Sterile?

Horse plus donkey — it seems like an unlikely combination. I mean, they're different species! And yet, when they get together, they can produce a mule or the lesser-known hinny. Either way, those offspring usually can't become parents themselves.

Hosted by: Rose Bear Don't Walk

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#SciShow

[Bigfoot_With_Internet_Access]

There's a mule watching this rn realizing that his wife shouldn't be pregnant

[ItsEmmaBear]

Phew! I was really worried mules were taking over the world. Thank you SciShow. I feel much better.

[siobhantheprawn]

"Why does he call you donkey?"
"Oh, he aw- he aw- he always calls me that"

[adueso]

i have an accounting exam in a few hours, i hope mules show up on the test

[haveagooddaytoo]

Sic show giving us the answers to questions everyone wants to but no one asks

[RohitPant]

These are questions i would think to myself back in the classroom of my school. I am so glad at the power of internet to provide a relief to my questions. Life is a process of learning indeed!

[ExtremePotato]

I could listen to her talk about animal breeding and genetics all day.

[LeoStaley]

Mules are so awesome. They're definitely smarter than either parent.

[nunyabiznes]

I guess this also mean I can go out without fear of a horde of ligers suddenly showing up to kill everyone.

[traildoggy]

"My mule don’t like people laughing, ”
-- Clint Eastwood

[militantpacifist]

Because they’re as stubborn as a mule when you tell them to have kids.

[adrob]

Hey SciShow. Why do we keep messing with things that hurt? Like a cut or a nail that is cut too short?

[rustyshackleford]

Not knowing this all my life makes me feel like a jackass.

[kirkmorrison]

I love mules, if you know how to handle them they are great. You can teach them to plow and cultivate. If you give them enough room to turn, they won't if trained right, they don't step on the crops. Horses will often take a short cut and trample the end of the rows unless you're very careful. You have to watch them like a hawk.

[arthanor]

2:25 That was a weird jump. The odd chromosome was always going to be unmatched since there's no other chromosome. It has nothing to do with pairs being made up of similar or different chromosomes.

[alexiswelsh]

A world run by hybrids, that’s Avatar. Platypus-Bears, Armadillo-Bears, Wolf-Bats, Badger-Moles, etc.

[hardworkingcriminal]

This was interesting. I knew this was the case but I'd never known the science behind why. This was well explained.

[DanMan]

Something I've been wondering about:
How did species evolve different number of chromosomes?
At some point, one member of the species would have gotten an extra chromosome. Hypothetically, a chromosome splits or maybe it is born with an extra copy due to meiosis misfires.
Wouldn't that member of the species have non-homologous chromosomes from every other member of their species? Isn't this what makes mules sterile?
Would two members need to have similar or analogous mutations to be able to breed a new species?

[karendegraaf]

Always an exception....I remember an article in Western Horsemen magazine in the 70s titled Never Say Never about a female mule who reproduced several times, once with a Saddllebred stalliom.

[drewharrison]

I actually knew this but I love hearing conformation of my knowledge. Although the explanation wasn't technical it was easier to understand than the fu story of meiosis. Not to be confused with mitosis.