If insect-resistant means tsetse fly (which was why the idea if taming zebras was briefly fasionable) then it’s worth noting that this wasn’t a problem until 1896, when the rinderpest killed all the cattle, whose grazing had kept the land grass not bush.

For the owners of said cattle, one answer is like the maize: they already had cows!

These farming and cow-herding people were busy replacing other african peoples. Why the others didn’t domesticate zebra... comes back to why weren’t they farming too? I don’t know if we have a great theory for why farming started when it did, anywhere: what kept the mesopotamians away from farming from 20000-10000 years ago?

> what kept the mesopotamians away from farming from 20000-10000 years ago?

Actually, this is one that we do have a good answer for: The most recent Ice Age was still well in effect during that time period.

Ah right, I forgot about that! Not that Iraq was anywhere near an ice sheet, but it was a whole lot drier.

Still, is the argument that there were no climatically suitable zones in 20k.BC? That they were smaller, too small for some critical mass of proto-farmers?

I believe Jared Diamond answers this question in Guns, Germs and Steel. Africans didn't have iron tools (or acquired them relatively late) and so were not as effective hunters. The animals therefore had a much longer time to adapt against their predators.

gwern rejects Diamond's hypothesis later down the thread, so I'm interested in hearing about any alternate hypothesizes he may have.