He won't because he can't. Even the most often referenced odds-against-evolution document here (Anyone remember? It was discussed on FR) doesn't work. I ran it past a Ph.D. math friend of mine and he says it's convincing -- to the layman who doesn't know any better.
You can be--believe--prove anything...
use it home---on your friends too!
Really, then perhaps your friend should go into some other profession, like garbage collection. The average gene codes for proteins of some 400 amino acids in length. There are 20 possible amino acids at each of those positions. The chances of constructing such a DNA sequence are 400^20 power. There are some 30,000 such genes in humans. Multiply the chances of the above, a larger number than all the atoms in the universe by some 30,000 times. In addition to which you need to do it many more times for the many different species out there many of whose genes are diffent from the closest species. So yes evolution is mathematically impossible.