There is a related long running argument about the ability of certain large simians and humans to interbred. Genetically humans are close enough to some species to make it at least plausible. If it worked, the result would probably be a mule of some sort, not quite fitting into either species.

The legal and ethical questions are rather ugly. Our legal system has not begun to address the fact that what we call 'human rights' should be 'sentient rights.'

Jay