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Sorry if this has been asked, i searched but found nothing. We can take these as facts, that humans/roumlans/vulans/klingons/betazoids/etc can interbreed and have non-sterile children. We also know that some species like Vulans, Romulans, exist and that in earth mythology those same names occur as names of gods.
It seems to me that this all seems to point to the fact that there was some founding species ages ago who spread their seed and culture through out the galaxy. From a genetic point of view, the fact that all these species can interbreed should show they diverged from the same genome at some period in the past, otherwise it is unprecedented to common medical knowledge.
Also imagine that these same founder gods left their culture, their myths, their stories, etc, with their offspring they left on the planet. Our myths of the gods Vulcan and Romulus/Remus are really just imprints left from the original founders and interpreted/mis-interpreted by us.
Anyway I am just wondering if someone has ever addressed this. Seems kinda interesting to me.