fab: If you look at the theory of evolution with a purely scientific mindset and using facts proven by science, you will find that there are so many gaps in it (and gaps that even Darwin admitted to) that it's not possible...in my opinion. Yours may differ :)
These "gaps" as you describe them, are why religion is prominent, why it began, why it continues, why all we atheists, of which I have always counted myself one, will never see it disappear.
The majority of people, the religious, see a gap in our understanding, and think "oh noes, we don't understand this, but everything has to have a reason, so.... GOD DID IT", and then they are happy with this, it resolves their internal conflict, the fear they have for not knowing.
Atheists, scientists, see a gap in our understanding and think "oh, I don't know how that works... well, I know how it started, and I know how it ended, I'm ok with the fact that I don't know the middle bit yet, I'm sure we'll work it out".
It's not just evolution.
Theist: "what happens when you die, ARGH, I don't know, it can't be nothing, that hurts my brain, so... we all go to heaven, that sounds nice"
Atheist: "what happens when you die, nothing, you cease to be, that is all"
Theist: "what was before the big bang, ARGH, I don't know, so... GOD made the universe!"
Atheist: "what was before the big bang, not really sure, maybe nothing, maybe a big crunch from a previous big bang and on through infinity, I'm sure we'll work it out sometime, but right now, we don't completely know"
At some point science does progress to "fill in all the gaps", and then the religious say "ohhh, yea" and accept it, they move their "point of unknowing" backwards slightly so that, ok God wasn't DIRECTLY responsible for that, but he must be responsible for this bit before that which we don't know then
Theist: "that big booming noise and flashing lights in the sky, I don't know what that is, it must be GOD, he must be really angry, Maude, light the pyre, we need to burn more Witches!"
Atheist: "hmm, I wonder what that is, I don't know yet, but I'm sure we can find out"
In fact, we are starting to see this in religion vs. evolution now quite a lot, with various religions (even Catholicism) accepting that evolution is, yea, pretty much a given, but NOW saying "well, yea, the evolutionary process seems to be pretty well shown in evidence now, but how did all those cells get there to begin with, I don't know, so, it must be GOD!"
Another 50 years, maybe 100, and the religious goal posts may be moved back further yet. But there is always a point FURTHER than they can be moved, and will be moved, because it is the nature of the majority of humans to be fearful, or unable to comprehend the unknown, and fill this "hole" with God in order to maintain their hold upon the world.
Atheists will never "get rid of" religion, and nor should we bother trying, it is a fundamental way of thinking for the majority of the worlds population, just as long as atheists, scientists, are not deprived of the ability to seek the answers for the questions that theists answer with "it must be god".
I see theists as, somewhat, deprived, poor, disabled people who atheists can help, not by "showing them the error of their ways" or "convincing them to discard religion", but by putting in the work and eventually providing to them the REAL explanations for the phenomena they don't yet understand, one by one. But they will probably always be theists.