Originally Posted by metaphysician
I'm not sure I'd say that Jotuns and Aesir are the same species. They probably do have a connection to the same power source, but that's simply because there are probably a common set of exotic physical laws and energies that superpowers of any kind tap, whether you are Jotun, Asgardian, or Human.
They share too much with each other-in mythology they have children all the time, Odin`s mother was Jotun for example and mother of Thor sons too and thous children retain all of the qualities of parents. It all can be count out as "in myth and MU all can interbreed", but if we go with scientific explanation it can be close to truth in my opinion.