Darwin was one of the smartest men ever lived next to Albert Einstein.
Evloution is pretty much possible because thats part of life and life change ALL the time but life NEVER stops.
Everything change from small to big from little improvement to big improvement and such...that's part of life.
It takes thousands and thousands of years for some animals to evolve while some animals are pretty much the same since because some has seperated as others just remain the same so...pretty much the same thing has happened with apes and men millions of years ago. Evloution happen with environments, pollution, mating, and so on.
From speices to the next speices and on, transferring genes to the next. The gene pool is kind of hard to explain but it is part of how evloution works.
In my "religious" view, I know that God is not human and he has created life so evloution is part of life that makes it happen.
You know the old saying..."Everything happens for a reason."