[donh]

Yes one would expect a lion and a tiger or a zebra and a horse to be able breed(altough producing sterile offspring) when forced by humans into an un-natural enviroment.

No, you wouldn't. By your lights, they are separately created species. If they are separately created species, there is no more particular reason to think that a lion and tiger might mate, and produce any sort of offspring, than to think that a turnip and turtle-dove could mate, and produce any kind of offspring.

[snowballinhell]

Dogs, wolves et al - Canis
lion, tigers et al - Panthera

Should be able to breed

Canis to Panthera - NO GO