Horses and donkeys can mate, but they produce a mule, which is always a sterile animal. This means that they cannot produce viable offspring and are reproductivelygeographicallytemporallybehaviorally isolated.
Horses and donkeys can mate, but they product a mule which is always a sterile animal. This means that horses and donkeys are reproductively isolated. Two organisms are reproductively isolated if they can not interbreed to produce a viable and fertile offspring.