A few power points it feel on the subject... It theoretically takes many lifetimes to be observed. We have only begun recording information for the last few thousand years... And that's being generous. It isn't as though there was a focus on the intricate details of random species until a few hundred years ago. My conclusion to that is this... Why have humans come to conclusions on the subject, with such a small amount of time passing? Would it not make more sense to observe over a longer period of time, instead of treating the occurrence as fact or fiction? On a social level, I've always seen the scientific and religious community as a " Mexican Standoff ", personally. A scientist and priest both require blind faith to be followed. Don't be confused by the wording. A priests beliefs requires faith within the majority of his system, whereas the scientists version is more " figurative ". The reason being that, there is a lot of theoretical ideas that a common human being cannot comprehend. You can scream it to the masses, wether it is accurate or not, but there will be many empty heads bobbing up and down, or left to right. I like these kind of discussions. More so from a Historians point of view ( why not add another imperfect area of belief to it? ). I find that both are guilty of indoctrinating masses of people into blind faith. From the religious corner, I'll simply quote " IN HOC SIGNO VINCES ", and leave it at that. As for the scientific community, the repression of highly intelligent individuals is astounding. More than a few who wouldn't be a talking head, or partake in their centuries version of " Manhattan project ", are pushed into obscurity. If I went to one of the most extreme individuals, I'd believe we descended from Aliens. If there was a modern day Constantine, perhaps he would have an Isotope in his insignia, along with the crown and cross.