[quote=@MangoJuice]
<Snipped quote by Joegreenbeen>

I don't believe it has before in Civ RP history. Would it be possible? Would their DNA be compatible? Maybe in the future you can splice genes.
[/quote]

By definition two different species cannot produced viable ofspring. However, similar species, usually within the same genus, can produce non fertile hybrids, think like a Donkey and Horse producing a Mule.