There is so much I could say about this topic that I'm going to try to keep my answer here very brief and save something more in-depth for a full-length article. Also, I assume we're talking about biological evolution.
Evolution should be taught in schools for one simple reason: Science should be taught in schools. What data we have, the method for acquiring that data, how it was tested, and how it was interpreted — these are the backbone of science education. Our current understanding of evolution has gone through the scientific process, and given the controversy surrounding it, evolution has been scrutinized far more carefully than many other ideas. A 2009 Pew poll found that 97 percent of scientists polled think that humans and other living things have evolved over time, and 87 percent say this is due to a natural process, such as natural selection. It's clear that, within the scientific community, evolution is the current prevailing theory.
Will evolution ever be proven to be incorrect? Maybe. If a competing hypothesis can stand up to the necessary scrutiny, then our ideas about evolution will change and the new theory will be taught. After all, that's what science is all about; improving our understanding of the natural world through constant observation and testing.
