text: It isn't known.  The only way to tell would be to try it and nobody seems interested in volunteering.\n\nHowever, it might be possible.  Horses and donkeys are genetically *less* similar to each other than humans and chimps, but can produce young, occasionally even fertile young.\n\nOh, and different chromosome number does not automatically preclude breeding.  There are some species of butterfly which are capable of producing fertile offspring between individuals with 20 chromosomes and those with over 60.  What matters is how similar the chromosomes are.  Chimpanzees had two of their chromosomes fuse not far back in evolutionary history.  You can still see the teleomeres ("endcaps" of the chromosomes) in the middle of the one that resulted from the fusion.  Since the structure of the genes on the chromosome hasn't chnaged much, we may well still be compatible to some extent.