When asked honestly, it's really not a bad question. It's an indication that the asker really doesn't understand evolution, but if he or she is genuinely seeking knowledge, it opens up what you might call a teaching opportunity. Unfortunately, this question is typically a disingenuous killing blow, expected to end or pre-empt a debate on the legitimacy of human evolution. It doesn't matter to these people what the answer is; they don't want to know, even if it is one of the easier questions in evolution to answer.
Now, I'm not a biologist. My formal biology education ended when I was 15, and my formal education on evolution pretty much never started. The full answer to this question by qualified evolutionary biologists is all over the internet (look here, here and here). So rather than make an inadequate attempt to answer the question directly, allow me instead to illustrate the answer by absurd analogy...
I was raised Lutheran. Lutherans are like Catholics in many ways. There are obvious similarities between the two, but they are fundamentally different, and of course as a young Lutheran, I felt that Lutherans were clearly superior. I was taught that the Lutheran Church split off of the Catholic Church during the Protestant Reformation in 16th century Germany and Scandinavia (many of my ancestors were Danish). But I didn't really believe my teachers; that was a long time ago and I wasn't there when it happened, nor was anyone else alive today, nor anyone else I've ever known, nor anyone who was ever known by anyone else alive today. It's clearly evident that the Lutheran Church has always existed in its current form ever since its creation.
So answer me this - if the Lutheran Church truly came from the Catholic Church, why is there still a Catholic Church?