What experiment would prove evolution? How could the evolution theory be falsified?
Many thousands of experiments have shown the validity of predictions based upon the theory of evolution through natural selection of genetic variation.
Here is a good one. One among many thousands.
http://www.newscientist.com/article/dn14094-bacteria-make-major-evolutionary-shift-in-the-lab.html
There are any number of ways the theory could be falsified. Another mechanism of genetic change could be discovered that was somehow not subject to natural selection. A genomic analysis that didn't conform to the nested hierarchies of phylogenetic analysis previously discovered would also falsify common descent.