Why and how are mules sterile?
First thing you have to realise is that all mules are NOT sterile. Most mules certainly are, but there have been numerous authenticated accounts of mules giving birth to perfectly healthy foals. Next thing to do is to ignore those people saying that it is because they are hybrids or because horses and donkeys are different species. Numerous species are perfectly interfertile despite being far more distantly related than horses and donkeys and having far more widely differing chromosomes numbers. Thirdly ignore those people saying that mules are clones. Mules are the product of sexual reporduction. If they were clones then by definition they would be either entirely horses or entirely donkeys. And finally mules have perfectly functional reproductive organs so that isn’t the reaosn. So why are mules sterile? That’s pretty complicated and to be quite honest we still don’t know the whole story. The basic problem is that after the ancestors of donkeys and horses split the chromosomes of BOT
