First of all, as others have already pointed out, evolution may not be a "reasonable explanation" for you, but it is for other people who have different belief systems. Just like the bible 또는 a 무지개, 레인 보우 aren't "reasonable explanations" of the existence of deities for me. If 당신 want to learn about other people's beliefs, 당신 can't dismiss them before 당신 have even given them a chance to respond. That is why 당신 have a lot of people giving 당신 crap on this question. The 질문 is not offensive, but the way 당신 have asked it is.
Secondly, there are lots of places around here where Atheists and people of other religions have discussed this topic respectfully. Here are some 링그 to answers, 포럼 and 기사 from the Atheism spot that 당신 might want to take a look at:
link link link link link link (we also have a couple of 'Ask A Christian' forms)
link link link If 당신 look through any of those 링그 you'll see that Atheists believe in a wide range of things for a wide range of reasons. We, for the most part, don't mind explaining our beliefs to people who want to learn about them, but we do require respectful debate.