[MHGinTN]

It would be interesting, from a scientific point of view, if the visitors actually turned out to be bipedal, have two eyes, swing two arms, etc. Is there some imperative for this evolutionary outcome? Know what I mean?

[Calvin Locke]

Probably. Opposable thumbs. Depth Perception. Four limbs frees the brain for *other* things, like thinking, logic.

Not to mention symmetry. Handy for clothing (shelter), and tool development.

[Vinnie]

It would be interesting, from a scientific point of view, if the visitors actually turned out to be bipedal, have two eyes, swing two arms, etc. Is there some imperative for this evolutionary outcome? Know what I mean?

That is something I have often thought. IF these 'grays' are for real, the similarities to humans is striking. Evolution or intelligent design, my vote is creation, the probability of two separate worlds evolving similar creatures light years apart is beyond remote.