Barring some sort of disaster destroys our race such as a virus, extra-terrestrial genocide, fools among us playing with nuclear weapons, or the like, could we last forever? I make no attempts to even guess what sort of form we would take after billions of years have past us by and our sun has long since burnt out. Could we survive the end of the universe? (if one exists)
If all the time that has passed since the beginning was a sandbox, human history would fit in 1/100th of a single grain.
I don’t think we are in any position to speculate about ‘forever’
i dont believe so. mankind at the state we’re in now is only a single step in evolution. therefore the more important question to ask is, will LIFE live forever? trees, cells, humans, any form of living being…cause anywhere else we look besides earth right now, theres no life. I bet life on Earth is a one in a million shot that actually happened.
if we can get somebody out of our solar system and then we’re able to colonize a nearby star system, i’d say the human race’d probably last forever.
Not forever, eventually all the stars will burn out, and everything will be absolute zero, and completely frozen in ice.
Alien, always remember what absolute zero is. It seems impossible to reach this state because it requires a complete lack of energy, which, to our currently knowledge, is theoretically impossible to reach. And with recent theories on null point energy, it seems highly unlikely that any point in space could ever have nill energy.
absolute zero is the coldest point anything can reach. THe universe is forever expanding, as matter expands, it cools. Since the universe is infinately expanding, then it’s infinately cooling as well. Maybe after everything is frozen, it will all contract back together and make “THE BIG CRUNCH”. But that is just a theory. The universe expanding at rates that completely defy gravity is observable.
Hm…concerning the ability of LIFE to live, I heard that death is pre-programmed not only within the life-cycle of a cell, but also for a whole species, i.e. any species, and hence, civilizaton has a fate of dying out because of a programme, which runs on genetic level and is aimed at self-destruction. In other words, there will come time, when we will be unable to reproduce ourselves 
or future generations of human will stop being capable of adapting to new environment and genetic pattern will become worse and worse with each following generation. This will lead to an inevitable wipe-out or, better to say, self-destruction of the human species. (Horrible scenario!)
In spite of all that, I still remain optimistic about the future. If I look at the current research which is being done in the field of genetic engineering and the advances, that man has achieved so far in manipulating and correcting his own genes, I am fairly confident, that with such huge steps made in research we will quite soon be able to stop this programme running and change it in such a way, that our life will be prolonged significantly as a result. 
HEHEHEHE!!! This is not really science and much less physics, in fact this will be more metaphysics, but according to Nostradamus arent we all suposed to die in 2009 where the end of the world will happen? hehehe
Now serious, first of all i think we must all have in concious what is the human being?! We were not always like we are today, our appearance at some million years ago was completly diferent from ours at the moment! now the question will be if you all think that at that time ago we were human beings or not?! If yes then, then we must not forget that before we start to appear more like we are today, we were very diferent, at the begining we were just some microscopics beings in a small stage of evolution! Having that in mind, if we see at our future generations, and i mean millions and millions years from now, we ( human beings ) will also be very diferent from what we are today, but we will still be human beings right?!
Now this create some many other questions about our evolution! i personaly think that we are in the most dangerous stage of evolution that the human being have passed and probably will ever pass trough! If we can pass this “test” with sucess then i think that the human being will last forever until the end of times where not only humans will dissapear, but also all existence will parish ( in a big crunch like someone already said here and which i completly agree )!!
Having in mind the question what is the human being we must also question ourselves what define us as human beings?! Could it be only our appearance, our way of thinking, our peculiar feeling?! Well actually the answer is all this things and some more! In my opinion we will only stop be human beings if we start to modificate ourselves unnaturally to become into something that would not permit us to have one of the things i have said that define the human being! Let us hope this will not happen, for some reason we were ment to evolve at a especific speed and not more faster then that specialy because if we try to turn ourselves faster then we should into something we think it will be our future, maybe we were wrong and the way we thing we will be in the future may not be what we will really be! doing that we will only be changing ourselves into a new specie and nothing else!
what do you people think of this? once againi most apologige for my errors, but i dont speak english very well
best regards
no. the human race will not last forever. i believe it is somewhat arrogant to believe that all of evolution has led up to us. are we the end-all be-all of evolutionary perfection? if not, then there will always be situations to which we must adapt.
even if we bend all of nature to will using technology, someday we come to a problem we cannot fix, and we will have to adapt. adaptation laeds to minor changes in physiology, and once we have changed (even once, even a little) can we still call ourselves the same species?
if you had the mutant son, would you call him your son?
as far as big changes, we either all die in a disaster, or we remain the dominant species/set of human-like species. the thing that guided evolution was the fact that animals reproduced as much as they possibly could, or at least at a roughly uniform rate across the species.
when a mutant was born, the new species would either die out, or it would, for some reason, have more children than anybody else. this is the ONLY mechanism that changes the shape of a species.
today, if a human was born with gills, would he neccesarily have more children? or a human who can breathe sulfer and gets energy from ultraviolet rays, would he have more kids? or would he just live a better life than everyone and have the same, average amount of kids?
just because somebodys body cahnges so that they are able to chase animals better, think about how to get food better, or anything besides a mutant uterus that fertilizes more than usual amount of eggs, anything else isnt going to matter in this society.
therefore, humans really are the ultimate culmination of natural selection-based evolution. next step, by the end of this century we will be evolving ourselves.
i think we should throw in a bit of population dynamics
if humanity could establish a large, complex meta-population (population of sub-populations) through-out the milky way, there’s a good chance we can last relatively long
if we can’t, we’re as good as dead…
a hopeful note: if there’s one thing humans have always been good at, it’s conquering foreign worlds and adapting to new environments