If given one atom of a radioactive material, you can't predict with certainty whether or not it will decay in the next one million years either. Does that make quantum mechanics unscientific?
Even though we can't predict with certainty what will happen to man as a result of evolution, we can predict that the natural processes which have taken place to cause the changes of the past will continue to take place into the future. You can look back and find out what the weather was like on this day last year in your home town, but can you predict what the weather will be like on this date next year? Does this inability render meteorology unscientific?
Both disciplines provide varying degrees of knowledge, but cannot be compared to evolution theory because the latter relies upon unobserved and unobservable phenomena to tell a story. Quantum mechanics has a present process to observe, and from it sets forth an understanding, or belief about that process. Evolution theory does no such thing. It is merely conjecture based upon, in most cases, the strata quo.