"Evolution is a theory. It is also a fact. And facts and theories are different things, not rungs in a hierarchy of increasing certainty. Facts are the world's data. Theories are structures of ideas that explain and interpret facts. Facts do not go away when scientists debate rival theories to explain them. Einstein's theory of gravitation replaced Newton's, but apples did not suspend themselves in mid-air, pending the outcome. And humans evolved from ape-like ancestors whether they did so by Darwin's proposed mechanism or by some other yet to be discovered"
I'm a fanatic evolutionist, I believe life, intelligent or not, exists elsewhere in the universe. So it's no surprise that I usually get into hot debates with people, educated people, about evolution and sadly they almost always voice pathetic objections to the theory of evolution, here are the top two:
1. Evolution is at odds with religion.
I respect people choosing to believe that the world was created as explained in the Holy Books: in 7 days with humans created directly by God. What I don't respect is people claiming that the theory of evolution is wrong because it claims that we evolved without having God in the picture. Evolution is just the tip of our understanding of how we got here. Our current scientific understanding begins with a single moment, the moment of the Big Bang. There's no time before it and there is no explanation of how this moment came to be, sounds familiar? Yes, that's the creation moment according to science. Science and Religion do not disagree on whether there was a creation moment or not, they simply differ on when it was! Agree with whichever version you like, but don't dismiss science as Godless.
2. If it is true, why are we not evolving anymore?
The short answer is that we are evolving, just slowly. You need to factor in that based on fossil evidence humans started evolving from chimpanzees around 5-8 million years ago. Mind you that currently the difference in DNA sequence between a chimpanzee and a human is ONLY 5%. Think about that, it took 5 million years for 5% change in DNA. So of course you can't spot OUR evolution because our total documented history is little less than 10,000 years. But to answer your question in insects like the fruit fly, where the average generation lifetime is a lot shorter, evolution has been spotted in various lab experiments. Google it.