My friend's argument against evolution goes like this:
It is extremely unlikely that life as we know it evolved from a random mutation process because every organism is like a machine, in that one "mistake" could render the whole machine unworkable. What makes this even more unlikely is that harmful mutations are more likely to occur than beneficial ones. If evolution were true, it would not last very long, most likely.
My rebuttal goes like this:
While it is true that evolution is influenced by a random mutation process, this process is not random in the sense that all mutations are equally likely. When evolutionary biologists say mutations are random, they mean that the environment has no influence on the type or frequency of mutations. They do not mean that all mutations are equally likely to occur. In fact, if you look at certain mutations in humans, you'll see that mutation rates for certain phenotypes are not equal, which means we have unequal probabilities. Also, while it is true that harmful mutations are more likely to occur than beneficial ones, neutral mutations are the most likely of all. Another issue I have is that it only appears unlikely if we are just working with one organism, but if we have a whole population of organisms, mutating and reproducing, then your argument seems to be undermined by this fact.
Was my rebuttal good? Is there anything wrong with my friend's argument against evolution?