Something In the Way

Evolution.  "Which is, of course, what this is all about."  Agent Smith, in The Matrix(1999, Fox Studios/Village roadshow pictures) faces a similar dilemma that we, as modern humans, do.  He wants out of his currently restrictive existence.  However, there is something in the way: Zion, the last human city.  The main difference between Agent Smith and many H.Sapiens is the fact that he knows how to solve his problem.  Get the codes to crack the mainframe, destroy the free humans, and he no longer needs to be inside the Matrix.  It's not  that easy for us.
Our Matrix, the planet Earth, holds us rather tightly.  It protects us with atmosphere and magnetic field.  It currently produces enough food for the human race to survive.  Barring a sudden natural catastrophe, on Earth, we humans have it pretty good.  Added to all that is the fact that we don't really have a need to evolve.
A 30.06 rifle is sufficient to take down any animal we consider food.  A combine and tractor is more than enough to harvest all the grain we need, and our hands are perfect for gathering vegetables and fruit.  A pair of boots, some rope, and minimal climbing gear are adequate to take the average human being to any part of our biosphere that has the ability to support them as an organism.  There is no earthly necessity for us, as a species, to evolve.  Again, this is barring unforeseen, sudden catastrophe.  Our lack of need to evolve in relation to the challenges provided by our environment is the roadblock for humanity.  Somethiiiiiiiiing in the way, ye-ah, mmmmmmmmm-mmmmm....(Nirvana)
Now, many die-offs in Earth's history are directly related to sudden, catastrophic events(I apologize, I so rarely use "catastrophe" in conversation, and it's such a nice word), I realize this.  However, many species that have disappeared did so gradually, as they lost the fight for food, the reigning champion among reasons for evolution.  I would like to think that, at least on Earth, our species has nothing to fear when it comes to competition for food sources.  However, a species that no longer evolves has the annoying habit of dying off.  So, where will the impetus for our evolution come from?
Ourselves.  The overall problem with Natural Evolution is that it lacks the ability to adapt an organism for, say, a caldera erupting on our planet, and smothering all life in ash.  This is a very likely scenario, should Yosemite decide to pop.
I believe we would survive as a species.  Face masks, mre's, wind-powered hydroponics houses, and human stubbornness would see us through.  Biodiversity would vanish, which would be a problem.  Again, this would not necessarily be a factor that would force evolution upon us.  Even if Yosemit should blow its top, it's not a guarantee that the power grid in Europe would be terribly effected.  Also, coal-fired, oil-fired and nuclear power-plants do not necessarily need the sun to function.  So, the possibility that humanity would have enough power to run successful, large-scale hydroponics operations coupled with indoor farms exists.
The new "nature" still would not present a case for us to evolve.  Nature, once our greatest cause for advancement, will be, or is, our primary impediment.  So, we are stuck with the fact that we need to expand our environment in order to introduce new factors for progression.
In order to expand our environment, we would need to become a space-faring species.  Radiation is the greatest problem we face as an extraterrestrial species, along with sustenance and space junk like micrometeorites, and space itself.
To ease the impact of these factors in the short run, bio-mechanical solutions can be made available in an incredibly short time.  As we speak(or read, in this case), prosthetic limbs are being developed that interface with the human nervous system.  This is to accomplish the task of making artificial limbs as fast as the biological limbs they seek to imitate or replace.  Also, devices that provide tactile feedback to the brain are being experimented with.
By "upgrading" our bodies, we may be able to become faster, stronger, and more durable.  The less outside help we need in the form of sustenance, the greater our survivability as an extraterrestrial species.  In essence, we would be forcing evolution on ourselves.  Going in the direction we choose.  Since nature won't give us what we need to progress as a species, we will do it ourselves.