LNH: War Without Worlds #3

[Dave Van Domelen]

     Closely related species can interbreed, but the result is USUALLY
sterile.  i.e. mules, ligers, etc.  But there are a handful of documented
cases of mules that were fertile.  The hard barrier of species is not as
rigid as once thought.

     Dave Van Domelen, and in comicbook settings, as long as the plumbing all
fits together properly, all saponts are interfertile....