It's quite simple to accept that aliens visited earth in the past to help human development if you accept that the universe is, in fact, banana-shaped.
Actually, the Romans invented concrete - they even built harbours and large domes out of it. http://en.wikipedia.org/wiki/Roman_concrete The Parthians (contemporaries of the Romans) may also have known about DC electricity, viz. the Baghdad battery, which might have been used to electroplate gold and silver: http://riversfromeden.wordpress.com/2011/08/18/electricity-in-the-ancient-world/ Perhaps this technology was the origin of Alchemy if the knowledge became corrupted through secrecy and mysticism? Human ingenuity 2, ancient aliens 0.
Evidently the Romans also invented time machines, which would explain why Asbo Zaprudder's post is almost six months late.
I will start by saying that I think RAMA's notion that technological singularity will happen in 50 years is all but excluded - indeed, the notion that the technological singularity is possible at all, given the psysical laws of the universe is in serious doubt (and is closer to being disproven that proven). These being said, the argument you just presented, newtype_alpha, is also highly unconvincing: -so, only a fraction of humanity will have access to changing themselves to be smarter and stronger. And? Evolution was NEVER an equal possibility process. This fraction of humanity will outcompete the rest - as in they/ their descendants will survive and the rest will dissappear, going the way of the dinosaurs -, as has happened many, many times in the history of life on Earth. -even today, very few natural disasters can endanger a race of humanity as a whole - these are the type of disasters that endanger all of humanity (a gigantic asteroid, few others). The regional disasters you mentioned don't even come close. You seem to think that all competitors surviving and having a share of the future is a requirement of evolution. Very 'happy ending', but the opposite of correct, newtype_alpha.
And that's just plain old "survival of the fittest" evolution like we've already had for millions of years. Significantly, we don't actually control which genetic modifications become the prevalent ones, or which populations in a competing genetic arms race actually win the battle for supremacy. Just because intelligent agency is involved doesn't change the underlying mechanism. It's a requirement of the type of evolution Stephen Hawking has in mind, where humans evolve based solely on what they NEED, not on the determinate and ruthless (and considerably slower) process of natural selection.
Of course the underlying mechanism doesn't change. What does change is the fact that slow random genetic mutations are replaced with fast intelligent modifications, genetic OR otherwise, which WILL give desirable traits (intelligence, for one). It remains ruthless. But it's no longer slow.
Duration doesn't necessarily reflect quality. The fact the Ancient Aliens show is still on the air tells us that.