I definitely loved the explanation Wanda and Kal give for their assumption that Kryptonians and (terran) humans are one and the same species. Pretty accurate, but there's one more thing to consider: Horses and donkeys are able to crossbreed, but their common offspring are infertile. In order to prove that the humans from Krypton and earth are one species, the children of Lois and Clark (or Wanda and Kal-El) must be proven fertile - preferably with both races mother races...
I am thinking in terms of natural, in the wild type breeding. I don't think horses and donkeys do it without human intervention. However, I recall reading that wolves and dogs do and have fertile offspring and I believe coyote/dog blends are fertile as well. I am of the opinion that humans and Kryptonians wouldn't even be interested in breeding if they weren't in fact close enough genetically to make breeding possible. (Unlike in Star Trek where it appears humans will breed with rabbits if given half a chance - that or Sarek was one pervy puppy going after a human woman.)
Besides, wouldn't a physical exam, even of a child, show whether or not the gonads had developed properly?
Now if the council believes this is another story.
