If you have not read Stories Versus Truth, you may want to read that before reading this.
Remember that, even if you show a scoffer that it is irrational to believe in Evolutionism, the scoffer cannot come to Christ unless the Holy Spirit moves on him or her. You will notice that very little of the Bible is addressed to scoffers and to those who persist in absolute unbelief. There is much in the form of warnings to Christians that they must be careful not to be influenced by such people. There is much written that Christians should not consider their philosophies to have any validity. There is much to say that Christians ought to be understanding their own experience with Christ and the Body of Christ so that they will be able to give a reason for the hope that is in them when they are asked. That implies that the Christian's life needs to be a life that prompts the question. That life ought to be a life of love, joy, peace, patience, meekness, kindness, gentleness, inner strength that comes from the Spirit of God, and the faith of God that comes as a free gift as we hear the utterance of God in every moment of our daily lives.
That being said, the link below deals with Natural Selection and Mutation.