I realize that I am baiting a rabid bear here, but....
First of all, evolution does not work in a closed system; evolution works in
open systems.
Secondly, evolution is actually defined as the change in the frequency of
one or more genes within a population of organisms. Read any textbook by
Douglas Futuyma for the empirical evidence of this that you seek.
No doubt you will maintain that only macroevolution is truely evolution in
the sense you mean it. There too Futuyma can provide the empirical evidence
you seek.
Enjoy.
Kevin L. O'Brien